using System.IO;
using System.Linq;
using System.Text;
using System.Text.Json;
using System.Windows;

namespace AxCopilot.Services;

/// <summary>
/// 격려 문구, 명언, 업계 상식, IT/AI, 과학, 역사, 생활영어, 드라마/영화 대사를 카테고리별로 관리합니다.
/// </summary>
public static class QuoteService
{
    private record FamousQuote(string Text, string Author);
    private record MovieQuote(string Text, string Movie, int Year, string? Character, long? Audience);

    // 카테고리별 콘텐츠 (Lazy 로딩)
    private static readonly Lazy<string[]>        _motivational = new(LoadMotivational);
    private static readonly Lazy<FamousQuote[]>   _famous       = new(LoadFamous);
    private static readonly Lazy<string[]>        _displaySemi  = new(() => LoadSimple("display_semiconductor.json"));
    private static readonly Lazy<string[]>        _itAi         = new(() => LoadSimple("it_ai.json"));
    private static readonly Lazy<string[]>        _science      = new(() => LoadSimple("science.json"));
    private static readonly Lazy<string[]>        _history      = new(() => LoadSimple("history.json"));
    private static readonly Lazy<string[]>        _english      = new(() => LoadSimple("english.json"));
    private static readonly Lazy<MovieQuote[]>    _movies       = new(LoadMovies);
    private static readonly Lazy<Dictionary<string, string[]>> _todayEvents = new(LoadTodayEvents);

    /// <summary>카테고리 정의: (key, label, countFunc). 설정 UI에서 다중 체크로 표시됨.</summary>
    public static readonly (string Key, string Label, Func<int> Count)[] Categories =
    [
        ("motivational",          "격려 문구",                () => _motivational.Value.Length),
        ("famous",                "유명 명언",                () => _famous.Value.Length),
        ("display_semiconductor", "디스플레이/반도체 상식",    () => _displaySemi.Value.Length),
        ("it_ai",                 "IT, AI 기술",              () => _itAi.Value.Length),
        ("science",               "일반 과학",                () => _science.Value.Length),
        ("history",               "역사",                     () => _history.Value.Length),
        ("english",               "생활영어",                 () => _english.Value.Length),
        ("movies",                "드라마/영화 명대사",        () => _movies.Value.Length),
        ("today_events",          "오늘의 역사/기념일",        () => GetTodayEventCount()),
    ];

    // ─── 로더 ──────────────────────────────────────────────────────────

    private static string[] LoadMotivational()
    {
        try
        {
            var uri    = new Uri("pack://application:,,,/Assets/Quotes/motivational.json");
            var stream = Application.GetResourceStream(uri)?.Stream;
            if (stream == null) return [];
            using var reader = new StreamReader(stream, Encoding.UTF8);
            return JsonSerializer.Deserialize<string[]>(reader.ReadToEnd()) ?? [];
        }
        catch (Exception ex) { LogService.Warn($"격려 문구 로드 실패: {ex.Message}"); return []; }
    }

    private static FamousQuote[] LoadFamous()
    {
        try
        {
            var uri    = new Uri("pack://application:,,,/Assets/Quotes/famous.json");
            var stream = Application.GetResourceStream(uri)?.Stream;
            if (stream == null) return [];
            using var reader = new StreamReader(stream, Encoding.UTF8);
            var opts = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
            return JsonSerializer.Deserialize<FamousQuote[]>(reader.ReadToEnd(), opts) ?? [];
        }
        catch (Exception ex) { LogService.Warn($"명언 로드 실패: {ex.Message}"); return []; }
    }

    private static string[] LoadSimple(string fileName)
    {
        try
        {
            var uri    = new Uri($"pack://application:,,,/Assets/Quotes/{fileName}");
            var stream = Application.GetResourceStream(uri)?.Stream;
            if (stream == null) return [];
            using var reader = new StreamReader(stream, Encoding.UTF8);
            return JsonSerializer.Deserialize<string[]>(reader.ReadToEnd()) ?? [];
        }
        catch (Exception ex) { LogService.Warn($"{fileName} 로드 실패: {ex.Message}"); return []; }
    }

    private static MovieQuote[] LoadMovies()
    {
        try
        {
            var uri = new Uri("pack://application:,,,/Assets/Quotes/movies.json");
            var stream = Application.GetResourceStream(uri)?.Stream;
            if (stream == null) return [];
            using var reader = new StreamReader(stream, Encoding.UTF8);
            var opts = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
            return JsonSerializer.Deserialize<MovieQuote[]>(reader.ReadToEnd(), opts) ?? [];
        }
        catch { return []; }
    }

    private static Dictionary<string, string[]> LoadTodayEvents()
    {
        try
        {
            var uri = new Uri("pack://application:,,,/Assets/Quotes/today_events.json");
            var stream = Application.GetResourceStream(uri)?.Stream;
            if (stream == null) return new();
            using var reader = new StreamReader(stream, Encoding.UTF8);
            return JsonSerializer.Deserialize<Dictionary<string, string[]>>(reader.ReadToEnd()) ?? new();
        }
        catch { return new(); }
    }

    // ─── 공개 API ──────────────────────────────────────────────────────

    /// <summary>
    /// 활성화된 카테고리에서 랜덤으로 하나를 반환합니다.
    /// 날짜 카테고리가 활성화되어 있으면 첫 호출 시 오늘의 이벤트를 우선 반환합니다.
    /// </summary>
    public static (string Text, string? Author) GetRandom(IEnumerable<string>? enabledCategories = null)
    {
        var enabled = enabledCategories?.ToHashSet(StringComparer.OrdinalIgnoreCase)
                      ?? new HashSet<string> { "motivational" };

        // 시간대별 인사 접두사
        var greeting = GetTimeGreeting();

        // 날짜 이벤트 우선 (해당 카테고리 선택 시)
        if (enabled.Contains("today_events"))
        {
            var todayKey = DateTime.Now.ToString("MM-dd");
            if (_todayEvents.Value.TryGetValue(todayKey, out var events) && events.Length > 0)
            {
                var evt = events[Random.Shared.Next(events.Length)];
                return (greeting + evt, "오늘의 역사");
            }
        }

        var pool = new List<(string Text, string? Author)>();

        if (enabled.Contains("motivational"))
            foreach (var q in _motivational.Value) pool.Add((q, null));

        if (enabled.Contains("famous"))
            foreach (var q in _famous.Value) pool.Add((q.Text, q.Author));

        if (enabled.Contains("display_semiconductor"))
            foreach (var q in _displaySemi.Value) pool.Add((q, "디스플레이/반도체"));

        if (enabled.Contains("it_ai"))
            foreach (var q in _itAi.Value) pool.Add((q, "IT/AI"));

        if (enabled.Contains("science"))
            foreach (var q in _science.Value) pool.Add((q, "과학"));

        if (enabled.Contains("history"))
            foreach (var q in _history.Value) pool.Add((q, "역사"));

        if (enabled.Contains("english"))
            foreach (var q in _english.Value) pool.Add((q, "생활영어"));

        if (enabled.Contains("movies"))
            foreach (var q in _movies.Value)
            {
                var medal = q.Audience >= 10_000_000 ? " 🥇" : q.Audience >= 7_000_000 ? " 🥈" : q.Audience >= 5_000_000 ? " 🥉" : "";
                var info = $"《{q.Movie}》({q.Year}){(q.Character != null ? $" — {q.Character}" : "")}{medal}";
                pool.Add(($"\"{q.Text}\"", info));
            }

        if (pool.Count == 0)
            return (greeting + "오늘도 열심히 해주셔서 고맙습니다!", null);

        var (text, author) = pool[Random.Shared.Next(pool.Count)];
        return (greeting + text, author);
    }

    /// <summary>시간대에 따른 인사 접두사를 반환합니다 (줄바꿈 포함).</summary>
    /// <remarks>
    /// 외부 파일(%APPDATA%\AxCopilot\Quotes\greetings.json) 우선 로드.
    /// 외부 파일이 없으면 내장 리소스(Assets/Quotes/greetings.json) 사용.
    /// 개발자가 외부 JSON만 수정하면 재빌드 없이 인사문구 변경/추가 가능.
    /// </remarks>
    private static string GetTimeGreeting()
    {
        var hour = DateTime.Now.Hour;
        string key;
        if (hour < 9) key = "morning";
        else if (hour >= 12 && hour < 15) key = "lunch";
        else if (hour >= 18) key = "evening";
        else return "";

        var greetings = LoadGreetings();
        if (greetings.TryGetValue(key, out var list) && list.Length > 0)
            return list[Random.Shared.Next(list.Length)] + "\n\n";

        return "";
    }

    private static Dictionary<string, string[]>? _greetingsCache;
    private static DateTime _greetingsCacheTime;

    /// <summary>인사문구를 로드합니다. 외부 파일 → 내장 리소스 순서.</summary>
    private static Dictionary<string, string[]> LoadGreetings()
    {
        // 5분간 캐시 (파일 수정 반영을 위해 주기적 리로드)
        if (_greetingsCache != null && (DateTime.Now - _greetingsCacheTime).TotalMinutes < 5)
            return _greetingsCache;

        var opts = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };

        // 1) 외부 파일 우선
        try
        {
            var externalPath = Path.Combine(
                Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
                "AxCopilot", "Quotes", "greetings.json");
            if (File.Exists(externalPath))
            {
                var json = File.ReadAllText(externalPath, Encoding.UTF8);
                var result = JsonSerializer.Deserialize<Dictionary<string, string[]>>(json, opts);
                if (result != null)
                {
                    _greetingsCache = result;
                    _greetingsCacheTime = DateTime.Now;
                    return result;
                }
            }
        }
        catch (Exception ex) { LogService.Warn($"외부 인사문구 로드 실패: {ex.Message}"); }

        // 2) 내장 리소스 폴백
        try
        {
            var uri = new Uri("pack://application:,,,/Assets/Quotes/greetings.json");
            var stream = Application.GetResourceStream(uri)?.Stream;
            if (stream != null)
            {
                using var reader = new StreamReader(stream, Encoding.UTF8);
                var result = JsonSerializer.Deserialize<Dictionary<string, string[]>>(reader.ReadToEnd(), opts);
                if (result != null)
                {
                    _greetingsCache = result;
                    _greetingsCacheTime = DateTime.Now;
                    return result;
                }
            }
        }
        catch (Exception ex) { LogService.Warn($"내장 인사문구 로드 실패: {ex.Message}"); }

        return _greetingsCache = new();
    }

    private static int GetTodayEventCount()
    {
        // 전체 이벤트 수 반환 (날짜별 합계)
        return _todayEvents.Value.Values.Sum(v => v.Length);
    }

    /// <summary>오늘 날짜에 해당하는 이벤트 수를 반환합니다.</summary>
    public static int GetTodayMatchCount()
    {
        var todayKey = DateTime.Now.ToString("MM-dd");
        return _todayEvents.Value.TryGetValue(todayKey, out var events) ? events.Length : 0;
    }

    /// <summary>로드된 전체 문구 수를 반환합니다.</summary>
    public static int TotalCount =>
        _motivational.Value.Length + _famous.Value.Length +
        _displaySemi.Value.Length + _itAi.Value.Length +
        _science.Value.Length + _history.Value.Length +
        _english.Value.Length + _movies.Value.Length;
}