import { appState } from '../state.js';
import { DETECTION_CONFIG } from '../config.js';
import { loadImage } from '../utils/imageUtils.js';

let cropState = {
    originalBox: null,
    currentBox: null,
    isDragging: false,
    isResizing: false,
    resizeHandle: null,
    dragStartX: 0,
    dragStartY: 0,
    imageWidth: 0,
    imageHeight: 0,
    loadedImage: null,
    canvas: null,
    scale: 1
};

export function initializeCropEditor() {
    const editCropBtn = document.getElementById('editCropBtn');
    const applyCropBtn = document.getElementById('applyCropBtn');
    const resetCropBtn = document.getElementById('resetCropBtn');
    const cropControls = document.getElementById('cropControls');

    if (editCropBtn) {
        editCropBtn.addEventListener('click', () => {
            showManualCropEditor();
        });
    }

    if (resetCropBtn) {
        resetCropBtn.addEventListener('click', () => {
            resetCropBox();
        });
    }

    if (applyCropBtn) {
        applyCropBtn.addEventListener('click', () => {
            applyCropSettings();
            hideManualCropEditor();
        });
    }
}

export function showCropEditor(embryoIndex) {
    const editCropBtn = document.getElementById('editCropBtn');
    const cropControls = document.getElementById('cropControls');
    const embryo = appState.croppedEmbryos[embryoIndex];
    
    if (!embryo || !embryo.box) {
        editCropBtn.style.display = 'none';
        if (cropControls) cropControls.style.display = 'none';
        return;
    }

    // Store original box coordinates
    cropState.originalBox = { ...embryo.box };
    cropState.currentBox = { ...embryo.box };

    editCropBtn.style.display = 'block';
    
    // Always hide crop controls when switching embryos
    if (cropControls) cropControls.style.display = 'none';
    
    // Reset the display to show the image, not the canvas
    const croppedImage = document.getElementById('croppedImage');
    if (croppedImage) croppedImage.style.display = 'block';
    
    // Hide crop canvas if exists
    const cropCanvas = document.getElementById('manualCropCanvas');
    if (cropCanvas) cropCanvas.style.display = 'none';
}

export function hideCropEditor() {
    const editCropBtn = document.getElementById('editCropBtn');
    const cropControls = document.getElementById('cropControls');
    editCropBtn.style.display = 'none';
    cropControls.style.display = 'none';
    hideManualCropEditor();
}

function showManualCropEditor() {
    const cropControls = document.getElementById('cropControls');
    const editCropBtn = document.getElementById('editCropBtn');
    
    cropControls.style.display = 'block';
    editCropBtn.style.display = 'none';
    
    // Show touch hint on touch devices
    const touchHint = document.querySelector('.touch-hint');
    const isTouchDevice = 'ontouchstart' in window || navigator.maxTouchPoints > 0;
    if (touchHint && isTouchDevice) {
        touchHint.style.display = 'block';
    }
    
    // Initialize the interactive crop canvas
    initializeInteractiveCrop();
}

function hideManualCropEditor() {
    const cropControls = document.getElementById('cropControls');
    const editCropBtn = document.getElementById('editCropBtn');
    const cropCanvas = document.getElementById('manualCropCanvas');
    const croppedImage = document.getElementById('croppedImage');
    
    cropControls.style.display = 'none';
    editCropBtn.style.display = 'block';
    
    if (cropCanvas) cropCanvas.style.display = 'none';
    if (croppedImage) croppedImage.style.display = 'block';
}

async function initializeInteractiveCrop() {
    if (!appState.currentImage || !cropState.originalBox) {
        console.error('Missing image or box data');
        return;
    }
    
    const container = document.getElementById('croppedImagePreview');
    const croppedImage = document.getElementById('croppedImage');
    
    if (!container) {
        console.error('Container not found');
        return;
    }
    
    // Hide the static image
    if (croppedImage) croppedImage.style.display = 'none';
    
    // Create or get canvas
    let canvas = document.getElementById('manualCropCanvas');
    if (!canvas) {
        canvas = document.createElement('canvas');
        canvas.id = 'manualCropCanvas';
        canvas.className = 'manual-crop-canvas';
        container.appendChild(canvas);
    }
    
    canvas.style.display = 'block';
    
    try {
        // Load the original full image
        const img = await loadImage(appState.currentImage);
        
        // Store the image in cropState for redraws
        cropState.loadedImage = img;
        
        // Set canvas size to fit container while maintaining aspect ratio
        const containerWidth = Math.max(container.clientWidth - 40, 300);
        const containerHeight = 400;
        const scale = Math.min(containerWidth / img.width, containerHeight / img.height, 1);
        
        canvas.width = Math.floor(img.width * scale);
        canvas.height = Math.floor(img.height * scale);
        cropState.imageWidth = canvas.width;
        cropState.imageHeight = canvas.height;
        cropState.scale = scale;
        
        console.log('Crop editor initialized:', {
            imageSize: `${img.width}x${img.height}`,
            canvasSize: `${canvas.width}x${canvas.height}`,
            scale: scale,
            originalBox: cropState.originalBox
        });
        
        // Scale the crop box coordinates
        cropState.currentBox = {
            x1: Math.floor(cropState.originalBox.x1 * scale),
            y1: Math.floor(cropState.originalBox.y1 * scale),
            x2: Math.floor(cropState.originalBox.x2 * scale),
            y2: Math.floor(cropState.originalBox.y2 * scale)
        };
        
        console.log('Scaled crop box:', cropState.currentBox);
        
        // Draw initial state
        drawCropInterface(canvas);
        
        // Add event listeners
        setupCanvasEventListeners(canvas);
    } catch (error) {
        console.error('Error initializing crop editor:', error);
    }
}

function drawCropInterface(canvas) {
    if (!canvas || !cropState.loadedImage || !cropState.currentBox) {
        console.error('Canvas, image, or crop box not available', {
            canvas: !!canvas,
            image: !!cropState.loadedImage,
            box: !!cropState.currentBox
        });
        return;
    }
    
    const ctx = canvas.getContext('2d');
    const img = cropState.loadedImage;
    
    // Clear canvas
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    
    // Draw the full image
    ctx.drawImage(img, 0, 0, canvas.width, canvas.height);
    
    // Ensure crop box is within bounds
    const box = cropState.currentBox;
    const x1 = Math.max(0, Math.min(box.x1, canvas.width));
    const y1 = Math.max(0, Math.min(box.y1, canvas.height));
    const x2 = Math.max(0, Math.min(box.x2, canvas.width));
    const y2 = Math.max(0, Math.min(box.y2, canvas.height));
    
    // Draw dark overlay outside crop box
    ctx.fillStyle = 'rgba(0, 0, 0, 0.5)';
    
    // Top
    ctx.fillRect(0, 0, canvas.width, y1);
    // Bottom
    ctx.fillRect(0, y2, canvas.width, canvas.height - y2);
    // Left
    ctx.fillRect(0, y1, x1, y2 - y1);
    // Right
    ctx.fillRect(x2, y1, canvas.width - x2, y2 - y1);
    
    // Draw crop box border
    ctx.strokeStyle = '#00B8D4';
    ctx.lineWidth = 3;
    ctx.strokeRect(
        x1,
        y1,
        x2 - x1,
        y2 - y1
    );
    
    // Determine if touch device (larger handles for touch)
    const isTouchDevice = 'ontouchstart' in window || navigator.maxTouchPoints > 0;
    const handleSize = isTouchDevice ? 20 : 12;
    
    // Draw resize handles with white border for better visibility
    ctx.fillStyle = '#00B8D4';
    ctx.strokeStyle = 'white';
    ctx.lineWidth = 2;
    
    // Corner handles
    const corners = [
        { x: x1, y: y1 },
        { x: x2, y: y1 },
        { x: x1, y: y2 },
        { x: x2, y: y2 }
    ];
    
    corners.forEach(corner => {
        ctx.fillRect(corner.x - handleSize / 2, corner.y - handleSize / 2, handleSize, handleSize);
        ctx.strokeRect(corner.x - handleSize / 2, corner.y - handleSize / 2, handleSize, handleSize);
    });
    
    // Edge handles
    const edges = [
        { x: (x1 + x2) / 2, y: y1 },
        { x: (x1 + x2) / 2, y: y2 },
        { x: x1, y: (y1 + y2) / 2 },
        { x: x2, y: (y1 + y2) / 2 }
    ];
    
    edges.forEach(edge => {
        ctx.fillRect(edge.x - handleSize / 2, edge.y - handleSize / 2, handleSize, handleSize);
        ctx.strokeRect(edge.x - handleSize / 2, edge.y - handleSize / 2, handleSize, handleSize);
    });
    
    // Draw center move icon (larger for touch)
    const centerX = (x1 + x2) / 2;
    const centerY = (y1 + y2) / 2;
    const centerRadius = isTouchDevice ? 20 : 15;
    ctx.fillStyle = 'rgba(0, 184, 212, 0.3)';
    ctx.beginPath();
    ctx.arc(centerX, centerY, centerRadius, 0, Math.PI * 2);
    ctx.fill();
    
    // Draw crosshair in center
    ctx.strokeStyle = 'white';
    ctx.lineWidth = 2;
    const crosshairSize = isTouchDevice ? 10 : 8;
    ctx.beginPath();
    ctx.moveTo(centerX - crosshairSize, centerY);
    ctx.lineTo(centerX + crosshairSize, centerY);
    ctx.moveTo(centerX, centerY - crosshairSize);
    ctx.lineTo(centerX, centerY + crosshairSize);
    ctx.stroke();
}

function setupCanvasEventListeners(canvas) {
    // Store canvas reference
    cropState.canvas = canvas;
    
    // Mouse events
    canvas.addEventListener('mousedown', handleMouseDown);
    canvas.addEventListener('mousemove', handleMouseMove);
    canvas.addEventListener('mouseup', handleMouseUp);
    canvas.addEventListener('mouseleave', handleMouseUp);
    
    // Touch events for mobile/tablet support
    canvas.addEventListener('touchstart', handleTouchStart, { passive: false });
    canvas.addEventListener('touchmove', handleTouchMove, { passive: false });
    canvas.addEventListener('touchend', handleTouchEnd, { passive: false });
    canvas.addEventListener('touchcancel', handleTouchEnd, { passive: false });
}

function handleMouseDown(e) {
    const canvas = e.target;
    const rect = canvas.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const y = e.clientY - rect.top;
    
    // Check if clicking on a resize handle
    const handle = getResizeHandle(x, y);
    if (handle) {
        cropState.isResizing = true;
        cropState.resizeHandle = handle;
        cropState.dragStartX = x;
        cropState.dragStartY = y;
        e.preventDefault();
        return;
    }
    
    // Check if clicking inside crop box for dragging
    if (isInsideCropBox(x, y)) {
        cropState.isDragging = true;
        cropState.dragStartX = x;
        cropState.dragStartY = y;
        e.preventDefault();
    }
}

function handleMouseMove(e) {
    const canvas = e.target;
    const rect = canvas.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const y = e.clientY - rect.top;
    
    // Update cursor
    if (!cropState.isDragging && !cropState.isResizing) {
        const handle = getResizeHandle(x, y);
        if (handle) {
            canvas.style.cursor = getCursorStyle(handle);
        } else if (isInsideCropBox(x, y)) {
            canvas.style.cursor = 'move';
        } else {
            canvas.style.cursor = 'default';
        }
    }
    
    if (cropState.isResizing) {
        handleResize(x, y);
        drawCropInterface(canvas);
        e.preventDefault();
    } else if (cropState.isDragging) {
        handleDrag(x, y);
        drawCropInterface(canvas);
        e.preventDefault();
    }
}

function handleMouseUp(e) {
    cropState.isDragging = false;
    cropState.isResizing = false;
    cropState.resizeHandle = null;
}

// Touch event handlers
function handleTouchStart(e) {
    // Only handle single touch
    if (e.touches.length !== 1) return;
    
    e.preventDefault(); // Prevent scrolling
    
    const canvas = e.target;
    const rect = canvas.getBoundingClientRect();
    const touch = e.touches[0];
    const x = touch.clientX - rect.left;
    const y = touch.clientY - rect.top;
    
    // Check if touching a resize handle (increased threshold for touch)
    const handle = getResizeHandle(x, y, true);
    if (handle) {
        cropState.isResizing = true;
        cropState.resizeHandle = handle;
        cropState.dragStartX = x;
        cropState.dragStartY = y;
        return;
    }
    
    // Check if touching inside crop box for dragging
    if (isInsideCropBox(x, y)) {
        cropState.isDragging = true;
        cropState.dragStartX = x;
        cropState.dragStartY = y;
    }
}

function handleTouchMove(e) {
    // Only handle single touch
    if (e.touches.length !== 1) return;
    
    // Prevent scrolling while manipulating crop box
    if (cropState.isDragging || cropState.isResizing) {
        e.preventDefault();
    }
    
    const canvas = e.target;
    const rect = canvas.getBoundingClientRect();
    const touch = e.touches[0];
    const x = touch.clientX - rect.left;
    const y = touch.clientY - rect.top;
    
    if (cropState.isResizing) {
        handleResize(x, y);
        drawCropInterface(canvas);
    } else if (cropState.isDragging) {
        handleDrag(x, y);
        drawCropInterface(canvas);
    }
}

function handleTouchEnd(e) {
    e.preventDefault();
    cropState.isDragging = false;
    cropState.isResizing = false;
    cropState.resizeHandle = null;
}

function getResizeHandle(x, y, isTouch = false) {
    // Larger threshold for touch screens
    const threshold = isTouch ? 25 : 15;
    
    // Corner handles
    if (Math.abs(x - cropState.currentBox.x1) < threshold && Math.abs(y - cropState.currentBox.y1) < threshold) return 'nw';
    if (Math.abs(x - cropState.currentBox.x2) < threshold && Math.abs(y - cropState.currentBox.y1) < threshold) return 'ne';
    if (Math.abs(x - cropState.currentBox.x1) < threshold && Math.abs(y - cropState.currentBox.y2) < threshold) return 'sw';
    if (Math.abs(x - cropState.currentBox.x2) < threshold && Math.abs(y - cropState.currentBox.y2) < threshold) return 'se';
    
    // Edge handles
    const centerX = (cropState.currentBox.x1 + cropState.currentBox.x2) / 2;
    const centerY = (cropState.currentBox.y1 + cropState.currentBox.y2) / 2;
    
    if (Math.abs(x - centerX) < threshold && Math.abs(y - cropState.currentBox.y1) < threshold) return 'n';
    if (Math.abs(x - centerX) < threshold && Math.abs(y - cropState.currentBox.y2) < threshold) return 's';
    if (Math.abs(x - cropState.currentBox.x1) < threshold && Math.abs(y - centerY) < threshold) return 'w';
    if (Math.abs(x - cropState.currentBox.x2) < threshold && Math.abs(y - centerY) < threshold) return 'e';
    
    return null;
}

function getCursorStyle(handle) {
    const cursors = {
        'nw': 'nw-resize',
        'ne': 'ne-resize',
        'sw': 'sw-resize',
        'se': 'se-resize',
        'n': 'n-resize',
        's': 's-resize',
        'w': 'w-resize',
        'e': 'e-resize'
    };
    return cursors[handle] || 'default';
}

function isInsideCropBox(x, y) {
    return x >= cropState.currentBox.x1 && x <= cropState.currentBox.x2 &&
           y >= cropState.currentBox.y1 && y <= cropState.currentBox.y2;
}

function handleResize(x, y) {
    const minSize = 50;
    
    switch (cropState.resizeHandle) {
        case 'nw':
            cropState.currentBox.x1 = Math.max(0, Math.min(x, cropState.currentBox.x2 - minSize));
            cropState.currentBox.y1 = Math.max(0, Math.min(y, cropState.currentBox.y2 - minSize));
            break;
        case 'ne':
            cropState.currentBox.x2 = Math.min(cropState.imageWidth, Math.max(x, cropState.currentBox.x1 + minSize));
            cropState.currentBox.y1 = Math.max(0, Math.min(y, cropState.currentBox.y2 - minSize));
            break;
        case 'sw':
            cropState.currentBox.x1 = Math.max(0, Math.min(x, cropState.currentBox.x2 - minSize));
            cropState.currentBox.y2 = Math.min(cropState.imageHeight, Math.max(y, cropState.currentBox.y1 + minSize));
            break;
        case 'se':
            cropState.currentBox.x2 = Math.min(cropState.imageWidth, Math.max(x, cropState.currentBox.x1 + minSize));
            cropState.currentBox.y2 = Math.min(cropState.imageHeight, Math.max(y, cropState.currentBox.y1 + minSize));
            break;
        case 'n':
            cropState.currentBox.y1 = Math.max(0, Math.min(y, cropState.currentBox.y2 - minSize));
            break;
        case 's':
            cropState.currentBox.y2 = Math.min(cropState.imageHeight, Math.max(y, cropState.currentBox.y1 + minSize));
            break;
        case 'w':
            cropState.currentBox.x1 = Math.max(0, Math.min(x, cropState.currentBox.x2 - minSize));
            break;
        case 'e':
            cropState.currentBox.x2 = Math.min(cropState.imageWidth, Math.max(x, cropState.currentBox.x1 + minSize));
            break;
    }
}

function handleDrag(x, y) {
    const dx = x - cropState.dragStartX;
    const dy = y - cropState.dragStartY;
    
    const boxWidth = cropState.currentBox.x2 - cropState.currentBox.x1;
    const boxHeight = cropState.currentBox.y2 - cropState.currentBox.y1;
    
    let newX1 = cropState.currentBox.x1 + dx;
    let newY1 = cropState.currentBox.y1 + dy;
    
    // Clamp to image bounds
    if (newX1 < 0) newX1 = 0;
    if (newY1 < 0) newY1 = 0;
    if (newX1 + boxWidth > cropState.imageWidth) newX1 = cropState.imageWidth - boxWidth;
    if (newY1 + boxHeight > cropState.imageHeight) newY1 = cropState.imageHeight - boxHeight;
    
    cropState.currentBox.x1 = newX1;
    cropState.currentBox.y1 = newY1;
    cropState.currentBox.x2 = newX1 + boxWidth;
    cropState.currentBox.y2 = newY1 + boxHeight;
    
    cropState.dragStartX = x;
    cropState.dragStartY = y;
}

function resetCropBox() {
    if (!cropState.originalBox || !cropState.scale) return;
    
    const canvas = document.getElementById('manualCropCanvas');
    if (!canvas) return;
    
    // Reset to original box with current scale
    cropState.currentBox = {
        x1: cropState.originalBox.x1 * cropState.scale,
        y1: cropState.originalBox.y1 * cropState.scale,
        x2: cropState.originalBox.x2 * cropState.scale,
        y2: cropState.originalBox.y2 * cropState.scale
    };
    
    drawCropInterface(canvas);
}

async function applyCropSettings() {
    if (appState.currentEmbryoIndex === undefined || !cropState.currentBox) return;

    const embryo = appState.croppedEmbryos[appState.currentEmbryoIndex];
    if (!embryo) return;

    // Load original image
    const img = await loadImage(appState.currentImage);
    
    // Convert canvas coordinates back to image coordinates
    const scaleX = img.width / cropState.imageWidth;
    const scaleY = img.height / cropState.imageHeight;
    
    const x1 = cropState.currentBox.x1 * scaleX;
    const y1 = cropState.currentBox.y1 * scaleY;
    const x2 = cropState.currentBox.x2 * scaleX;
    const y2 = cropState.currentBox.y2 * scaleY;
    
    // Crop the image
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    canvas.width = x2 - x1;
    canvas.height = y2 - y1;
    
    ctx.drawImage(img, x1, y1, x2 - x1, y2 - y1, 0, 0, canvas.width, canvas.height);
    
    const croppedImageData = canvas.toDataURL();
    
    // Update the embryo's cropped image
    embryo.imageData = croppedImageData;
    
    // Update the box coordinates
    embryo.box = {
        x1: x1,
        y1: y1,
        x2: x2,
        y2: y2
    };
    
    // Update display
    const croppedImage = document.getElementById('croppedImage');
    if (croppedImage) {
        croppedImage.src = croppedImageData;
        croppedImage.style.display = 'block';
    }
    
    // Update thumbnail
    updateThumbnail(appState.currentEmbryoIndex, croppedImageData);
}

function updateThumbnail(index, imageData) {
    const thumbnail = document.querySelector(`[data-embryo-index="${index}"] img`);
    if (thumbnail) {
        thumbnail.src = imageData;
    }
}