import { ref, computed, onMounted, onUnmounted } from 'vue'
import { ElMessage } from 'element-plus'

export function useImageTool() {
  const filePath = ref('')
  const filePreview = ref('')
  const imageInfo = ref(null)
  const processing = ref(false)
  const resultInfo = ref(null)
  const outputPath = ref('')
  const compareImages = ref({ original: '', processed: '' })
  const config = ref({ defaultOutputDir: '' })

  const showPreview = ref(false)
  const previewSrc = ref('')
  const previewIndex = ref(0)
  const previewScale = ref(1)
  const previewX = ref(0)
  const previewY = ref(0)
  const isDragging = ref(false)
  const dragStart = ref({ x: 0, y: 0 })

  onMounted(async () => {
    try {
      config.value = await window.go.main.FileHandler.GetConfig()
    } catch (e) {}
  })

  function formatSize(bytes) {
    if (!bytes) return '0 B'
    const k = 1024
    const sizes = ['B', 'KB', 'MB', 'GB']
    const i = Math.floor(Math.log(bytes) / Math.log(k))
    return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i]
  }

  function getFileName() {
    if (!filePath.value) return '未选择文件'
    return filePath.value.split(/[/\\]/).pop()
  }

  async function selectFile(fileFilters) {
    try {
      const path = await window.go.main.FileHandler.OpenFileDialog('选择文件', fileFilters)
      if (path) {
        filePath.value = path
        resetState()
        outputPath.value = ''
        await loadFilePreview()
      }
    } catch (e) {
      ElMessage.error('选择文件失败: ' + e.message)
    }
  }

  async function loadFilePreview() {
    if (!filePath.value) return
    try {
      const b64 = await window.go.main.FileHandler.GetImageBase64(filePath.value)
      if (b64) {
        filePreview.value = b64
        const info = await window.go.main.FileHandler.GetFileInfo(filePath.value)
        imageInfo.value = info
      }
    } catch (e) {
      console.error('加载预览失败:', e)
    }
  }

  function resetState() {
    resultInfo.value = null
    compareImages.value = { original: '', processed: '' }
    previewScale.value = 1
    previewX.value = 0
    previewY.value = 0
    filePreview.value = ''
    imageInfo.value = null
  }

  function clearImageFile() {
    filePath.value = ''
    filePreview.value = ''
    imageInfo.value = null
    resultInfo.value = null
    compareImages.value = { original: '', processed: '' }
    outputPath.value = ''
  }

  async function processFile(req) {
    if (!filePath.value) {
      ElMessage.warning('请先选择文件')
      return
    }

    processing.value = true
    resultInfo.value = null
    compareImages.value = { original: '', processed: '' }

    try {
      const result = await window.go.main.FileHandler.ProcessFile(req)

      if (result.success) {
        resultInfo.value = {
          path: result.path,
          size: formatSize(result.size),
          sizeBytes: result.size,
          originalSize: result.originalSize ? formatSize(result.originalSize) : '',
          originalSizeBytes: result.originalSize || 0,
          tempPath: result.path,
          isImageOp: true,
        }

        try {
          const b64 = await window.go.main.FileHandler.GetImageBase64(filePath.value)
          compareImages.value.original = b64
          compareImages.value.processed = await window.go.main.FileHandler.GetImageBase64(result.path)
          if (!compareImages.value.processed) {
            compareImages.value.processed = b64
          }
        } catch (e) {}

        await window.go.main.FileHandler.AddRecentUse({
          id: req.format,
          name: '',
          category: 'image',
          usedAt: Date.now(),
        })

        ElMessage.success('处理完成')
      } else {
        ElMessage.error(result.message)
      }
    } catch (e) {
      ElMessage.error('处理失败: ' + e.message)
    } finally {
      processing.value = false
    }
  }

  async function selectOutputPath(outputFilters, defaultName) {
    try {
      const path = await window.go.main.FileHandler.OpenSaveDialog('保存文件', defaultName, outputFilters)
      if (path) {
        outputPath.value = path
      }
    } catch (e) {}
  }

  async function downloadResult(outputFilters, getOutputExtFn, getOutputDefaultNameFn) {
    if (!resultInfo.value?.tempPath) return

    try {
      const ext = getOutputExtFn ? getOutputExtFn() : '.png'
      const defaultName = getOutputDefaultNameFn ? getOutputDefaultNameFn() : ('output' + ext)
      const savePath = await window.go.main.FileHandler.OpenSaveDialog('保存文件', defaultName, outputFilters)

      if (savePath) {
        const result = await window.go.main.FileHandler.SaveResult(resultInfo.value.tempPath, savePath)
        if (result.success) {
          ElMessage.success('文件已保存到: ' + savePath)
          resultInfo.value.path = savePath
        } else {
          ElMessage.error(result.message)
        }
      }
    } catch (e) {
      ElMessage.error('保存失败: ' + e.message)
    }
  }

  function openPreview(src, index) {
    previewSrc.value = src
    previewIndex.value = index
    previewScale.value = 1
    previewX.value = 0
    previewY.value = 0
    showPreview.value = true
  }

  function closePreview() {
    showPreview.value = false
  }

  function onWheel(e) {
    e.preventDefault()
    const delta = e.deltaY > 0 ? -0.1 : 0.1
    previewScale.value = Math.max(0.1, Math.min(5, previewScale.value + delta))
  }

  function onMouseDown(e) {
    if (e.button !== 0) return
    isDragging.value = true
    dragStart.value = { x: e.clientX - previewX.value, y: e.clientY - previewY.value }
  }

  function onMouseMove(e) {
    if (!isDragging.value) return
    previewX.value = e.clientX - dragStart.value.x
    previewY.value = e.clientY - dragStart.value.y
  }

  function onMouseUp() {
    isDragging.value = false
  }

  function resetPreview() {
    previewScale.value = 1
    previewX.value = 0
    previewY.value = 0
  }

  function switchPreview(dir) {
    previewIndex.value = dir
    previewSrc.value = dir === 0 ? compareImages.value.original : compareImages.value.processed
    resetPreview()
  }

  async function openOutputFolder() {
    if (resultInfo.value?.path) {
      const dir = resultInfo.value.path.replace(/[/\\][^/\\]+$/, '')
      try {
        await window.go.main.FileHandler.OpenFolder(dir)
      } catch (e) {
        ElMessage.error('打开文件夹失败')
      }
    }
  }

  return {
    filePath,
    filePreview,
    imageInfo,
    processing,
    resultInfo,
    outputPath,
    compareImages,
    config,
    showPreview,
    previewSrc,
    previewIndex,
    previewScale,
    previewX,
    previewY,
    isDragging,
    dragStart,
    formatSize,
    getFileName,
    selectFile,
    loadFilePreview,
    resetState,
    clearImageFile,
    processFile,
    selectOutputPath,
    downloadResult,
    openPreview,
    closePreview,
    onWheel,
    onMouseDown,
    onMouseMove,
    onMouseUp,
    resetPreview,
    switchPreview,
    openOutputFolder,
  }
}