document.addEventListener('DOMContentLoaded', () => {
    const uploadInput = document.getElementById('image-upload');
    const uploadButton = document.getElementById('upload-button');
    const uploadDropzone = document.getElementById('upload-dropzone');
    const uploadedPreviews = document.getElementById('uploaded-previews');
    const imageSpots = Array.from(document.querySelectorAll('.image-spot'));
    const textPrompt = document.getElementById('text-prompt');
    const remixButton = document.getElementById('remix-button');
    const statusMessage = document.getElementById('status-message');
    const remixResult = document.getElementById('remix-result');
    const resultImage = document.getElementById('result-image');
    const resultPlaceholder = document.getElementById('result-placeholder');

    // Store base64 data for images in spots
    const imageSpotData = Array(3).fill(null);
    // Store original draggable elements created from uploaded images
    const draggableImages = new Map(); // Map<id, {element, src}>

    let uploadedImageCounter = 0;

    // --- Utility Functions ---
    const showStatus = (message, type = 'loading') => {
        statusMessage.textContent = message;
        statusMessage.className = `status-message ${type}`;
        statusMessage.style.display = 'block';
    };

    const hideStatus = () => {
        statusMessage.style.display = 'none';
        statusMessage.textContent = '';
    };

    const clearResult = () => {
        resultImage.style.display = 'none';
        resultImage.src = '';
        resultPlaceholder.style.display = 'block';
    };

    // --- File Upload Logic ---
    uploadButton.addEventListener('click', () => uploadInput.click());

    uploadInput.addEventListener('change', (event) => {
        handleFiles(event.target.files);
    });

    uploadDropzone.addEventListener('dragover', (event) => {
        event.preventDefault();
        uploadDropzone.classList.add('drag-over');
    });

    uploadDropzone.addEventListener('dragleave', () => {
        uploadDropzone.classList.remove('drag-over');
    });

    uploadDropzone.addEventListener('drop', (event) => {
        event.preventDefault();
        uploadDropzone.classList.remove('drag-over');
        handleFiles(event.dataTransfer.files);
    });

    function handleFiles(files) {
        if (files.length === 0) return;

        Array.from(files).forEach(file => {
            if (!file.type.startsWith('image/')) return;

            const reader = new FileReader();
            reader.onload = (e) => {
                const imgId = `uploaded-img-${uploadedImageCounter++}`;
                createDraggableImage(e.target.result, imgId);
            };
            reader.readAsDataURL(file);
        });
    }

    function createDraggableImage(src, id) {
        const wrapper = document.createElement('div');
        wrapper.className = 'uploaded-image-wrapper';
        wrapper.draggable = true;
        wrapper.id = id;

        const img = document.createElement('img');
        img.src = src;
        img.alt = `Uploaded image ${id}`;

        const removeBtn = document.createElement('button');
        removeBtn.className = 'remove-image';
        removeBtn.textContent = 'x';
        removeBtn.title = 'Remove image';
        removeBtn.addEventListener('click', (e) => {
            e.stopPropagation(); // Prevent drag event from firing
            wrapper.remove();
            draggableImages.delete(id);
            // Also check if this image was in any spot and remove it
            for (let i = 0; i < imageSpotData.length; i++) {
                if (imageSpotData[i] && imageSpotData[i].id === id) {
                    clearImageSpot(imageSpots[i], i);
                }
            }
        });

        wrapper.appendChild(img);
        wrapper.appendChild(removeBtn);
        uploadedPreviews.appendChild(wrapper);

        draggableImages.set(id, { element: wrapper, src: src });

        wrapper.addEventListener('dragstart', (e) => {
            e.dataTransfer.setData('text/plain', id);
            e.dataTransfer.effectAllowed = 'copyMove';
            // Optional: add a class to the original to make it transparent or similar
            // e.target.classList.add('dragging');
        });

        // wrapper.addEventListener('dragend', (e) => {
        //     e.target.classList.remove('dragging');
        // });
    }

    // --- Image Spot Drag & Drop Logic ---
    imageSpots.forEach((spot) => {
        spot.addEventListener('dragover', (event) => {
            event.preventDefault();
            spot.classList.add('drag-over');
            event.dataTransfer.dropEffect = 'copy';
        });

        spot.addEventListener('dragleave', () => {
            spot.classList.remove('drag-over');
        });

        spot.addEventListener('drop', (event) => {
            event.preventDefault();
            spot.classList.remove('drag-over');
            const draggedId = event.dataTransfer.getData('text/plain');
            const draggedImageData = draggableImages.get(draggedId);

            if (draggedImageData) {
                const spotIndex = parseInt(spot.dataset.index);
                renderImageInSpot(spot, draggedImageData.src);
                imageSpotData[spotIndex] = { src: draggedImageData.src, id: draggedId };
            }
        });
    });

    function renderImageInSpot(spotElement, imgSrc) {
        const imgElement = spotElement.querySelector('.spot-image');
        imgElement.src = imgSrc;
        spotElement.classList.add('has-image');
        imgElement.alt = `Image in spot ${spotElement.dataset.index + 1}`;
        // Remove old image's alt if it exists and wasn't placeholder.
    }

    function clearImageSpot(spotElement, spotIndex) {
        const imgElement = spotElement.querySelector('.spot-image');
        imgElement.src = 'assets/img/placeholder.png'; // Reset to placeholder
        spotElement.classList.remove('has-image');
        imgElement.alt = `Image spot ${spotIndex + 1}`;
        imageSpotData[spotIndex] = null;
    }

    // --- Remix Logic ---
    remixButton.addEventListener('click', remixImages);

    async function remixImages() {
        hideStatus();
        clearResult();

        const images = imageSpotData.filter(data => data !== null);
        const prompt = textPrompt.value.trim();
        const selectedModel = document.querySelector('input[name="ai-model"]:checked').value;

        if (images.length === 0) {
            showStatus('Please drag at least one image into a spot.', 'error');
            return;
        }

        if (!prompt) {
            showStatus('Please enter a text prompt.', 'error');
            return;
        }

        showStatus(`Remixing with ${selectedModel}... This is a simulation.`, 'loading');

        try {
            // Simulate API call
            await new Promise(resolve => setTimeout(resolve, 3000)); // Simulate network delay

            // In a real application, you would send `images` (base64 or URLs), `prompt`, and `selectedModel`
            // to a backend API that integrates with Gemini-2 or GPT Image-1.
            // The backend would then return the generated image's URL or base64.

            // For simulation, we'll use a placeholder image based on the model
            const placeholderResult = selectedModel === 'gemini-2'
                ? 'https://picsum.photos/seed/gemini/800/600?grayscale' // A bit more abstract
                : 'https://picsum.photos/seed/gpt/800/600'; // Standard realistic

            resultImage.src = placeholderResult;
            resultImage.style.display = 'block';
            resultPlaceholder.style.display = 'none';
            showStatus('Remix successful! (Simulated)', 'success');
            statusMessage.style.backgroundColor = '#d4edda'; // Light green for success
            statusMessage.style.color = '#155724';
            statusMessage.style.borderColor = '#28a745';

        } catch (error) {
            console.error('Remix error (simulated):', error);
            showStatus('Failed to remix images. Please try again. (Simulated Error)', 'error');
        }
    }
});

// Initial state for result section
document.addEventListener('DOMContentLoaded', () => {
    const resultImage = document.getElementById('result-image');
    const resultPlaceholder = document.getElementById('result-placeholder');
    resultImage.style.display = 'none';
    resultPlaceholder.style.display = 'block';
});