const EmailClient = require("../core/EmailClient");
const TemplateManager = require("../core/TemplateManager");

/**
 * AuthEmailService handles all authentication and account security related emails
 * This service is responsible for:
 * - Sending email verification links
 * - Sending password reset links
 * - Sending password changed confirmations
 */
class AuthEmailService {
  constructor() {
    this.emailClient = new EmailClient();
    this.templateManager = new TemplateManager();
    this.initialized = false;
  }

  /**
   * Initialize the auth email service
   * @returns {Promise<void>}
   */
  async initialize() {
    if (this.initialized) return;

    await Promise.all([
      this.emailClient.initialize(),
      this.templateManager.initialize(),
    ]);

    this.initialized = true;
    console.log("Auth Email Service initialized successfully");
  }

  /**
   * Send email verification email to new users
   * @param {Object} user - User object
   * @param {string} user.firstName - User's first name
   * @param {string} user.email - User's email address
   * @param {string} verificationToken - Email verification token
   * @returns {Promise<{success: boolean, messageId?: string, error?: string}>}
   */
  async sendVerificationEmail(user, verificationToken) {
    if (!this.initialized) {
      await this.initialize();
    }

    const frontendUrl = process.env.FRONTEND_URL || "http://localhost:3000";
    const verificationUrl = `${frontendUrl}/verify-email?token=${verificationToken}`;

    const variables = {
      recipientName: user.firstName || "there",
      verificationUrl: verificationUrl,
      verificationCode: verificationToken, // 6-digit code for display in email
    };

    const htmlContent = await this.templateManager.renderTemplate(
      "emailVerificationToUser",
      variables
    );

    return await this.emailClient.sendEmail(
      user.email,
      "Verify Your Email - Village Share",
      htmlContent
    );
  }

  /**
   * Send password reset email with reset link
   * @param {Object} user - User object
   * @param {string} user.firstName - User's first name
   * @param {string} user.email - User's email address
   * @param {string} resetToken - Password reset token
   * @returns {Promise<{success: boolean, messageId?: string, error?: string}>}
   */
  async sendPasswordResetEmail(user, resetToken) {
    if (!this.initialized) {
      await this.initialize();
    }

    const frontendUrl = process.env.FRONTEND_URL || "http://localhost:3000";
    const resetUrl = `${frontendUrl}/reset-password?token=${resetToken}`;

    const variables = {
      recipientName: user.firstName || "there",
      resetUrl: resetUrl,
    };

    const htmlContent = await this.templateManager.renderTemplate(
      "passwordResetToUser",
      variables
    );

    return await this.emailClient.sendEmail(
      user.email,
      "Reset Your Password - Village Share",
      htmlContent
    );
  }

  /**
   * Send password changed confirmation email
   * @param {Object} user - User object
   * @param {string} user.firstName - User's first name
   * @param {string} user.email - User's email address
   * @returns {Promise<{success: boolean, messageId?: string, error?: string}>}
   */
  async sendPasswordChangedEmail(user) {
    if (!this.initialized) {
      await this.initialize();
    }

    const timestamp = new Date().toLocaleString("en-US", {
      dateStyle: "long",
      timeStyle: "short",
    });

    const variables = {
      recipientName: user.firstName || "there",
      email: user.email,
      timestamp: timestamp,
    };

    const htmlContent = await this.templateManager.renderTemplate(
      "passwordChangedToUser",
      variables
    );

    return await this.emailClient.sendEmail(
      user.email,
      "Password Changed Successfully - Village Share",
      htmlContent
    );
  }

  /**
   * Send personal information changed notification email
   * @param {Object} user - User object
   * @param {string} user.firstName - User's first name
   * @param {string} user.email - User's email address
   * @returns {Promise<{success: boolean, messageId?: string, error?: string}>}
   */
  async sendPersonalInfoChangedEmail(user) {
    if (!this.initialized) {
      await this.initialize();
    }

    const timestamp = new Date().toLocaleString("en-US", {
      dateStyle: "long",
      timeStyle: "short",
    });

    const variables = {
      recipientName: user.firstName || "there",
      email: user.email,
      timestamp: timestamp,
    };

    const htmlContent = await this.templateManager.renderTemplate(
      "personalInfoChangedToUser",
      variables
    );

    return await this.emailClient.sendEmail(
      user.email,
      "Personal Information Updated - Village Share",
      htmlContent
    );
  }

  /**
   * Send two-factor authentication OTP email
   * @param {Object} user - User object
   * @param {string} user.firstName - User's first name
   * @param {string} user.email - User's email address
   * @param {string} otpCode - 6-digit OTP code
   * @returns {Promise<{success: boolean, messageId?: string, error?: string}>}
   */
  async sendTwoFactorOtpEmail(user, otpCode) {
    if (!this.initialized) {
      await this.initialize();
    }

    const variables = {
      recipientName: user.firstName || "there",
      otpCode: otpCode,
    };

    const htmlContent = await this.templateManager.renderTemplate(
      "twoFactorOtpToUser",
      variables
    );

    return await this.emailClient.sendEmail(
      user.email,
      "Your Verification Code - Village Share",
      htmlContent
    );
  }

  /**
   * Send two-factor authentication enabled confirmation email
   * @param {Object} user - User object
   * @param {string} user.firstName - User's first name
   * @param {string} user.email - User's email address
   * @returns {Promise<{success: boolean, messageId?: string, error?: string}>}
   */
  async sendTwoFactorEnabledEmail(user) {
    if (!this.initialized) {
      await this.initialize();
    }

    const timestamp = new Date().toLocaleString("en-US", {
      dateStyle: "long",
      timeStyle: "short",
    });

    const variables = {
      recipientName: user.firstName || "there",
      timestamp: timestamp,
    };

    const htmlContent = await this.templateManager.renderTemplate(
      "twoFactorEnabledToUser",
      variables
    );

    return await this.emailClient.sendEmail(
      user.email,
      "Multi-Factor Authentication Enabled - Village Share",
      htmlContent
    );
  }

  /**
   * Send two-factor authentication disabled notification email
   * @param {Object} user - User object
   * @param {string} user.firstName - User's first name
   * @param {string} user.email - User's email address
   * @returns {Promise<{success: boolean, messageId?: string, error?: string}>}
   */
  async sendTwoFactorDisabledEmail(user) {
    if (!this.initialized) {
      await this.initialize();
    }

    const timestamp = new Date().toLocaleString("en-US", {
      dateStyle: "long",
      timeStyle: "short",
    });

    const variables = {
      recipientName: user.firstName || "there",
      timestamp: timestamp,
    };

    const htmlContent = await this.templateManager.renderTemplate(
      "twoFactorDisabledToUser",
      variables
    );

    return await this.emailClient.sendEmail(
      user.email,
      "Multi-Factor Authentication Disabled - Village Share",
      htmlContent
    );
  }

  /**
   * Send recovery code used notification email
   * @param {Object} user - User object
   * @param {string} user.firstName - User's first name
   * @param {string} user.email - User's email address
   * @param {number} remainingCodes - Number of remaining recovery codes
   * @returns {Promise<{success: boolean, messageId?: string, error?: string}>}
   */
  async sendRecoveryCodeUsedEmail(user, remainingCodes) {
    if (!this.initialized) {
      await this.initialize();
    }

    const timestamp = new Date().toLocaleString("en-US", {
      dateStyle: "long",
      timeStyle: "short",
    });

    // Determine color based on remaining codes
    let remainingCodesColor = "#28a745"; // Green
    if (remainingCodes <= 2) {
      remainingCodesColor = "#dc3545"; // Red
    } else if (remainingCodes <= 5) {
      remainingCodesColor = "#fd7e14"; // Orange
    }

    const variables = {
      recipientName: user.firstName || "there",
      remainingCodes: remainingCodes,
      remainingCodesColor: remainingCodesColor,
      lowCodesWarning: remainingCodes <= 2,
      timestamp: timestamp,
    };

    const htmlContent = await this.templateManager.renderTemplate(
      "recoveryCodeUsedToUser",
      variables
    );

    return await this.emailClient.sendEmail(
      user.email,
      "Recovery Code Used - Village Share",
      htmlContent
    );
  }
}

module.exports = AuthEmailService;