// Author: fruit.com.cn

import 'dart:async';
import 'dart:math' as math;

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

import '../../../core/data/models/comment.dart';
import '../../../core/data/services/auth_controller.dart';
import '../../../core/data/services/comment_controller.dart';
import '../../../core/platform/haptics.dart';
import '../../../core/platform/keyboard_inset.dart';
import '../../../core/theme/app_colors.dart';
import '../../../core/widgets/auth_gate.dart';
import '../../../l10n/app_localizations.dart';

const double _sheetRadius = 20;
const double _inputRadius = 12;
const double _postButtonHeight = 32;
const int _maxCommentLength = 300;

/// 独立评论输入弹窗，复用原评论控制器的发布与列表更新能力。
class CommentComposerSheet extends StatefulWidget {
  const CommentComposerSheet({
    super.key,
    required this.controller,
    required this.onDismiss,
    required this.onPosted,
    this.replyTo,
  });

  final CommentController controller;
  final VoidCallback onDismiss;
  final VoidCallback onPosted;
  final DramaComment? replyTo;

  @override
  State<CommentComposerSheet> createState() => _CommentComposerSheetState();
}

class _CommentComposerSheetState extends State<CommentComposerSheet> {
  final _input = TextEditingController();
  final _inputFocus = FocusNode();
  final _keyboardInset = KeyboardInsetNotifier.instance;
  double _pinnedKeyboardInset = 0;

  @override
  void initState() {
    super.initState();
    _input.addListener(_onInputChanged);
    _keyboardInset.addListener(_onKeyboardInsetChanged);
    widget.controller.addListener(_onControllerChanged);
    unawaited(_keyboardInset.start());
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) _inputFocus.requestFocus();
    });
  }

  @override
  void dispose() {
    _input.removeListener(_onInputChanged);
    _keyboardInset.removeListener(_onKeyboardInsetChanged);
    widget.controller.removeListener(_onControllerChanged);
    _inputFocus.unfocus();
    _input.dispose();
    _inputFocus.dispose();
    super.dispose();
  }

  void _onInputChanged() {
    if (mounted) setState(() {});
  }

  void _onControllerChanged() {
    if (mounted) setState(() {});
  }

  void _onKeyboardInsetChanged() {
    if (!mounted) return;
    setState(() {});
  }

  double _keyboardHeight(BuildContext context) => math.max(
    MediaQuery.viewInsetsOf(context).bottom,
    _keyboardInset.value / MediaQuery.devicePixelRatioOf(context),
  );

  Future<void> _submit() async {
    if (widget.controller.submitting) return;
    final text = _input.text.trim();
    if (text.isEmpty) return;
    unawaited(context.read<Haptics>().lightImpact());
    final result = await widget.controller.publish(
      text,
      replyTo: widget.replyTo,
    );
    if (!mounted) return;
    if (result.isSuccess) {
      _input.clear();
      widget.onPosted();
      return;
    }
    final l10n = AppLocalizations.of(context)!;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(result.errorMessage ?? l10n.commentPostFailed)),
    );
  }

  Future<void> _authenticate() async {
    await ensureSignedIn(context);
    if (!mounted || !context.read<AuthController>().isSignedIn) return;
    _inputFocus.requestFocus();
  }

  @override
  Widget build(BuildContext context) {
    final currentKeyboardInset = _keyboardHeight(context);
    _pinnedKeyboardInset = math.max(_pinnedKeyboardInset, currentKeyboardInset);
    final l10n = AppLocalizations.of(context)!;
    final signedIn = context.watch<AuthController>().isSignedIn;
    final hasContent = _input.text.trim().isNotEmpty;
    final canPost = signedIn && hasContent && !widget.controller.submitting;
    final multiline = _input.text.contains('\n');

    return Stack(
      key: const Key('comment-composer-overlay'),
      fit: StackFit.expand,
      children: [
        Positioned.fill(
          child: GestureDetector(
            key: const Key('comment-composer-dismiss-layer'),
            behavior: HitTestBehavior.opaque,
            onTap: widget.onDismiss,
          ),
        ),
        Positioned(
          left: 0,
          right: 0,
          bottom: 0,
          child: GestureDetector(
            behavior: HitTestBehavior.opaque,
            onTap: () {},
            child: Material(
              key: const Key('comment-composer-panel'),
              color: AppColors.card,
              clipBehavior: Clip.antiAlias,
              borderRadius: const BorderRadius.vertical(
                top: Radius.circular(_sheetRadius),
              ),
              child: SafeArea(
                top: false,
                child: Padding(
                  padding: EdgeInsets.only(bottom: _pinnedKeyboardInset),
                  child: Padding(
                    key: const Key('comment-composer-sheet'),
                    padding: const EdgeInsets.fromLTRB(16, 12, 16, 12),
                    child: TextFieldTapRegion(
                      child: Column(
                        mainAxisSize: MainAxisSize.min,
                        crossAxisAlignment: CrossAxisAlignment.stretch,
                        children: [
                          if (widget.replyTo != null)
                            Padding(
                              padding: const EdgeInsets.only(bottom: 8),
                              child: Text(
                                l10n.replyingTo(
                                  widget.replyTo!.nickname.isEmpty
                                      ? l10n.anonymousUser
                                      : widget.replyTo!.nickname,
                                ),
                                style: const TextStyle(
                                  color: AppColors.muted,
                                  fontSize: 12,
                                ),
                              ),
                            ),
                          Container(
                            decoration: BoxDecoration(
                              color: AppColors.commentInput,
                              borderRadius: BorderRadius.circular(_inputRadius),
                            ),
                            child: TextField(
                              key: const Key('comment-composer-input'),
                              controller: _input,
                              focusNode: _inputFocus,
                              readOnly: !signedIn,
                              canRequestFocus: signedIn,
                              minLines: 1,
                              maxLines: 4,
                              maxLength: _maxCommentLength,
                              textAlignVertical: multiline
                                  ? TextAlignVertical.top
                                  : TextAlignVertical.center,
                              style: TextStyle(
                                color: AppColors.cream,
                                fontSize: 15,
                                height: multiline ? 1.4 : null,
                              ),
                              cursorColor: AppColors.blue,
                              decoration: InputDecoration(
                                hintText: signedIn
                                    ? l10n.writeComment
                                    : l10n.commentLoginHint,
                                hintStyle: const TextStyle(
                                  color: AppColors.muted,
                                  fontSize: 14,
                                ),
                                counterText: '',
                                contentPadding: const EdgeInsets.symmetric(
                                  horizontal: 16,
                                  vertical: 12,
                                ),
                                border: InputBorder.none,
                                enabledBorder: InputBorder.none,
                                focusedBorder: InputBorder.none,
                              ),
                              onTap: signedIn ? null : _authenticate,
                            ),
                          ),
                          const SizedBox(height: 12),
                          Align(
                            alignment: Alignment.centerRight,
                            child: SizedBox(
                              height: _postButtonHeight,
                              child: TextButton(
                                key: const Key('comment-composer-post'),
                                onPressed: canPost ? _submit : null,
                                style: TextButton.styleFrom(
                                  minimumSize: const Size(0, _postButtonHeight),
                                  padding: const EdgeInsets.symmetric(
                                    horizontal: 16,
                                  ),
                                  tapTargetSize:
                                      MaterialTapTargetSize.shrinkWrap,
                                  backgroundColor: hasContent
                                      ? AppColors.blue.withValues(alpha: 0.12)
                                      : AppColors.raised,
                                  foregroundColor: AppColors.blue,
                                  disabledForegroundColor: AppColors.muted,
                                  disabledBackgroundColor: AppColors.raised,
                                  shape: RoundedRectangleBorder(
                                    borderRadius: BorderRadius.circular(8),
                                  ),
                                ),
                                child: Text(
                                  l10n.postComment,
                                  style: const TextStyle(
                                    fontSize: 14,
                                    fontWeight: FontWeight.w600,
                                  ),
                                ),
                              ),
                            ),
                          ),
                        ],
                      ),
                    ),
                  ),
                ),
              ),
            ),
          ),
        ),
      ],
    );
  }
}