import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../../providers/battle_provider.dart';
import '../../game/model/item.dart';
import '../../game/enums.dart';
import '../../utils/item_utils.dart';
import '../../game/config/theme_config.dart';
import '../../game/config/app_strings.dart';

class InventoryGridWidget extends StatelessWidget {
  const InventoryGridWidget({super.key});

  @override
  Widget build(BuildContext context) {
    return Consumer<BattleProvider>(
      builder: (context, battleProvider, child) {
        final player = battleProvider.player;
        return Column(
          children: [
            Padding(
              padding: const EdgeInsets.symmetric(
                horizontal: 16.0,
                vertical: 8.0,
              ),
              child: Align(
                alignment: Alignment.centerLeft,
                child: Text(
                  "${AppStrings.bag} (${player.inventory.length}/${player.maxInventorySize})",
                  style: const TextStyle(
                    fontSize: ThemeConfig.fontSizeHeader,
                    fontWeight: ThemeConfig.fontWeightBold,
                  ),
                ),
              ),
            ),
            Expanded(
              child: GridView.builder(
                padding: const EdgeInsets.all(16.0),
                gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                  crossAxisCount: 4,
                  crossAxisSpacing: 8.0,
                  mainAxisSpacing: 8.0,
                ),
                itemCount: player.maxInventorySize,
                itemBuilder: (context, index) {
                  if (index < player.inventory.length) {
                    final item = player.inventory[index];
                    return InkWell(
                      onTap: () {
                        _showItemActionDialog(context, battleProvider, item);
                      },
                      child: Card(
                        color: ThemeConfig.inventoryCardBg,
                        shape: item.rarity != ItemRarity.magic
                            ? RoundedRectangleBorder(
                                side: BorderSide(
                                  color: ItemUtils.getRarityColor(item.rarity),
                                  width: 2.0,
                                ),
                                borderRadius: BorderRadius.circular(4.0),
                              )
                            : null,
                        child: Stack(
                          children: [
                            Positioned(
                              left: 4,
                              top: 4,
                              child: Opacity(
                                opacity: 0.5,
                                child: Image.asset(
                                  ItemUtils.getIconPath(item.slot),
                                  width: 40,
                                  height: 40,
                                  fit: BoxFit.contain,
                                  filterQuality: FilterQuality.high,
                                ),
                              ),
                            ),
                            Center(
                              child: Padding(
                                padding: const EdgeInsets.all(4.0),
                                child: Column(
                                  mainAxisAlignment: MainAxisAlignment.center,
                                  children: [
                                    FittedBox(
                                      fit: BoxFit.scaleDown,
                                      child: Text(
                                        item.name,
                                        textAlign: TextAlign.center,
                                        style: TextStyle(
                                          fontSize: ThemeConfig.fontSizeSmall,
                                          fontWeight:
                                              ThemeConfig.fontWeightBold,
                                          color: ItemUtils.getRarityColor(
                                            item.rarity,
                                          ),
                                        ),
                                        maxLines: 2,
                                        overflow: TextOverflow.ellipsis,
                                      ),
                                    ),
                                    FittedBox(
                                      fit: BoxFit.scaleDown,
                                      child: _buildItemStatText(item),
                                    ),
                                  ],
                                ),
                              ),
                            ),
                          ],
                        ),
                      ),
                    );
                  } else {
                    return Container(
                      decoration: BoxDecoration(
                        border: Border.all(color: ThemeConfig.textColorGrey),
                        color: ThemeConfig.emptySlotBg,
                      ),
                      child: const Center(
                        child: Icon(
                          Icons.add_box,
                          color: ThemeConfig.textColorGrey,
                        ),
                      ),
                    );
                  }
                },
              ),
            ),
          ],
        );
      },
    );
  }

  void _showItemActionDialog(
    BuildContext context,
    BattleProvider provider,
    Item item,
  ) {
    bool isShop = provider.currentStage.type == StageType.shop;

    showDialog(
      context: context,
      builder: (ctx) => SimpleDialog(
        title: Text("${item.name} Actions"),
        children: [
          SimpleDialogOption(
            onPressed: () {
              Navigator.pop(ctx);
              _showEquipConfirmationDialog(context, provider, item);
            },
            child: const Padding(
              padding: EdgeInsets.symmetric(vertical: 8.0),
              child: Row(
                children: [
                  Icon(Icons.shield, color: ThemeConfig.btnDefendActive),
                  SizedBox(width: 10),
                  Text(AppStrings.equip),
                ],
              ),
            ),
          ),
          if (isShop)
            SimpleDialogOption(
              onPressed: () {
                Navigator.pop(ctx);
                _showSellConfirmationDialog(context, provider, item);
              },
              child: Padding(
                padding: const EdgeInsets.symmetric(vertical: 8.0),
                child: Row(
                  children: [
                    const Icon(
                      Icons.attach_money,
                      color: ThemeConfig.statGoldColor,
                    ),
                    const SizedBox(width: 10),
                    Text("${AppStrings.sell} (${item.price} G)"),
                  ],
                ),
              ),
            ),
          SimpleDialogOption(
            onPressed: () {
              Navigator.pop(ctx);
              _showDiscardConfirmationDialog(context, provider, item);
            },
            child: const Padding(
              padding: EdgeInsets.symmetric(vertical: 8.0),
              child: Row(
                children: [
                  Icon(Icons.delete, color: ThemeConfig.btnActionActive),
                  SizedBox(width: 10),
                  Text(AppStrings.discard),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  void _showSellConfirmationDialog(
    BuildContext context,
    BattleProvider provider,
    Item item,
  ) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text("Sell Item"),
        content: Text("Sell ${item.name} for ${item.price} G?"),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            child: const Text(AppStrings.cancel),
          ),
          ElevatedButton(
            style: ElevatedButton.styleFrom(
              backgroundColor: ThemeConfig.statGoldColor,
            ),
            onPressed: () {
              provider.sellItem(item);
              Navigator.pop(ctx);
            },
            child: const Text(
              AppStrings.sell,
              style: TextStyle(color: Colors.black),
            ),
          ),
        ],
      ),
    );
  }

  void _showDiscardConfirmationDialog(
    BuildContext context,
    BattleProvider provider,
    Item item,
  ) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text("Discard Item"),
        content: Text("Are you sure you want to discard ${item.name}?"),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            child: const Text(AppStrings.cancel),
          ),
          ElevatedButton(
            style: ElevatedButton.styleFrom(
              backgroundColor: ThemeConfig.btnActionActive,
            ),
            onPressed: () {
              provider.discardItem(item);
              Navigator.pop(ctx);
            },
            child: const Text(AppStrings.discard),
          ),
        ],
      ),
    );
  }

  void _showEquipConfirmationDialog(
    BuildContext context,
    BattleProvider provider,
    Item newItem,
  ) {
    final player = provider.player;
    final oldItem = player.equipment[newItem.slot];

    final currentMaxHp = player.totalMaxHp;
    final currentAtk = player.totalAtk;
    final currentDef = player.totalDefense;
    final currentHp = player.hp;

    int newMaxHp = currentMaxHp - (oldItem?.hpBonus ?? 0) + newItem.hpBonus;
    int newAtk = currentAtk - (oldItem?.atkBonus ?? 0) + newItem.atkBonus;
    int newDef = currentDef - (oldItem?.armorBonus ?? 0) + newItem.armorBonus;

    double ratio = currentMaxHp > 0 ? currentHp / currentMaxHp : 0.0;
    int newHp = (newMaxHp * ratio).toInt();
    if (newHp < 0) newHp = 0;
    if (newHp > newMaxHp) newHp = newMaxHp;

    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text("Change Equipment"),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(
              "${AppStrings.equip} ${newItem.name}?",
              style: const TextStyle(fontWeight: ThemeConfig.fontWeightBold),
            ),
            if (oldItem != null)
              Text(
                "Replaces ${oldItem.name}",
                style: const TextStyle(
                  fontSize: 12,
                  color: ThemeConfig.textColorGrey,
                ),
              ),
            const SizedBox(height: 16),
            _buildStatChangeRow("Max HP", currentMaxHp, newMaxHp),
            _buildStatChangeRow("Current HP", currentHp, newHp),
            _buildStatChangeRow(AppStrings.atk, currentAtk, newAtk),
            _buildStatChangeRow(AppStrings.def, currentDef, newDef),
            _buildStatChangeRow(
              "LUCK",
              player.totalLuck,
              player.totalLuck - (oldItem?.luck ?? 0) + newItem.luck,
            ),
          ],
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            child: const Text(AppStrings.cancel),
          ),
          ElevatedButton(
            onPressed: () {
              provider.equipItem(newItem);
              Navigator.pop(ctx);
            },
            child: const Text(AppStrings.confirm),
          ),
        ],
      ),
    );
  }

  Widget _buildStatChangeRow(String label, int oldVal, int newVal) {
    int diff = newVal - oldVal;
    Color color = diff > 0
        ? ThemeConfig.statDiffPositive
        : (diff < 0
              ? ThemeConfig.statDiffNegative
              : ThemeConfig.statDiffNeutral);
    String diffText = diff > 0 ? "(+$diff)" : (diff < 0 ? "($diff)" : "");

    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4.0),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Text(label),
          Row(
            children: [
              Text(
                "$oldVal",
                style: const TextStyle(color: ThemeConfig.textColorGrey),
              ),
              const Icon(
                Icons.arrow_right,
                size: 16,
                color: ThemeConfig.textColorGrey,
              ),
              Text(
                "$newVal",
                style: const TextStyle(fontWeight: ThemeConfig.fontWeightBold),
              ),
              const SizedBox(width: 4),
              Text(
                diffText,
                style: TextStyle(
                  color: color,
                  fontSize: 12,
                  fontWeight: ThemeConfig.fontWeightBold,
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }

  Widget _buildItemStatText(Item item) {
    List<String> stats = [];
    if (item.atkBonus > 0) stats.add("+${item.atkBonus} ${AppStrings.atk}");
    if (item.hpBonus > 0) stats.add("+${item.hpBonus} ${AppStrings.hp}");
    if (item.armorBonus > 0) stats.add("+${item.armorBonus} ${AppStrings.def}");
    if (item.luck > 0) stats.add("+${item.luck} ${AppStrings.luck}");

    List<String> effectTexts = item.effects.map((e) => e.description).toList();

    if (stats.isEmpty && effectTexts.isEmpty) return const SizedBox.shrink();

    return Column(
      children: [
        if (stats.isNotEmpty)
          Padding(
            padding: const EdgeInsets.only(top: 2.0, bottom: 2.0),
            child: Text(
              stats.join(", "),
              style: const TextStyle(
                fontSize: ThemeConfig.fontSizeSmall,
                color: ThemeConfig.statAtkColor,
              ),
              textAlign: TextAlign.center,
            ),
          ),
        if (effectTexts.isNotEmpty)
          Padding(
            padding: const EdgeInsets.only(bottom: 2.0),
            child: Text(
              effectTexts.join("\n"),
              style: const TextStyle(
                fontSize: ThemeConfig.fontSizeTiny,
                color: ThemeConfig.rarityLegendary,
              ),
            ),
          ),
      ],
    );
  }
}