import { removeBackground } from "https://cdn.jsdelivr.net/npm/@imgly/background-removal@1.0.0/dist/index.mjs";

document.addEventListener('DOMContentLoaded', () => {
    const dropArea = document.getElementById('drop-area');
    const fileInput = document.getElementById('file-input');
    const browseBtn = document.getElementById('browse-btn');
    const uploadUI = document.getElementById('upload-ui');
    const processingUI = document.getElementById('processing-ui');
    const originalImage = document.getElementById('original-image');
    const resultImage = document.getElementById('result-image');
    const downloadBtn = document.getElementById('download-btn');
    const downloadSection = document.getElementById('download-section');
    const progressText = document.getElementById('progress-text');
    const progressBar = document.getElementById('progress-bar');
    const firstRunNotice = document.getElementById('first-run-notice');
    let isFirstRun = true;
    let processing = false;
    let currentFile = null;
// Prevent default drag behaviors
    ['dragenter', 'dragover', 'dragleave', 'drop'].forEach(eventName => {
        dropArea.addEventListener(eventName, preventDefaults, false);
    });

    function preventDefaults(e) {
        e.preventDefault();
        e.stopPropagation();
    }

    // Highlight drop area when item is dragged over it
    ['dragenter', 'dragover'].forEach(eventName => {
        dropArea.addEventListener(eventName, highlight, false);
    });

    ['dragleave', 'drop'].forEach(eventName => {
        dropArea.addEventListener(eventName, unhighlight, false);
    });

    function highlight() {
        dropArea.classList.add('highlight');
    }

    function unhighlight() {
        dropArea.classList.remove('highlight');
    }

    // Handle dropped files
    dropArea.addEventListener('drop', handleDrop, false);

    function handleDrop(e) {
        const dt = e.dataTransfer;
        const files = dt.files;
        if (files.length && !processing) {
            handleFiles(files);
        }
    }

    // Handle file input
    fileInput.addEventListener('change', function() {
        if (this.files.length && !processing) {
            handleFiles(this.files);
        }
    });

    // Browse button click
    browseBtn.addEventListener('click', () => {
        fileInput.click();
    });

    // Handle file processing
    async function handleFiles(files) {
        const file = files[0];
        if (!file.type.match('image.*')) {
            alert('Please select an image file');
            return;
        }

        currentFile = file;
        processing = true;
        
        // Show original image
        const reader = new FileReader();
        reader.onload = function(e) {
            originalImage.src = e.target.result;
            originalImage.classList.remove('hidden');
        };
        reader.readAsDataURL(file);

        // Show processing UI
        uploadUI.classList.add('hidden');
        processingUI.classList.remove('hidden');
        
        if (isFirstRun) {
            progressText.textContent = 'Loading models for the first time (20-40MB)...';
            progressBar.style.width = '10%';
        } else {
            progressText.textContent = 'Processing image...';
            progressBar.style.width = '30%';
        }

        try {
            // Initialize the background removal
            const blobURL = URL.createObjectURL(file);
            // Revoke the blob URL after use to prevent memory leaks
            setTimeout(() => URL.revokeObjectURL(blobURL), 1000);
const progressCallback = (progress) => {
                const percent = Math.floor(progress * 100);
                progressBar.style.width = `${percent}%`;
                
                if (isFirstRun) {
                    if (progress < 0.9) {
                        progressText.textContent = `Downloading models... ${percent}%`;
                    } else {
                        progressText.textContent = 'Processing image...';
                    }
                } else {
                    progressText.textContent = `Processing... ${percent}%`;
                }
            };
            // Convert file to Blob URL
            const blob = await fetch(blobURL).then(r => r.blob());
            // Use the imported removeBackground function
            const result = await removeBackground(blob, {
                progress: progressCallback,
                publicPath: 'https://cdn.jsdelivr.net/npm/@imgly/background-removal@1.0.0/dist/',  // Required for loading models
                debug: true
            });
// Convert Blob to URL for display
            // Convert result to PNG if it's not already
            const pngBlob = await result.convertToBlob('image/png');
            const resultURL = URL.createObjectURL(pngBlob);
// Display result
            resultImage.src = resultURL;
            resultImage.classList.remove('hidden');
            
            // Enable download button
            downloadBtn.onclick = function() {
                const a = document.createElement('a');
                a.href = resultURL;
                a.download = `background-removed-${file.name}`;
                document.body.appendChild(a);
                a.click();
                document.body.removeChild(a);
                setTimeout(() => URL.revokeObjectURL(resultURL), 100);
            };
            
            downloadSection.classList.remove('hidden');
            
            // Reset UI
            processing = false;
            uploadUI.classList.remove('hidden');
            processingUI.classList.add('hidden');
            if (isFirstRun) {
                isFirstRun = false;
                firstRunNotice.classList.add('hidden');
            }
} catch (error) {
            console.error('Error during background removal:', error);
            
            // Show error message
            progressText.textContent = `Error: ${error.message || 'Failed to process image'}`;
            progressBar.style.width = '0%';
            progressBar.classList.add('bg-red-500');
            
            // Show retry button
            const retryBtn = document.createElement('button');
            retryBtn.className = 'bg-primary-500 hover:bg-primary-600 text-white font-medium py-2 px-6 rounded-lg transition-colors duration-200 mt-4';
            retryBtn.textContent = 'Try Again';
            retryBtn.onclick = () => {
                if (currentFile) {
                    handleFiles([currentFile]);
                }
            };
            
            processingUI.querySelector('.flex').appendChild(retryBtn);
            
            setTimeout(() => {
                // Reset UI if user doesn't retry
                processing = false;
                uploadUI.classList.remove('hidden');
                processingUI.classList.add('hidden');
                progressBar.classList.remove('bg-red-500');
                if (processingUI.contains(retryBtn)) {
                    processingUI.querySelector('.flex').removeChild(retryBtn);
                }
            }, 8000);
        }
}
});