import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:prasule/api/wallet.dart';
import 'package:prasule/api/walletmanager.dart';
import 'package:prasule/main.dart';
import 'package:prasule/pw/platformbutton.dart';
import 'package:prasule/pw/platformroute.dart';
import 'package:prasule/util/drawer.dart';
import 'package:prasule/util/graphs.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';
import 'package:prasule/views/settings/settings.dart';
import 'package:prasule/views/setup.dart';

class GraphView extends StatefulWidget {
  const GraphView({super.key});

  @override
  State<GraphView> createState() => _GraphViewState();
}

class _GraphViewState extends State<GraphView> {
  var _selectedDate = DateTime.now();
  Wallet? selectedWallet;
  List<Wallet> wallets = [];
  String? locale;
  var yearlyBtnSet = {"monthly"};
  bool get yearly => yearlyBtnSet.contains("yearly");

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    locale ??= Localizations.localeOf(context).languageCode;
  }

  List<double> generateChartData() {
    if (selectedWallet == null) return [0];
    var data = List<double>.filled(
        (yearly)
            ? 12
            : DateTime(_selectedDate.year, _selectedDate.month, 0).day,
        0.0);
    for (var i = 0; i < data.length; i++) {
      var entriesForRange = selectedWallet!.entries.where((element) => (!yearly)
          ? element.date.month == _selectedDate.month &&
              element.date.year == _selectedDate.year &&
              element.date.day == i + 1
          : element.date.month == i + 1 &&
              element.date.year == _selectedDate.year);
      var sum = 0.0;
      for (var e in entriesForRange) {
        sum += e.data.amount;
      }
      data[i] = sum;
    }
    return data;
  }

  void loadWallet() async {
    wallets = await WalletManager.listWallets();
    if (wallets.isEmpty && mounted) {
      Navigator.of(context).pushReplacement(
          MaterialPageRoute(builder: (c) => const SetupView()));
      return;
    }
    selectedWallet = wallets.first;
    setState(() {});
  }

  @override
  void initState() {
    super.initState();
    loadWallet();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: DropdownButton<int>(
          value:
              (selectedWallet == null) ? -1 : wallets.indexOf(selectedWallet!),
          items: [
            ...wallets.map(
              (e) => DropdownMenuItem(
                value: wallets.indexOf(
                  e,
                ),
                child: Text(e.name),
              ),
            ),
            DropdownMenuItem(
              value: -1,
              child: Text(AppLocalizations.of(context)!.newWallet),
            )
          ],
          onChanged: (v) async {
            if (v == null || v == -1) {
              await Navigator.of(context).push(
                platformRoute(
                  (c) => const SetupView(
                    newWallet: true,
                  ),
                ),
              );
              wallets = await WalletManager.listWallets();
              logger.i(wallets.length);
              selectedWallet = wallets.last;
              setState(() {});
              return;
            }
            selectedWallet = wallets[v];
            setState(() {});
          },
        ),
        actions: [
          PopupMenuButton(
            itemBuilder: (context) => [
              AppLocalizations.of(context)!.settings,
              AppLocalizations.of(context)!.about
            ].map((e) => PopupMenuItem(value: e, child: Text(e))).toList(),
            onSelected: (value) {
              if (value == AppLocalizations.of(context)!.settings) {
                Navigator.of(context).push(
                  MaterialPageRoute(
                    builder: (context) => const SettingsView(),
                  ),
                );
              } else if (value == AppLocalizations.of(context)!.about) {
                showAboutDialog(
                    context: context,
                    applicationLegalese: AppLocalizations.of(context)!.license,
                    applicationName: "Prašule");
              }
            },
          )
        ],
      ),
      drawer: makeDrawer(context, 2),
      body: SingleChildScrollView(
        child: Center(
          child: SizedBox(
            width: MediaQuery.of(context).size.width * 0.9,
            height: MediaQuery.of(context).size.height,
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                SegmentedButton<String>(
                  segments: [
                    ButtonSegment<String>(
                      value: "spending",
                      label: Text(AppLocalizations.of(context)!.spendingStats),
                    )
                  ],
                  selected: const {"spending"},
                  // TODO: onSelectionChanged
                ),
                const SizedBox(
                  height: 5,
                ),
                SegmentedButton<String>(
                  segments: [
                    ButtonSegment<String>(
                      value: "yearly",
                      label: Text(AppLocalizations.of(context)!.yearly),
                    ),
                    ButtonSegment<String>(
                      value: "monthly",
                      label: Text(AppLocalizations.of(context)!.monthly),
                    ),
                  ],
                  selected: yearlyBtnSet,
                  onSelectionChanged: (selection) {
                    yearlyBtnSet = selection;
                    setState(() {});
                  },
                ),
                const SizedBox(height: 5),
                PlatformButton(
                  text: (yearly)
                      ? DateFormat.y(locale).format(_selectedDate)
                      : DateFormat.yMMMM(locale).format(_selectedDate),
                  onPressed: () async {
                    var firstDate = (selectedWallet!.entries
                          ..sort((a, b) => a.date.compareTo(b.date)))
                        .first
                        .date;
                    var lastDate = (selectedWallet!.entries
                          ..sort((a, b) => b.date.compareTo(a.date)))
                        .first
                        .date;
                    var newDate = await showDatePicker(
                        context: context,
                        initialDate: _selectedDate,
                        firstDate: firstDate,
                        lastDate: lastDate,
                        initialEntryMode: (yearly)
                            ? DatePickerEntryMode.input
                            : DatePickerEntryMode.calendar,
                        initialDatePickerMode: (yearly)
                            ? DatePickerMode.year
                            : DatePickerMode.day);
                    if (newDate == null) return;
                    _selectedDate = newDate;
                    setState(() {});
                  },
                ),
                const SizedBox(
                  height: 5,
                ),
                SizedBox(
                  width: MediaQuery.of(context).size.width * 0.9,
                  height: 300,
                  child: ExpensesChart(
                    date: _selectedDate,
                    locale: locale ?? "en",
                    yearly: yearly,
                    data: generateChartData(),
                  ),
                )
              ],
            ),
          ),
        ),
      ),
    );
  }
}