/**
 * Inline Detection View - Show all detected embryos on the main image
 */

import { appState, setCurrentEmbryoIndex, getEmbryoRemark } from '../state.js';
import { loadImage } from '../utils/imageUtils.js';
import { showToast } from './toast.js';
import { showConfirmModal } from './modal.js';

let canvas, ctx;
let selectedEmbryoIndex = null;
let isDragging = false;
let dragType = null; // 'move', 'nw', 'ne', 'sw', 'se', 'n', 's', 'e', 'w'
let dragStart = { x: 0, y: 0 };
let originalBox = null;
let imageElement = null;
let scaleFactor = 1;
let offsetX = 0;
let offsetY = 0;

const HANDLE_SIZE = 10;
const COLORS = [
    '#FF6B6B', '#4ECDC4', '#45B7D1', '#FFA07A', '#98D8C8',
    '#F7DC6F', '#BB8FCE', '#85C1E2', '#F8B739', '#52B788'
];

/**
 * Initialize the inline detection canvas
 */
export async function initializeInlineDetection(imageData, detections) {
    canvas = document.getElementById('detectionCanvas');
    if (!canvas) {
        console.error('Detection canvas not found');
        showToast('Failed to initialize detection view', 'error');
        return;
    }

    ctx = canvas.getContext('2d');
    if (!ctx) {
        console.error('Failed to get canvas context');
        showToast('Canvas not supported', 'error');
        return;
    }
    
    // Load the original image
    imageElement = await loadImage(imageData);
    
    // Set canvas size to match image
    canvas.width = imageElement.width;
    canvas.height = imageElement.height;
    
    // Calculate scale factor for display
    const container = canvas.parentElement;
    if (!container) {
        console.error('Canvas container not found');
        return;
    }
    
    const maxWidth = container.clientWidth - 40;
    const maxHeight = 600;
    
    scaleFactor = Math.min(
        maxWidth / imageElement.width,
        maxHeight / imageElement.height,
        1
    );
    
    canvas.style.width = `${imageElement.width * scaleFactor}px`;
    canvas.style.height = `${imageElement.height * scaleFactor}px`;
    
    // Draw initial view
    drawDetections();
    
    // Add event listeners
    canvas.addEventListener('mousedown', handleMouseDown);
    canvas.addEventListener('mousemove', handleMouseMove);
    canvas.addEventListener('mouseup', handleMouseUp);
    canvas.addEventListener('mouseleave', handleMouseUp);
    
    // Touch events for mobile
    canvas.addEventListener('touchstart', handleTouchStart);
    canvas.addEventListener('touchmove', handleTouchMove);
    canvas.addEventListener('touchend', handleTouchEnd);
    
    // Update embryo list
    updateEmbryoList(detections);
    
    // Setup detection info with manual add button
    const info = document.getElementById('detectionInfo');
    if (info) {
        info.innerHTML = `
            <p>Click on an embryo to adjust its crop area</p>
            <button class="btn btn-secondary" id="addManualEmbryoBtn" style="margin-top: 10px;">
                + Add Embryo Manually
            </button>
        `;
    }
    
    // Setup manual add button
    setupManualAddButton();
}

/**
 * Draw all detections on the canvas
 */
function drawDetections() {
    if (!imageElement || !ctx) return;
    
    // Clear canvas
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    
    // Draw the original image
    ctx.drawImage(imageElement, 0, 0, canvas.width, canvas.height);
    
    // Draw all bounding boxes
    appState.croppedEmbryos.forEach((detection, index) => {
        const isSelected = index === selectedEmbryoIndex;
        const color = COLORS[index % COLORS.length];
        
        drawBoundingBox(detection.box, color, isSelected, index);
    });
}

/**
 * Draw a single bounding box
 */
function drawBoundingBox(box, color, isSelected, index) {
    const lineWidth = isSelected ? 3 : 2;
    const alpha = isSelected ? 1 : 0.7;
    
    // Draw box
    ctx.strokeStyle = color;
    ctx.lineWidth = lineWidth;
    ctx.globalAlpha = alpha;
    ctx.strokeRect(box.x1, box.y1, box.x2 - box.x1, box.y2 - box.y1);
    
    // Draw label background
    const label = `Embryo ${index + 1}`;
    ctx.font = '14px Arial';
    const textWidth = ctx.measureText(label).width;
    const labelHeight = 20;
    
    ctx.fillStyle = color;
    ctx.globalAlpha = 0.9;
    ctx.fillRect(box.x1, box.y1 - labelHeight, textWidth + 10, labelHeight);
    
    // Draw label text
    ctx.fillStyle = 'white';
    ctx.globalAlpha = 1;
    ctx.fillText(label, box.x1 + 5, box.y1 - 5);
    
    // Draw resize handles if selected
    if (isSelected) {
        drawResizeHandles(box, color);
    }
    
    ctx.globalAlpha = 1;
}

/**
 * Draw resize handles on the selected box
 */
function drawResizeHandles(box, color) {
    const handles = [
        { x: box.x1, y: box.y1, type: 'nw' },
        { x: box.x2, y: box.y1, type: 'ne' },
        { x: box.x1, y: box.y2, type: 'sw' },
        { x: box.x2, y: box.y2, type: 'se' },
        { x: (box.x1 + box.x2) / 2, y: box.y1, type: 'n' },
        { x: (box.x1 + box.x2) / 2, y: box.y2, type: 's' },
        { x: box.x1, y: (box.y1 + box.y2) / 2, type: 'w' },
        { x: box.x2, y: (box.y1 + box.y2) / 2, type: 'e' }
    ];
    
    ctx.fillStyle = color;
    handles.forEach(handle => {
        ctx.fillRect(
            handle.x - HANDLE_SIZE / 2,
            handle.y - HANDLE_SIZE / 2,
            HANDLE_SIZE,
            HANDLE_SIZE
        );
    });
}

/**
 * Get mouse position relative to canvas
 */
function getMousePos(e) {
    const rect = canvas.getBoundingClientRect();
    const scaleX = canvas.width / rect.width;
    const scaleY = canvas.height / rect.height;
    
    return {
        x: (e.clientX - rect.left) * scaleX,
        y: (e.clientY - rect.top) * scaleY
    };
}

/**
 * Get handle at position
 */
function getHandleAtPosition(box, x, y) {
    const handles = [
        { x: box.x1, y: box.y1, type: 'nw' },
        { x: box.x2, y: box.y1, type: 'ne' },
        { x: box.x1, y: box.y2, type: 'sw' },
        { x: box.x2, y: box.y2, type: 'se' },
        { x: (box.x1 + box.x2) / 2, y: box.y1, type: 'n' },
        { x: (box.x1 + box.x2) / 2, y: box.y2, type: 's' },
        { x: box.x1, y: (box.y1 + box.y2) / 2, type: 'w' },
        { x: box.x2, y: (box.y1 + box.y2) / 2, type: 'e' }
    ];
    
    for (const handle of handles) {
        const dist = Math.sqrt(
            Math.pow(x - handle.x, 2) + Math.pow(y - handle.y, 2)
        );
        if (dist < HANDLE_SIZE) {
            return handle.type;
        }
    }
    
    return null;
}

/**
 * Check if point is inside a box
 */
function isPointInBox(box, x, y) {
    return x >= box.x1 && x <= box.x2 && y >= box.y1 && y <= box.y2;
}

/**
 * Handle mouse down
 */
function handleMouseDown(e) {
    const pos = getMousePos(e);
    
    // If in manual draw mode, start drawing new box
    if (isDrawingNewBox) {
        newBoxStart = pos;
        return;
    }
    
    // Check if clicking on selected box handles first
    if (selectedEmbryoIndex !== null) {
        const box = appState.croppedEmbryos[selectedEmbryoIndex].box;
        const handle = getHandleAtPosition(box, pos.x, pos.y);
        
        if (handle) {
            isDragging = true;
            dragType = handle;
            dragStart = pos;
            originalBox = { ...box };
            return;
        }
        
        // Check if clicking inside selected box to move it
        if (isPointInBox(box, pos.x, pos.y)) {
            isDragging = true;
            dragType = 'move';
            dragStart = pos;
            originalBox = { ...box };
            return;
        }
    }
    
    // Check if clicking on any box to select it
    for (let i = appState.croppedEmbryos.length - 1; i >= 0; i--) {
        const box = appState.croppedEmbryos[i].box;
        if (isPointInBox(box, pos.x, pos.y)) {
            selectEmbryo(i);
            return;
        }
    }
    
    // Clicked outside all boxes - deselect
    selectedEmbryoIndex = null;
    drawDetections();
    updateEmbryoList(appState.croppedEmbryos);
    
    // Reset detection info with button
    const info = document.getElementById('detectionInfo');
    if (info) {
        info.innerHTML = `
            <p>Click on an embryo to adjust its crop area</p>
            <button class="btn btn-secondary" id="addManualEmbryoBtn" style="margin-top: 10px;">
                + Add Embryo Manually
            </button>
        `;
        setupManualAddButton();
    }
}

/**
 * Handle mouse move
 */
function handleMouseMove(e) {
    const pos = getMousePos(e);
    
    // If drawing new box, show preview
    if (isDrawingNewBox && newBoxStart) {
        drawDetections();
        
        // Draw preview box
        ctx.strokeStyle = '#00B8D4';
        ctx.lineWidth = 3;
        ctx.setLineDash([5, 5]);
        ctx.strokeRect(
            newBoxStart.x,
            newBoxStart.y,
            pos.x - newBoxStart.x,
            pos.y - newBoxStart.y
        );
        ctx.setLineDash([]);
        return;
    }
    
    if (!isDragging || selectedEmbryoIndex === null) {
        // Update cursor based on hover
        updateCursor(pos);
        return;
    }
    
    const dx = pos.x - dragStart.x;
    const dy = pos.y - dragStart.y;
    
    const box = appState.croppedEmbryos[selectedEmbryoIndex].box;
    
    if (dragType === 'move') {
        // Move the entire box
        box.x1 = Math.max(0, Math.min(originalBox.x1 + dx, canvas.width - (originalBox.x2 - originalBox.x1)));
        box.y1 = Math.max(0, Math.min(originalBox.y1 + dy, canvas.height - (originalBox.y2 - originalBox.y1)));
        box.x2 = box.x1 + (originalBox.x2 - originalBox.x1);
        box.y2 = box.y1 + (originalBox.y2 - originalBox.y1);
    } else {
        // Resize the box based on handle
        resizeBox(box, originalBox, dx, dy, dragType);
    }
    
    drawDetections();
    updateEmbryoCrop(selectedEmbryoIndex);
}

/**
 * Resize box based on drag type
 */
function resizeBox(box, original, dx, dy, type) {
    const minSize = 30;
    
    switch (type) {
        case 'nw':
            box.x1 = Math.max(0, Math.min(original.x1 + dx, original.x2 - minSize));
            box.y1 = Math.max(0, Math.min(original.y1 + dy, original.y2 - minSize));
            break;
        case 'ne':
            box.x2 = Math.min(canvas.width, Math.max(original.x2 + dx, original.x1 + minSize));
            box.y1 = Math.max(0, Math.min(original.y1 + dy, original.y2 - minSize));
            break;
        case 'sw':
            box.x1 = Math.max(0, Math.min(original.x1 + dx, original.x2 - minSize));
            box.y2 = Math.min(canvas.height, Math.max(original.y2 + dy, original.y1 + minSize));
            break;
        case 'se':
            box.x2 = Math.min(canvas.width, Math.max(original.x2 + dx, original.x1 + minSize));
            box.y2 = Math.min(canvas.height, Math.max(original.y2 + dy, original.y1 + minSize));
            break;
        case 'n':
            box.y1 = Math.max(0, Math.min(original.y1 + dy, original.y2 - minSize));
            break;
        case 's':
            box.y2 = Math.min(canvas.height, Math.max(original.y2 + dy, original.y1 + minSize));
            break;
        case 'w':
            box.x1 = Math.max(0, Math.min(original.x1 + dx, original.x2 - minSize));
            break;
        case 'e':
            box.x2 = Math.min(canvas.width, Math.max(original.x2 + dx, original.x1 + minSize));
            break;
    }
}

/**
 * Update cursor based on position
 */
function updateCursor(pos) {
    // If in drawing mode, show crosshair cursor
    if (isDrawingNewBox) {
        canvas.style.cursor = 'crosshair';
        return;
    }
    
    if (selectedEmbryoIndex !== null) {
        const box = appState.croppedEmbryos[selectedEmbryoIndex].box;
        const handle = getHandleAtPosition(box, pos.x, pos.y);
        
        if (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'
            };
            canvas.style.cursor = cursors[handle];
            return;
        }
        
        if (isPointInBox(box, pos.x, pos.y)) {
            canvas.style.cursor = 'move';
            return;
        }
    }
    
    // Check if over any box
    for (const detection of appState.croppedEmbryos) {
        if (isPointInBox(detection.box, pos.x, pos.y)) {
            canvas.style.cursor = 'pointer';
            return;
        }
    }
    
    canvas.style.cursor = 'default';
}

/**
 * Handle mouse up
 */
function handleMouseUp(e) {
    // If finishing drawing new box
    if (isDrawingNewBox && newBoxStart) {
        const pos = getMousePos(e);
        const newBox = {
            x1: newBoxStart.x,
            y1: newBoxStart.y,
            x2: pos.x,
            y2: pos.y
        };
        
        completeManualCrop(newBox);
        return;
    }
    
    if (isDragging && selectedEmbryoIndex !== null) {
        // Finalize the crop update
        updateEmbryoCrop(selectedEmbryoIndex);
        showToast('Crop area updated', 'success');
    }
    
    isDragging = false;
    dragType = null;
}

/**
 * Handle touch events
 */
function handleTouchStart(e) {
    e.preventDefault();
    const touch = e.touches[0];
    const mouseEvent = new MouseEvent('mousedown', {
        clientX: touch.clientX,
        clientY: touch.clientY
    });
    canvas.dispatchEvent(mouseEvent);
}

function handleTouchMove(e) {
    e.preventDefault();
    const touch = e.touches[0];
    const mouseEvent = new MouseEvent('mousemove', {
        clientX: touch.clientX,
        clientY: touch.clientY
    });
    canvas.dispatchEvent(mouseEvent);
}

function handleTouchEnd(e) {
    e.preventDefault();
    // Get the last touch position or use changedTouches
    const touch = e.changedTouches[0];
    const mouseEvent = new MouseEvent('mouseup', {
        clientX: touch.clientX,
        clientY: touch.clientY
    });
    canvas.dispatchEvent(mouseEvent);
}

/**
 * Select an embryo
 */
function selectEmbryo(index) {
    selectedEmbryoIndex = index;
    setCurrentEmbryoIndex(index);
    drawDetections();
    updateEmbryoList(appState.croppedEmbryos);
    
    const info = document.getElementById('detectionInfo');
    if (info) {
        info.innerHTML = `
            <p><strong>Embryo ${index + 1} selected</strong> - Drag to move, drag handles to resize</p>
            <button class="btn btn-secondary" id="addManualEmbryoBtn" style="margin-top: 10px;">
                + Add Embryo Manually
            </button>
        `;
        setupManualAddButton();
    }
}

/**
 * Update embryo crop after modification
 */
async function updateEmbryoCrop(index) {
    const detection = appState.croppedEmbryos[index];
    const box = detection.box;
    
    // Create a temporary canvas to crop the image
    const tempCanvas = document.createElement('canvas');
    const tempCtx = tempCanvas.getContext('2d');
    
    const width = box.x2 - box.x1;
    const height = box.y2 - box.y1;
    
    tempCanvas.width = width;
    tempCanvas.height = height;
    
    // Draw the cropped portion
    tempCtx.drawImage(
        imageElement,
        box.x1, box.y1, width, height,
        0, 0, width, height
    );
    
    // Update the detection's imageData
    detection.imageData = tempCanvas.toDataURL('image/png');
    
    // Update the list
    updateEmbryoList(appState.croppedEmbryos);
}

/**
 * Update the embryo list in the sidebar
 */
function updateEmbryoList(detections) {
    const listContainer = document.getElementById('embryoList');
    if (!listContainer) return;
    
    listContainer.innerHTML = '';
    
    detections.forEach((detection, index) => {
        const card = document.createElement('div');
        card.className = 'embryo-card';
        if (index === selectedEmbryoIndex) {
            card.classList.add('selected');
        }
        
        const hasRemark = getEmbryoRemark(index).trim().length > 0;
        
        card.innerHTML = `
            <div class="embryo-card-thumbnail">
                <img src="${detection.imageData}" alt="Embryo ${index + 1}">
            </div>
            <div class="embryo-card-info">
                <div class="embryo-card-title">
                    Embryo ${index + 1}
                </div>
                <div class="embryo-card-confidence">
                    Confidence: ${(detection.confidence * 100).toFixed(1)}%
                </div>
            </div>
            <div class="embryo-card-actions">
                <button class="embryo-card-btn discard" data-index="${index}">
                    Discard
                </button>
            </div>
        `;
        
        // Click to select
        card.addEventListener('click', (e) => {
            if (!e.target.classList.contains('embryo-card-btn')) {
                selectEmbryo(index);
            }
        });
        
        // Discard button
        const discardBtn = card.querySelector('.discard');
        discardBtn.addEventListener('click', (e) => {
            e.stopPropagation();
            discardEmbryo(index);
        });
        
        listContainer.appendChild(card);
    });
}

/**
 * Discard an embryo
 */
async function discardEmbryo(index) {
    if (appState.croppedEmbryos.length <= 1) {
        showToast('Cannot discard the last embryo', 'warning');
        return;
    }
    
    const confirmed = await showConfirmModal(
        `Are you sure you want to discard Embryo ${index + 1}?`,
        'Discard Embryo'
    );
    
    if (!confirmed) {
        return;
    }
    
    // Remove embryo
    appState.croppedEmbryos.splice(index, 1);
    
    // Adjust selected index
    if (selectedEmbryoIndex === index) {
        selectedEmbryoIndex = Math.max(0, Math.min(selectedEmbryoIndex, appState.croppedEmbryos.length - 1));
    } else if (selectedEmbryoIndex > index) {
        selectedEmbryoIndex--;
    }
    
    // Redraw
    drawDetections();
    updateEmbryoList(appState.croppedEmbryos);
    
    showToast('Embryo discarded', 'success');
}

/**
 * Setup manual add embryo button
 */
function setupManualAddButton() {
    const addBtn = document.getElementById('addManualEmbryoBtn');
    if (!addBtn) return;
    
    addBtn.addEventListener('click', startManualCrop);
}

let isDrawingNewBox = false;
let newBoxStart = null;

/**
 * Start manual crop mode
 */
function startManualCrop() {
    isDrawingNewBox = true;
    selectedEmbryoIndex = null;
    
    const detectionInfo = document.getElementById('detectionInfo');
    if (detectionInfo) {
        detectionInfo.innerHTML = `
            <p style="color: var(--primary-color); font-weight: 600;">Draw a box around the embryo</p>
            <p style="font-size: 0.9em;">Click and drag on the image to create a new bounding box</p>
            <button class="btn btn-secondary" id="cancelManualAdd" style="margin-top: 10px;">Cancel</button>
        `;
        
        const cancelBtn = document.getElementById('cancelManualAdd');
        if (cancelBtn) {
            cancelBtn.addEventListener('click', cancelManualCrop);
        }
    }
    
    drawDetections();
    showToast('Draw a box around the embryo', 'info');
}

/**
 * Cancel manual crop mode
 */
function cancelManualCrop() {
    isDrawingNewBox = false;
    newBoxStart = null;
    
    const detectionInfo = document.getElementById('detectionInfo');
    if (detectionInfo) {
        detectionInfo.innerHTML = `
            <p>Click on an embryo to adjust its crop area</p>
            <button class="btn btn-secondary" id="addManualEmbryoBtn" style="margin-top: 10px;">
                + Add Embryo Manually
            </button>
        `;
        setupManualAddButton();
    }
    
    drawDetections();
}

/**
 * Complete manual crop and add embryo
 */
async function completeManualCrop(box) {
    // Validate box size
    const minSize = 50;
    const boxWidth = Math.abs(box.x2 - box.x1);
    const boxHeight = Math.abs(box.y2 - box.y1);
    
    if (boxWidth < minSize || boxHeight < minSize) {
        showToast('Box too small. Please draw a larger area.', 'warning');
        return;
    }
    
    // Normalize box coordinates
    const normalizedBox = {
        x1: Math.min(box.x1, box.x2),
        y1: Math.min(box.y1, box.y2),
        x2: Math.max(box.x1, box.x2),
        y2: Math.max(box.y1, box.y2)
    };
    
    // Crop the embryo from the original image
    const croppedCanvas = document.createElement('canvas');
    const croppedCtx = croppedCanvas.getContext('2d');
    
    croppedCanvas.width = normalizedBox.x2 - normalizedBox.x1;
    croppedCanvas.height = normalizedBox.y2 - normalizedBox.y1;
    
    croppedCtx.drawImage(
        imageElement,
        normalizedBox.x1, normalizedBox.y1,
        croppedCanvas.width, croppedCanvas.height,
        0, 0,
        croppedCanvas.width, croppedCanvas.height
    );
    
    const croppedImageData = croppedCanvas.toDataURL();
    
    // Add to embryos array
    const newEmbryo = {
        imageData: croppedImageData,
        box: normalizedBox,
        confidence: 1.0, // Manual additions have 100% confidence
        isManual: true
    };
    
    appState.croppedEmbryos.push(newEmbryo);
    
    // Reset manual mode
    isDrawingNewBox = false;
    newBoxStart = null;
    
    // Update UI
    cancelManualCrop();
    drawDetections();
    updateEmbryoList(appState.croppedEmbryos);
    
    // Enable next button if this is the first embryo
    if (appState.croppedEmbryos.length > 0) {
        import('./stepper.js').then(module => {
            module.enableNextButton(2);
        });
    }
    
    showToast('Embryo added successfully', 'success');
}

/**
 * Export functions
 */
export function getSelectedEmbryoIndex() {
    return selectedEmbryoIndex;
}

export function redrawDetections() {
    drawDetections();
}