using FlatRender.IdentitySvc.Application.Services.Interfaces;
using FlatRender.IdentitySvc.Domain.Entities;
using FlatRender.IdentitySvc.Domain.Enums;
using FlatRender.IdentitySvc.Infrastructure.Data;
using FlatRender.IdentitySvc.Models.Responses;
using Microsoft.EntityFrameworkCore;

namespace FlatRender.IdentitySvc.Application.Services;

public class GamificationService(IdentityDbContext db) : IGamificationService
{
    public async Task<List<QuestResponse>> GetActiveQuestsAsync(Guid userId, Guid tenantId)
    {
        var quests = await db.Quests
            .Where(q => q.IsActive &&
                        (q.TenantId == null || q.TenantId == tenantId) &&
                        (q.StartsAt == null || q.StartsAt <= DateTime.UtcNow) &&
                        (q.ExpiresAt == null || q.ExpiresAt > DateTime.UtcNow))
            .OrderBy(q => q.OrderValue)
            .ToListAsync();

        var progressMap = await db.UserQuestProgresses
            .Where(p => p.UserId == userId && quests.Select(q => q.Id).Contains(p.QuestId))
            .ToDictionaryAsync(p => p.QuestId, p => p);

        return quests.Select(q =>
        {
            progressMap.TryGetValue(q.Id, out var progress);
            return new QuestResponse(
                q.Id, q.Title, q.Challenge, q.Why, q.Hint, q.Icon,
                q.QuestType.ToString(), q.TargetCount,
                progress?.CurrentCount ?? 0,
                progress?.IsCompleted ?? false,
                progress?.PrizeClaimed ?? false,
                q.PrizeType.ToString(), q.PrizeAmount, q.ExpiresAt
            );
        }).ToList();
    }

    public async Task ClaimQuestPrizeAsync(Guid userId, Guid questId)
    {
        var progress = await db.UserQuestProgresses
            .FirstOrDefaultAsync(p => p.UserId == userId && p.QuestId == questId && p.IsCompleted && !p.PrizeClaimed)
            ?? throw new InvalidOperationException("Quest not completed or prize already claimed");

        var quest = await db.Quests.FindAsync(questId)
            ?? throw new KeyNotFoundException("Quest not found");

        await ApplyPrizeAsync(userId, quest.PrizeType, quest.PrizeAmount);

        progress.PrizeClaimed = true;
        progress.PrizeClaimedAt = DateTime.UtcNow;
        await db.SaveChangesAsync();
    }

    public async Task<List<EarnedGiftResponse>> GetEarnedGiftsAsync(Guid userId)
    {
        var gifts = await db.EarnedGifts
            .Include(eg => eg.Gift)
            .Where(eg => eg.UserId == userId && !eg.IsUsed && (eg.ExpiresAt == null || eg.ExpiresAt > DateTime.UtcNow))
            .OrderByDescending(eg => eg.EarnedAt)
            .ToListAsync();

        return gifts.Select(eg => new EarnedGiftResponse(
            eg.Id, eg.GiftId, eg.Gift.Name, eg.Gift.Description,
            eg.Gift.PrizeType.ToString(), eg.Gift.Value, eg.Gift.Unit,
            eg.EarnedAt, eg.ExpiresAt, eg.IsUsed
        )).ToList();
    }

    public async Task UseEarnedGiftAsync(Guid userId, Guid earnedGiftId)
    {
        var earned = await db.EarnedGifts
            .Include(eg => eg.Gift)
            .FirstOrDefaultAsync(eg => eg.Id == earnedGiftId && eg.UserId == userId && !eg.IsUsed &&
                                       (eg.ExpiresAt == null || eg.ExpiresAt > DateTime.UtcNow))
            ?? throw new InvalidOperationException("Earned gift not found or already used");

        await ApplyPrizeAsync(userId, earned.Gift.PrizeType, earned.Gift.Value);

        earned.IsUsed = true;
        earned.UsedAt = DateTime.UtcNow;
        await db.SaveChangesAsync();
    }

    public async Task IncrementQuestProgressAsync(Guid userId, Guid tenantId, string targetEvent)
    {
        var matchingQuests = await db.Quests
            .Where(q => q.IsActive && q.TargetEvent == targetEvent &&
                        (q.TenantId == null || q.TenantId == tenantId) &&
                        (q.ExpiresAt == null || q.ExpiresAt > DateTime.UtcNow))
            .ToListAsync();

        foreach (var quest in matchingQuests)
        {
            var today = DateOnly.FromDateTime(DateTime.UtcNow);
            DateOnly? periodStart = quest.QuestType switch
            {
                QuestType.Daily => today,
                QuestType.Weekly => today.AddDays(-(int)DateTime.UtcNow.DayOfWeek),
                _ => null
            };

            var progress = await db.UserQuestProgresses
                .FirstOrDefaultAsync(p => p.UserId == userId && p.QuestId == quest.Id && p.PeriodStart == periodStart);

            if (progress == null)
            {
                progress = new UserQuestProgress
                {
                    UserId = userId,
                    QuestId = quest.Id,
                    PeriodStart = periodStart,
                };
                db.UserQuestProgresses.Add(progress);
            }

            if (progress.IsCompleted) continue;

            progress.CurrentCount++;
            if (progress.CurrentCount >= quest.TargetCount)
            {
                progress.IsCompleted = true;
                progress.CompletedAt = DateTime.UtcNow;
            }
        }

        await db.SaveChangesAsync();
    }

    private async Task ApplyPrizeAsync(Guid userId, PrizeType prizeType, long amount)
    {
        var user = await db.Users.FindAsync(userId) ?? throw new KeyNotFoundException("User not found");

        switch (prizeType)
        {
            case PrizeType.Balance:
                user.BalanceMinor += amount;
                break;
            case PrizeType.RenderSeconds:
                user.UserDailyFreeChargeSec += (int)amount;
                break;
            case PrizeType.LoyaltyPoints:
                user.LoyaltyScore += (int)amount;
                break;
            // StorageGB, Plan, Discount require more complex handling (not inline)
        }

        user.UpdatedAt = DateTime.UtcNow;
    }
}