// Author: fruit.com.cn

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../../../core/data/models/comment.dart';
import '../../../core/data/models/drama.dart';
import '../../../core/data/repositories/comment_repository.dart';
import '../../../core/data/repositories/interaction_repository.dart';
import '../../../core/data/services/comment_controller.dart';
import '../../../core/formatting/error_text.dart';
import '../../../core/platform/haptics.dart';
import '../../../core/theme/app_colors.dart';
import '../../../core/widgets/auth_gate.dart';
import '../../../l10n/app_localizations.dart';
import '../../interaction/widgets/report_dialog.dart';
import 'comment_tile.dart';

const double _minSheetHeight = 240;
const double _maxSheetHeight = 460;
const int _maxCommentLength = 300;

/// 服务端评论底部弹窗：匿名列表、游标翻页、回复、点赞和本人删除。
class DramaCommentsSheet extends StatefulWidget {
  const DramaCommentsSheet({super.key, required this.drama});

  final Drama drama;

  @override
  State<DramaCommentsSheet> createState() => _DramaCommentsSheetState();
}

class _DramaCommentsSheetState extends State<DramaCommentsSheet> {
  final _input = TextEditingController();
  final _inputFocus = FocusNode();
  late final CommentController _controller;
  DramaComment? _replyTo;

  @override
  void initState() {
    super.initState();
    _controller = CommentController(
      comments: context.read<CommentRepository>(),
      interactions: context.read<InteractionRepository>(),
      dramaId: widget.drama.id,
    );
    unawaited(_controller.load());
  }

  @override
  void dispose() {
    _controller.dispose();
    _input.dispose();
    _inputFocus.dispose();
    super.dispose();
  }

  Future<void> _post() async {
    if (_controller.submitting) return;
    if (_input.text.trim().isEmpty) return;
    if (!await ensureSignedIn(context) || !mounted) return;
    unawaited(context.read<Haptics>().lightImpact());
    final result = await _controller.publish(_input.text, replyTo: _replyTo);
    if (!mounted) return;
    if (result.isSuccess) {
      _input.clear();
      setState(() => _replyTo = null);
      return;
    }
    _showMessage(
      result.errorMessage ?? AppLocalizations.of(context)!.commentPostFailed,
    );
  }

  void _beginReply(DramaComment comment) {
    setState(() => _replyTo = comment);
    _inputFocus.requestFocus();
  }

  void _cancelReply() {
    if (_replyTo == null) return;
    setState(() => _replyTo = null);
  }

  Future<void> _like(DramaComment comment) async {
    if (!await ensureSignedIn(context) || !mounted) return;
    unawaited(context.read<Haptics>().lightImpact());
    final result = await _controller.toggleLike(comment);
    if (!result.isSuccess && mounted) {
      _showMessage(
        result.errorMessage ?? AppLocalizations.of(context)!.commentPostFailed,
      );
    }
  }

  Future<void> _confirmDelete(DramaComment comment) async {
    final l10n = AppLocalizations.of(context)!;
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: Text(l10n.deleteCommentTitle),
        content: Text(l10n.deleteCommentMessage),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(dialogContext).pop(false),
            child: Text(l10n.cancel),
          ),
          FilledButton(
            key: const Key('comment-delete-confirm'),
            onPressed: () => Navigator.of(dialogContext).pop(true),
            child: Text(l10n.delete),
          ),
        ],
      ),
    );
    if (confirmed != true || !mounted) return;
    final result = await _controller.delete(comment);
    if (!result.isSuccess && mounted) {
      _showMessage(
        result.errorMessage ??
            AppLocalizations.of(context)!.commentDeleteFailed,
      );
    }
  }

  Future<void> _report(DramaComment comment) async {
    if (!await ensureSignedIn(context) || !mounted) return;
    final l10n = AppLocalizations.of(context)!;
    final draft = await showReportDialog(context, title: l10n.reportComment);
    if (draft == null || !mounted) return;
    unawaited(context.read<Haptics>().lightImpact());
    final result = await _controller.report(
      comment,
      reason: draft.reason,
      description: draft.description,
    );
    if (!mounted) return;
    _showMessage(
      result.isSuccess
          ? l10n.reportSubmitted
          : result.errorMessage ?? l10n.reportFailed,
    );
  }

  void _showMessage(String message) {
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(message)));
  }

  @override
  Widget build(BuildContext context) {
    final available =
        MediaQuery.sizeOf(context).height -
        MediaQuery.viewInsetsOf(context).bottom -
        24;
    return Padding(
      padding: EdgeInsets.only(bottom: MediaQuery.viewInsetsOf(context).bottom),
      child: SizedBox(
        height: available.clamp(_minSheetHeight, _maxSheetHeight),
        child: SafeArea(
          top: false,
          child: Padding(
            padding: const EdgeInsets.fromLTRB(16, 12, 16, 8),
            child: ListenableBuilder(
              listenable: _controller,
              builder: (context, _) => _content(context),
            ),
          ),
        ),
      ),
    );
  }

  Widget _content(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          l10n.comments,
          style: const TextStyle(fontSize: 20, fontWeight: FontWeight.w700),
        ),
        const SizedBox(height: 8),
        Expanded(child: _list(l10n)),
        if (_replyTo != null) _replyBanner(l10n, _replyTo!),
        _composer(l10n),
      ],
    );
  }

  Widget _list(AppLocalizations l10n) {
    if (_controller.loading && _controller.comments.isEmpty) {
      return const Center(
        child: CircularProgressIndicator(key: Key('comment-list-loading')),
      );
    }
    if (_controller.error != null && _controller.comments.isEmpty) {
      return Center(
        key: const Key('comment-list-error'),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(
              errorText(l10n, _controller.error, l10n.commentsLoadFailed),
              textAlign: TextAlign.center,
              style: const TextStyle(color: AppColors.muted),
            ),
            const SizedBox(height: 8),
            TextButton(
              key: const Key('comment-list-retry'),
              onPressed: _controller.load,
              child: Text(l10n.retry),
            ),
          ],
        ),
      );
    }
    if (_controller.comments.isEmpty) {
      return Center(
        key: const Key('comment-list-empty'),
        child: Text(
          l10n.noComments,
          style: const TextStyle(color: AppColors.muted),
        ),
      );
    }
    return ListView.builder(
      key: const Key('comment-list'),
      itemCount: _controller.comments.length + 1,
      itemBuilder: (context, index) {
        if (index == _controller.comments.length) return _footer(l10n);
        return _CommentThread(
          comment: _controller.comments[index],
          controller: _controller,
          handlers: CommentInteractionHandlers(
            onReply: _beginReply,
            onLike: _like,
            onDelete: _confirmDelete,
            onReport: _report,
          ),
        );
      },
    );
  }

  Widget _footer(AppLocalizations l10n) {
    if (_controller.loadingMore) {
      return const Padding(
        padding: EdgeInsets.symmetric(vertical: 12),
        child: Center(child: CircularProgressIndicator()),
      );
    }
    if (_controller.hasMore) {
      return TextButton(
        key: const Key('comment-list-load-more'),
        onPressed: _controller.loadMore,
        child: Text(l10n.loadMore),
      );
    }
    return const SizedBox(height: 8);
  }

  Widget _replyBanner(AppLocalizations l10n, DramaComment replyTo) => Padding(
    padding: const EdgeInsets.only(bottom: 6),
    child: Row(
      children: [
        Expanded(
          child: Text(
            l10n.replyingTo(
              replyTo.nickname.isEmpty ? l10n.anonymousUser : replyTo.nickname,
            ),
            style: const TextStyle(color: AppColors.blueSoft, fontSize: 12),
          ),
        ),
        IconButton(
          key: const Key('comment-cancel-reply'),
          tooltip: l10n.cancelReply,
          onPressed: _cancelReply,
          visualDensity: VisualDensity.compact,
          icon: const Icon(Icons.close_rounded, size: 18),
        ),
      ],
    ),
  );

  Widget _composer(AppLocalizations l10n) => Row(
    children: [
      Expanded(
        child: TextField(
          key: const Key('comment-input'),
          controller: _input,
          focusNode: _inputFocus,
          maxLength: _maxCommentLength,
          maxLines: 1,
          decoration: InputDecoration(
            hintText: l10n.writeComment,
            counterText: '',
            filled: true,
            fillColor: const Color(0xFF35353A),
            border: OutlineInputBorder(
              borderRadius: BorderRadius.circular(14),
              borderSide: BorderSide.none,
            ),
          ),
          onSubmitted: (_) => _post(),
        ),
      ),
      const SizedBox(width: 8),
      IconButton.filled(
        key: const Key('comment-post'),
        tooltip: l10n.postComment,
        onPressed: _controller.submitting ? null : _post,
        icon: _controller.submitting
            ? const SizedBox.square(
                dimension: 18,
                child: CircularProgressIndicator(strokeWidth: 2),
              )
            : const Icon(Icons.send_rounded),
      ),
    ],
  );
}

class _CommentThread extends StatelessWidget {
  const _CommentThread({
    required this.comment,
    required this.controller,
    required this.handlers,
  });

  final DramaComment comment;
  final CommentController controller;
  final CommentInteractionHandlers handlers;

  @override
  Widget build(BuildContext context) {
    final replies = controller.repliesFor(comment.id);
    final expanded = controller.repliesExpanded(comment.id);
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        CommentTile(
          comment: comment,
          controller: controller,
          handlers: handlers,
        ),
        if (comment.replyCount > 0 || replies.isNotEmpty)
          Padding(
            padding: const EdgeInsets.only(left: 44, bottom: 8),
            child: TextButton(
              key: Key('comment-replies-${comment.id}'),
              onPressed: () => _toggleReplies(context),
              child: Text(
                expanded
                    ? AppLocalizations.of(context)!.hideReplies
                    : AppLocalizations.of(
                        context,
                      )!.viewReplies(comment.replyCount),
              ),
            ),
          ),
        if (expanded)
          Padding(
            padding: const EdgeInsets.only(left: 28),
            child: Column(
              children: [
                if (controller.repliesLoading(comment.id))
                  const Padding(
                    padding: EdgeInsets.symmetric(vertical: 8),
                    child: CircularProgressIndicator(),
                  ),
                for (final reply in replies)
                  CommentTile(
                    comment: reply,
                    controller: controller,
                    handlers: handlers,
                    isReply: true,
                  ),
                if (controller.repliesHasMore(comment.id))
                  TextButton(
                    onPressed: () => controller.loadMoreReplies(comment.id),
                    child: Text(AppLocalizations.of(context)!.loadMore),
                  ),
              ],
            ),
          ),
        const Divider(height: 1),
      ],
    );
  }

  Future<void> _toggleReplies(BuildContext context) async {
    if (controller.repliesExpanded(comment.id)) {
      controller.hideReplies(comment.id);
      return;
    }
    await controller.loadReplies(comment.id);
  }
}