.drone.yml

@@ -1,25 +0,0 @@
-kind: pipeline
-type: kubernetes
-name: build-apk
-
-clone:
-  depth: 1
-
-steps:
-  - name: build
-    image: cirrusci/flutter:stable
-    pull: true
-    commands:
-      - flutter packages get
-      - flutter build apk --release --split-per-abi
-      - mkdir apks
-      - mv build/app/outputs/apk/*/*/*.apk apks
-
-  - name: Publish APK
-    image: plugins/gitea-release
-    settings:
-      api_key:
-        from_secret: GITEA_TOKEN
-trigger:
-  event:
-    - push

.gitea/workflows/backed_build-image.yaml

@@ -0,0 +1,31 @@
+on:
+  pull_request:
+    branches:
+      - main
+
+name: Build and push docker image
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+
+    - uses: https://gitea.com/actions/checkout@v4
+    
+    - name: Login to Docker Registry
+      uses: docker/login-action@v3
+      with:
+        registry: git.kluster.moll.re
+        username: ${{ gitea.repository_owner }}
+        password: ${{ secrets.GITEA_TOKEN}}
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
+
+    - name: Build and push
+      uses: docker/build-push-action@v5
+      with:
+        context: backend
+        tags: git.kluster.moll.re/remoll/fast_network_navigation/backend:latest
+        push: true

.gitea/workflows/build-android.yaml

@@ -1,42 +0,0 @@
-on: push
-name: Test, Build and Release apk
-jobs:
-  build:
-    name: Build APK
-    runs-on: k8s
-    steps:
-
-    - name: Install prerequisites
-      run: |
-        sudo apt-get update
-        sudo apt-get install -y xz-utils unzip
-    - uses: https://gitea.com/actions/checkout@v4
-
-    - uses: https://github.com/actions/setup-java@v4
-      with:
-        java-version: '17'
-        distribution: 'zulu'
-
-    - uses: https://github.com/subosito/flutter-action@v2
-      with:
-        channel: stable
-        flutter-version: 3.19.6
-        cache: true
-    - name: Setup Android SDK
-      uses: https://github.com/android-actions/setup-android@v3
-
-    - run: flutter pub get
-    # - run: flutter test
-    - run: flutter build apk --debug --split-per-abi
-    
-    - name: Release APK
-      uses: https://gitea.com/akkuman/gitea-release-action@v1
-      with:
-        files: build/app/outputs/flutter-apk/*.apk
-        tag: testing
-        release_name: Testing release
-        release_body: "This is a testing release."
-        prerelease: true
-        token: ${{ secrets.GITEA_TOKEN }}
-      env:
-        NODE_OPTIONS: '--experimental-fetch'

.gitea/workflows/frontend_build-android.yaml

@@ -0,0 +1,65 @@
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - frontend/**
+
+
+name: Build and release APK
+
+jobs:
+  build:
+    name: Build APK
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Install prerequisites
+      run: |
+        apt-get update
+        apt-get install -y jq
+
+    - uses: https://gitea.com/actions/checkout@v4
+
+
+    - uses: https://github.com/actions/setup-java@v4
+      with:
+        java-version: '17'
+        distribution: 'zulu'
+
+    - name: Fix flutter SDK folder permission
+      run: git config --global --add safe.directory "*"
+
+    - uses: https://github.com/subosito/flutter-action@v2
+      with:
+        channel: stable
+        flutter-version: 3.22.0
+        cache: true
+
+    - name: Setup Android SDK
+      uses: https://github.com/android-actions/setup-android@v3
+
+    - run: flutter pub get
+      working-directory: ./frontend
+
+    - name: Add required secrets
+      run: |
+        echo ${{ secrets.ANDROID_SECRETS_BASE64 }} | base64 -d > ./android/secrets.properties
+      working-directory: ./frontend
+
+    - name: Sanity check
+      run: |
+        ls
+        ls -lah android
+      working-directory: ./frontend
+
+    - run: flutter build apk --release --split-per-abi --build-number=${{ gitea.run_number }}
+      working-directory: ./frontend
+
+    - name: Upload APKs to artifacts
+      uses: https://gitea.com/actions/upload-artifact@v3
+      with:
+        name: app-release
+        path: frontend/build/app/outputs/flutter-apk/
+        if-no-files-found: error
+        retention-days: 15

.gitea/workflows/frontend_build-web.yaml

@@ -1,21 +1,34 @@
-on: push
-name: Test, Build and Release web
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - frontend/**
+
+
+name: Build web
+
 jobs:
   build:
     name: Build Web
-    runs-on: k8s
+    runs-on: ubuntu-latest
     steps:
+
     - name: Install prerequisites
       run: |
         sudo apt-get update
         sudo apt-get install -y xz-utils
 
     - uses: actions/checkout@v4
+
     - uses: https://github.com/subosito/flutter-action@v2
       with:
         channel: stable
         flutter-version: 3.19.6
         cache: true
-    - run: flutter pub get
-    # - run: flutter test
 
+    - run: flutter pub get
+      working-directory: ./frontend
+
+    - run: flutter build web
+      working-directory: ./frontend

.vscode/launch.json

@@ -0,0 +1,28 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "frontend",
+            "cwd": "frontend",
+            "request": "launch",
+            "type": "dart"
+        },
+        {
+            "name": "frontend (profile mode)",
+            "cwd": "frontend",
+            "request": "launch",
+            "type": "dart",
+            "flutterMode": "profile"
+        },
+        {
+            "name": "frontend (release mode)",
+            "cwd": "frontend",
+            "request": "launch",
+            "type": "dart",
+            "flutterMode": "release"
+        },
+    ]
+}

backend/.gitignore

@@ -0,0 +1,164 @@
+# osm-cache
+cache/
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+#poetry.lock
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#pdm.lock
+#   pdm stores project-wide configurations in .pdm.toml, but it is recommended to not include it
+#   in version control.
+#   https://pdm.fming.dev/latest/usage/project/#working-with-version-control
+.pdm.toml
+.pdm-python
+.pdm-build/
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#.idea/

backend/Dockerfile

@@ -0,0 +1,11 @@
+FROM python:3
+
+WORKDIR /app
+COPY Pipfile Pipfile.lock .
+
+RUN pip install pipenv
+RUN pipenv install --deploy --system
+
+COPY . /src
+
+CMD ["pipenv", "run", "python", "/app/src/main.py"]

backend/Pipfile

@@ -0,0 +1,12 @@
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+numpy = "*"
+scipy = "*"
+fastapi = "*"
+osmpythontools = "*"
+
+[dev-packages]

backend/app/dependencies.py

@@ -0,0 +1 @@
+import app.src

backend/app/main.py

@@ -0,0 +1,34 @@
+from .src.optimizer import solve_optimization
+from .src.landmarks_manager import Landmark
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/optimize/{max_steps}/{print_details}")
+def main(max_steps: int, print_details: bool):
+    
+    # CONSTRAINT TO RESPECT MAX NUMBER OF STEPS
+    #max_steps = 16
+
+
+    # Initialize all landmarks (+ start and goal). Order matters here
+    landmarks = []
+    landmarks.append(Landmark("départ", -1, (0, 0)))
+    landmarks.append(Landmark("tour eiffel", 99, (0,2)))                           # PUT IN JSON
+    landmarks.append(Landmark("arc de triomphe", 99, (0,4)))
+    landmarks.append(Landmark("louvre", 99, (0,6)))
+    landmarks.append(Landmark("montmartre", 99, (0,10)))
+    landmarks.append(Landmark("concorde", 99, (0,8)))
+    landmarks.append(Landmark("arrivée", -1, (0, 0)))
+
+
+    visiting_order = solve_optimization(landmarks, max_steps, print_details)
+
+    #return visiting_order
+
+    return("max steps :", max_steps, "\n", visiting_order)
+
+
+"""if __name__ == "__main__":
+    main()"""

backend/app/src/landmarks_manager.py

@@ -0,0 +1,57 @@
+from OSMPythonTools.api import Api
+from OSMPythonTools.overpass import Overpass
+from dataclasses import dataclass
+
+
+# Defines the landmark class (aka some place there is to visit)
+@dataclass
+class Landmarkkkk :
+    name : str
+    attractiveness : int
+    id : int
+    
+@dataclass
+class Landmark :
+    name : str
+    attractiveness : int
+    loc : tuple
+
+# Converts a OSM id to a landmark
+def add_from_id(id: int, score: int) :
+
+    try :
+        s = 'way/' + str(id)           # prepare string for query
+        obj =  api.query(s)                             # object to add
+    except :
+        s = 'relation/' + str(id)           # prepare string for query
+        obj =  api.query(s)                             # object to add
+
+    return Landmarkkkk(obj.tag('name:fr'), score, id)      # create Landmark out of it
+
+
+# take a lsit of tuples (id, score) to generate a list of landmarks
+def generate_landmarks(ids_and_scores: list) :
+
+    L = []
+    for tup in ids_and_scores :
+        L.append(add_from_id(tup[0], tup[1]))
+
+    return L
+
+api = Api()
+
+
+l = (7515426, 70)
+t = (5013364, 100)
+n = (201611261, 99)
+a = (226413508, 50)
+m = (23762981, 30)
+
+
+ids_and_scores = [t, l, n, a, m]
+
+landmarks = generate_landmarks(ids_and_scores)
+
+
+for obj in landmarks :
+    print(obj)

backend/app/src/main_example.py

@@ -0,0 +1,23 @@
+import fastapi
+from dataclasses import dataclass
+
+
+@dataclass
+class Destination:
+    name: str
+    location: tuple
+    attractiveness: int
+
+
+
+d = Destination()
+
+
+
+def get_route() -> list[Destination]:
+    return {"route": "Hello World"}
+
+endpoint = ("/get_route", get_route)
+end
+if __name__ == "__main__":
+    fastapi.run()

backend/app/src/optimizer.py

@@ -0,0 +1,323 @@
+from scipy.optimize import linprog
+import numpy as np
+from scipy.linalg import block_diag
+
+
+# landmarks = [Landmark_1, Landmark_2, ...]
+
+# Convert the solution of the optimization into the list of edges to follow. Order is taken into account
+def untangle(resx: list) :
+    N = len(resx)                   # length of res
+    L = int(np.sqrt(N))             # number of landmarks. CAST INTO INT but should not be a problem because N = L**2 by def.
+    n_edges = resx.sum()      # number of edges
+
+    order = []
+    nonzeroind = np.nonzero(resx)[0] # the return is a little funny so I use the [0]
+
+    nonzero_tup = np.unravel_index(nonzeroind, (L,L))
+
+    indx = nonzero_tup[0].tolist()
+    indy = nonzero_tup[1].tolist()
+
+    vert = (indx[0], indy[0])
+
+    order.append(vert[0])
+    order.append(vert[1])
+    
+    while len(order) < n_edges + 1 :
+        ind = indx.index(vert[1])
+
+        vert = (indx[ind], indy[ind])
+
+        order.append(vert[1])
+
+    return order
+
+# Just to print the result
+def print_res(res, landmarks: list, P) :
+    X = abs(res.x)
+    order = untangle(X)
+    things = []
+
+    """N = int(np.sqrt(len(X)))
+    for i in range(N):
+        print(X[i*N:i*N+N])
+    print("Optimal value:", -res.fun)  # Minimization, so we negate to get the maximum
+    print("Optimal point:", res.x)
+    for i,x in enumerate(X) : X[i] = round(x,0)
+    print(order)"""
+
+    if (X.sum()+1)**2 == len(X) : 
+        print('\nAll landmarks can be visited within max_steps, the following order is suggested : ')
+    else :
+        print('Could not visit all the landmarks, the following order is suggested : ')
+
+    for idx in order : 
+        print('- ' + landmarks[idx].name)
+        things.append(landmarks[idx].name)
+
+    steps = path_length(P, abs(res.x))
+    print("\nSteps walked : " + str(steps))
+
+    return things
+
+# Checks for cases of circular symmetry in the result
+def has_circle(resx: list) :
+    N = len(resx)                   # length of res
+    L = int(np.sqrt(N))             # number of landmarks. CAST INTO INT but should not be a problem because N = L**2 by def.
+    n_edges = resx.sum()      # number of edges
+
+    
+    nonzeroind = np.nonzero(resx)[0] # the return is a little funny so I use the [0]
+
+    nonzero_tup = np.unravel_index(nonzeroind, (L,L))
+
+    indx = nonzero_tup[0].tolist()
+    indy = nonzero_tup[1].tolist()
+    
+
+    verts = []
+
+    for i, x in enumerate(indx) :
+        verts.append((x, indy[i]))
+
+    
+    for vert in verts :
+        visited = []
+        visited.append(vert)
+
+        while len(visited) < n_edges + 1 :
+
+            try : 
+                ind = indx.index(vert[1])
+
+                vert = (indx[ind], indy[ind])
+
+                if vert in visited :
+                    return visited
+                else :
+                    visited.append(vert)
+            except :
+                break
+
+    return []
+
+# Constraint to not have d14 and d41 simultaneously. Does not prevent circular symmetry with more elements
+def break_sym(landmarks, A_ub, b_ub):
+    L = len(landmarks)
+    upper_ind = np.triu_indices(L,0,L)
+
+    up_ind_x = upper_ind[0]
+    up_ind_y = upper_ind[1]
+
+    for i, _ in enumerate(up_ind_x) :
+        l = [0]*L*L
+        if up_ind_x[i] != up_ind_y[i] :
+            l[up_ind_x[i]*L + up_ind_y[i]] = 1
+            l[up_ind_y[i]*L + up_ind_x[i]] = 1
+
+            A_ub = np.vstack((A_ub,l))
+            b_ub.append(1)
+
+            """for i in range(7):
+                print(l[i*7:i*7+7])
+            print("\n")"""
+
+    return A_ub, b_ub
+
+# Constraint to not have circular paths. Want to go from start -> finish without unconnected loops
+def break_circle(landmarks, A_ub, b_ub, circle) :
+    N = len(landmarks)
+    l = [0]*N*N
+
+    for index in circle :
+        x = index[0]
+        y = index[1]
+        l[x*N+y] = 1
+
+    A_ub = np.vstack((A_ub,l))
+    b_ub.append(len(circle)-1)
+
+    """print("\n\nPREVENT CIRCLE")
+    for i in range(7):
+        print(l[i*7:i*7+7])
+    print("\n")"""
+
+    return A_ub, b_ub
+
+# Constraint to respect max number of travels
+def respect_number(landmarks, A_ub, b_ub):
+    h = []
+    for i in range(len(landmarks)) : h.append([1]*len(landmarks))
+    T = block_diag(*h)
+    """for l in T :
+        for i in range(7):
+            print(l[i*7:i*7+7])
+        print("\n")"""
+    return np.vstack((A_ub, T)), b_ub + [1]*len(landmarks)
+
+# Constraint to tie the problem together. Necessary but not sufficient to avoid circles
+def respect_order(landmarks: list, A_eq, b_eq): 
+    N = len(landmarks)
+    for i in range(N-1) :     # Prevent stacked ones
+        if i == 0 :
+            continue
+        else : 
+            l = [0]*N
+            l[i] = -1
+            l = l*N
+            for j in range(N) :
+                l[i*N + j] = 1
+
+            A_eq = np.vstack((A_eq,l))
+            b_eq.append(0)
+
+            """for i in range(7):
+                print(l[i*7:i*7+7])
+            print("\n")"""
+
+    return A_eq, b_eq
+
+# Compute manhattan distance between 2 locations
+def manhattan_distance(loc1: tuple, loc2: tuple):
+    x1, y1 = loc1
+    x2, y2 = loc2
+    return abs(x1 - x2) + abs(y1 - y2)
+
+# Constraint to not stay in position
+def init_eq_not_stay(landmarks): 
+    L = len(landmarks)
+    l = [0]*L*L
+
+
+    for i in range(L) :
+        for j in range(L) :
+            if j == i :
+                l[j + i*L] = 1
+    l[L-1] = 1      # cannot skip from start to finish
+    #A_eq = np.array([np.array(xi) for xi in A_eq])                  # Must convert A_eq into an np array
+    l = np.array(np.array(l))
+
+    """for i in range(7):
+        print(l[i*7:i*7+7])"""
+
+    return [l], [0]
+
+# Initialize A and c. Compute the distances from all landmarks to each other and store attractiveness
+# We want to maximize the sightseeing :  max(c) st. A*x < b   and   A_eq*x = b_eq
+def init_ub_dist(landmarks: list, max_steps: int):
+    # Objective function coefficients. a*x1 + b*x2 + c*x3 + ...
+    c = []
+    # Coefficients of inequality constraints (left-hand side)
+    A = []
+    for i, spot1 in enumerate(landmarks) :
+        dist_table = [0]*len(landmarks)
+        c.append(-spot1.attractiveness)
+        for j, spot2 in enumerate(landmarks) :
+            dist_table[j] = manhattan_distance(spot1.loc, spot2.loc)
+        A.append(dist_table)
+    c = c*len(landmarks)
+    A_ub = []
+    for line in A :
+        #print(line)
+        A_ub += line
+    return c, A_ub, [max_steps]
+
+# Go through the landmarks and force the optimizer to use landmarks where attractiveness is set to -1
+def respect_user_mustsee(landmarks: list, A_eq: list, b_eq: list) :
+    L = len(landmarks)
+    H = 0       # sort of heuristic to get an idea of the number of steps needed
+    for i in landmarks : 
+        if i.name == "départ" : elem_prev = i              # list of all matches
+    for i, elem in enumerate(landmarks) :
+        if elem.attractiveness == -1 :
+            l = [0]*L*L
+            if elem.name != "arrivée" :
+                for j in range(L) :
+                    l[j +i*L] = 1
+                    
+            else :                          # This ensures we go to goal
+                for k in range(L-1) :
+                        l[k*L+L-1] = 1  
+
+            H += manhattan_distance(elem.loc, elem_prev.loc)
+            elem_prev = elem
+
+            """for i in range(7):
+                print(l[i*7:i*7+7])
+            print("\n")"""
+
+            A_eq = np.vstack((A_eq,l))
+            b_eq.append(1)
+    return A_eq, b_eq, H
+
+# Computes the path length given path matrix (dist_table) and a result
+def path_length(P: list, resx: list) :
+    return np.dot(P, resx)
+
+# Main optimization pipeline
+def solve_optimization (landmarks, max_steps, printing_details) :
+
+    # SET CONSTRAINTS FOR INEQUALITY
+    c, A_ub, b_ub = init_ub_dist(landmarks, max_steps)              # Add the distances from each landmark to the other
+    P = A_ub                                                        # store the paths for later. Needed to compute path length
+    A_ub, b_ub = respect_number(landmarks, A_ub, b_ub)              # Respect max number of visits. 
+
+    # TODO : Problems with circular symmetry
+    A_ub, b_ub = break_sym(landmarks, A_ub, b_ub)                  # break the symmetry. Only use the upper diagonal values
+
+    # SET CONSTRAINTS FOR EQUALITY
+    A_eq, b_eq = init_eq_not_stay(landmarks)                       # Force solution not to stay in same place
+    A_eq, b_eq, H = respect_user_mustsee(landmarks, A_eq, b_eq)       # Check if there are user_defined must_see. Also takes care of start/goal
+
+    A_eq, b_eq = respect_order(landmarks, A_eq, b_eq)              # Respect order of visit (only works when max_steps is limiting factor)
+
+    # Bounds for variables (x can only be 0 or 1)
+    x_bounds = [(0, 1)] * len(c)
+
+    # Solve linear programming problem
+
+    res = linprog(c, A_ub=A_ub, b_ub=b_ub, A_eq=A_eq, b_eq = b_eq, bounds=x_bounds, method='highs', integrality=3)
+    
+
+
+    # Raise error if no solution is found
+    if not res.success :
+
+        # Override the max_steps using the heuristic
+        for i, val in enumerate(b_ub) :
+            if val == max_steps : b_ub[i] = H
+
+        # Solve problem again :
+        res = linprog(c, A_ub=A_ub, b_ub=b_ub, A_eq=A_eq, b_eq = b_eq, bounds=x_bounds, method='highs', integrality=3)
+
+        if not res.success :
+            s = "No solution could be found, even when increasing max_steps using the heuristic"
+            return s
+            #raise ValueError("No solution could be found, even when increasing max_steps using the heuristic")
+    
+    # If there is a solution, we're good to go, just check for
+    else :
+        circle = has_circle(res.x)
+        i = 0
+
+        # Break the circular symmetry if needed
+        while len(circle) != 0 :
+            A_ub, b_ub = break_circle(landmarks, A_ub, b_ub, circle)
+            res = linprog(c, A_ub=A_ub, b_ub=b_ub, A_eq=A_eq, b_eq = b_eq, bounds=x_bounds, method='highs', integrality=3)
+            circle = has_circle(res.x)
+            i += 1
+
+        if printing_details is True :
+            if i != 0 :
+                print(f"Neded to recompute paths {i} times because of unconnected loops...")
+            X = print_res(res, landmarks, P)
+            return X
+        else :
+            return untangle(res.x)
+
+
+
+
+
+

frontend/android/.gitignore

@@ -4,6 +4,7 @@ gradle-wrapper.jar
 /gradlew
 /gradlew.bat
 /local.properties
+/secrets.properties
 GeneratedPluginRegistrant.java
 
 # Remember to never publicly share your keystore.

frontend/android/README.md

@@ -0,0 +1,48 @@
+## Android Setup
+
+### Keystore setup
+```bash
+keytool -genkey -v -keystore release.keystore -keyalg RSA -keysize 2048 -validity 10000 -alias release
+```
+- This is required to store local credentials securely (not used for now).
+- But necesseary in order to restrict the particular api key to a particular app (through the sha1 of the associated keystore).
+
+
+### Building and secret credentials
+Following the guide under [https://developers.google.com/maps/flutter-package/config#android_1](https://developers.google.com/maps/flutter-package/config#android_1).
+- Add the following to `android/build.gradle`:
+    ```gradle
+    buildscript {
+        dependencies {
+            classpath "com.google.android.libraries.mapsplatform.secrets-gradle-plugin:secrets-gradle-plugin:2.0.1"
+        }
+    }
+    ```
+- Add the following to `android/app/build.gradle`:
+    ```gradle
+    plugins {
+        // ...
+        id 'com.google.android.libraries.mapsplatform.secrets-gradle-plugin'
+    }
+    ```
+- Add the credentials to `android/secrets.properties`:
+    ```properties
+    MAPS_API_KEY=YOUR_API_KEY
+    ```
+- Reference the credentials in `android/app/src/main/AndroidManifest.xml`:
+    ```xml
+    <meta-data
+        android:name="com.google.android.geo.API_KEY"
+        android:value="${MAPS_API_KEY}" />
+    ```
+
+
+### Using the credentials in CI
+- Add the base64 encoded credentials to the repository secrets (e.g. `ANDROID_SECRETS`).
+    ```bash
+    base64 -i android/secrets.properties
+    ```
+- Use the following in the CI script:
+    ```bash
+    echo {{ secrets.ANDROID_SECRETS }} | base64 -d > android/secrets.properties
+    ```

frontend/android/app/build.gradle

@@ -2,14 +2,19 @@ plugins {
     id "com.android.application"
     id "kotlin-android"
     id "dev.flutter.flutter-gradle-plugin"
+    id 'com.google.android.libraries.mapsplatform.secrets-gradle-plugin'
+    // last is probably not needed
 }
 
-def localProperties = new Properties()
 def localPropertiesFile = rootProject.file('local.properties')
+def localProperties = new Properties()
+
 if (localPropertiesFile.exists()) {
     localPropertiesFile.withReader('UTF-8') { reader ->
         localProperties.load(reader)
     }
+} else {
+    throw new GradleException("local.properties not found")
 }
 
 def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
@@ -22,6 +27,20 @@ if (flutterVersionName == null) {
     flutterVersionName = '1.0'
 }
 
+
+
+def secretPropertiesFile = rootProject.file('secrets.properties')
+def secretProperties = new Properties()
+
+if (secretPropertiesFile.exists()) {
+    secretPropertiesFile.withReader('UTF-8') { reader ->
+        secretProperties.load(reader)
+    }
+} else {
+    throw new GradleException("Secrets file secrets.properties not found")
+}
+
+
 android {
     namespace "com.example.fast_network_navigation"
     compileSdk flutter.compileSdkVersion
@@ -45,10 +64,16 @@ android {
         applicationId "com.example.fast_network_navigation"
         // You can update the following values to match your application needs.
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
+        // Minimum Android version for Google Maps SDK
+        // https://developers.google.com/maps/flutter-package/config#android
+        minSdk = 21
         minSdkVersion flutter.minSdkVersion
         targetSdkVersion flutter.targetSdkVersion
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
+        // // Placeholders of keys that are replaced by the build system.
+        manifestPlaceholders += ['MAPS_API_KEY': secretProperties.getProperty('MAPS_API_KEY')]
+
     }
 
     buildTypes {

frontend/android/app/src/main/AndroidManifest.xml

@@ -1,4 +1,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- Required to fetch data from the internet. -->
+    <uses-permission android:name="android.permission.INTERNET"/>
+
     <application
         android:label="fast_network_navigation"
         android:name="${applicationName}"
@@ -28,8 +31,14 @@
              This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
         <meta-data
             android:name="flutterEmbedding"
-            android:value="2" />
+            android:value="2"
+        />
+        <meta-data
+            android:name="com.google.android.geo.API_KEY"
+            android:value="${MAPS_API_KEY}"
+        />
     </application>
+    
     <!-- Required to query activities that can process text, see:
          https://developer.android.com/training/package-visibility?hl=en and
          https://developer.android.com/reference/android/content/Intent#ACTION_PROCESS_TEXT.

frontend/android/build.gradle

@@ -16,3 +16,14 @@ subprojects {
 tasks.register("clean", Delete) {
     delete rootProject.buildDir
 }
+
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath "com.google.android.libraries.mapsplatform.secrets-gradle-plugin:secrets-gradle-plugin:2.0.1"
+    }
+}

frontend/android/fallback.properties

@@ -0,0 +1 @@
+MAPS_API_KEY=Key

frontend/lib/layout.dart

@@ -0,0 +1,134 @@
+import 'package:fast_network_navigation/modules/trips_overview.dart';
+import 'package:fast_network_navigation/pages/new_trip.dart';
+import 'package:fast_network_navigation/pages/tutorial.dart';
+import 'package:fast_network_navigation/structs/trip.dart';
+import 'package:fast_network_navigation/utils/load_trips.dart';
+import 'package:flutter/material.dart';
+
+import 'package:fast_network_navigation/pages/overview.dart';
+import 'package:fast_network_navigation/pages/profile.dart';
+
+// BasePage is the scaffold that holds all other pages
+// A side drawer is used to switch between pages
+class BasePage extends StatefulWidget {
+  final String mainScreen;
+  final Future<Trip>? trip;
+  
+  const BasePage({
+    super.key,
+    required this.mainScreen,
+    this.trip
+  });
+
+  @override
+  State<BasePage> createState() => _BasePageState();
+}
+
+class _BasePageState extends State<BasePage> {
+
+  @override
+  Widget build(BuildContext context) {
+    Widget currentView = const Text("loading...");
+    Future<List<Trip>> trips = loadTrips();
+    
+    
+    if (widget.mainScreen == "map") {
+      currentView = NavigationOverview(trip: widget.trip ?? getFirstTrip(trips));
+    } else if (widget.mainScreen == "tutorial") {
+      currentView = TutorialPage();
+    } else if (widget.mainScreen == "profile") {
+      currentView = ProfilePage();
+    }
+
+    final ThemeData theme = Theme.of(context);
+    
+    return Scaffold(
+      appBar: AppBar(title: Text("City Nav")),
+      body: Center(child: currentView),
+      drawer: Drawer(
+        child: Column(
+          children: [
+            DrawerHeader(
+              decoration: BoxDecoration(
+                gradient: LinearGradient(colors: [Colors.cyan, theme.primaryColor])
+              ),
+              child: Center(
+                child: Text(
+                  'City Nav',
+                  style: TextStyle(
+                    color: Colors.white,
+                    fontSize: 24,
+                    fontWeight: FontWeight.bold,
+                  ),
+                ),
+              ),
+            ),
+            ListTile(
+              title: const Text('Your Trips'),
+              leading: const Icon(Icons.map),
+              selected: widget.mainScreen == "map",
+              onTap: () {},
+              trailing: ElevatedButton(
+                onPressed: () {
+                  Navigator.of(context).push(
+                    MaterialPageRoute(
+                      builder: (context) => const NewTripPage()
+                    )
+                  );
+                },
+                child: const Text('New'),
+              ),
+            ),
+
+            // Adds a ListView to the drawer. This ensures the user can scroll
+            // through the options in the drawer if there isn't enough vertical
+            // space to fit everything.
+            Expanded(
+              child: TripsOverview(trips: trips),
+            ),
+            ElevatedButton(
+              onPressed: () async {
+                removeAllTripsFromPrefs();
+              },
+              child: const Text('Clear trips'),
+            ),
+            const Divider(),
+            ListTile(
+              title: const Text('How to use'),
+              leading: Icon(Icons.help),
+              selected: widget.mainScreen == "tutorial",
+              onTap: () {
+                Navigator.of(context).push(
+                  MaterialPageRoute(
+                    builder: (context) => BasePage(mainScreen: "tutorial")
+                  )
+                );
+              },
+            ),
+
+            // settings in the bottom of the drawer
+            ListTile(
+              title: const Text('Settings'),
+              leading: const Icon(Icons.settings),
+              selected: widget.mainScreen == "profile",
+              onTap: () {
+                Navigator.of(context).push(
+                  MaterialPageRoute(
+                    builder: (context) => BasePage(mainScreen: "profile")
+                  )
+                );
+              },
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+
+
+Future<Trip> getFirstTrip (Future<List<Trip>> trips) async {
+  List<Trip> tripsf = await trips;
+  return tripsf[0];
+}

frontend/lib/main.dart

@@ -1,5 +1,5 @@
 import 'package:flutter/material.dart';
-import 'package:fast_network_navigation/modules/scaffold.dart';
+import 'package:fast_network_navigation/layout.dart';
 
 void main() => runApp(const App());
 
@@ -12,9 +12,8 @@ class App extends StatelessWidget {
   Widget build(BuildContext context) {
     return MaterialApp(
       title: appTitle,
-      home: BasePage(title: appTitle),
+      home: BasePage(mainScreen: "map"),
       theme: ThemeData(useMaterial3: true, colorSchemeSeed: Colors.green),
     );
   }
 }
-

frontend/lib/modules/greeter.dart

@@ -0,0 +1,73 @@
+import 'package:fast_network_navigation/structs/trip.dart';
+
+import 'package:flutter/material.dart';
+
+class Greeter extends StatefulWidget {
+  final Future<Trip> trip;
+  final bool standalone;
+
+  Greeter({
+    required this.standalone,
+    required this.trip
+  });
+
+  @override
+  State<Greeter> createState() => _GreeterState();
+}
+
+
+
+class _GreeterState extends State<Greeter> {
+  Widget greeterBuild (BuildContext context, AsyncSnapshot<Trip> snapshot) {
+    ThemeData theme = Theme.of(context);
+    String cityName = "";
+    if (snapshot.hasData) {
+      cityName = snapshot.data?.cityName ?? '...';
+    } else if (snapshot.hasError) {
+      cityName = "error";
+    } else { // still awaiting the cityname
+      cityName = "...";
+    }
+
+    Widget topGreeter = Text(
+      'Welcome to $cityName!',
+      style: TextStyle(color: theme.primaryColor, fontWeight: FontWeight.bold, fontSize: 24),
+    );
+
+    if (widget.standalone) {
+      return Center(
+        child: Padding(
+          padding: EdgeInsets.only(top: 24.0),
+          child: topGreeter,
+        ),
+      );
+    } else {
+      return Center(
+        child: Column(
+          children: [
+            Padding(padding: EdgeInsets.only(top: 24.0)),
+            topGreeter,
+            bottomGreeter,
+            Padding(padding: EdgeInsets.only(bottom: 24.0)),
+          ],
+        )
+      );
+    }
+  }
+
+  Widget bottomGreeter = const Text(
+    "Busy day ahead? Here is how to make the most of it!",
+    style: TextStyle(color: Colors.black, fontSize: 18),
+    textAlign: TextAlign.center,
+  );
+
+
+
+  @override
+  Widget build(BuildContext context) {
+    return FutureBuilder(
+      future: widget.trip,
+      builder: greeterBuild,
+    );
+  }
+}

frontend/lib/modules/landmark_card.dart

@@ -0,0 +1,80 @@
+import 'package:fast_network_navigation/structs/landmark.dart';
+import 'package:flutter/material.dart';
+
+
+class LandmarkCard extends StatefulWidget {
+  final Landmark landmark;
+  @override
+  _LandmarkCardState createState() => _LandmarkCardState();
+
+  LandmarkCard(this.landmark);
+
+}
+
+class _LandmarkCardState extends State<LandmarkCard> {
+  @override
+  Widget build(BuildContext context) {
+    ThemeData theme = Theme.of(context);
+    return Container(
+      height: 160,
+      child: Card(
+        shape: RoundedRectangleBorder(
+          borderRadius: BorderRadius.circular(15.0),
+        ),
+        elevation: 5,
+        clipBehavior: Clip.antiAliasWithSaveLayer,
+        child: Row(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Container( // the image on the left
+              // inherit the height of the parent container
+              height: double.infinity,
+              // force a fixed width
+              width: 160,
+              child: Image.network(
+                widget.landmark.imageURL ?? '',
+                errorBuilder: (context, error, stackTrace) => Icon(Icons.question_mark_outlined),
+                // TODO: make this a switch statement to load a placeholder if null
+                // cover the whole container meaning the image will be cropped
+                fit: BoxFit.cover,
+              ),
+            ),
+            Flexible(
+              child: Padding(
+                padding: EdgeInsets.all(10),
+                child: Column(
+                  children: [
+                    Row(
+                      children: [
+                        Flexible(
+                          child: Text(
+                            widget.landmark.name,
+                            style: const TextStyle(
+                              fontSize: 18,
+                              fontWeight: FontWeight.bold,
+                            ),
+                            maxLines: 2,
+                          ),
+                        )
+                      ],
+                    ),
+                    Row(
+                      children: [
+                        Flexible(
+                          child: Text(
+                            "${widget.landmark.name} (${widget.landmark.type.name})",
+                            style: const TextStyle(fontSize: 14),
+                          ),
+                        )
+                      ]
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

frontend/lib/modules/landmarks_overview.dart

@@ -0,0 +1,130 @@
+import 'dart:collection';
+
+import 'package:fast_network_navigation/modules/landmark_card.dart';
+import 'package:fast_network_navigation/structs/landmark.dart';
+
+import 'package:fast_network_navigation/structs/trip.dart';
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+
+
+
+class LandmarksOverview extends StatefulWidget {
+  final Future<Trip>? trip;
+  const LandmarksOverview({super.key, this.trip});
+
+  @override
+  State<LandmarksOverview> createState() => _LandmarksOverviewState();
+}
+
+class _LandmarksOverviewState extends State<LandmarksOverview> {
+  // final Future<List<Landmark>> _landmarks = fetchLandmarks();
+
+  @override
+  Widget build(BuildContext context) {
+    final Future<LinkedList<Landmark>> _landmarks = getLandmarks(widget.trip);
+    return DefaultTextStyle(
+      style: Theme.of(context).textTheme.displayMedium!,
+      textAlign: TextAlign.center,
+      child: FutureBuilder<LinkedList<Landmark>>(
+        future: _landmarks,
+        builder: (BuildContext context, AsyncSnapshot<LinkedList<Landmark>> snapshot) {
+          List<Widget> children;
+          if (snapshot.hasData) {
+            children = [landmarksWithSteps(snapshot.data!), saveButton()];
+          } else if (snapshot.hasError) {
+            children = <Widget>[
+              const Icon(
+                Icons.error_outline,
+                color: Colors.red,
+                size: 60,
+              ),
+              Padding(
+                padding: const EdgeInsets.only(top: 16),
+                child: Text('Error: ${snapshot.error}', style: TextStyle(fontSize: 12)),
+              ),
+            ];
+          } else {
+            children = [Center(child: CircularProgressIndicator())];
+          }
+          return Center(
+            child: Column(
+              mainAxisAlignment: MainAxisAlignment.center,
+              children: children,
+            ),
+          );
+        },
+      ),
+    );
+  }
+  Widget saveButton() => ElevatedButton(
+    onPressed: () async {
+      Trip? trip = await widget.trip;
+      SharedPreferences prefs = await SharedPreferences.getInstance();
+      trip?.toPrefs(prefs);
+    },
+    child: const Text('Save'),
+  );
+
+}
+
+Widget landmarksWithSteps(LinkedList<Landmark> landmarks) {
+  List<Widget> children = [];
+  for (Landmark landmark in landmarks) {
+    children.add(LandmarkCard(landmark));
+    if (landmark.next != null) {
+      Widget step = stepBetweenLandmarks(landmark, landmark.next!);
+      children.add(step);
+    }
+  }
+
+  return Column(
+    children: children
+  );
+}
+
+
+Widget stepBetweenLandmarks(Landmark before, Landmark after) {
+  // This is a simple widget that draws a line between landmark-cards
+  // It's a vertical dotted line
+  // Next to the line is the icon for the mode of transport (walking for now) and the estimated time
+  // There is also a button to open the navigation instructions as a new intent
+  return Container(
+    margin: EdgeInsets.all(10),
+    padding: EdgeInsets.all(10),
+    decoration: BoxDecoration(
+      border: Border(
+        left: BorderSide(width: 3.0, color: Colors.black),
+      ),
+      // gradient: LinearGradient(
+      //   begin: Alignment.topLeft,
+      //   end: Alignment.bottomRight,
+      //   colors: [Colors.grey, Colors.white, Colors.white],
+      // ),
+    ),
+    child: Row( 
+      children: [
+        Column(
+          children: [
+            Icon(Icons.directions_walk),
+            Text("5 min", style: TextStyle(fontSize: 10)),
+          ],
+        ),
+        Spacer(),
+        ElevatedButton(
+          onPressed: () {
+            // Open navigation instructions
+          },
+          child: Text("Navigate"),
+        ),
+      ],
+    ),
+  );
+}
+
+Future<LinkedList<Landmark>> getLandmarks (Future<Trip>? trip) async {
+  Trip tripf = await trip!;
+  return tripf.landmarks;
+}
+

frontend/lib/modules/map.dart

@@ -0,0 +1,75 @@
+import 'dart:collection';
+
+import 'package:fast_network_navigation/structs/landmark.dart';
+import 'package:fast_network_navigation/structs/trip.dart';
+import 'package:flutter/material.dart';
+import 'package:google_maps_flutter/google_maps_flutter.dart';
+
+class MapWidget extends StatefulWidget {
+
+  final Future<Trip>? trip;
+
+  MapWidget({
+    this.trip
+  });
+
+  @override
+  State<MapWidget> createState() => _MapWidgetState();
+}
+
+class _MapWidgetState extends State<MapWidget> {
+  late GoogleMapController mapController;
+  // coordinates of Paris
+  CameraPosition _cameraPosition = CameraPosition(
+    target: LatLng(48.8566, 2.3522),
+    zoom: 11.0,
+  );
+  Set<Marker> markers = <Marker>{};
+  
+
+  void _onMapCreated(GoogleMapController controller) async {
+    mapController = controller;
+    Trip? trip = await widget.trip;
+    List<double>? newLocation = trip?.landmarks.first.location;
+    if (newLocation != null) {
+      CameraUpdate update = CameraUpdate.newLatLng(LatLng(newLocation[0], newLocation[1]));
+      controller.moveCamera(update);
+    }
+    drawLandmarks();
+  }
+
+
+  void _onCameraIdle() {
+    // print(mapController.getLatLng(ScreenCoordinate(x: 0, y: 0)));
+  }
+
+
+  void drawLandmarks() async {
+    // (re)draws landmarks on the map
+    Trip? trip = await widget.trip;
+    LinkedList<Landmark>? landmarks = trip?.landmarks;
+    if (landmarks != null){
+      setState(() {
+        for (Landmark landmark in landmarks) {
+          markers.add(Marker(
+            markerId: MarkerId(landmark.name),
+            position: LatLng(landmark.location[0], landmark.location[1]),
+            infoWindow: InfoWindow(title: landmark.name, snippet: landmark.type.name),
+          ));
+        }
+      });
+    }
+  }
+
+
+  @override
+  Widget build(BuildContext context) {
+    return GoogleMap(
+      onMapCreated: _onMapCreated,
+      initialCameraPosition: _cameraPosition,
+      onCameraIdle: _onCameraIdle,
+      // onLongPress: ,
+      markers: markers,
+    );
+  }
+}

frontend/lib/modules/trips_overview.dart

@@ -0,0 +1,67 @@
+import 'package:flutter/material.dart';
+
+import 'package:fast_network_navigation/layout.dart';
+import 'package:fast_network_navigation/structs/trip.dart';
+
+
+class TripsOverview extends StatefulWidget {
+  final Future<List<Trip>> trips;
+  const TripsOverview({
+    super.key,
+    required this.trips,
+    });
+
+  @override
+  State<TripsOverview> createState() => _TripsOverviewState();
+}
+
+class _TripsOverviewState extends State<TripsOverview> {
+  // final Future<List<Trip>> _trips = loadTrips();
+
+
+  Widget listBuild (BuildContext context, AsyncSnapshot<List<Trip>> snapshot) {
+    List<Widget> children;
+    if (snapshot.hasData) {
+      children = List<Widget>.generate(snapshot.data!.length, (index) {
+        Trip trip = snapshot.data![index];
+        return ListTile(
+          title: Text("Trip to ${trip.cityName}"),
+          leading: Icon(Icons.pin_drop),
+          onTap: () {
+            Navigator.of(context).push(
+              MaterialPageRoute(
+                builder: (context) => BasePage(mainScreen: "map", trip: Future.value(trip))
+              )
+            );
+          },
+        );
+      });
+    } else if (snapshot.hasError) {
+      children = [
+        const Icon(
+          Icons.error_outline,
+          color: Colors.red,
+          size: 60,
+        ),
+        Padding(
+          padding: const EdgeInsets.only(top: 16),
+          child: Text('Error: ${snapshot.error}'),
+        ),
+      ];
+    } else {
+      children = [Center(child: CircularProgressIndicator())];
+    }
+
+    return ListView(
+      children: children,
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return FutureBuilder(
+      future: widget.trips,
+      builder: listBuild,
+    );
+  }
+}

frontend/lib/pages/new_trip.dart

@@ -0,0 +1,30 @@
+
+import 'package:flutter/material.dart';
+
+class NewTripPage extends StatefulWidget {
+  const NewTripPage({Key? key}) : super(key: key);
+
+  @override
+  _NewTripPageState createState() => _NewTripPageState();
+}
+
+class _NewTripPageState extends State<NewTripPage> {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('New Trip'),
+      ),
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: <Widget>[
+            const Text(
+              'Create a new trip',
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

frontend/lib/pages/overview.dart

@@ -0,0 +1,79 @@
+import 'package:flutter/material.dart';
+import 'package:sliding_up_panel/sliding_up_panel.dart';
+
+import 'package:fast_network_navigation/structs/trip.dart';
+
+import 'package:fast_network_navigation/modules/landmarks_overview.dart';
+import 'package:fast_network_navigation/modules/map.dart';
+import 'package:fast_network_navigation/modules/greeter.dart';
+
+
+
+class NavigationOverview extends StatefulWidget {
+  final Future<Trip> trip;
+
+  NavigationOverview({
+    required this.trip
+  });
+
+  @override
+  State<NavigationOverview> createState() => _NavigationOverviewState();
+}
+
+
+
+class _NavigationOverviewState extends State<NavigationOverview> {
+
+  @override
+  Widget build(BuildContext context) {
+    return SlidingUpPanel(
+        renderPanelSheet: false,
+        panel: _floatingPanel(),
+        collapsed: _floatingCollapsed(),
+        body: MapWidget(trip: widget.trip)
+    );
+  }
+
+  Widget _floatingCollapsed(){
+    final ThemeData theme = Theme.of(context);
+    return Container(
+      decoration: BoxDecoration(
+        color: theme.canvasColor,
+        borderRadius: BorderRadius.only(topLeft: Radius.circular(24.0), topRight: Radius.circular(24.0)),
+        boxShadow: []
+      ),
+      
+      child: Greeter(standalone: true, trip: widget.trip)
+    );
+  }
+
+  Widget _floatingPanel(){
+    final ThemeData theme = Theme.of(context);
+    return Container(
+      decoration: BoxDecoration(
+        color: Colors.white,
+        borderRadius: BorderRadius.all(Radius.circular(24.0)),
+        boxShadow: [
+          BoxShadow(
+            blurRadius: 20.0,
+            color: theme.shadowColor,
+          ),
+        ]
+      ),
+      child: Center(
+        child: Padding(
+        padding: EdgeInsets.all(8.0),
+        child: SingleChildScrollView(
+          child: Column(
+            children: <Widget>[
+              Greeter(standalone: false, trip: widget.trip),
+              LandmarksOverview(trip: widget.trip),
+            ],
+          ),
+        ),
+      ),
+    ),
+    );
+  }
+
+}

frontend/lib/pages/profile.dart

@@ -0,0 +1,89 @@
+import 'package:fast_network_navigation/structs/preferences.dart';
+import 'package:flutter/material.dart';
+
+
+
+class ProfilePage extends StatefulWidget {
+  @override
+  _ProfilePageState createState() => _ProfilePageState();
+}
+
+class _ProfilePageState extends State<ProfilePage> {
+  @override
+  Widget build(BuildContext context) {
+    return ListView(
+      children: [
+        // First a round, centered image
+        Center(
+          child: CircleAvatar(
+            radius: 100,
+            child: Icon(Icons.person, size: 100),
+          )
+        ),
+        Center(
+          child: Text('Curious traveler', style: TextStyle(fontSize: 24))
+        ),
+
+        Padding(padding: EdgeInsets.all(10)),
+        Divider(indent: 25, endIndent: 25),
+        Padding(padding: EdgeInsets.all(10)),
+
+        Padding(
+          padding: EdgeInsets.only(left: 10, right: 10, top: 0, bottom: 10),
+          child: Text('Please rate your personal preferences so that we can taylor your experience.', style: TextStyle(fontSize: 18))
+        ),
+
+        // Now the sliders
+        ImportanceSliders()
+      ]
+    );
+  }
+}
+
+
+
+class ImportanceSliders extends StatefulWidget {
+
+  @override
+  State<ImportanceSliders> createState() => _ImportanceSlidersState();
+}
+
+
+class _ImportanceSlidersState extends State<ImportanceSliders> {
+
+  UserPreferences _prefs = UserPreferences();
+
+  List<Card> _createSliders() {
+    List<Card> sliders = [];
+    for (SinglePreference pref in _prefs.preferences) {
+      sliders.add(Card(
+        child: ListTile(
+          leading: pref.icon,
+          title: Text(pref.name),
+          subtitle: Slider(
+            value: pref.value.toDouble(),
+            min: 0,
+            max: 10,
+            divisions: 10,
+            label: pref.value.toString(),
+            onChanged: (double newValue) {
+              setState(() {
+                pref.value = newValue.toInt();
+                _prefs.save();
+              });
+            },
+          )
+        ),
+        margin: const EdgeInsets.only(left: 10, right: 10, top: 10, bottom: 0),
+        shadowColor: Colors.grey,
+      ));
+    }
+    return sliders;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+
+    return Column(children: _createSliders());
+  }
+}

frontend/lib/pages/tutorial.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/material.dart';
+
+
+
+class TutorialPage extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("Tutorial"),
+      ),
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: <Widget>[
+            Text(
+              'Welcome to the tutorial page!',
+            ),
+            Text(
+              'This is where you will learn how to use the app.',
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

frontend/lib/structs/landmark.dart

@@ -0,0 +1,116 @@
+import 'dart:collection';
+import 'dart:convert';
+
+import 'package:shared_preferences/shared_preferences.dart';
+
+final class Landmark extends LinkedListEntry<Landmark>{
+  // A linked node of a list of Landmarks
+  final String uuid;
+  final String name;
+  final List<double> location;
+  final LandmarkType type;
+  final bool? isSecondary;
+
+  // description to be shown in the overview
+  final String? imageURL;
+  final String? description;
+  final Duration? duration;
+  final bool? visited;
+
+  // Next node
+  // final Landmark? next;
+  final Duration? tripTime;
+
+
+  Landmark({
+    required this.uuid,
+    required this.name,
+    required this.location,
+    required this.type,
+    this.isSecondary,
+
+    this.imageURL,
+    this.description,
+    this.duration,
+    this.visited,
+
+    // this.next,
+    this.tripTime,
+  });
+
+
+  factory Landmark.fromJson(Map<String, dynamic> json) {
+    if (json
+      case { // automatically match all the non-optionals and cast them to the right type
+        'uuid': String uuid,
+        'name': String name,
+        'location': List<dynamic> location,
+        'type': String type,
+      }) {
+      // refine the parsing on a few
+      List<double> locationFixed = List<double>.from(location);
+      // parse the rest separately, they could be missing
+      LandmarkType typeFixed = LandmarkType(name: type);
+      final isSecondary = json['is_secondary'] as bool?;
+      final imageURL = json['image_url'] as String?;
+      final description = json['description'] as String?;
+      var duration = Duration(minutes: json['duration'] ?? 0) as Duration?;
+      if (duration == const Duration()) {duration = null;};
+      final visited = json['visited'] as bool?;
+      
+      return Landmark(
+        uuid: uuid, name: name, location: locationFixed, type: typeFixed, isSecondary: isSecondary, imageURL: imageURL, description: description, duration: duration, visited: visited);
+    } else {
+      throw FormatException('Invalid JSON: $json');
+    }
+  }
+
+
+  @override
+  bool operator ==(Object other) {
+    return other is Landmark && uuid == other.uuid;
+  }
+
+
+  Map<String, dynamic> toJson() => {
+    'uuid': uuid,
+    'name': name,
+    'location': location,
+    'type': type.name,
+    'is_secondary': isSecondary,
+    'image_url': imageURL,
+    'description': description,
+    'duration': duration?.inMinutes,
+    'visited': visited
+  };
+}
+
+
+class LandmarkType {
+  final String name;
+  // final String description;
+  // final Icon icon;
+  
+  const LandmarkType({
+    required this.name,
+    // required this.description,
+    // required this.icon,
+  });
+}
+
+
+// Helpers
+// Handling the landmarks requires a little bit of special care because the linked list is not directly representable in json
+(Landmark, String?) getLandmarkFromPrefs(SharedPreferences prefs, String uuid) {
+  String? content = prefs.getString('landmark_$uuid');
+  Map<String, dynamic> json = jsonDecode(content!);
+  String? nextUUID = json['next_uuid'];
+  return (Landmark.fromJson(json), nextUUID);
+}
+
+
+void landmarkToPrefs(SharedPreferences prefs, Landmark current, Landmark? next) {
+  Map<String, dynamic> json = current.toJson();
+  json['next_uuid'] = next?.uuid;
+  prefs.setString('landmark_${current.uuid}', jsonEncode(json));
+}

frontend/lib/structs/linked_landmarks.dart

@@ -0,0 +1,46 @@
+// import "package:fast_network_navigation/structs/landmark.dart";
+
+// class Linked<Landmark> {
+//   Landmark? head;
+  
+//   Linked();
+
+//   // class methods
+//   bool get isEmpty => head == null;
+
+//   // Add a new node to the end of the list
+//   void add(Landmark value) {
+//     if (isEmpty) {
+//       // If the list is empty, set the new node as the head
+//       head = value;
+//     } else {
+//       Landmark? current = head;
+//       while (current!.next != null) {
+//         // Traverse the list to find the last node
+//         current = current.next;
+//       }
+//       current.next = value; // Set the new node as the next node of the last node
+//     }
+//   }
+
+//   // Remove the first node with the given value
+//   void remove(Landmark value) {
+//     if (isEmpty) return;
+
+//     // If the value is in the head node, update the head to the next node
+//     if (head! == value) {
+//       head = head.next;
+//       return;
+//     }
+
+//     var current = head;
+//     while (current!.next != null) {
+//       if (current.next! == value) {
+//         // If the value is found in the next node, skip the next node
+//         current.next = current.next.next;
+//         return;
+//       }
+//       current = current.next;
+//     }
+//   }
+// }

frontend/lib/structs/preferences.dart

@@ -0,0 +1,82 @@
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+
+class SinglePreference {
+  String name;
+  String description;
+  int value;
+  Icon icon;
+  String key;
+
+  SinglePreference({
+    required this.name,
+    required this.description,
+    required this.value,
+    required this.icon,
+    required this.key,
+  });
+}
+
+
+class UserPreferences {
+  List<SinglePreference> preferences = [
+    SinglePreference(
+      name: "Sightseeing",
+      description: "How much do you like sightseeing?",
+      value: 0,
+      icon: Icon(Icons.church),
+      key: "sightseeing",
+    ),
+    SinglePreference(
+      name: "Shopping",
+      description: "How much do you like shopping?",
+      value: 0,
+      icon: Icon(Icons.shopping_bag),
+      key: "shopping",
+    ),
+    SinglePreference(
+      name: "Foods & Drinks",
+      description: "How much do you like eating?",
+      value: 0,
+      icon: Icon(Icons.restaurant),
+      key: "eating",
+    ),
+    SinglePreference(
+      name: "Nightlife",
+      description: "How much do you like nightlife?",
+      value: 0,
+      icon: Icon(Icons.wine_bar),
+      key: "nightlife",
+    ),
+    SinglePreference(
+      name: "Nature",
+      description: "How much do you like nature?",
+      value: 0,
+      icon: Icon(Icons.landscape),
+      key: "nature",
+    ),
+    SinglePreference(
+      name: "Culture",
+      description: "How much do you like culture?",
+      value: 0,
+      icon: Icon(Icons.palette),
+      key: "culture",
+    ),
+  ];
+
+
+  void save() async {
+    SharedPreferences sharedPrefs = await SharedPreferences.getInstance();
+    for (SinglePreference pref in preferences) {
+      sharedPrefs.setInt(pref.key, pref.value);
+    }
+  }
+
+  void load() async {
+    SharedPreferences sharedPrefs = await SharedPreferences.getInstance();
+    for (SinglePreference pref in preferences) {
+      pref.value = sharedPrefs.getInt(pref.key) ?? 0;
+    }
+  }
+}

frontend/lib/structs/route.dart

@@ -0,0 +1,14 @@
+import "package:fast_network_navigation/structs/landmark.dart";
+
+
+class Route {
+  final String name;
+  final Duration duration;
+  final List<Landmark> landmarks;
+
+  Route({
+    required this.name,
+    required this.duration,
+    required this.landmarks
+  });
+}