using WorkCameraExport.Models;
using WorkCameraExport.Services;
using WorkCameraExport.Services.Interfaces;

namespace WorkCameraExport.Forms
{
    /// <summary>
    /// 登录窗体
    /// </summary>
    public partial class LoginForm : Form
    {
        private readonly ApiService _apiService;
        private readonly IConfigService? _configService;
        private readonly AppSettings _settings;

        // 验证码相关
        private string _captchaUuid = "";
        private bool _captchaRequired = true;

        /// <summary>
        /// 登录成功后的 Token
        /// </summary>
        public string? Token { get; private set; }

        /// <summary>
        /// 登录成功后的用户信息
        /// </summary>
        public UserInfo? UserInfo { get; private set; }

        /// <summary>
        /// 是否为自动登录成功
        /// </summary>
        public bool IsAutoLogin { get; private set; }

        public LoginForm(ApiService apiService, IConfigService? configService = null)
        {
            InitializeComponent();
            _apiService = apiService;
            _configService = configService;
            _settings = AppSettings.Load();
            LoadSettings();
        }

        /// <summary>
        /// 加载保存的设置
        /// </summary>
        private void LoadSettings()
        {
            txtServerUrl.Text = _settings.ServerUrl;
            txtUsername.Text = _settings.Username;
            chkRememberMe.Checked = _settings.RememberMe;

            // 如果记住登录且 Token 未过期，尝试自动登录
            if (_settings.RememberMe && 
                !string.IsNullOrEmpty(_settings.SavedToken) &&
                _settings.TokenExpireTime.HasValue &&
                _settings.TokenExpireTime.Value > DateTime.Now)
            {
                TryAutoLogin();
            }
        }

        /// <summary>
        /// 尝试自动登录
        /// </summary>
        private async void TryAutoLogin()
        {
            if (string.IsNullOrEmpty(_settings.ServerUrl) || 
                string.IsNullOrEmpty(_settings.SavedToken))
            {
                return;
            }

            SetControlsEnabled(false);
            lblStatus.Text = "正在自动登录...";
            lblStatus.ForeColor = Color.Blue;

            try
            {
                _apiService.SetBaseUrl(_settings.ServerUrl);
                _apiService.SetToken(_settings.SavedToken);

                // 验证 Token 是否有效（通过获取当前用户信息）
                var (success, _, _) = await _apiService.GetCurrentUserAsync();

                if (success)
                {
                    Token = _settings.SavedToken;
                    IsAutoLogin = true;
                    DialogResult = DialogResult.OK;
                    Close();
                    return;
                }

                // Token 无效，清除保存的登录信息并提示用户
                _settings.ClearLoginInfo();
                _configService?.ClearCredentials();
                lblStatus.Text = "登录已失效，请重新登录";
                lblStatus.ForeColor = Color.Orange;
            }
            catch
            {
                _settings.ClearLoginInfo();
                _configService?.ClearCredentials();
                lblStatus.Text = "自动登录失败，请重新登录";
                lblStatus.ForeColor = Color.Red;
            }
            finally
            {
                SetControlsEnabled(true);
                // 加载验证码
                await LoadCaptchaAsync();
            }
        }

        /// <summary>
        /// 服务器地址输入框失去焦点时加载验证码
        /// </summary>
        private async void txtServerUrl_Leave(object sender, EventArgs e)
        {
            if (!string.IsNullOrWhiteSpace(txtServerUrl.Text))
            {
                await LoadCaptchaAsync();
            }
        }

        /// <summary>
        /// 加载验证码
        /// </summary>
        private async Task LoadCaptchaAsync()
        {
            if (string.IsNullOrWhiteSpace(txtServerUrl.Text))
            {
                return;
            }

            try
            {
                _apiService.SetBaseUrl(txtServerUrl.Text.Trim());
                
                var (success, message, data) = await _apiService.GetCaptchaAsync();

                if (success && data != null)
                {
                    _captchaUuid = data.Uuid;
                    _captchaRequired = data.CaptchaOff?.ToLower() != "off";

                    // 显示或隐藏验证码控件
                    SetCaptchaVisible(_captchaRequired);

                    if (_captchaRequired && !string.IsNullOrEmpty(data.Img))
                    {
                        // 将 Base64 转换为图片
                        var imageBytes = Convert.FromBase64String(data.Img);
                        using var ms = new MemoryStream(imageBytes);
                        picCaptcha.Image?.Dispose();
                        picCaptcha.Image = Image.FromStream(ms);
                    }

                    lblStatus.Text = "";
                }
                else
                {
                    lblStatus.Text = "获取验证码失败，点击图片重试";
                    lblStatus.ForeColor = Color.Orange;
                }
            }
            catch (Exception ex)
            {
                lblStatus.Text = $"连接服务器失败: {ex.Message}";
                lblStatus.ForeColor = Color.Red;
            }
        }

        /// <summary>
        /// 设置验证码控件可见性
        /// </summary>
        private void SetCaptchaVisible(bool visible)
        {
            lblCaptcha.Visible = visible;
            txtCaptcha.Visible = visible;
            picCaptcha.Visible = visible;

            // 调整其他控件位置
            if (visible)
            {
                chkRememberMe.Location = new Point(30, 265);
                btnLogin.Location = new Point(30, 300);
                btnCancel.Location = new Point(210, 300);
                lblStatus.Location = new Point(30, 355);
                this.ClientSize = new Size(400, 450);
            }
            else
            {
                chkRememberMe.Location = new Point(30, 200);
                btnLogin.Location = new Point(30, 240);
                btnCancel.Location = new Point(210, 240);
                lblStatus.Location = new Point(30, 295);
                this.ClientSize = new Size(400, 390);
            }
        }

        /// <summary>
        /// 点击验证码图片刷新
        /// </summary>
        private async void picCaptcha_Click(object sender, EventArgs e)
        {
            txtCaptcha.Text = "";
            await LoadCaptchaAsync();
        }

        /// <summary>
        /// 登录按钮点击事件
        /// </summary>
        private async void btnLogin_Click(object sender, EventArgs e)
        {
            // 验证输入
            if (string.IsNullOrWhiteSpace(txtServerUrl.Text))
            {
                ShowError("请输入服务器地址");
                txtServerUrl.Focus();
                return;
            }

            if (string.IsNullOrWhiteSpace(txtUsername.Text))
            {
                ShowError("请输入用户名");
                txtUsername.Focus();
                return;
            }

            if (string.IsNullOrWhiteSpace(txtPassword.Text))
            {
                ShowError("请输入密码");
                txtPassword.Focus();
                return;
            }

            if (_captchaRequired && string.IsNullOrWhiteSpace(txtCaptcha.Text))
            {
                ShowError("请输入验证码");
                txtCaptcha.Focus();
                return;
            }

            await DoLoginAsync();
        }

        /// <summary>
        /// 执行登录
        /// </summary>
        private async Task DoLoginAsync()
        {
            SetControlsEnabled(false);
            lblStatus.Text = "正在登录...";
            lblStatus.ForeColor = Color.Blue;

            try
            {
                var serverUrl = txtServerUrl.Text.Trim();
                var username = txtUsername.Text.Trim();
                var password = txtPassword.Text;
                var captchaCode = txtCaptcha.Text.Trim();

                _apiService.SetBaseUrl(serverUrl);

                var (success, message, data) = await _apiService.LoginAsync(
                    username, password, captchaCode, _captchaUuid);

                if (success && data != null)
                {
                    Token = data.Token;
                    UserInfo = data.User;

                    // 保存设置
                    SaveSettings(serverUrl, username, data.Token);

                    lblStatus.Text = "登录成功";
                    lblStatus.ForeColor = Color.Green;

                    DialogResult = DialogResult.OK;
                    Close();
                }
                else
                {
                    ShowError(message);
                    SetControlsEnabled(true);
                    
                    // 登录失败后刷新验证码
                    if (_captchaRequired)
                    {
                        txtCaptcha.Text = "";
                        await LoadCaptchaAsync();
                    }
                }
            }
            catch (Exception ex)
            {
                ShowError($"登录异常: {ex.Message}");
                SetControlsEnabled(true);
            }
        }

        /// <summary>
        /// 保存设置
        /// </summary>
        private void SaveSettings(string serverUrl, string username, string token)
        {
            _settings.ServerUrl = serverUrl;
            _settings.Username = username;
            _settings.RememberMe = chkRememberMe.Checked;

            if (chkRememberMe.Checked)
            {
                _settings.SavedToken = token;
                // Token 有效期设为 7 天
                _settings.TokenExpireTime = DateTime.Now.AddDays(7);
                
                // 同时保存到 ConfigService（加密存储）
                _configService?.SaveCredentials(serverUrl, token, username);
            }
            else
            {
                _settings.SavedToken = "";
                _settings.TokenExpireTime = null;
                _configService?.ClearCredentials();
            }

            _settings.Save();
        }

        /// <summary>
        /// 显示错误信息
        /// </summary>
        private void ShowError(string message)
        {
            lblStatus.Text = message;
            lblStatus.ForeColor = Color.Red;
        }

        /// <summary>
        /// 设置控件启用状态
        /// </summary>
        private void SetControlsEnabled(bool enabled)
        {
            txtServerUrl.Enabled = enabled;
            txtUsername.Enabled = enabled;
            txtPassword.Enabled = enabled;
            txtCaptcha.Enabled = enabled;
            picCaptcha.Enabled = enabled;
            chkRememberMe.Enabled = enabled;
            btnLogin.Enabled = enabled;
            btnCancel.Enabled = enabled;
        }

        /// <summary>
        /// 取消按钮点击事件
        /// </summary>
        private void btnCancel_Click(object sender, EventArgs e)
        {
            DialogResult = DialogResult.Cancel;
            Close();
        }

        /// <summary>
        /// 验证码输入框按键事件 - 支持回车登录
        /// </summary>
        private void txtCaptcha_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                e.SuppressKeyPress = true;
                btnLogin_Click(sender, e);
            }
        }

        /// <summary>
        /// 窗体加载事件
        /// </summary>
        private async void LoginForm_Load(object sender, EventArgs e)
        {
            // 设置焦点
            if (string.IsNullOrEmpty(txtServerUrl.Text))
            {
                txtServerUrl.Focus();
            }
            else if (string.IsNullOrEmpty(txtUsername.Text))
            {
                txtUsername.Focus();
            }
            else
            {
                txtPassword.Focus();
            }

            // 如果已有服务器地址，加载验证码
            if (!string.IsNullOrWhiteSpace(txtServerUrl.Text))
            {
                await LoadCaptchaAsync();
            }
        }
    }
}