import 'dart:convert';
import 'dart:io' show File;

import 'package:flutter_cache_manager/flutter_cache_manager.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';

import '../../../common/storage/preferences_storage.dart';
import '../data/ads_api_client.dart';

class SplashAdEntry {
  const SplashAdEntry(this.ad, this.dailyCap, this.assetPath, this.cachedAtMs);
  final AdCreative ad;
  final int dailyCap;
  final String? assetPath;
  final int cachedAtMs;
  bool get valid =>
      ad.isRenderable &&
      DateTime.now().millisecondsSinceEpoch <
          cachedAtMs + const Duration(hours: 24).inMilliseconds &&
      (ad.endAtMs <= 0 || ad.endAtMs > DateTime.now().millisecondsSinceEpoch);
  Map<String, dynamic> toJson() => {
    'ad': ad.toJson(),
    'dailyCap': dailyCap,
    'assetPath': assetPath,
    'cachedAtMs': cachedAtMs,
  };
  factory SplashAdEntry.fromJson(Map<String, dynamic> map) => SplashAdEntry(
    AdCreative.fromJson(Map<String, dynamic>.from(map['ad'] as Map)),
    (map['dailyCap'] as num?)?.toInt() ?? 0,
    map['assetPath'] as String?,
    (map['cachedAtMs'] as num?)?.toInt() ?? 0,
  );
}

class SplashAdController {
  SplashAdController(this._api, this._preferences);
  final AdsApiClient _api;
  final PreferencesStorage _preferences;
  static const _entryKey = 'ads.splash.entry';
  static const _dailyKey = 'ads.splash.daily';
  Future<SplashAdEntry?> coldLaunchDecision() async {
    final raw = _preferences.getString(_entryKey);
    if (raw == null) return null;
    try {
      final entry = SplashAdEntry.fromJson(
        Map<String, dynamic>.from(jsonDecode(raw) as Map),
      );
      if (!entry.valid || !_underCap(entry) || !await _ready(entry)) {
        return null;
      }
      return entry;
    } catch (_) {
      await clearCache();
      return null;
    }
  }

  bool _underCap(SplashAdEntry entry) {
    final value = _preferences.getString(_dailyKey);
    final today = DateTime.now().toIso8601String().substring(0, 10);
    if (value == null) return true;
    final map = Map<String, dynamic>.from(jsonDecode(value) as Map);
    return map['date'] != today ||
        entry.dailyCap <= 0 ||
        ((map['count'] as num?)?.toInt() ?? 0) < entry.dailyCap;
  }

  Future<bool> _ready(SplashAdEntry entry) async =>
      entry.assetPath != null && await File(entry.assetPath!).exists();
  Future<void> markShown(SplashAdEntry entry) async {
    final today = DateTime.now().toIso8601String().substring(0, 10);
    final raw = _preferences.getString(_dailyKey);
    var count = 0;
    if (raw != null) {
      final m = Map<String, dynamic>.from(jsonDecode(raw) as Map);
      if (m['date'] == today) count = (m['count'] as num?)?.toInt() ?? 0;
    }
    await _preferences.setString(
      _dailyKey,
      jsonEncode({'date': today, 'count': count + 1}),
    );
    await _report(entry.ad, 'ad_impression');
  }

  Future<void> refresh() async {
    try {
      final result = await _api.getAdResult(splashAdPlacement);
      if (!result.enabled || result.ad == null) {
        await _clearEntry();
        return;
      }
      final file = await DefaultCacheManager().getSingleFile(
        result.ad!.imageUrl,
      );
      if (!await file.exists()) return;
      await _preferences.setString(
        _entryKey,
        jsonEncode(
          SplashAdEntry(
            result.ad!,
            result.dailyCap,
            file.path,
            DateTime.now().millisecondsSinceEpoch,
          ).toJson(),
        ),
      );
    } catch (_) {}
  }

  Future<void> _report(AdCreative ad, String event, {String? clickId}) async {
    try {
      await _api.report(ad, event, clickId: clickId);
    } catch (_) {}
  }

  Future<void> skip(SplashAdEntry entry) => _report(entry.ad, 'ad_skip');
  Future<void> clearCache() async {
    await _clearEntry();
    await _preferences.remove(_dailyKey);
  }

  Future<void> _clearEntry() async {
    await _preferences.remove(_entryKey);
  }
}

final splashAdControllerProvider = Provider(
  (ref) => SplashAdController(
    ref.watch(adsApiClientProvider),
    ref.watch(preferencesStorageProvider),
  ),
);