/**
 * Firebase Service - Handle data persistence and authentication
 */

import { initializeApp } from 'https://www.gstatic.com/firebasejs/10.7.1/firebase-app.js';
import { getFirestore, collection, addDoc, serverTimestamp } from 'https://www.gstatic.com/firebasejs/10.7.1/firebase-firestore.js';
import { getAuth, signInWithEmailAndPassword, signInWithPopup, GoogleAuthProvider, signOut, onAuthStateChanged } from 'https://www.gstatic.com/firebasejs/10.7.1/firebase-auth.js';

// Firebase configuration
const firebaseConfig = {
    apiKey: "AIzaSyAYbKEaWT99sDO7bUC76LcXKDRK3BBMZ00",
    authDomain: "embryo-one.firebaseapp.com",
    projectId: "embryo-one",
    storageBucket: "embryo-one.firebasestorage.app",
    messagingSenderId: "23510355257",
    appId: "1:23510355257:web:0ae7edce822704820f6ce8",
    measurementId: "G-140V7Z1GRK"
};

// Initialize Firebase
let app;
let db;
let auth;

try {
    app = initializeApp(firebaseConfig);
    db = getFirestore(app);
    auth = getAuth(app);
    console.log('Firebase initialized successfully');
} catch (error) {
    console.error('Firebase initialization error:', error);
}

/**
 * Save embryo grading results to Firebase
 * @param {Object} resultData - The grading result data
 * @returns {Promise<string>} - Document ID
 */
export async function saveGradingResults(resultData) {
    try {
        const docRef = await addDoc(collection(db, 'embryo_gradings'), {
            ...resultData,
            createdAt: serverTimestamp()
        });
        
        console.log('Results saved with ID:', docRef.id);
        return docRef.id;
    } catch (error) {
        console.error('Error saving results:', error);
        throw error;
    }
}

/**
 * Prepare embryo data for saving
 * @param {Array} embryos - Array of embryo objects
 * @param {string} mainImageUrl - URL of the main uploaded image
 * @param {Array} results - Array of evaluation results
 * @param {Object} remarks - Object mapping index to remarks
 * @returns {Object} - Formatted data for Firebase
 */
export function prepareEmbryoData(embryos, mainImageUrl, results = [], remarks = {}) {
    console.log('Preparing embryo data for Firebase:');
    console.log('- Embryos count:', embryos.length);
    console.log('- Results count:', results.length);
    console.log('- Remarks:', remarks);
    
    return {
        mainImage: mainImageUrl,
        embryos: embryos.map((embryo, index) => {
            // Get result for this embryo
            const resultData = results[index];
            const result = resultData?.result;
            
            const embryoData = {
                embryoNumber: index + 1,
                croppedImage: embryo.imageData,
                predictedGrade: result?.grade || embryo.grade || 'Unknown',
                actualGrade: embryo.actualGrade || '',
                quality: result?.quality || embryo.quality || 'Unknown',
                confidence: result?.confidence || embryo.confidence || 0,
                poorGoodConfidence: result?.poorGoodConfidence || 0,
                remarks: remarks[index] || embryo.remarks || '',
                isManual: embryo.isManual || false,
                detectionConfidence: embryo.confidence || 0
            };
            
            console.log(`Embryo ${index + 1} data:`, {
                grade: embryoData.predictedGrade,
                quality: embryoData.quality,
                remarks: embryoData.remarks
            });
            
            return embryoData;
        }),
        totalEmbryos: embryos.length,
        timestamp: new Date().toISOString()
    };
}

/**
 * Check if Firebase is initialized
 * @returns {boolean}
 */
export function isFirebaseReady() {
    return db !== null && db !== undefined && auth !== null && auth !== undefined;
}

/**
 * Authentication Functions
 */

/**
 * Sign in with email and password
 * @param {string} email - User email
 * @param {string} password - User password
 * @returns {Promise<Object>} - User credential
 */
export async function signIn(email, password) {
    try {
        const userCredential = await signInWithEmailAndPassword(auth, email, password);
        console.log('User signed in:', userCredential.user.email);
        return userCredential;
    } catch (error) {
        console.error('Sign in error:', error);
        throw error;
    }
}

/**
 * Sign in with Google
 * @returns {Promise<Object>} - User credential
 */
export async function signInWithGoogle() {
    try {
        const provider = new GoogleAuthProvider();
        provider.setCustomParameters({
            prompt: 'select_account'
        });
        const userCredential = await signInWithPopup(auth, provider);
        console.log('User signed in with Google:', userCredential.user.email);
        return userCredential;
    } catch (error) {
        console.error('Google sign in error:', error);
        throw error;
    }
}

/**
 * Sign out current user
 * @returns {Promise<void>}
 */
export async function signOutUser() {
    try {
        await signOut(auth);
        console.log('User signed out');
    } catch (error) {
        console.error('Sign out error:', error);
        throw error;
    }
}

/**
 * Get current user
 * @returns {Object|null} - Current user or null
 */
export function getCurrentUser() {
    return auth?.currentUser || null;
}

/**
 * Listen to authentication state changes
 * @param {Function} callback - Callback function to execute on auth state change
 * @returns {Function} - Unsubscribe function
 */
export function onAuthChange(callback) {
    if (!auth) {
        console.error('Auth not initialized');
        return () => {};
    }
    return onAuthStateChanged(auth, callback);
}