using System.Text.Json;
using Hokm.Server.Data;
using Microsoft.EntityFrameworkCore;

namespace Hokm.Server.Profiles;

public class ProfileService
{
    private readonly AppDbContext _db;
    public ProfileService(AppDbContext db) => _db = db;

    public static readonly CoinPackDto[] Packs =
    {
        new() { Id = "p1", Coins = 5000, Bonus = 0, PriceToman = 99000, Tag = "starter" },
        new() { Id = "p2", Coins = 11000, Bonus = 1000, PriceToman = 199000, Tag = "popular" },
        new() { Id = "p3", Coins = 24000, Bonus = 4000, PriceToman = 399000, Tag = "best" },
        new() { Id = "p4", Coins = 50000, Bonus = 15000, PriceToman = 799000 },
    };

    private static ProfileDto Default(string userId, string? name) => new()
    {
        Id = userId,
        Username = "player_" + (userId.Length >= 4 ? userId[^4..] : userId),
        DisplayName = string.IsNullOrWhiteSpace(name) ? "بازیکن" : name!,
        CreatedAt = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(),
    };

    public async Task<ProfileDto> GetOrCreate(string userId, string? name)
    {
        var row = await _db.Profiles.FindAsync(userId);
        if (row == null)
        {
            var dto = Default(userId, name);
            await SaveInternal(dto);
            return dto;
        }
        return JsonSerializer.Deserialize<ProfileDto>(row.Json, JsonOpts.Default) ?? Default(userId, name);
    }

    private async Task SaveInternal(ProfileDto p)
    {
        var json = JsonSerializer.Serialize(p, JsonOpts.Default);
        var row = await _db.Profiles.FindAsync(p.Id);
        if (row == null) _db.Profiles.Add(new ProfileRow { Id = p.Id, Json = json, UpdatedAt = DateTime.UtcNow });
        else { row.Json = json; row.UpdatedAt = DateTime.UtcNow; }
        await _db.SaveChangesAsync();
    }

    public async Task<ProfileDto> Save(ProfileDto p) { await SaveInternal(p); return p; }

    private async Task Ledger(string uid, string kind, int amount, string? @ref)
    {
        _db.Ledger.Add(new LedgerRow { UserId = uid, Kind = kind, Amount = amount, Ref = @ref, CreatedAt = DateTime.UtcNow });
        await _db.SaveChangesAsync();
    }

    public async Task<ProfileDto> Update(string uid, JsonElement patch)
    {
        var p = await GetOrCreate(uid, null);
        if (patch.TryGetProperty("displayName", out var dn) && dn.ValueKind == JsonValueKind.String) p.DisplayName = dn.GetString()!;
        if (patch.TryGetProperty("avatar", out var av) && av.ValueKind == JsonValueKind.String) p.Avatar = av.GetString()!;
        // Custom photo upload is gated behind level 25.
        if (p.Level >= 25 && patch.TryGetProperty("avatarImage", out var ai) && ai.ValueKind == JsonValueKind.String) p.AvatarImage = ai.GetString();
        if (patch.TryGetProperty("title", out var ti) && ti.ValueKind == JsonValueKind.String) p.Title = ti.GetString();
        if (patch.TryGetProperty("cardFront", out var cf) && cf.ValueKind == JsonValueKind.String) p.CardFront = cf.GetString()!;
        if (patch.TryGetProperty("cardBack", out var cb) && cb.ValueKind == JsonValueKind.String) p.CardBack = cb.GetString()!;
        // social
        if (patch.TryGetProperty("gender", out var ge) && ge.ValueKind == JsonValueKind.String) p.Gender = ge.GetString()!;
        if (patch.TryGetProperty("socialsVisibility", out var sv) && sv.ValueKind == JsonValueKind.String) p.SocialsVisibility = sv.GetString()!;
        if (patch.TryGetProperty("socials", out var so) && so.ValueKind == JsonValueKind.Object)
            p.Socials = JsonSerializer.Deserialize<SocialLinksDto>(so.GetRawText(), JsonOpts.Default) ?? p.Socials;
        return await Save(p);
    }

    public async Task<ProfileDto> UpgradePlan(string uid)
    {
        var p = await GetOrCreate(uid, null);
        p.Plan = "pro";
        p.PlanUntil = DateTimeOffset.UtcNow.AddDays(30).ToUnixTimeMilliseconds();
        return await Save(p);
    }

    public async Task<(bool ok, ProfileDto? profile, int coins)> BuyCoins(string uid, string packId)
    {
        var pack = Packs.FirstOrDefault(x => x.Id == packId);
        if (pack == null) return (false, null, 0);
        // NOTE: real payment (Zarinpal/IDPay) verification goes here.
        var p = await GetOrCreate(uid, null);
        int added = pack.Coins + pack.Bonus;
        p.Coins += added;
        await Save(p);
        await Ledger(uid, "purchase", added, packId);
        return (true, p, added);
    }

    public async Task<(RewardResultDto reward, ProfileDto profile)> ApplyMatch(string uid, MatchSummaryDto s)
    {
        var p = await GetOrCreate(uid, null);
        // No real opponent rating tracked yet — treat as an even match.
        var reward = Gamification.ApplyMatch(p, s, p.Rating);
        await Save(p);
        await Ledger(uid, "match", reward.CoinsDelta, s.Ranked ? "ranked" : "casual");
        return (reward, p);
    }

    /// <summary>Deduct a ranked entry/stake up front. Returns null if not enough coins.</summary>
    public async Task<ProfileDto?> ChargeEntry(string uid, int amount)
    {
        var p = await GetOrCreate(uid, null);
        if (amount <= 0) return p;
        if (p.Coins < amount) return null;
        p.Coins -= amount;
        await Save(p);
        await Ledger(uid, "entry", -amount, "ranked");
        return p;
    }

    /* ----------------------------- shop ------------------------------- */

    // Coin-priced XP packs (XP is intentionally expensive). Server-authoritative.
    public static readonly Dictionary<string, (int Price, int Xp)> XpPacks = new()
    {
        ["xp1"] = (1500, 200),
        ["xp2"] = (4000, 600),
        ["xp3"] = (8000, 1500),
    };

    // Gated gifts encode their tier in the id (`-t<n>-`); the gate is derived from
    // the tier so the server enforces it without a 100-entry catalog mirror.
    // Mirrors GIFT_TIERS in src/lib/online/types.ts.
    private static readonly (int Level, int Rating)[] GiftGate =
        { (0, 0), (0, 0), (10, 0), (20, 0), (35, 0), (0, 1700) }; // index = tier (1..5)

    private static (int Level, int Rating) GiftGateFor(string id)
    {
        var m = System.Text.RegularExpressions.Regex.Match(id, @"-t(\d)-");
        if (m.Success && int.TryParse(m.Groups[1].Value, out var tier) && tier >= 1 && tier <= 5)
            return GiftGate[tier];
        return (0, 0);
    }

    public async Task<(bool ok, ProfileDto? profile, string error)> ShopBuy(string uid, string kind, string id, int price)
    {
        var p = await GetOrCreate(uid, null);

        // Gated gift: locked until the player meets the tier's level/rating gate.
        var gate = GiftGateFor(id);
        if (p.Level < gate.Level || p.Rating < gate.Rating) return (false, p, "locked");

        // XP packs are consumable (grant XP, may level up) — not added to an owned list.
        if (kind == "xp")
        {
            if (!XpPacks.TryGetValue(id, out var pk)) return (false, p, "bad_kind");
            if (p.Coins < pk.Price) return (false, p, "insufficient");
            p.Coins -= pk.Price;
            Gamification.GrantXp(p, pk.Xp);
            Gamification.EvaluateAchievements(p); // unlock any level milestones reached
            await Save(p);
            await Ledger(uid, "xp", -pk.Price, id);
            return (true, p, "");
        }

        var list = kind switch
        {
            "avatar" => p.OwnedAvatars,
            "cardfront" => p.OwnedCardFronts,
            "cardback" => p.OwnedCardBacks,
            "reactionpack" => p.OwnedReactionPacks,
            "stickerpack" => p.OwnedStickerPacks,
            "title" => p.OwnedTitles,
            _ => null,
        };
        if (list == null) return (false, null, "bad_kind");
        if (list.Contains(id)) return (false, p, "owned");
        if (price < 0 || p.Coins < price) return (false, p, "insufficient");
        p.Coins -= price;
        list.Add(id);
        await Save(p);
        await Ledger(uid, "shop", -price, $"{kind}:{id}");
        return (true, p, "");
    }

    /* ----------------------------- daily ------------------------------ */

    // Mirror the client DAILY_REWARDS (src/lib/online/gamification.ts) exactly.
    private static readonly int[] DailyRewards = { 100, 150, 200, 300, 400, 600, 1500 };
    private static string Today => DateTime.UtcNow.ToString("yyyy-MM-dd");

    public async Task<(int day, string? lastClaimed, bool available)> GetDaily(string uid)
    {
        var p = await GetOrCreate(uid, null);
        return (p.DailyDay, p.DailyLastClaimed, p.DailyLastClaimed != Today);
    }

    public async Task<(int reward, ProfileDto profile, int day)> ClaimDaily(string uid)
    {
        var p = await GetOrCreate(uid, null);
        if (p.DailyLastClaimed == Today) return (0, p, p.DailyDay);
        int day = p.DailyDay;
        int reward = DailyRewards[Math.Min(day, DailyRewards.Length) - 1];
        p.Coins += reward;
        p.DailyDay = day >= 7 ? 1 : day + 1;
        p.DailyLastClaimed = Today;
        await Save(p);
        await Ledger(uid, "daily", reward, "day" + day);
        return (reward, p, day);
    }
}