using Microsoft.Extensions.Logging;
using System.Security.Cryptography;
using System.Text;
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using YD_Event.Application.Client.Dtos;
using YD_Event.Core.Utils;
using YD_Event.Application.Auth;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json;

namespace YD_Event.Application.Client;

/// <summary>
/// 微信小程序认证接口
/// </summary>
[ApiDescriptionSettings("微信小程序接口")]
public class OAuthController : IDynamicApiController
{
    private readonly WeChatTool _weChatTool;
    private readonly ISqlSugarRepository<AuthAccount> _accountRepository;
    private readonly ISqlSugarRepository<YD_Event.Core.Entities.AppUser> _appUserRepository;
    private readonly ISqlSugarRepository<SysRole> _roleRepository;
    private readonly ISqlSugarRepository<SysUserRole> _userRoleRepository;
    private readonly IEasyCachingProvider _easyCachingProvider;
    private readonly IIdGenerator _idGenerator;
    private readonly ILogger<OAuthController> _logger;

    private const string SessionKeyCachePrefix = "wechat_session_";

    public OAuthController(
        WeChatTool weChatTool,
        ISqlSugarRepository<AuthAccount> accountRepository,
        ISqlSugarRepository<YD_Event.Core.Entities.AppUser> appUserRepository,
        ISqlSugarRepository<SysRole> roleRepository,
        ISqlSugarRepository<SysUserRole> userRoleRepository,
        IEasyCachingProvider easyCachingProvider,
        IIdGenerator idGenerator,
        ILogger<OAuthController> logger)
    {
        _weChatTool = weChatTool;
        _accountRepository = accountRepository;
        _appUserRepository = appUserRepository;
        _roleRepository = roleRepository;
        _userRoleRepository = userRoleRepository;
        _easyCachingProvider = easyCachingProvider;
        _idGenerator = idGenerator;
        _logger = logger;
    }

    /// <summary>
    /// 登录接口
    /// </summary>
    /// <param name="input"></param>
    /// <returns></returns>
    [HttpPost("login")]
    [AllowAnonymous]
    public async Task<WeChatLoginOutput> Login([FromBody] WeChatLoginInput input)
    {
        // 1. code2Session
        var sessionResult = await _weChatTool.Code2Session(input.Code);
        string openid = sessionResult.OpenId;
        string sessionKey = sessionResult.SessionKey;

        // 缓存 session_key，用于后续解密
        await _easyCachingProvider.SetAsync($"{SessionKeyCachePrefix}{openid}", sessionKey, TimeSpan.FromHours(2));

        // 2. 校验签名 (可选，根据业务严谨性)
        // var signature2 = Hash(input.RawData + sessionKey);
        // if (signature2 != input.Signature) throw Oops.Bah("签名校验失败");

        // 3. 查找用户
        var account = await _accountRepository.GetFirstAsync(x => x.OAuthId == openid && x.Type == "WeChat");

        string accessToken = null;
        string refreshToken = null;
        object userInfo = null;
        int expiresIn = 7200;

        if (account != null)
        {
            // 生成 Token
            (accessToken, refreshToken) = GenerateTokens(account);
            
            // 获取用户信息
            var appUser = await _appUserRepository.GetFirstAsync(x => x.UserId == account.Id);
            if (appUser != null)
            {
                userInfo = new { appUser.Name, appUser.Id, appUser.Mobile, appUser.Avatar, appUser.NickName };
            }
            else
            {
                userInfo = new { account.Name, account.Avatar };
            }
        }

        return new WeChatLoginOutput
        {
            Openid = openid,
            SessionKey = sessionKey, // 需求要求返回
            AccessToken = accessToken,
            RefreshToken = refreshToken,
            ExpiresIn = expiresIn,
            UserInfo = userInfo
        };
    }

    /// <summary>
    /// 注册接口
    /// </summary>
    /// <param name="input"></param>
    /// <returns></returns>
    [HttpPost("register")]
    [AllowAnonymous]
    [UnitOfWork]
    public async Task<WeChatRegisterOutput> Register([FromBody] WeChatRegisterInput input)
    {
        // 1. 获取 session_key
        var cacheKey = $"{SessionKeyCachePrefix}{input.Openid}";
        var sessionKeyCache = await _easyCachingProvider.GetAsync<string>(cacheKey);
        if (!sessionKeyCache.HasValue) throw Oops.Bah("SessionKey已过期，请重新登录");
        string sessionKey = sessionKeyCache.Value;

        // 2. 解密用户信息
        string json = DecryptWeChatData(input.EncryptedData, sessionKey, input.Iv);
        var wxUser = JsonConvert.DeserializeObject<WeChatUserInfo>(json);
        if (wxUser == null) throw Oops.Bah("解密用户信息失败");
        
        // 验证 watermark
        var configAppId = App.Configuration["WeChat:AppId"];
        if (!string.IsNullOrEmpty(configAppId) && wxUser.Watermark?.Appid != configAppId)
        {
             // 仅记录警告，防止配置不一致导致注册失败
             _logger.LogWarning($"Watermark AppId mismatch: {wxUser.Watermark?.Appid} vs {configAppId}");
        }

        // 3. 写入 AuthAccount
        // 检查是否已存在
        if (await _accountRepository.IsAnyAsync(x => x.OAuthId == input.Openid && x.Type == "WeChat"))
        {
            throw Oops.Bah("该用户已注册");
        }

        long accountId = _idGenerator.NewLong();
        var account = new AuthAccount
        {
            Id = accountId,
            OAuthId = input.Openid,
            Type = "WeChat",
            Name = wxUser.NickName,
            Avatar = wxUser.AvatarUrl,
            Gender = (Gender)wxUser.Gender, // 假设 Gender 枚举兼容
            CreatedTime = DateTime.Now,
            CreatedUserId = accountId // 自指
        };
        await _accountRepository.InsertAsync(account);

        // 4. 写入 AppUser (Profile)
        long appUserId = _idGenerator.NewLong();
        var appUser = new YD_Event.Core.Entities.AppUser
        {
            Id = appUserId,
            UserId = accountId,
            Name = wxUser.NickName,
            NickName = wxUser.NickName,
            Avatar = wxUser.AvatarUrl,
            Gender = (Gender)wxUser.Gender,
            PersonType = 0, // 普通用户
            Status = AvailabilityStatus.Enable,
            AuditStatus = AuditStatus.Pass,
            CreatedTime = DateTime.Now,
            CreatedUserId = accountId
        };
        await _appUserRepository.InsertAsync(appUser);

        // 5. 初始化默认角色
        // 查找默认角色，假设为 "OrdinaryUser" 或 "User"
        var defaultRole = await _roleRepository.GetFirstAsync(x => x.Code == "User" || x.Code == "OrdinaryUser");
        if (defaultRole == null)
        {
            // 如果不存在，创建一个默认角色
             defaultRole = new SysRole
             {
                 Id = _idGenerator.NewLong(),
                 Name = "普通用户",
                 Code = "User",
                 Status = AvailabilityStatus.Enable,
                 CreatedTime = DateTime.Now
             };
             await _roleRepository.InsertAsync(defaultRole);
        }

        // 绑定角色 (这里是 AppUser 还是 AuthAccount 绑定角色？ SysUserRole 关联 UserId，通常指 AuthAccount.Id 或 SysUser.Id)
        // 假设 SysUserRole.UserId 对应 AuthAccount.Id (因为 AuthAccount 是登录主体)
        await _userRoleRepository.InsertAsync(new SysUserRole
        {
            Id = _idGenerator.NewLong(),
            UserId = accountId,
            RoleId = defaultRole.Id,
            CreatedTime = DateTime.Now
        });

        return new WeChatRegisterOutput
        {
            UserId = accountId,
            Nickname = account.Name,
            AvatarUrl = account.Avatar,
            RegisterTime = account.CreatedTime
        };
    }

    /// <summary>
    /// 找回密码接口
    /// </summary>
    /// <param name="input"></param>
    /// <returns></returns>
    [HttpPost("reset-password")]
    [AllowAnonymous]
    public async Task<WeChatResetPasswordOutput> ResetPassword([FromBody] WeChatResetPasswordInput input)
    {
        // 1. 获取 session_key
        var cacheKey = $"{SessionKeyCachePrefix}{input.Openid}";
        var sessionKeyCache = await _easyCachingProvider.GetAsync<string>(cacheKey);
        if (!sessionKeyCache.HasValue) throw Oops.Bah("SessionKey已过期，请重新登录");
        string sessionKey = sessionKeyCache.Value;

        // 2. 验证微信身份 (尝试解密)
        try 
        {
            string json = DecryptWeChatData(input.EncryptedData, sessionKey, input.Iv);
            var wxUser = JsonConvert.DeserializeObject<WeChatUserInfo>(json);
            if (wxUser.OpenId != input.Openid) throw Oops.Bah("身份验证失败: OpenId不匹配");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "ResetPassword Decrypt Failed");
            throw Oops.Bah("身份验证失败");
        }

        // 3. 生成一次性 Token
        string resetToken = Guid.NewGuid().ToString("N");
        
        // 4. 发送邮件/短信 (Mock)
        string sendChannel = "none";
        if (!string.IsNullOrEmpty(input.Email))
        {
            // Mock send email
            _logger.LogInformation($"Send Reset Token {resetToken} to Email {input.Email}");
            sendChannel = "email";
        }
        else if (!string.IsNullOrEmpty(input.SmsCode))
        {
            // Verify Sms Code (Mock)
            // Mock send sms
            _logger.LogInformation($"Verify SMS Code {input.SmsCode} and generate token");
            sendChannel = "sms";
        }

        return new WeChatResetPasswordOutput
        {
            ResetToken = resetToken,
            ExpireTime = DateTime.Now.AddMinutes(15),
            SendChannel = sendChannel
        };
    }

    /// <summary>
    /// AES-128-CBC 解密
    /// </summary>
    private string DecryptWeChatData(string encryptedData, string sessionKey, string iv)
    {
        try
        {
            byte[] encryptedBytes = Convert.FromBase64String(encryptedData);
            byte[] keyBytes = Convert.FromBase64String(sessionKey);
            byte[] ivBytes = Convert.FromBase64String(iv);

            using var aes = Aes.Create();
            aes.KeySize = 128;
            aes.BlockSize = 128;
            aes.Mode = CipherMode.CBC;
            aes.Padding = PaddingMode.PKCS7;
            aes.Key = keyBytes;
            aes.IV = ivBytes;

            using var decryptor = aes.CreateDecryptor(aes.Key, aes.IV);
            using var ms = new MemoryStream(encryptedBytes);
            using var cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read);
            using var sr = new StreamReader(cs);
            return sr.ReadToEnd();
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "AES Decrypt Error");
            throw Oops.Bah("数据解密失败");
        }
    }

    /// <summary>
    /// 生成自定义 Token
    /// </summary>
    private (string AccessToken, string RefreshToken) GenerateTokens(AuthAccount account)
    {
        long uniqueId = _idGenerator.NewLong();
        string accessToken = JWTEncryption.Encrypt(new Dictionary<string, object>()
        {
            [AuthClaimsConst.AuthIdKey] = account.Id,
            [AuthClaimsConst.AccountKey] = account.OAuthId,
            [AuthClaimsConst.UuidKey] = uniqueId,
            [AuthClaimsConst.AuthPlatformTypeKey] = AuthPlatformType.WeChatApplet
        });

        // 获取刷新 token
        string refreshToken = JWTEncryption.GenerateRefreshToken(accessToken);

        return (accessToken, refreshToken);
    }
}