anyway/frontend/lib/modules/landmarks_overview.dart

import 'dart:developer';
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';

import 'package:anyway/modules/landmark_card.dart';
import 'package:anyway/structs/landmark.dart';
import 'package:anyway/structs/trip.dart';




class LandmarksOverview extends StatefulWidget {
  final Trip? trip;
  const LandmarksOverview({super.key, this.trip});

  @override
  State<LandmarksOverview> createState() => _LandmarksOverviewState();
}

class _LandmarksOverviewState extends State<LandmarksOverview> {

  @override
  Widget build(BuildContext context) {
    return ListenableBuilder(
      listenable: widget.trip!,
      builder: (BuildContext context, Widget? child) {
        Trip trip = widget.trip!;
        log("Trip ${trip.uuid} ${trip.landmarks.length} landmarks");
        
        List<Widget> children;
        
        if (trip.uuid != 'pending' && trip.uuid != 'error') {
          log("Trip ${trip.uuid} ${trip.landmarks.length} landmarks");
          if (trip.landmarks.length <= 1) {
            children = [
              const Text("No landmarks in this trip"),
            ];
          } else {
            children = [
              landmarksWithSteps(),
              saveButton(),
            ];
          }
        } else if(trip.uuid == 'pending') {
          // the trip is still being fetched from the api
          children = [Center(child: CircularProgressIndicator())];
        } else {
            // trip.uuid == 'error'
            // show the error raised by the api
            // String error = 
            children = [
              const Icon(
                Icons.error_outline,
                color: Colors.red,
                size: 60,
              ),
              Padding(
                padding: const EdgeInsets.only(top: 16),
                child: Text('Error: ${trip.errorDescription}'),
              ),
            ];
        }

        return Column(
          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() {
    return ListenableBuilder(
      listenable: widget.trip!,
      builder: (BuildContext context, Widget? child) {
        List<Widget> children = [];
        for (Landmark landmark in widget.trip!.landmarks) {
          children.add(
            Dismissible(
              key: ValueKey<int>(landmark.hashCode),
              child: LandmarkCard(landmark),
              dismissThresholds: {DismissDirection.endToStart: 0.6},
              onDismissed: (direction) {
                // Remove the item from the data source.
                  log(landmark.name);
                setState(() {
                  widget.trip!.removeLandmark(landmark);
                });
                // Then show a snackbar.
                ScaffoldMessenger.of(context)
                    .showSnackBar(SnackBar(content: Text("We won't show ${landmark.name} again")));
              },
              background: Container(color: Colors.red),
              secondaryBackground: Container(
                color: Colors.red,
                child: Icon(
                  Icons.delete,
                  color: Colors.white,
                ),
                padding: EdgeInsets.all(15),
                alignment: Alignment.centerRight,
              ),
            )
          );
          if (landmark.next != null) {
            Widget step = stepBetweenLandmarks(landmark, landmark.next!);
            children.add(step);
          }
        }
        return Column(
          children: children  
        );
      },
    );
  }
}


Widget stepBetweenLandmarks(Landmark current, Landmark next) {
  int timeRounded = 5 * (current.tripTime?.inMinutes ?? 0) ~/ 5;
  // ~/ is integer division (rounding)
  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("~$timeRounded min", style: TextStyle(fontSize: 10)),
          ],
        ),
        Spacer(),
        ElevatedButton(
          onPressed: () {
            // Open navigation instructions
          },
          child: Row(
            children: [
              Icon(Icons.directions),
              Text("Directions"),
            ],
          ),
        )
      ],
    ),
  );
}