// Copyright 2019 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:collection';
import 'dart:html';

import 'package:intl/intl.dart';
import 'package:flutter_web/material.dart';

import '../models/providers.dart';
import '../models/repository_status.dart';

class RepositoryDetails<T extends RepositoryStatus> extends StatelessWidget {
  const RepositoryDetails({@required this.icon});

  final Widget icon;

  @override
  Widget build(BuildContext context) {
    final T repositoryStatus = ModelBinding.of<T>(context);
    final FlutterRepositoryStatus flutterStatus =
        ModelBinding.of<FlutterRepositoryStatus>(context);
    return RefreshRepository<T>(
      child:
          Row(crossAxisAlignment: CrossAxisAlignment.start, children: <Widget>[
        _RepositoryInfoWidget<T>(icon: icon),
        // The Flutter repository contains labels relevant to some other repos like plugins, engine, etc. Avoiding displaying twice in the Flutter repository widget.
        if (repositoryStatus.runtimeType != flutterStatus.runtimeType)
          _TopicListWidget(
              title: 'Flutter Pull Request Labels',
              countByTopic: flutterStatus.pullRequestCountByLabelName,
              labelEvaluation: repositoryStatus.labelEvaluation,
              baseUrl:
                  'https://github.com/flutter/flutter/pulls?q=is%3Apr+is%3Aopen+label%3A'),
        _TopicListWidget(
            title: 'Pull Request Labels',
            countByTopic: repositoryStatus.pullRequestCountByLabelName,
            labelEvaluation: (String label) => !label.startsWith('cla:'),
            baseUrl:
                'https://github.com/flutter/${repositoryStatus.name}/pulls?q=is%3Apr+is%3Aopen+label%3A'),
        _TopicListWidget(
            title: 'Pull Requests by Topic',
            countByTopic: repositoryStatus.pullRequestCountByTitleTopic,
            baseUrl:
                'https://github.com/flutter/${repositoryStatus.name}/pulls?q=is%3Apr+is%3Aopen+in%3Atitle+')
      ]),
    );
  }
}

class _RepositoryInfoWidget<T extends RepositoryStatus>
    extends StatelessWidget {
  const _RepositoryInfoWidget({@required this.icon});

  final Widget icon;

  @override
  Widget build(BuildContext context) {
    final T repositoryStatus = ModelBinding.of<T>(context);
    return Expanded(
        child: Padding(
            padding: const EdgeInsets.only(right: 50.0),
            child: Column(children: <Widget>[
              _MetadataWidget<T>(icon: icon),
              if (repositoryStatus.pullRequestCount > 0)
                _PullRequestWidget<T>(),
              if (repositoryStatus.issueCount > 0) _IssueWidget<T>(),
              if (repositoryStatus.issuesByTriageLabelName.length > 0)
                const Divider(height: 40.0),
              _TopicListWidget(
                  title: 'Triage Issues',
                  countByTopic: repositoryStatus.issuesByTriageLabelName,
                  severe: true,
                  baseUrl:
                      'https://github.com/flutter/${repositoryStatus.name}/issues?q=is%3Aissue+is%3Aopen+label%3A'),
            ])));
  }
}

class _MetadataWidget<T extends RepositoryStatus> extends StatelessWidget {
  const _MetadataWidget({@required this.icon});

  final Widget icon;

  @override
  Widget build(BuildContext context) {
    final NumberFormat numberFormat = NumberFormat('#,###');
    final T repositoryStatus = ModelBinding.of<T>(context);

    List<Widget> issueWidgets = <Widget>[
      ListTile(
          leading: IconTheme(
              data: IconTheme.of(context).copyWith(
                  size: 56.0, color: Theme.of(context).primaryColorLight),
              child: icon),
          title: Text(toBeginningOfSentenceCase(repositoryStatus.name)),
          onTap: () => window.open(
              'https://github.com/flutter/${repositoryStatus.name}', '_blank')),
      _DetailItem(
          title: 'Watchers',
          value: numberFormat.format(repositoryStatus.watchersCount)),
      _DetailItem(
          title: 'Subscribers',
          value: numberFormat.format(repositoryStatus.subscribersCount)),
      _DetailItem(
          title: 'TODOs',
          value: numberFormat.format(repositoryStatus.todoCount)),
    ];
    return Column(children: issueWidgets);
  }
}

class _IssueWidget<T extends RepositoryStatus> extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final NumberFormat numberFormat = NumberFormat('#,###');
    final NumberFormat percentFormat = NumberFormat.percentPattern();
    final T repositoryStatus = ModelBinding.of<T>(context);

    final DateTime staleDate = DateTime.now().subtract(
        const Duration(days: RepositoryStatus.staleIssueThresholdInDays));
    final String staleDateQuery = DateFormat('yyyy-MM-dd').format(staleDate);

    final int issueCount = repositoryStatus.issueCount;
    return Column(children: <Widget>[
      const Divider(height: 40.0),
      const _DetailTitle(title: 'Issues'),
      InkWell(
          child: _DetailItem(
              title: 'Open', value: numberFormat.format(issueCount)),
          onTap: () => window.open(
              'https://github.com/flutter/${repositoryStatus.name}/issues',
              '_blank')),
      InkWell(
          child: _DetailItem(
              title: 'No Labels',
              value:
                  '${numberFormat.format(repositoryStatus.missingLabelsIssuesCount)} (${percentFormat.format(repositoryStatus.missingLabelsIssuesCount / issueCount)})'),
          onTap: () => window.open(
              'https://github.com/flutter/${repositoryStatus.name}/issues?q=is%3Aissue+is%3Aopen+no%3Alabel',
              '_blank')),
      InkWell(
          child: _DetailItem(
              title: 'Unmodified in month',
              value:
                  '${numberFormat.format(repositoryStatus.staleIssueCount)} (${percentFormat.format(repositoryStatus.staleIssueCount / issueCount)})'),
          onTap: () => window.open(
              'https://github.com/flutter/${repositoryStatus.name}/issues?q=is%3Aissue+is%3Aopen+updated:<=$staleDateQuery',
              '_blank')),
    ]);
  }
}

class _PullRequestWidget<T extends RepositoryStatus> extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final NumberFormat numberFormat = NumberFormat('#,###');
    final NumberFormat percentFormat = NumberFormat.percentPattern();
    final T repositoryStatus = ModelBinding.of<T>(context);

    final int pullRequestCount = repositoryStatus.pullRequestCount;

    final int ageDays =
        (repositoryStatus.totalAgeOfAllPullRequests / pullRequestCount).round();
    final String age = Intl.plural(ageDays,
        zero: '0 days', one: '1 day', other: '$ageDays days');

    final DateTime staleDate = DateTime.now().subtract(
        const Duration(days: RepositoryStatus.stalePullRequestThresholdInDays));
    final String staleDateQuery = DateFormat('yyyy-MM-dd').format(staleDate);

    return Semantics(
      label: 'Pull Requests',
      child: Column(children: <Widget>[
        const Divider(height: 40.0),
        const _DetailTitle(title: 'Pull Requests'),
        InkWell(
            child: _DetailItem(
                title: 'Open', value: numberFormat.format(pullRequestCount)),
            onTap: () => window.open(
                'https://github.com/flutter/${repositoryStatus.name}/pulls',
                '_blank')),
        InkWell(
            child: _DetailItem(title: 'Average Age', value: age),
            onTap: () => window.open(
                'https://github.com/flutter/${repositoryStatus.name}/pulls?q=is%3Apr+is%3Aopen+sort%3Acreated-asc',
                '_blank')),
        InkWell(
            child: _DetailItem(
                title: 'Unmodified in week',
                value:
                    '${numberFormat.format(repositoryStatus.stalePullRequestCount)} (${percentFormat.format(repositoryStatus.stalePullRequestCount / pullRequestCount)})'),
            onTap: () => window.open(
                'https://github.com/flutter/${repositoryStatus.name}/pulls?q=is%3Apr+is%3Aopen+updated:<=$staleDateQuery',
                '_blank')),
      ]),
    );
  }
}

class _TopicListWidget extends StatelessWidget {
  const _TopicListWidget(
      {@required this.title,
      @required this.countByTopic,
      this.labelEvaluation,
      this.severe = false,
      @required this.baseUrl});

  final String title;
  final LabelEvaluator labelEvaluation;
  final MapMixin<String, int> countByTopic;
  final bool severe;
  final String baseUrl;

  @override
  Widget build(BuildContext context) {
    final NumberFormat numberFormat = NumberFormat('#,###');

    final List<Widget> labelWidgets = <Widget>[];

    countByTopic.forEach((String labelName, int count) {
      if ((labelEvaluation == null || labelEvaluation(labelName)) &&
          labelWidgets.length < 17) {
        labelWidgets.add(InkWell(
            child: _DetailItem(
                title: labelName, value: numberFormat.format(count)),
            onTap: () => window.open('$baseUrl"$labelName"', '_blank')));
      }
    });
    if (labelWidgets.isNotEmpty) {
      labelWidgets.insert(0, _DetailTitle(title: title, severe: severe));
    } else {
      return const SizedBox();
    }
    return Expanded(
      child: Semantics(
        label: title,
        child: Column(children: labelWidgets),
      ),
    );
  }
}

class _DetailTitle extends StatelessWidget {
  const _DetailTitle({@required this.title, this.severe = false});
  final String title;
  final bool severe;

  @override
  Widget build(BuildContext context) {
    return Align(
        alignment: AlignmentDirectional.centerStart,
        child: Padding(
            padding: const EdgeInsets.only(bottom: 10.0),
            child: Text(title,
                style: Theme.of(context).textTheme.headline.copyWith(
                      color: severe
                          ? Colors.redAccent
                          : Theme.of(context).primaryColor,
                    ))));
  }
}

class _DetailItem extends StatelessWidget {
  const _DetailItem({@required this.title, @required this.value});
  final String title;
  final String value;

  @override
  Widget build(BuildContext context) {
    final TextTheme textTheme = Theme.of(context).textTheme;
    return Padding(
        padding: const EdgeInsets.symmetric(vertical: 5.0),
        child: Row(
          mainAxisAlignment: MainAxisAlignment.start,
          children: <Widget>[
            Text('$title: ',
                style: textTheme.subtitle
                    .copyWith(fontSize: textTheme.subhead.fontSize)),
            Text(value, style: textTheme.subhead),
          ],
        ));
  }
}