import 'package:ac_web/Api/AcApi.dart';
import 'package:ac_web/Api/Dtos/EReportType.dart';
import 'package:ac_web/Api/Dtos/ReportDto.dart';
import 'package:ac_web/Pages/ReportDetails.dart';
import 'package:ac_web/Widgets/LatestReportEntry.dart';
import 'package:ac_web/Widgets/LatestReportHeader.dart';
import 'package:ac_web/Widgets/ReportTypeIcons.dart';
import 'package:flutter/material.dart';

class LatestReportColumn extends StatefulWidget{
  const LatestReportColumn({super.key, this.title = "Latest Reports", this.filterType});

  /// Headline drawn above the first day header.
  final String title;

  /// When set, only reports of this type are shown.
  final EReportType? filterType;

  @override
  State<LatestReportColumn> createState() => _LatestReportColumnState();
}

class _LatestReportColumnState extends State<LatestReportColumn>{

  late Future<List<ReportDto>> mReportsFuture;

  @override
  void initState() {
    super.initState();
    mReportsFuture = AcApi.instance.reports.getReports();
  }

  @override
  Widget build(BuildContext context) {
    return FutureBuilder<List<ReportDto>>(
      future: mReportsFuture,
      builder: (context, snapshot) {

        if (snapshot.connectionState != ConnectionState.done) {
          return const Center(child: CircularProgressIndicator());
        }

        if (snapshot.hasError) {
          return Center(child: Text('Could not load reports: ${snapshot.error}'));
        }

        // The list of reports fetched from the ReportsController.
        List<ReportDto> reports = snapshot.data ?? <ReportDto>[];

        if (widget.filterType != null) {
          reports = reports
              .where((report) => report.type == widget.filterType)
              .toList();
        }

        return _buildList(reports);
      },
    );
  }

  Widget _buildList(List<ReportDto> reports) {

    List<Widget> widgets = <Widget>[];

    if (reports.isEmpty) {
      return ListView(
        padding: EdgeInsetsGeometry.all(8),
        children: <Widget>[
          LatestReportHeader(text: widget.title, bigHeader: true,),
          const SizedBox(height: 16),
          const Text("No reports available."),
        ],
      );
    }

    // Title Entry
    widgets.add(LatestReportHeader(text: widget.title, bigHeader: true,));

    DateTime? lastDay;

    // Iterate through the reports and create Report entries accordingly
    for(int i = 0; i < reports.length; i++){

      // Add a day header above the first entry of every day
      final DateTime day = _dayOf(reports[i].timestamp);

      if(lastDay == null || day != lastDay){
        widgets.add(LatestReportHeader(text: _dayLabel(day)));
        lastDay = day;
      }

      final ReportDto report = reports[i];

      final IconData icon = reports[i].type.icon;

      widgets.add(LatestReportEntry(
        text: reports[i].title,
        icon: icon,
        author: reports[i].author,
        timestamp: reports[i].timestamp,
        onTap: () => _openReport(report),
      ));
    }

    return ListView(
      padding: EdgeInsetsGeometry.all(8),
      children: widgets,
    );
  }

  /// Opens a new page that shows all details of the given report.
  void _openReport(ReportDto report) {
    Navigator.of(context).push(
      MaterialPageRoute<void>(
        builder: (context) => ReportDetails(report: report),
      ),
    );
  }

  /// Strips the time part, so that two timestamps of the same day are equal.
  DateTime _dayOf(DateTime timestamp) {
    final DateTime local = timestamp.toLocal();
    return DateTime(local.year, local.month, local.day);
  }

  /// "Today", "Yesterday" or e.g. "15. August" for all other days.
  String _dayLabel(DateTime day) {
    final DateTime today = _dayOf(DateTime.now());
    final DateTime yesterday = DateTime(today.year, today.month, today.day - 1);

    if (day == today) {
      return "Today";
    }

    if (day == yesterday) {
      return "Yesterday";
    }

    return "${day.day}. ${_monthNames[day.month - 1]}";
  }

  static const List<String> _monthNames = <String>[
    "January",
    "February",
    "March",
    "April",
    "May",
    "June",
    "July",
    "August",
    "September",
    "October",
    "November",
    "December",
  ];
}