// 🎨 프로필 커스텀 화면 (UI 전용). 공부시간으로 적립한 캐시로 프로필 카드 테마를
// 구매/장착하는 상점. 서버 통신/상태는 lib/function/profile_shop_controller.dart가 담당한다.
import 'package:flutter/material.dart';
import '../function/profile_shop_controller.dart';
import '../theme/app_palette.dart';
import '../theme/profile_themes.dart';
import 'app_notice.dart';
import 'title_pill.dart';

class ProfileCustomizeScreen extends StatefulWidget {
  final String studentId;
  final String studentName;

  const ProfileCustomizeScreen({
    super.key,
    required this.studentId,
    required this.studentName,
  });

  @override
  State<ProfileCustomizeScreen> createState() => _ProfileCustomizeScreenState();
}

class _ProfileCustomizeScreenState extends State<ProfileCustomizeScreen> {
  final ProfileShopController _controller = ProfileShopController();

  // 🚧 첫 버전은 "기본 프로필 꾸미기"만 실제로 동작한다. 나머지 두 카테고리는
  // 와이어프레임 자리만 잡아둔 준비중 상태.
  String _selectedCategory = 'basic_profile';

  // 👀 사기 전에도 눌러보면 바로 위 큰 타일이 그 테마로 바뀌어 보이는 미리보기 상태.
  // null = 아직 직접 고르지 않음(장착된 테마를 그대로 보여줌), -1 = "기본 모습"을 명시적으로 미리보는 중.
  int? _previewTemplateId;

  // 🎨 지금 실제로 장착 중인 테마 - 화면 배경/상점 타일 자체를 이걸로 물들인다.
  // (미리보기는 큰 타일 하나만 바뀌는 것과 별개로, 이건 "진짜 내 테마"를 화면 전체에 반영)
  ProfileTheme? _equippedTheme;

  @override
  void initState() {
    super.initState();
    _controller.loadCatalog(widget.studentId);
    _loadEquippedTheme();
  }

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

  Future<void> _loadEquippedTheme() async {
    final theme = await ProfileShopController.fetchEquippedTheme(
      widget.studentId,
    );
    if (!mounted) return;
    setState(() => _equippedTheme = theme);
  }

  /// 지금 큰 타일에 보여줄 테마를 고른다. 직접 미리보기를 누른 게 있으면 그걸,
  /// 없으면 실제 장착 중인 테마를, 그마저도 없으면 null(기본 모습)을 돌려준다.
  ShopTemplate? _resolvePreviewTemplate() {
    if (_previewTemplateId == -1) return null;
    if (_previewTemplateId != null) {
      for (final t in _controller.templates) {
        if (t.id == _previewTemplateId) return t;
      }
    }
    for (final t in _controller.templates) {
      if (t.equipped) return t;
    }
    return null;
  }

  Future<void> _handlePurchase(ShopTemplate template) async {
    setState(() => _previewTemplateId = template.id);
    final (success, message) = await _controller.purchase(
      widget.studentId,
      template.id,
    );
    if (!mounted) return;
    AppNotice.show(
      context,
      message,
      color: success ? AppPalette.success : AppPalette.danger,
    );
  }

  Future<void> _handleEquip(int? templateId) async {
    setState(() => _previewTemplateId = templateId ?? -1);
    final (success, message) = await _controller.equip(
      widget.studentId,
      templateId,
    );
    if (success) await _loadEquippedTheme();
    if (!mounted) return;
    AppNotice.show(
      context,
      message,
      color: success ? AppPalette.approved : AppPalette.danger,
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: _equippedTheme?.background ?? AppPalette.mist,
      appBar: AppBar(
        backgroundColor: Colors.transparent,
        foregroundColor: AppPalette.ink,
        elevation: 0,
        centerTitle: true,
        title: const TitlePill('프로필 꾸미기'),
      ),
      body: ListenableBuilder(
        listenable: _controller,
        builder: (context, _) {
          return Center(
            child: ConstrainedBox(
              constraints: const BoxConstraints(maxWidth: 720),
              child: RefreshIndicator(
                onRefresh: () => _controller.loadCatalog(widget.studentId),
                child: ListView(
                  padding: const EdgeInsets.all(20),
                  children: [
                    _buildCashBalance(),
                    const SizedBox(height: 20),
                    _buildCategoryTiles(),
                    const SizedBox(height: 24),
                    if (_controller.isLoading)
                      const Padding(
                        padding: EdgeInsets.symmetric(vertical: 40),
                        child: Center(child: CircularProgressIndicator()),
                      )
                    else
                      _buildTemplateGrid(),
                  ],
                ),
              ),
            ),
          );
        },
      ),
    );
  }

  Widget _buildCashBalance() {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 14),
      decoration: BoxDecoration(
        color: _equippedTheme?.secondary ?? AppPalette.ink,
        borderRadius: BorderRadius.circular(18),
      ),
      child: Row(
        children: [
          const Icon(Icons.savings_rounded, color: Colors.white, size: 22),
          const SizedBox(width: 10),
          const Text(
            '보유 캐시',
            style: TextStyle(color: Colors.white70, fontSize: 13),
          ),
          const Spacer(),
          Text(
            '${_controller.cashBalance} 캐시',
            style: const TextStyle(
              color: Colors.white,
              fontSize: 18,
              fontWeight: FontWeight.bold,
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildCategoryTiles() {
    final previewTemplate = _resolvePreviewTemplate();
    // 📏 ListView(스크롤 영역) 안에서는 높이가 정해져 있지 않아 Row에
    // stretch 정렬만 주면 자식 크기 계산이 깨진다. SizedBox로 높이를 못박아둔다.
    return SizedBox(
      height: 210,
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Expanded(
            flex: 3,
            child: _CategoryTile(
              title: '기본 프로필 꾸미기',
              icon: Icons.person_rounded,
              selected: _selectedCategory == 'basic_profile',
              enabled: true,
              onTap: () => setState(() => _selectedCategory = 'basic_profile'),
              previewPrimary: previewTemplate?.primaryColor,
              previewSecondary: previewTemplate?.secondaryColor,
            ),
          ),
          const SizedBox(width: 12),
          Expanded(
            flex: 4,
            child: Column(
              children: [
                Expanded(
                  child: _CategoryTile(
                    title: '랭킹 · 친구창 배경',
                    subtitle: '준비중',
                    icon: Icons.leaderboard_rounded,
                    selected: false,
                    enabled: false,
                    onTap: null,
                  ),
                ),
                const SizedBox(height: 12),
                Expanded(
                  child: _CategoryTile(
                    title: '출석 · 그룹창 표시',
                    subtitle: '준비중',
                    icon: Icons.groups_rounded,
                    selected: false,
                    enabled: false,
                    onTap: null,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildTemplateGrid() {
    final templates = _controller.templates
        .where((t) => t.category == _selectedCategory)
        .toList();
    final hasEquippedTemplate = templates.any((t) => t.equipped);
    final previewId = _resolvePreviewTemplate()?.id; // null이면 "기본 모습"을 미리보는 중.

    return GridView.count(
      crossAxisCount: 2,
      shrinkWrap: true,
      physics: const NeverScrollableScrollPhysics(),
      mainAxisSpacing: 12,
      crossAxisSpacing: 12,
      childAspectRatio: 1.15,
      children: [
        _DefaultTemplateTile(
          equipped: !hasEquippedTemplate,
          previewing: previewId == null,
          theme: _equippedTheme,
          onEquip: () => _handleEquip(null),
          onPreview: () => setState(() => _previewTemplateId = -1),
        ),
        for (final template in templates)
          _TemplateTile(
            template: template,
            canAfford: _controller.cashBalance >= template.price,
            previewing: previewId == template.id,
            theme: _equippedTheme,
            onPurchase: () => _handlePurchase(template),
            onEquip: () => _handleEquip(template.id),
            onPreview: () => setState(() => _previewTemplateId = template.id),
          ),
      ],
    );
  }
}

class _CategoryTile extends StatelessWidget {
  final String title;
  final String? subtitle;
  final IconData icon;
  final bool selected;
  final bool enabled;
  final VoidCallback? onTap;
  // 👀 미리보기 중인 테마 색상 - selected일 때만 의미가 있다 (기본 프로필 타일 전용).
  final Color? previewPrimary;
  final Color? previewSecondary;

  const _CategoryTile({
    required this.title,
    this.subtitle,
    required this.icon,
    required this.selected,
    required this.enabled,
    required this.onTap,
    this.previewPrimary,
    this.previewSecondary,
  });

  @override
  Widget build(BuildContext context) {
    final bool hasPreview = selected && previewPrimary != null;
    return Material(
      color: hasPreview
          ? Colors.transparent
          : (selected
                ? AppPalette.ink
                : (enabled ? AppPalette.paper : AppPalette.linen)),
      borderRadius: BorderRadius.circular(20),
      child: InkWell(
        borderRadius: BorderRadius.circular(20),
        onTap: onTap,
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 10),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(20),
            gradient: hasPreview
                ? LinearGradient(
                    begin: Alignment.topLeft,
                    end: Alignment.bottomRight,
                    colors: [previewPrimary!, previewSecondary!],
                  )
                : null,
            border: Border.all(
              color: hasPreview
                  ? previewSecondary!
                  : (selected ? AppPalette.ink : AppPalette.sage),
              width: hasPreview ? 2 : 1,
            ),
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            mainAxisAlignment: MainAxisAlignment.center,
            mainAxisSize: MainAxisSize.min,
            children: [
              Icon(
                icon,
                size: 22,
                color: selected
                    ? Colors.white
                    : (enabled ? AppPalette.ink : Colors.grey),
              ),
              const SizedBox(height: 8),
              Text(
                title,
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
                style: TextStyle(
                  fontWeight: FontWeight.bold,
                  fontSize: 13,
                  color: selected
                      ? Colors.white
                      : (enabled ? AppPalette.ink : Colors.grey[600]),
                ),
              ),
              if (subtitle != null) ...[
                const SizedBox(height: 2),
                Text(
                  subtitle!,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: TextStyle(fontSize: 10, color: Colors.grey[500]),
                ),
              ],
            ],
          ),
        ),
      ),
    );
  }
}

class _DefaultTemplateTile extends StatelessWidget {
  final bool equipped;
  final bool previewing;
  final ProfileTheme? theme;
  final VoidCallback onEquip;
  final VoidCallback onPreview;

  const _DefaultTemplateTile({
    required this.equipped,
    required this.previewing,
    required this.theme,
    required this.onEquip,
    required this.onPreview,
  });

  @override
  Widget build(BuildContext context) {
    final onBackground = theme?.onBackground ?? AppPalette.ink;
    final borderColor = equipped
        ? AppPalette.approved
        : (previewing ? onBackground : (theme?.border ?? AppPalette.sage));
    final borderWidth = equipped || previewing ? 2.0 : 1.0;

    return Material(
      color: theme?.surface ?? AppPalette.paper,
      borderRadius: BorderRadius.circular(18),
      child: InkWell(
        borderRadius: BorderRadius.circular(18),
        onTap: onPreview,
        child: Container(
          padding: const EdgeInsets.all(14),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(18),
            border: Border.all(color: borderColor, width: borderWidth),
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Expanded(
                child: Container(
                  width: double.infinity,
                  decoration: BoxDecoration(
                    color: AppPalette.ink,
                    borderRadius: BorderRadius.circular(12),
                  ),
                ),
              ),
              const SizedBox(height: 10),
              Row(
                children: [
                  Expanded(
                    child: Text(
                      '기본 모습',
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 13,
                        color: onBackground,
                      ),
                    ),
                  ),
                  if (previewing && !equipped)
                    Text(
                      '미리보기',
                      style: TextStyle(
                        fontSize: 10,
                        fontWeight: FontWeight.bold,
                        color: onBackground,
                      ),
                    ),
                ],
              ),
              const SizedBox(height: 8),
              SizedBox(
                width: double.infinity,
                child: equipped
                    ? OutlinedButton(
                        onPressed: null,
                        style: OutlinedButton.styleFrom(
                          foregroundColor: AppPalette.approved,
                          side: const BorderSide(color: AppPalette.approved),
                        ),
                        child: const Text('장착중'),
                      )
                    : OutlinedButton(
                        onPressed: onEquip,
                        style: OutlinedButton.styleFrom(
                          foregroundColor: theme?.accent,
                          side: theme == null
                              ? null
                              : BorderSide(color: theme!.accent),
                        ),
                        child: const Text('장착하기'),
                      ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _TemplateTile extends StatelessWidget {
  final ShopTemplate template;
  final bool canAfford;
  final bool previewing;
  final ProfileTheme? theme;
  final VoidCallback onPurchase;
  final VoidCallback onEquip;
  final VoidCallback onPreview;

  const _TemplateTile({
    required this.template,
    required this.canAfford,
    required this.previewing,
    required this.theme,
    required this.onPurchase,
    required this.onEquip,
    required this.onPreview,
  });

  @override
  Widget build(BuildContext context) {
    final onBackground = theme?.onBackground ?? AppPalette.ink;
    final borderColor = template.equipped
        ? AppPalette.approved
        : (previewing ? onBackground : (theme?.border ?? AppPalette.sage));
    final borderWidth = template.equipped || previewing ? 2.0 : 1.0;

    return Material(
      color: theme?.surface ?? AppPalette.paper,
      borderRadius: BorderRadius.circular(18),
      child: InkWell(
        borderRadius: BorderRadius.circular(18),
        onTap: onPreview,
        child: Container(
          padding: const EdgeInsets.all(14),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(18),
            border: Border.all(color: borderColor, width: borderWidth),
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Expanded(
                child: Container(
                  width: double.infinity,
                  decoration: BoxDecoration(
                    gradient: LinearGradient(
                      begin: Alignment.topLeft,
                      end: Alignment.bottomRight,
                      colors: [template.primaryColor, template.secondaryColor],
                    ),
                    borderRadius: BorderRadius.circular(12),
                  ),
                ),
              ),
              const SizedBox(height: 10),
              Row(
                children: [
                  Expanded(
                    child: Text(
                      template.name,
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                      style: TextStyle(
                        fontWeight: FontWeight.bold,
                        fontSize: 13,
                        color: onBackground,
                      ),
                    ),
                  ),
                  if (previewing && !template.equipped)
                    Text(
                      '미리보기',
                      style: TextStyle(
                        fontSize: 10,
                        fontWeight: FontWeight.bold,
                        color: onBackground,
                      ),
                    ),
                ],
              ),
              const SizedBox(height: 2),
              Text(
                '${template.price} 캐시',
                style: TextStyle(
                  fontSize: 12,
                  color: onBackground.withValues(alpha: 0.6),
                ),
              ),
              const SizedBox(height: 8),
              if (template.equipped)
                SizedBox(
                  width: double.infinity,
                  child: OutlinedButton(
                    onPressed: null,
                    style: OutlinedButton.styleFrom(
                      foregroundColor: AppPalette.approved,
                      side: const BorderSide(color: AppPalette.approved),
                    ),
                    child: const Text('장착중'),
                  ),
                )
              else if (template.owned)
                SizedBox(
                  width: double.infinity,
                  child: OutlinedButton(
                    onPressed: onEquip,
                    style: OutlinedButton.styleFrom(
                      foregroundColor: theme?.accent,
                      side: theme == null
                          ? null
                          : BorderSide(color: theme!.accent),
                    ),
                    child: const Text('장착하기'),
                  ),
                )
              else
                Row(
                  children: [
                    Expanded(
                      child: OutlinedButton(
                        onPressed: onPreview,
                        style: OutlinedButton.styleFrom(
                          foregroundColor: theme?.accent,
                          side: theme == null
                              ? null
                              : BorderSide(color: theme!.accent),
                        ),
                        child: const Text('체험하기'),
                      ),
                    ),
                    const SizedBox(width: 8),
                    Expanded(
                      child: ElevatedButton(
                        onPressed: canAfford ? onPurchase : null,
                        style: ElevatedButton.styleFrom(
                          backgroundColor: theme?.secondary ?? AppPalette.ink,
                          foregroundColor: Colors.white,
                          disabledBackgroundColor: AppPalette.sage,
                        ),
                        child: const Text('구매하기'),
                      ),
                    ),
                  ],
                ),
            ],
          ),
        ),
      ),
    );
  }
}