<template>
  <div class="spritesheet-preview w-full">
    <!-- Controls Container -->
    <div class="bg-white dark:bg-gray-800 rounded-lg border border-gray-200 dark:border-gray-700 p-4">
      <div class="flex flex-col gap-4 sm:flex-row sm:flex-wrap">
        <!-- Playback Controls -->
        <div class="flex items-center gap-2">
          <div class="space-y-2">
            <button @click="togglePlayback" class="flex items-center gap-1.5 bg-blue-500 hover:bg-blue-600 text-white px-4 py-2 rounded-md transition-colors w-full cursor-pointer">
              <span v-if="isPlaying" class="flex items-center gap-1.5">
                <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor" class="w-5 h-5">
                  <path fill-rule="evenodd" d="M6.75 5.25a.75.75 0 01.75-.75H9a.75.75 0 01.75.75v13.5a.75.75 0 01-.75.75H7.5a.75.75 0 01-.75-.75V5.25zm7.5 0A.75.75 0 0115 4.5h1.5a.75.75 0 01.75.75v13.5a.75.75 0 01-.75.75H15a.75.75 0 01-.75-.75V5.25z" clip-rule="evenodd" />
                </svg>
                <span class="hidden sm:inline">Pause</span>
              </span>
              <span v-else class="flex items-center gap-1.5">
                <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor" class="w-5 h-5">
                  <path fill-rule="evenodd" d="M4.5 5.653c0-1.426 1.529-2.33 2.779-1.643l11.54 6.348c1.295.712 1.295 2.573 0 3.285L7.28 19.991c-1.25.687-2.779-.217-2.779-1.643V5.653z" clip-rule="evenodd" />
                </svg>
                <span class="hidden sm:inline">Play</span>
              </span>
            </button>

            <div class="flex items-center gap-1">
              <button @click="previousFrame" class="bg-gray-200 hover:bg-gray-300 dark:bg-gray-700 dark:hover:bg-gray-600 p-2 rounded-md transition-colors duration-200 w-full cursor-pointer" :disabled="isPlaying" :class="{ 'opacity-50 cursor-not-allowed': isPlaying }">
                <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor" class="w-5 h-5 mx-auto dark:text-gray-200">
                  <path fill-rule="evenodd" d="M11.78 5.22a.75.75 0 01.75.75v12.06l4.72-4.72a.75.75 0 111.06 1.06l-6 6a.75.75 0 01-1.06 0l-6-6a.75.75 0 011.06-1.06l4.72 4.72V5.97a.75.75 0 01.75-.75z" clip-rule="evenodd" transform="rotate(90 12 12)" />
                </svg>
              </button>
              <button @click="nextFrame" class="bg-gray-200 hover:bg-gray-300 dark:bg-gray-700 dark:hover:bg-gray-600 p-2 rounded-md transition-colors duration-200 w-full cursor-pointer" :disabled="isPlaying" :class="{ 'opacity-50 cursor-not-allowed': isPlaying }">
                <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor" class="w-5 h-5 mx-auto dark:text-gray-200">
                  <path fill-rule="evenodd" d="M11.78 5.22a.75.75 0 01.75.75v12.06l4.72-4.72a.75.75 0 111.06 1.06l-6 6a.75.75 0 01-1.06 0l-6-6a.75.75 0 011.06-1.06l4.72 4.72V5.97a.75.75 0 01.75-.75z" clip-rule="evenodd" transform="rotate(-90 12 12)" />
                </svg>
              </button>
            </div>

            <!-- Checkboxes -->
            <div class="flex flex-wrap gap-4 items-center">
              <label class="flex items-center gap-2 cursor-pointer">
                <input type="checkbox" v-model="isDraggable" class="w-4 h-4 text-blue-500 focus:ring-blue-400 rounded border-gray-300 dark:border-gray-600 dark:bg-gray-700" />
                <span class="text-sm whitespace-nowrap dark:text-gray-200">Reposition</span>
              </label>

              <label class="flex items-center gap-2 cursor-pointer">
                <input type="checkbox" v-model="showAllSprites" class="w-4 h-4 text-blue-500 focus:ring-blue-400 rounded border-gray-300 dark:border-gray-600 dark:bg-gray-700" />
                <span class="text-sm whitespace-nowrap dark:text-gray-200">Compare sprites</span>
              </label>

              <label class="flex items-center gap-2 cursor-pointer">
                <input type="checkbox" v-model="settingsStore.pixelPerfect" class="w-4 h-4 text-blue-500 focus:ring-blue-400 rounded border-gray-300 dark:border-gray-600 dark:bg-gray-700" @change="drawPreviewCanvas" />
                <span class="text-sm whitespace-nowrap dark:text-gray-200">Pixel perfect</span>
              </label>
            </div>
          </div>
        </div>
        <!-- Frame Controls -->
        <div class="flex-1 min-w-[200px] space-y-6">
          <!-- Frame Navigation -->
          <div class="flex items-center gap-2">
            <span class="text-sm font-medium w-30 dark:text-gray-200">Frame {{ visibleFrameNumber }}/{{ visibleFramesCount }}</span>
            <input type="range" min="0" :max="visibleFrames.length - 1" :value="visibleFrameIndex" @input="handleSliderInput" class="flex-1 h-2 bg-gray-200 dark:bg-gray-700 rounded-lg appearance-none cursor-pointer accent-blue-500" :disabled="isPlaying" :class="{ 'opacity-50': isPlaying }" />
          </div>

          <!-- FPS Control -->
          <div class="flex items-center gap-2">
            <span class="text-sm font-medium w-30 dark:text-gray-200">FPS: {{ fps }}</span>
            <input type="range" min="1" max="60" v-model.number="fps" class="flex-1 h-2 bg-gray-200 dark:bg-gray-700 rounded-lg appearance-none cursor-pointer accent-blue-500" />
          </div>

          <!-- Zoom Control -->
          <div class="flex items-center gap-2">
            <span class="text-sm font-medium w-30 dark:text-gray-200">{{ Math.round(zoom * 100) }}%</span>
            <input type="range" min="0.5" max="5" step="0.1" v-model.number="zoom" class="flex-1 h-2 bg-gray-200 dark:bg-gray-700 rounded-lg appearance-none cursor-pointer accent-blue-500" />
          </div>
        </div>
      </div>

      <div v-if="showAllSprites" class="w-full mt-3">
        <div class="flex items-center mb-2">
          <label class="block text-sm font-medium text-gray-700 dark:text-gray-200">Select visible frames:</label>
          <div class="ml-auto flex gap-2">
            <button @click="showAllFrames" class="px-2 py-1 text-sm bg-blue-500 hover:bg-blue-600 text-white rounded-md transition-colors">Show All</button>
            <button @click="hideAllFrames" class="px-2 py-1 text-sm bg-gray-500 hover:bg-gray-600 text-white rounded-md transition-colors">Hide All</button>
          </div>
        </div>
        <div class="w-full rounded-md border border-gray-300 dark:border-gray-600 shadow-sm focus-within:ring-1 focus-within:ring-blue-500 focus-within:border-blue-500 dark:bg-gray-800">
          <div class="max-h-[200px] overflow-y-auto">
            <div class="grid grid-cols-2 gap-2">
              <div v-for="(sprite, index) in props.sprites" :key="sprite.id" class="flex items-center gap-3 px-3 py-2 hover:bg-gray-50 dark:hover:bg-gray-700 cursor-pointer" @click="toggleHiddenFrame(index)">
                <input type="checkbox" :checked="!hiddenFrames.includes(index)" class="w-4 h-4 text-blue-500 focus:ring-blue-400 rounded border-gray-300 dark:border-gray-600 dark:bg-gray-700" @click.stop @change="toggleHiddenFrame(index)" />
                <div class="w-12 h-12 bg-gray-100 dark:bg-gray-700 rounded flex items-center justify-center overflow-hidden">
                  <img :src="sprite.img.src" class="max-w-full max-h-full object-contain" :style="settingsStore.pixelPerfect ? { 'image-rendering': 'pixelated' } : {}" />
                </div>
                <span class="text-sm dark:text-gray-200">Frame {{ index + 1 }}</span>
              </div>
            </div>
          </div>
        </div>
      </div>
    </div>

    <div class="mt-3 relative bg-gray-50 dark:bg-gray-800 border border-gray-300 dark:border-gray-700 rounded-lg mb-4 sm:mb-6 overflow-auto min-h-[300px] sm:min-h-[520px] shadow-sm hover:shadow-md transition-shadow duration-200">
      <canvas
        ref="previewCanvasRef"
        @mousedown="startDrag"
        @mousemove="drag"
        @mouseup="stopDrag"
        @mouseleave="stopDrag"
        @touchstart="handleTouchStart"
        @touchmove="handleTouchMove"
        @touchend="stopDrag"
        class="block touch-manipulation"
        :class="{ 'cursor-move': isDraggable }"
        :style="{ transform: `scale(${zoom})`, transformOrigin: 'top left', ...(settingsStore.pixelPerfect ? { 'image-rendering': 'pixelated' } : {}) }"
      >
      </canvas>

      <!-- Mobile zoom controls -->
      <div class="absolute bottom-3 right-3 flex space-x-2 sm:hidden bg-white/80 dark:bg-gray-800/80 p-2 rounded-lg shadow-md">
        <button @click="increaseZoom" class="p-2 bg-gray-100 hover:bg-gray-200 dark:bg-gray-700 dark:hover:bg-gray-600 text-gray-700 dark:text-gray-100 rounded-lg transition-colors">
          <i class="fas fa-plus"></i>
        </button>
        <button @click="decreaseZoom" class="p-2 bg-gray-100 hover:bg-gray-200 dark:bg-gray-700 dark:hover:bg-gray-600 text-gray-700 dark:text-gray-100 rounded-lg transition-colors">
          <i class="fas fa-minus"></i>
        </button>
      </div>
    </div>
  </div>
</template>

<script setup lang="ts">
  import { ref, onMounted, watch, onUnmounted, computed } from 'vue';
  import { useSettingsStore } from '@/stores/useSettingsStore';

  interface Sprite {
    id: string;
    img: HTMLImageElement;
    width: number;
    height: number;
    x: number;
    y: number;
  }

  const props = defineProps<{
    sprites: Sprite[];
    columns: number;
  }>();

  const emit = defineEmits<{
    (e: 'updateSprite', id: string, x: number, y: number): void;
  }>();

  const previewCanvasRef = ref<HTMLCanvasElement | null>(null);
  const ctx = ref<CanvasRenderingContext2D | null>(null);

  // Preview state
  const currentFrameIndex = ref(0);
  const isPlaying = ref(false);
  const fps = ref(12);
  const zoom = ref(1);
  const isDraggable = ref(false);
  const showAllSprites = ref(false);
  const animationFrameId = ref<number | null>(null);
  const lastFrameTime = ref(0);

  // Dragging state
  const isDragging = ref(false);
  const activeSpriteId = ref<string | null>(null);
  const dragStartX = ref(0);
  const dragStartY = ref(0);
  const spritePosBeforeDrag = ref({ x: 0, y: 0 });

  // Add this after other refs
  const hiddenFrames = ref<number[]>([]);

  // Get settings from store
  const settingsStore = useSettingsStore();

  // Add these computed properties
  const visibleFrames = computed(() => props.sprites.filter((_, index) => !hiddenFrames.value.includes(index)));
  const visibleFramesCount = computed(() => visibleFrames.value.length);
  const visibleFrameIndex = computed(() => {
    return visibleFrames.value.findIndex((_, idx) => idx === visibleFrames.value.findIndex(s => s === props.sprites[currentFrameIndex.value]));
  });
  const visibleFrameNumber = computed(() => visibleFrameIndex.value + 1);

  // Canvas drawing
  const calculateMaxDimensions = () => {
    let maxWidth = 0;
    let maxHeight = 0;

    props.sprites.forEach(sprite => {
      maxWidth = Math.max(maxWidth, sprite.width);
      maxHeight = Math.max(maxHeight, sprite.height);
    });

    return { maxWidth, maxHeight };
  };

  const drawPreviewCanvas = () => {
    if (!previewCanvasRef.value || !ctx.value || props.sprites.length === 0) return;

    const currentSprite = props.sprites[currentFrameIndex.value];
    if (!currentSprite) return;

    const { maxWidth, maxHeight } = calculateMaxDimensions();

    // Apply pixel art optimization consistently from store
    ctx.value.imageSmoothingEnabled = !settingsStore.pixelPerfect;

    // Set canvas size to just fit one sprite cell
    previewCanvasRef.value.width = maxWidth;
    previewCanvasRef.value.height = maxHeight;

    // Clear canvas
    ctx.value.clearRect(0, 0, previewCanvasRef.value.width, previewCanvasRef.value.height);

    // Draw grid background (cell)
    ctx.value.fillStyle = '#f9fafb';
    ctx.value.fillRect(0, 0, maxWidth, maxHeight);

    // Keep pixel art optimization consistent throughout all drawing operations
    ctx.value.imageSmoothingEnabled = !settingsStore.pixelPerfect;

    // Draw all sprites with transparency if enabled
    if (showAllSprites.value && props.sprites.length > 1) {
      ctx.value.globalAlpha = 0.3;
      props.sprites.forEach((sprite, index) => {
        if (index !== currentFrameIndex.value && !hiddenFrames.value.includes(index)) {
          // Use Math.floor for pixel-perfect positioning
          ctx.value?.drawImage(sprite.img, Math.floor(sprite.x), Math.floor(sprite.y));
        }
      });
      ctx.value.globalAlpha = 1.0;
    }

    // Draw current sprite with integer positions for pixel-perfect rendering
    ctx.value.drawImage(currentSprite.img, Math.floor(currentSprite.x), Math.floor(currentSprite.y));

    // Draw cell border
    ctx.value.strokeStyle = '#e5e7eb';
    ctx.value.lineWidth = 1;
    ctx.value.strokeRect(0, 0, maxWidth, maxHeight);
  };

  // Animation control
  const togglePlayback = () => {
    isPlaying.value = !isPlaying.value;

    if (isPlaying.value) {
      startAnimation();
    } else {
      stopAnimation();
    }
  };

  const startAnimation = () => {
    lastFrameTime.value = performance.now();
    animateFrame();
  };

  const stopAnimation = () => {
    if (animationFrameId.value !== null) {
      cancelAnimationFrame(animationFrameId.value);
      animationFrameId.value = null;
    }
  };

  const animateFrame = () => {
    const now = performance.now();
    const elapsed = now - lastFrameTime.value;
    const frameTime = 1000 / fps.value;

    if (elapsed >= frameTime) {
      lastFrameTime.value = now - (elapsed % frameTime);
      nextFrame();
    }

    animationFrameId.value = requestAnimationFrame(animateFrame);
  };

  const nextFrame = () => {
    if (visibleFrames.value.length === 0) return;

    const currentVisibleIndex = visibleFrameIndex.value;
    const nextVisibleIndex = (currentVisibleIndex + 1) % visibleFrames.value.length;
    currentFrameIndex.value = props.sprites.indexOf(visibleFrames.value[nextVisibleIndex]);
    drawPreviewCanvas();
  };

  const previousFrame = () => {
    if (visibleFrames.value.length === 0) return;

    const currentVisibleIndex = visibleFrameIndex.value;
    const prevVisibleIndex = (currentVisibleIndex - 1 + visibleFrames.value.length) % visibleFrames.value.length;
    currentFrameIndex.value = props.sprites.indexOf(visibleFrames.value[prevVisibleIndex]);
    drawPreviewCanvas();
  };

  // Add this method to handle slider input
  const handleSliderInput = (event: Event) => {
    const target = event.target as HTMLInputElement;
    const index = parseInt(target.value);
    currentFrameIndex.value = props.sprites.indexOf(visibleFrames.value[index]);
  };

  // Drag functionality
  const startDrag = (event: MouseEvent) => {
    if (!isDraggable.value || !previewCanvasRef.value) return;

    const rect = previewCanvasRef.value.getBoundingClientRect();
    const scaleX = previewCanvasRef.value.width / (rect.width / zoom.value);
    const scaleY = previewCanvasRef.value.height / (rect.height / zoom.value);

    const mouseX = ((event.clientX - rect.left) / zoom.value) * scaleX;
    const mouseY = ((event.clientY - rect.top) / zoom.value) * scaleY;

    const sprite = props.sprites[currentFrameIndex.value];

    // Check if click is on sprite
    if (sprite && mouseX >= sprite.x && mouseX <= sprite.x + sprite.width && mouseY >= sprite.y && mouseY <= sprite.y + sprite.height) {
      isDragging.value = true;
      activeSpriteId.value = sprite.id;
      dragStartX.value = mouseX;
      dragStartY.value = mouseY;
      spritePosBeforeDrag.value = { x: sprite.x, y: sprite.y };
    }
  };

  const drag = (event: MouseEvent) => {
    if (!isDragging.value || !activeSpriteId.value || !previewCanvasRef.value) return;

    const rect = previewCanvasRef.value.getBoundingClientRect();
    const scaleX = previewCanvasRef.value.width / (rect.width / zoom.value);
    const scaleY = previewCanvasRef.value.height / (rect.height / zoom.value);

    const mouseX = ((event.clientX - rect.left) / zoom.value) * scaleX;
    const mouseY = ((event.clientY - rect.top) / zoom.value) * scaleY;

    const deltaX = Math.round(mouseX - dragStartX.value);
    const deltaY = Math.round(mouseY - dragStartY.value);

    const sprite = props.sprites[currentFrameIndex.value];
    if (!sprite || sprite.id !== activeSpriteId.value) return;

    const { maxWidth, maxHeight } = calculateMaxDimensions();

    // Calculate new position with constraints and round to integers
    let newX = Math.round(spritePosBeforeDrag.value.x + deltaX);
    let newY = Math.round(spritePosBeforeDrag.value.y + deltaY);

    // Constrain movement within cell
    newX = Math.max(0, Math.min(maxWidth - sprite.width, newX));
    newY = Math.max(0, Math.min(maxHeight - sprite.height, newY));

    emit('updateSprite', activeSpriteId.value, newX, newY);
    drawPreviewCanvas();
  };

  const stopDrag = () => {
    isDragging.value = false;
    activeSpriteId.value = null;
  };

  // Add helper methods for mobile zoom controls
  const increaseZoom = () => {
    const zoomValues = [0.5, 1, 2, 3, 4];
    const currentIndex = zoomValues.indexOf(Number(zoom.value));
    if (currentIndex < zoomValues.length - 1) {
      zoom.value = zoomValues[currentIndex + 1];
    }
  };

  const decreaseZoom = () => {
    const zoomValues = [0.5, 1, 2, 3, 4];
    const currentIndex = zoomValues.indexOf(Number(zoom.value));
    if (currentIndex > 0) {
      zoom.value = zoomValues[currentIndex - 1];
    }
  };

  const handleTouchStart = (event: TouchEvent) => {
    if (!isDraggable.value) return;

    if (event.touches.length === 1) {
      const touch = event.touches[0];
      const mouseEvent = new MouseEvent('mousedown', {
        clientX: touch.clientX,
        clientY: touch.clientY,
      });
      startDrag(mouseEvent);
    }
  };

  const handleTouchMove = (event: TouchEvent) => {
    if (!isDraggable.value) return;

    if (isDragging.value) {
      event.preventDefault(); // Only prevent default when actually dragging
    }

    if (event.touches.length === 1) {
      const touch = event.touches[0];
      const mouseEvent = new MouseEvent('mousemove', {
        clientX: touch.clientX,
        clientY: touch.clientY,
      });
      drag(mouseEvent);
    }
  };

  // Lifecycle hooks
  onMounted(() => {
    if (previewCanvasRef.value) {
      ctx.value = previewCanvasRef.value.getContext('2d');
      drawPreviewCanvas();
    }

    // Listen for forceRedraw event from App.vue
    window.addEventListener('forceRedraw', handleForceRedraw);
  });

  onUnmounted(() => {
    stopAnimation();
    window.removeEventListener('forceRedraw', handleForceRedraw);
  });

  // Handler for force redraw event
  const handleForceRedraw = () => {
    // Ensure we're using integer positions for pixel-perfect rendering
    props.sprites.forEach(sprite => {
      sprite.x = Math.floor(sprite.x);
      sprite.y = Math.floor(sprite.y);
    });

    // Force a redraw with the correct image smoothing settings
    if (ctx.value) {
      ctx.value.imageSmoothingEnabled = !settingsStore.pixelPerfect;
      drawPreviewCanvas();
    }
  };

  // Watchers
  watch(() => props.sprites, drawPreviewCanvas, { deep: true });
  watch(currentFrameIndex, drawPreviewCanvas);
  watch(zoom, drawPreviewCanvas);
  watch(isDraggable, drawPreviewCanvas);
  watch(showAllSprites, drawPreviewCanvas);
  watch(hiddenFrames, drawPreviewCanvas);
  watch(() => settingsStore.pixelPerfect, drawPreviewCanvas);

  // Initial draw
  if (props.sprites.length > 0) {
    drawPreviewCanvas();
  }

  const toggleHiddenFrame = (index: number) => {
    const currentIndex = hiddenFrames.value.indexOf(index);
    if (currentIndex === -1) {
      // Adding to hidden frames
      hiddenFrames.value.push(index);

      // If we're hiding the current frame, switch to the next visible frame
      if (index === currentFrameIndex.value) {
        const nextVisibleSprite = props.sprites.findIndex((_, i) => i !== index && !hiddenFrames.value.includes(i));
        if (nextVisibleSprite !== -1) {
          currentFrameIndex.value = nextVisibleSprite;
        }
      }
    } else {
      // Removing from hidden frames
      hiddenFrames.value.splice(currentIndex, 1);
    }

    // Force a redraw
    drawPreviewCanvas();
  };

  const showAllFrames = () => {
    hiddenFrames.value = [];
    drawPreviewCanvas();
  };

  const hideAllFrames = () => {
    hiddenFrames.value = props.sprites.map((_, index) => index);
    // Keep at least one frame visible
    if (hiddenFrames.value.length > 0) {
      hiddenFrames.value.splice(currentFrameIndex.value, 1);
    }
    drawPreviewCanvas();
  };
</script>

<style scoped>
  /* Custom styling for range inputs */
  input[type='range']::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: #3b82f6;
    cursor: pointer;
  }

  input[type='range']::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: #3b82f6;
    cursor: pointer;
    border: none;
  }
</style>
