/* 
 * Green Horizon - Enhanced Authentication System with Email Verification
 * Complete authentication flow with email verification and proper redirects
 */

// Initialize Firebase
const firebaseConfig = {
  apiKey: "AIzaSyB2zDTDlPGGY1-vofuJTG8sT5W1yfBBW3A",
  authDomain: "green-horizon-web.firebaseapp.com",
  projectId: "green-horizon-web",
  storageBucket: "green-horizon-web.firebasestorage.app",
  messagingSenderId: "873381929701",
  appId: "1:873381929701:web:d4d610bb64347bd56dea0c",
  measurementId: "G-T4F71XBRRY"
};

firebase.initializeApp(firebaseConfig);
const auth = firebase.auth();
const db = firebase.firestore(); // If you're using Firestore

// Password validation function
function validatePassword(password) {
  const minLength = 10;
  const hasUpperCase = /[A-Z]/.test(password);
  const hasLowerCase = /[a-z]/.test(password);
  const hasNumbers = /\d/.test(password);
  const hasSpecialChar = /[!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?]/.test(password);
  
  return {
    isValid: password.length >= minLength && hasUpperCase && hasLowerCase && hasNumbers && hasSpecialChar,
    minLength: password.length >= minLength,
    hasUpperCase,
    hasLowerCase,
    hasNumbers,
    hasSpecialChar
  };
}

// Enhanced SIGN UP with email verification
function signUp() {
  const email = document.getElementById("register-email").value;
  const password = document.getElementById("register-password").value;
  
  // Validate password
  const passwordValidation = validatePassword(password);
  if (!passwordValidation.isValid) {
    showNotification("Please ensure your password meets all requirements", "error");
    return;
  }
  
  // Validate email
  if (!validateEmail(email)) {
    showNotification("Please enter a valid email address", "error");
    return;
  }
  
  // Show loading state
  const submitButton = document.querySelector('#register-form button[type="submit"]');
  if (submitButton) {
    submitButton.innerHTML = '<i class="fas fa-spinner fa-spin"></i> Creating Account...';
    submitButton.disabled = true;
  }
  
  auth.createUserWithEmailAndPassword(email, password)
    .then((userCredential) => {
      const user = userCredential.user;
      
      // Send email verification
      return user.sendEmailVerification()
        .then(() => {
          // Store user data in Firestore (optional)
          return db.collection('users').doc(user.uid).set({
            email: user.email,
            createdAt: firebase.firestore.FieldValue.serverTimestamp(),
            emailVerified: false,
            lastLogin: null
          });
        })
        .then(() => {
          // Show success message with instructions
          showNotification(`Verification email sent to ${user.email}. Please verify your email before logging in.`, "success");
          
          // Redirect to login after a delay
          setTimeout(() => {
            window.location.href = "login.html?message=verify_email";
          }, 5000);
        });
    })
    .catch((error) => {
      // Reset button state
      if (submitButton) {
        submitButton.innerHTML = 'Create Account';
        submitButton.disabled = false;
      }
      
      // Handle specific error cases
      let errorMessage = error.message;
      
      if (error.code === 'auth/email-already-in-use') {
        errorMessage = "This email is already registered. Please try logging in or use a different email.";
      } else if (error.code === 'auth/invalid-email') {
        errorMessage = "The email address is not valid.";
      } else if (error.code === 'auth/operation-not-allowed') {
        errorMessage = "Email/password accounts are not enabled. Please contact support.";
      } else if (error.code === 'auth/weak-password') {
        errorMessage = "The password is too weak. Please use a stronger password.";
      }
      
      showNotification(errorMessage, "error");
    });
}

// Enhanced LOGIN with email verification check
function login() {
  const email = document.getElementById("login-email").value;
  const password = document.getElementById("login-password").value;
  
  // Validate email
  if (!validateEmail(email)) {
    showNotification("Please enter a valid email address", "error");
    return;
  }
  
  // Show loading state
  const submitButton = document.querySelector('#login-form button[type="submit"]');
  if (submitButton) {
    submitButton.innerHTML = '<i class="fas fa-spinner fa-spin"></i> Logging In...';
    submitButton.disabled = true;
  }
  
  auth.signInWithEmailAndPassword(email, password)
    .then((userCredential) => {
      const user = userCredential.user;
      
      if (user.emailVerified) {
        // Update last login in Firestore (optional)
        db.collection('users').doc(user.uid).update({
          lastLogin: firebase.firestore.FieldValue.serverTimestamp()
        });
        
        showNotification(`Login successful! Welcome back, ${user.email}`, "success");
        
        // Redirect to dashboard after a short delay
        setTimeout(() => {
          window.location.href = "../dashboard/index.html";
        }, 1500);
      } else {
        // Reset button state
        if (submitButton) {
          submitButton.innerHTML = 'Log In';
          submitButton.disabled = false;
        }
        
        showNotification("Please verify your email before logging in. Check your spam folder if you can't find the verification email.", "warning");
        
        // Option to resend verification email
        if (confirm("Would you like us to resend the verification email?")) {
          user.sendEmailVerification()
            .then(() => {
              showNotification("Verification email sent. Please check your inbox.", "success");
            })
            .catch((error) => {
              showNotification("Error sending verification email: " + error.message, "error");
            });
        }
      }
    })
    .catch((error) => {
      // Reset button state
      if (submitButton) {
        submitButton.innerHTML = 'Log In';
        submitButton.disabled = false;
      }
      
      // Handle specific error cases
      let errorMessage = error.message;
      
      if (error.code === 'auth/user-not-found') {
        errorMessage = "No account found with this email. Please sign up first.";
      } else if (error.code === 'auth/wrong-password') {
        errorMessage = "Incorrect password. Please try again or reset your password.";
      } else if (error.code === 'auth/invalid-email') {
        errorMessage = "The email address is not valid.";
      } else if (error.code === 'auth/user-disabled') {
        errorMessage = "This account has been disabled. Please contact support.";
      }
      
      showNotification(errorMessage, "error");
    });
}

// Enhanced FORGOT PASSWORD with validation
function resetPassword() {
  const email = document.getElementById("forgot-email").value;
  
  // Validate email
  if (!validateEmail(email)) {
    showNotification("Please enter a valid email address", "error");
    return;
  }
  
  // Show loading state
  const submitButton = document.querySelector('#forgot-password-form button[type="submit"]');
  if (submitButton) {
    submitButton.innerHTML = '<i class="fas fa-spinner fa-spin"></i> Sending...';
    submitButton.disabled = true;
  }
  
  auth.sendPasswordResetEmail(email)
    .then(() => {
      showNotification("Password reset email sent! Check your inbox for instructions.", "success");
      
      // Redirect to login after a delay
      setTimeout(() => {
        window.location.href = "login.html?message=reset_email_sent";
      }, 3000);
    })
    .catch((error) => {
      // Reset button state
      if (submitButton) {
        submitButton.innerHTML = 'Reset Password';
        submitButton.disabled = false;
      }
      
      // Handle specific error cases
      let errorMessage = error.message;
      
      if (error.code === 'auth/user-not-found') {
        errorMessage = "No account found with this email. Please sign up first.";
      } else if (error.code === 'auth/invalid-email') {
        errorMessage = "The email address is not valid.";
      }
      
      showNotification(errorMessage, "error");
    });
}

// LOGOUT function
function logout() {
  // Show confirmation dialog
  if (confirm("Are you sure you want to log out?")) {
    auth.signOut()
      .then(() => {
        showNotification("You have been logged out successfully", "success");
        setTimeout(() => {
          window.location.href = "../auth/login.html";
        }, 1500);
      })
      .catch((error) => {
        showNotification("Error logging out: " + error.message, "error");
      });
  }
}

// Check authentication state and redirect if needed
function checkAuthState() {
  auth.onAuthStateChanged((user) => {
    if (user) {
      console.log("User logged in:", user.email);
      
      // If user is on auth pages but already logged in, redirect to dashboard
      if (window.location.pathname.includes('auth/') && 
          user.emailVerified) {
        window.location.href = "../dashboard/index.html";
      }
      
      // If user's email is not verified, show reminder
      if (!user.emailVerified && !window.location.pathname.includes('register.html')) {
        showNotification("Please verify your email address to access all features", "warning");
      }
    } else {
      console.log("No user logged in");
      
      // If on protected pages, redirect to login
      if (window.location.pathname.includes('dashboard/')) {
        window.location.href = "../auth/login.html";
      }
    }
  });
}

// Email validation helper function
function validateEmail(email) {
  const re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
  return re.test(String(email).toLowerCase());
}

// Notification function
function showNotification(message, type = "info") {
  // Create notification element
  const notification = document.createElement('div');
  notification.className = `notification ${type}`;
  
  // Set icon based on type
  let icon = 'fa-info-circle';
  if (type === 'success') icon = 'fa-check-circle';
  if (type === 'error') icon = 'fa-exclamation-circle';
  if (type === 'warning') icon = 'fa-exclamation-triangle';
  
  notification.innerHTML = `
    <i class="fas ${icon}"></i>
    <div>${message}</div>
    <button class="notification-close" onclick="this.parentElement.remove()">
      <i class="fas fa-times"></i>
    </button>
  `;
  
  // Add to notification area or create one if it doesn't exist
  let notificationArea = document.getElementById('notificationArea');
  if (!notificationArea) {
    notificationArea = document.createElement('div');
    notificationArea.id = 'notificationArea';
    notificationArea.className = 'notification-area';
    document.body.appendChild(notificationArea);
  }
  
  notificationArea.appendChild(notification);
  
  // Auto remove after 5 seconds
  setTimeout(() => {
    if (notification.parentElement) {
      notification.remove();
    }
  }, 5000);
}

// Initialize when DOM is loaded
document.addEventListener('DOMContentLoaded', function() {
  // Set up password validation for all forms
  setupPasswordValidation();
  
  // Check authentication state
  checkAuthState();
  
  // Check for URL parameters to show specific messages
  const urlParams = new URLSearchParams(window.location.search);
  const message = urlParams.get('message');
  
  if (message === 'verify_email') {
    showNotification("Please check your email to verify your account before logging in", "info");
  } else if (message === 'reset_email_sent') {
    showNotification("Password reset email sent. Please check your inbox.", "success");
  }
  
  // Add event listeners to forms to prevent default submission
  const forms = document.querySelectorAll('form');
  forms.forEach(form => {
    form.addEventListener('submit', function(e) {
      e.preventDefault();
    });
  });
});

// Real-time password validation feedback
function setupPasswordValidation() {
  const passwordInputs = document.querySelectorAll('input[type="password"]');
  
  passwordInputs.forEach(input => {
    input.addEventListener('input', function() {
      const validation = validatePassword(this.value);
      const feedbackElement = document.getElementById(`${this.id}-feedback`);
      
      if (feedbackElement) {
        let feedbackHTML = '';
        
        if (this.value.length > 0) {
          feedbackHTML = `
            <div class="password-feedback">
              <div class="requirement ${validation.minLength ? 'valid' : 'invalid'}">
                <i class="fas ${validation.minLength ? 'fa-check-circle' : 'fa-times-circle'}"></i>
                At least 10 characters
              </div>
              <div class="requirement ${validation.hasUpperCase ? 'valid' : 'invalid'}">
                <i class="fas ${validation.hasUpperCase ? 'fa-check-circle' : 'fa-times-circle'}"></i>
                Uppercase letter
              </div>
              <div class="requirement ${validation.hasLowerCase ? 'valid' : 'invalid'}">
                <i class="fas ${validation.hasLowerCase ? 'fa-check-circle' : 'fa-times-circle'}"></i>
                Lowercase letter
              </div>
              <div class="requirement ${validation.hasNumbers ? 'valid' : 'invalid'}">
                <i class="fas ${validation.hasNumbers ? 'fa-check-circle' : 'fa-times-circle'}"></i>
                Number
              </div>
              <div class="requirement ${validation.hasSpecialChar ? 'valid' : 'invalid'}">
                <i class="fas ${validation.hasSpecialChar ? 'fa-check-circle' : 'fa-times-circle'}"></i>
                Special character
              </div>
            </div>
          `;
        }
        
        feedbackElement.innerHTML = feedbackHTML;
      }
      
      // Enable/disable submit button based on validation
      const form = this.closest('form');
      if (form) {
        const submitButton = form.querySelector('button[type="submit"]');
        if (submitButton && submitButton.id !== 'login-button') {
          submitButton.disabled = !validation.isValid;
        }
      }
    });
  });
}