using Avalonia_Common.Core;
using Avalonia_EFCore.Database;
using Avalonia_EFCore.Models;
using Avalonia_Services.Core;
using Avalonia_Services.Services.AuthService;
using Microsoft.EntityFrameworkCore;
using System.Text.Json;

namespace Avalonia_API.Authentication
{
    public sealed class ApiAuthEndpointService(
        AppDataContext db,
        JwtTokenService jwtTokenService,
        RefreshTokenService refreshTokenService) : IApiAuthEndpointService
    {
        private static readonly JsonSerializerOptions JsonOptions = new()
        {
            PropertyNameCaseInsensitive = true,
        };

        public async Task<object?> LoginAsync(ServiceEndpointContext ctx)
        {
            var request = Deserialize<ApiLoginRequest>(ctx.Body);
            if (string.IsNullOrWhiteSpace(request?.Account))
            {
                ctx.StatusCode = 400;
                return ResponseHelper.Failure(400, "账号不能为空");
            }

            var user = await db.Users.FirstOrDefaultAsync(
                x => x.Email == request.Account || x.Name == request.Account);

            if (user is null)
            {
                user = new UserEntity
                {
                    Name = request.Account,
                    Email = request.Account.Contains('@') ? request.Account : null,
                };
                db.Users.Add(user);
                await db.SaveChangesAsync();
            }

            var roles = NormalizeRoles(request.Roles);
            var accessToken = jwtTokenService.CreateAccessToken(user, roles);
            var refreshToken = await refreshTokenService.CreateAsync(
                user.Id,
                ctx.GetHeader("User-Agent"),
                GetRemoteIpAddress(ctx));

            return ResponseHelper.Ok(new AuthTokenResponse(
                accessToken.Token,
                refreshToken.Token,
                accessToken.ExpiresAt,
                refreshToken.Entity.ExpiresAt,
                roles), "登录成功");
        }

        public async Task<object?> RefreshAsync(ServiceEndpointContext ctx)
        {
            var request = Deserialize<ApiRefreshTokenRequest>(ctx.Body);
            var rotated = await refreshTokenService.RotateAsync(
                request?.RefreshToken,
                ctx.GetHeader("User-Agent"),
                GetRemoteIpAddress(ctx));

            if (rotated is null)
            {
                ctx.StatusCode = 401;
                return ResponseHelper.Failure(401, "刷新 token 无效或已过期");
            }

            var user = await db.Users.FindAsync(rotated.Value.Entity.UserId);
            if (user is null)
            {
                ctx.StatusCode = 401;
                return ResponseHelper.Failure(401, "用户不存在");
            }

            var roles = new[] { "Admin" };
            var accessToken = jwtTokenService.CreateAccessToken(user, roles);

            return ResponseHelper.Ok(new AuthTokenResponse(
                accessToken.Token,
                rotated.Value.Token,
                accessToken.ExpiresAt,
                rotated.Value.Entity.ExpiresAt,
                roles), "刷新成功");
        }

        public async Task<object?> LogoutAsync(ServiceEndpointContext ctx)
        {
            var request = Deserialize<ApiLogoutRequest>(ctx.Body);
            await refreshTokenService.RevokeAsync(request?.RefreshToken);
            return ResponseHelper.Succeed("退出成功");
        }

        private static T? Deserialize<T>(string? body)
        {
            return string.IsNullOrWhiteSpace(body)
                ? default
                : JsonSerializer.Deserialize<T>(body, JsonOptions);
        }

        private static string? GetRemoteIpAddress(ServiceEndpointContext ctx)
        {
            return ctx.Items.TryGetValue("HttpContext", out var value) && value is HttpContext httpContext
                ? httpContext.Connection.RemoteIpAddress?.ToString()
                : null;
        }

        private static string[] NormalizeRoles(string[]? roles)
        {
            var normalized = roles?
                .Where(role => !string.IsNullOrWhiteSpace(role))
                .Select(role => role.Trim())
                .Distinct(StringComparer.OrdinalIgnoreCase)
                .ToArray();

            return normalized is { Length: > 0 } ? normalized : ["Admin"];
        }
    }
}