import 'dart:io';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../../providers/app_provider.dart';
import '../../models/data_models.dart';
import '../../utils/toast_util.dart';

/// 添加/编辑影评页面
class MovieReviewFormPage extends StatefulWidget {
  final String movieId;
  final MovieReview? review;

  const MovieReviewFormPage({super.key, required this.movieId, this.review});

  @override
  State<MovieReviewFormPage> createState() => _MovieReviewFormPageState();
}

class _MovieReviewFormPageState extends State<MovieReviewFormPage> {
  final _formKey = GlobalKey<FormState>();
  late TextEditingController _contentController;
  late TextEditingController _reviewerController;
  late TextEditingController _sourceController;
  late int _reviewType;

  @override
  void initState() {
    super.initState();
    _contentController = TextEditingController(text: widget.review?.content ?? '');
    _reviewerController = TextEditingController(text: widget.review?.reviewer ?? '');
    _sourceController = TextEditingController(text: widget.review?.source ?? '');
    _reviewType = widget.review?.reviewType ?? 1;
  }

  @override
  void dispose() {
    _contentController.dispose();
    _reviewerController.dispose();
    _sourceController.dispose();
    super.dispose();
  }

  Movie? _getMovie() {
    return context.read<AppProvider>().movies.where((m) => m.id == widget.movieId).firstOrNull;
  }

  // ═══════════════════════════════════════════════════════════════════

  @override
  Widget build(BuildContext context) {
    final colors = Theme.of(context).colorScheme;
    final isEdit = widget.review != null;
    final movie = _getMovie();

    return Scaffold(
      backgroundColor: colors.surface,
      appBar: AppBar(
        title: Text(isEdit ? '编辑影评' : '写影评'),
      ),
      body: Form(
        key: _formKey,
        child: Column(
          children: [
            Expanded(
              child: SingleChildScrollView(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    // ── 电影信息卡片 ──────────────────
                    if (movie != null) _buildMovieCard(movie, colors),
                    const SizedBox(height: 20),

                    // ── 类型选择 ──────────────────────
                    Text('影评类型', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w500, color: colors.onSurface.withValues(alpha: 0.5))),
                    const SizedBox(height: 8),
                    _buildTypeSelector(colors),
                    const SizedBox(height: 20),

                    // ── 元信息 ────────────────────────
                    _buildMetaField(
                      icon: Icons.person_outline,
                      hint: '评论人（选填）',
                      controller: _reviewerController,
                      colors: colors,
                    ),
                    const SizedBox(height: 12),
                    _buildMetaField(
                      icon: Icons.link,
                      hint: '来源（选填）',
                      controller: _sourceController,
                      colors: colors,
                    ),
                    const SizedBox(height: 20),

                    // ── 评论内容 ──────────────────────
                    Text('评论内容', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w500, color: colors.onSurface.withValues(alpha: 0.5))),
                    const SizedBox(height: 8),
                    _buildContentField(colors),
                  ],
                ),
              ),
            ),

            // ── 底部保存按钮 ──────────────────────
            Container(
              padding: EdgeInsets.only(
                left: 16, right: 16, top: 12,
                bottom: MediaQuery.of(context).padding.bottom + 12,
              ),
              decoration: BoxDecoration(
                color: colors.surface,
                border: Border(top: BorderSide(color: colors.outlineVariant, width: 0.5)),
              ),
              child: SizedBox(
                width: double.infinity,
                height: 48,
                child: ElevatedButton(
                  onPressed: _saveReview,
                  style: ElevatedButton.styleFrom(
                    backgroundColor: colors.primary,
                    foregroundColor: colors.onPrimary,
                    elevation: 0,
                    shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
                  ),
                  child: Text(isEdit ? '更新影评' : '保存影评',
                      style: const TextStyle(fontSize: 16, fontWeight: FontWeight.w600)),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════
  // 电影信息卡片
  // ═══════════════════════════════════════════════════════════════════

  Widget _buildMovieCard(Movie movie, ColorScheme colors) {
    return Container(
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: colors.surfaceContainerHighest,
        borderRadius: BorderRadius.circular(12),
      ),
      child: Row(
        children: [
          Container(
            width: 56, height: 72,
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(6),
              color: colors.outlineVariant,
            ),
            clipBehavior: Clip.antiAlias,
            child: movie.posterPath != null
                ? Image.file(File(movie.posterPath!), fit: BoxFit.cover,
                    errorBuilder: (_, __, ___) => Icon(Icons.movie_outlined, size: 24, color: colors.onSurface.withValues(alpha: 0.25)))
                : Icon(Icons.movie_outlined, size: 24, color: colors.onSurface.withValues(alpha: 0.25)),
          ),
          const SizedBox(width: 14),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(movie.title, style: TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: colors.onSurface), maxLines: 2, overflow: TextOverflow.ellipsis),
                if (movie.rating != null) ...[
                  const SizedBox(height: 4),
                  Row(children: [
                    Icon(Icons.star, size: 14, color: const Color(0xFFFFB800)),
                    const SizedBox(width: 2),
                    Text('${movie.rating}', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w600, color: colors.onSurface.withValues(alpha: 0.6))),
                  ]),
                ],
              ],
            ),
          ),
        ],
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════
  // 类型选择器（分段按钮）
  // ═══════════════════════════════════════════════════════════════════

  Widget _buildTypeSelector(ColorScheme colors) {
    return SegmentedButton<int>(
      segments: const [
        ButtonSegment(value: 1, label: Text('短评'), icon: Icon(Icons.short_text)),
        ButtonSegment(value: 2, label: Text('长评'), icon: Icon(Icons.menu_book)),
      ],
      selected: {_reviewType},
      onSelectionChanged: (v) => setState(() => _reviewType = v.first),
      style: ButtonStyle(
        backgroundColor: WidgetStateProperty.resolveWith((states) {
          if (states.contains(WidgetState.selected)) return colors.primary;
          return colors.surfaceContainerHighest;
        }),
        foregroundColor: WidgetStateProperty.resolveWith((states) {
          if (states.contains(WidgetState.selected)) return colors.onPrimary;
          return colors.onSurface.withValues(alpha: 0.6);
        }),
        iconColor: WidgetStateProperty.resolveWith((states) {
          if (states.contains(WidgetState.selected)) return colors.onPrimary;
          return colors.onSurface.withValues(alpha: 0.4);
        }),
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════
  // 元信息输入
  // ═══════════════════════════════════════════════════════════════════

  Widget _buildMetaField({
    required IconData icon,
    required String hint,
    required TextEditingController controller,
    required ColorScheme colors,
  }) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 14),
      decoration: BoxDecoration(
        color: colors.surfaceContainerHighest,
        borderRadius: BorderRadius.circular(10),
      ),
      child: Row(
        children: [
          Icon(icon, size: 18, color: colors.onSurface.withValues(alpha: 0.35)),
          const SizedBox(width: 10),
          Expanded(
            child: TextField(
              controller: controller,
              style: TextStyle(fontSize: 14, color: colors.onSurface),
              decoration: InputDecoration(
                hintText: hint,
                hintStyle: TextStyle(fontSize: 14, color: colors.onSurface.withValues(alpha: 0.3)),
                border: InputBorder.none,
                enabledBorder: InputBorder.none,
                focusedBorder: InputBorder.none,
                contentPadding: const EdgeInsets.symmetric(vertical: 12),
              ),
            ),
          ),
        ],
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════
  // 内容输入区 + 字数统计
  // ═══════════════════════════════════════════════════════════════════

  Widget _buildContentField(ColorScheme colors) {
    return Container(
      decoration: BoxDecoration(
        color: colors.surfaceContainerHighest,
        borderRadius: BorderRadius.circular(10),
      ),
      child: Column(
        children: [
          TextFormField(
            controller: _contentController,
            maxLines: 10,
            minLines: 6,
            textAlignVertical: TextAlignVertical.top,
            style: TextStyle(fontSize: 15, color: colors.onSurface, height: 1.7),
            decoration: InputDecoration(
              hintText: '写下你的影评...',
              hintStyle: TextStyle(fontSize: 15, color: colors.onSurface.withValues(alpha: 0.25)),
              border: InputBorder.none,
              enabledBorder: InputBorder.none,
              focusedBorder: InputBorder.none,
              contentPadding: const EdgeInsets.all(14),
            ),
            validator: (value) {
              if (value == null || value.trim().isEmpty) return '请输入评论内容';
              return null;
            },
          ),
          Padding(
            padding: const EdgeInsets.only(right: 14, bottom: 10),
            child: Align(
              alignment: Alignment.centerRight,
              child: Text(
                '${_contentController.text.length} 字',
                style: TextStyle(fontSize: 11, color: colors.onSurface.withValues(alpha: 0.3)),
              ),
            ),
          ),
        ],
      ),
    );
  }

  // ═══════════════════════════════════════════════════════════════════
  // 保存
  // ═══════════════════════════════════════════════════════════════════

  Future<void> _saveReview() async {
    if (!_formKey.currentState!.validate()) return;

    final now = DateTime.now();

    if (widget.review == null) {
      final newReview = MovieReview(
        id: now.millisecondsSinceEpoch.toString(),
        movieId: widget.movieId,
        content: _contentController.text.trim(),
        reviewer: _reviewerController.text.trim(),
        source: _sourceController.text.trim(),
        reviewType: _reviewType,
        createdAt: now,
        updatedAt: now,
      );
      await context.read<AppProvider>().addMovieReview(newReview);
    } else {
      final updatedReview = widget.review!.copyWith(
        content: _contentController.text.trim(),
        reviewer: _reviewerController.text.trim(),
        source: _sourceController.text.trim(),
        reviewType: _reviewType,
        updatedAt: now,
      );
      await context.read<AppProvider>().updateMovieReview(updatedReview);
    }

    if (!mounted) return;
    ToastUtil.show(context, widget.review == null ? '添加成功' : '更新成功');
    Navigator.pop(context);
  }
}