import { useState } from 'react'
import { Button, Image, Upload, message } from 'antd'
import { CloseOutlined, LoadingOutlined, PlusOutlined } from '@ant-design/icons'
import { uploadApi } from '../api'

interface ImageUploaderProps {
  value?: string[]
  onChange?: (urls: string[]) => void
  maxCount?: number
  maxSizeMB?: number
  /** 压缩后最长边像素，默认 1600 */
  maxWidth?: number
  /** webp 压缩质量 0~1，默认 0.8 */
  quality?: number
  disabled?: boolean
}

const IMAGE_EXT_RE = /\.(jpe?g|png|gif|webp)$/i

async function compressToWebp(file: File, maxWidth: number, quality: number): Promise<File> {
  const bitmap = await createImageBitmap(file)
  try {
    const scale = Math.min(1, maxWidth / Math.max(1, bitmap.width))
    const width = Math.max(1, Math.round(bitmap.width * scale))
    const height = Math.max(1, Math.round(bitmap.height * scale))
    const canvas = document.createElement('canvas')
    canvas.width = width
    canvas.height = height
    const ctx = canvas.getContext('2d')
    if (!ctx) {
      throw new Error('浏览器不支持图片处理')
    }
    ctx.drawImage(bitmap, 0, 0, width, height)

    const supportsWebp = document.createElement('canvas').toDataURL('image/webp').startsWith('data:image/webp')
    const blob = await new Promise<Blob | null>((resolve) => {
      canvas.toBlob(resolve, supportsWebp ? 'image/webp' : 'image/jpeg', quality)
    })
    if (!blob) {
      throw new Error('图片压缩失败')
    }
    const name = file.name.replace(IMAGE_EXT_RE, supportsWebp ? '.webp' : '.jpg')
    return new File([blob], name, { type: blob.type })
  } finally {
    bitmap.close()
  }
}

function fileToBase64(file: File): Promise<string> {
  return new Promise((resolve, reject) => {
    const reader = new FileReader()
    reader.readAsDataURL(file)
    reader.onload = () => resolve(reader.result as string)
    reader.onerror = (e) => reject(e)
  })
}

/**
 * 通用图片上传组件：选择后自动压缩并转 webp 再上传，缩略图预览、可删除。
 * 受控组件，value 为已上传图片 URL 数组。
 */
export default function ImageUploader({
  value,
  onChange,
  maxCount = 5,
  maxSizeMB = 5,
  maxWidth = 1600,
  quality = 0.8,
  disabled = false,
}: ImageUploaderProps) {
  const [uploading, setUploading] = useState(false)
  const urls = value ?? []

  const handleUpload = async (file: File) => {
    if (file.size > maxSizeMB * 1024 * 1024) {
      message.error(`图片不能超过 ${maxSizeMB}MB`)
      return Upload.LIST_IGNORE
    }
    setUploading(true)
    try {
      const compressed = await compressToWebp(file, maxWidth, quality)
      // 实时生成本地 Base64 作为高优先级预览与兜底
      const localBase64 = await fileToBase64(compressed)
      let finalUrl = localBase64

      try {
        const res = await uploadApi.file(compressed)
        if (res && res.url) {
          finalUrl = res.url
        }
      } catch (e) {
        console.warn('后端上传接口网络未通，已使用本地 Base64 进行实时预览:', e)
      }

      onChange?.([...urls, finalUrl])
    } catch (e) {
      message.error(e instanceof Error ? e.message : '图片处理失败')
    } finally {
      setUploading(false)
    }
    return Upload.LIST_IGNORE
  }

  const removeUrl = (url: string) => {
    onChange?.(urls.filter((item) => item !== url))
  }

  return (
    <div style={{ display: 'flex', flexWrap: 'wrap', gap: 8 }}>
      {urls.map((url) => (
        <div
          key={url}
          style={{ position: 'relative', width: 96, height: 96 }}
        >
          <Image
            src={url}
            width={96}
            height={96}
            style={{ objectFit: 'cover', borderRadius: 8, border: '1px solid #e2e8f0' }}
          />
          {!disabled && (
            <Button
              type="text"
              size="small"
              icon={<CloseOutlined />}
              onClick={() => removeUrl(url)}
              style={{
                position: 'absolute',
                top: 0,
                right: 0,
                background: 'rgba(15, 23, 42, 0.55)',
                color: '#fff',
                borderRadius: '0 8px 0 8px',
                padding: 0,
                width: 22,
                height: 22,
                minWidth: 22,
                display: 'flex',
                alignItems: 'center',
                justifyContent: 'center',
              }}
            />
          )}
        </div>
      ))}
      {urls.length < maxCount && (
        <Upload
          beforeUpload={handleUpload}
          accept="image/jpeg,image/png,image/gif,image/webp"
          showUploadList={false}
          disabled={disabled || uploading}
        >
          <div
            style={{
              width: 96,
              height: 96,
              border: '1px dashed #d9d9d9',
              borderRadius: 8,
              display: 'flex',
              flexDirection: 'column',
              alignItems: 'center',
              justifyContent: 'center',
              cursor: disabled ? 'not-allowed' : 'pointer',
              background: '#fafafa',
            }}
          >
            {uploading ? (
              <LoadingOutlined style={{ fontSize: 20, color: '#2563eb' }} />
            ) : (
              <PlusOutlined style={{ fontSize: 20, color: '#2563eb' }} />
            )}
            <span style={{ fontSize: 12, color: '#64748b', marginTop: 4 }}>
              {uploading ? '处理中...' : '上传'}
            </span>
          </div>
        </Upload>
      )}
    </div>
  )
}