import { View, Text, Image } from '@tarojs/components'
import Taro from '@tarojs/taro'
import { useState, useEffect, useRef } from 'react'
import './index.scss'
import { getDesignList, updateDesign, type StickerItem } from '../../../utils/store'
import { sketchImage, updateDesign as updateDesignApi } from '../../../utils/api'
import { useThemeContext } from '../../../context/ThemeContext'
import { useSafeArea } from '../../../hooks/useSafeArea'
import { useStatusBar } from '../../../hooks/useStatusBar'
import ThemedPageMeta from '../../../components/ThemedPageMeta'
import ScrollTopMask from '../../../components/ScrollTopMask'
import BottomActionBar from '../../../components/BottomActionBar'

/* ============================================================
   贴纸编辑（亮度/色相/对比度/裁剪/线稿）
   问题5 修正：edits 参数化保存（src 不变），预览用 Image + CSS filter
   所见即所得，不再依赖 Canvas 2D ctx.filter（开发者工具不支持）；
   DIY 渲染端按同一 edits 套 CSS filter 呈现（契约 §4：edits 不进 WCD
   document.json，仅 manifest.meta，src 保持原样对 R4 无影响）。
   ============================================================ */

const clamp = (v: number, min: number, max: number) => Math.min(Math.max(v, min), max)

/** 拖动手势滑块组件（问题5 修正：选择器查询按 id 定位，touchstart 时缓存 rect） */
interface SliderProps {
  id: string
  value: number
  min: number
  max: number
  onChange: (val: number) => void
  format?: (v: number) => string
}

function TouchSlider({ id, value, min, max, onChange, format }: SliderProps) {
  const rectRef = useRef<{ left: number; width: number } | null>(null)

  const measure = (cb?: () => void) => {
    Taro.createSelectorQuery()
      .select(`#${id}`)
      .boundingClientRect((rect: any) => {
        if (rect && rect.width > 0) rectRef.current = { left: rect.left, width: rect.width }
        if (cb) cb()
      })
      .exec()
  }

  const valueFromX = (clientX: number) => {
    const rect = rectRef.current
    if (!rect || !rect.width) return value
    const ratio = clamp((clientX - rect.left) / rect.width, 0, 1)
    return clamp(min + (max - min) * ratio, min, max)
  }

  const handleTouchStart = (e: any) => {
    const touch = e.touches && e.touches[0]
    if (!touch) return
    measure(() => onChange(valueFromX(touch.clientX)))
  }

  const handleTouchMove = (e: any) => {
    const touch = e.touches && e.touches[0]
    if (!touch) return
    if (!rectRef.current) {
      measure(() => onChange(valueFromX(touch.clientX)))
      return
    }
    onChange(valueFromX(touch.clientX))
  }

  const pct = `${((value - min) / (max - min)) * 100}%`

  return (
    <View className='slider-wrap'>
      <View
        id={id}
        className='slider-track'
        onTouchStart={handleTouchStart}
        onTouchMove={handleTouchMove}
        onTouchEnd={() => { /* rect 已缓存，无需处理 */ }}
      >
        <View className='slider-fill' style={{ width: pct }} />
        <View className='slider-thumb' style={{ left: pct }} />
      </View>
      <Text className='slider-value'>{format ? format(value) : value}</Text>
    </View>
  )
}

export default function StickerEditPage() {
  const { resolvedTheme } = useThemeContext()
  const safe = useSafeArea()
  useStatusBar(resolvedTheme)
  const [designId, setDesignId] = useState('')
  const [stickerId, setStickerId] = useState('')
  const [sticker, setSticker] = useState<StickerItem | null>(null)
  const [notFound, setNotFound] = useState(false)
  // 裁剪/线稿产生的 src 替换（保存时一并落库；取消则丢弃）
  const [pendingSrc, setPendingSrc] = useState<string | null>(null)

  // 编辑参数
  const [brightness, setBrightness] = useState(0)
  const [hue, setHue] = useState(0)
  const [contrast, setContrast] = useState(0)
  const [loading, setLoading] = useState(false)

  useEffect(() => {
    const router = Taro.getCurrentInstance().router
    const params = router ? router.params : undefined
    const dId = params ? params.designId : ''
    const sId = params ? params.stickerId : ''
    setDesignId(dId)
    setStickerId(sId)

    const list = getDesignList()
    const design = list.find(d => d.id === dId)
    const st = design && design.designData && design.designData.stickers ? design.designData.stickers.find(s => s.id === sId) : undefined
    if (st) {
      setSticker(st)
      setBrightness((st.edits && st.edits.brightness) || 0)
      setHue((st.edits && st.edits.hue) || 0)
      setContrast((st.edits && st.edits.contrast) || 0)
    } else {
      // 问题4 留意点：找不到贴纸时给出空态，而不是停在空白 Canvas
      setNotFound(true)
    }
  }, [])

  /** 保存：edits 参数化持久化（src 不变），裁剪/线稿的 src 替换一并落库 */
  const handleSave = () => {
    if (!sticker || !designId) return
    setLoading(true)
    const dList = getDesignList()
    const dIdx = dList.findIndex(d => d.id === designId)
    if (dIdx === -1) { setLoading(false); setNotFound(true); return }
    const d = dList[dIdx]
    const stickers = (d.designData && d.designData.stickers) || []
    const sIdx = stickers.findIndex(s => s.id === stickerId)
    if (sIdx === -1) { setLoading(false); setNotFound(true); return }
    stickers[sIdx] = {
      ...stickers[sIdx],
      ...(pendingSrc ? { src: pendingSrc } : {}),
      edits: { brightness, hue, contrast }
    }
    // WCD 红线：基于服务端已有 designData 合并（保留 wordcloud 分组），只覆盖 stickers
    const designData = { ...d.designData, stickers }
    updateDesign(designId, { designData }) // 本地缓存同步
    // 服务端保存（items 全量替换，必须带全 4 个基本字段）；失败暂存本地
    updateDesignApi(designId, {
      item: {
        productId: d.productId,
        productName: d.productName,
        unitPrice: d.unitPrice,
        count: d.count,
        designData
      }
    }).catch(() => Taro.showToast({ title: '网络不可用，已暂存到本地', icon: 'none' }))
    setLoading(false)
    Taro.showToast({ title: '保存成功', icon: 'success' })
    Taro.navigateBack()
  }

  /** 裁剪：调用微信cropImage */
  const handleCrop = () => {
    if (!sticker) return
    // @ts-ignore
    if (!Taro.cropImage) {
      Taro.showToast({ title: '当前微信版本不支持裁剪', icon: 'none' })
      return
    }
    // @ts-ignore
    Taro.cropImage({
      src: sticker.src,
      cropScale: '1:1',
      success: (res) => {
        const newSticker = { ...sticker, src: res.tempFilePath }
        setSticker(newSticker)
        setPendingSrc(res.tempFilePath)
      }
    })
  }

  /** 线稿：调真实后端接口（POST /api/sketch，带 token）；失败降级前端灰度参数 */
  const handleSketch = async () => {
    if (!sticker) return
    setLoading(true)
    try {
      const res = await sketchImage(sticker.src)
      if (res?.imageUrl) {
        setSticker({ ...sticker, src: res.imageUrl })
        setPendingSrc(res.imageUrl)
        setLoading(false)
        Taro.showToast({ title: '线稿生成成功', icon: 'success' })
      } else {
        throw new Error('no imageUrl')
      }
    } catch {
      // 如果接口不可用/失败，降级为前端灰度滤镜参数（保存时随 edits 持久化）
      Taro.showToast({ title: '使用本地线稿', icon: 'none' })
      setBrightness(20)
      setContrast(80)
      setHue(0)
      setLoading(false)
    }
  }

  const previewFilter = brightness === 0 && hue === 0 && contrast === 0
    ? 'none'
    : `brightness(${100 + brightness}%) hue-rotate(${hue}deg) contrast(${100 + contrast}%)`

  if (notFound) {
    return (
      <View className={`theme-${resolvedTheme}`}>
        <ThemedPageMeta />
        <ScrollTopMask title="编辑贴纸" targetSelector=".edit-header" showBack />
        <View className='sticker-edit-page'>
          <View className='edit-header' style={{ paddingTop: `${safe.statusBarHeight + 12}px` }}>
            <Text className='edit-back' onTap={() => Taro.navigateBack()}>←</Text>
            <Text className='edit-title'>编辑贴纸</Text>
            <Text className='edit-save' />
          </View>
          <View className='edit-empty surface-card mt-20'>
            <Text className='edit-empty-title'>未找到该贴纸</Text>
            <Text className='edit-empty-desc'>贴纸可能已被删除，请返回工作台重新添加</Text>
            <View className='btn-primary' onTap={() => Taro.navigateBack()}>
              <Text>返回工作台</Text>
            </View>
          </View>
        </View>
      </View>
    )
  }

  return (
    <View className={`theme-${resolvedTheme}`}>
      <ThemedPageMeta />
      <ScrollTopMask title="编辑贴纸" targetSelector=".edit-header" showBack />
      <View className='sticker-edit-page'>
        {/* Header */}
        <View className='edit-header' style={{ paddingTop: `${safe.statusBarHeight + 12}px` }}>
          <Text className='edit-back' onTap={() => Taro.navigateBack()}>←</Text>
          <Text className='edit-title'>编辑贴纸</Text>
          <Text className='edit-save' onTap={handleSave}>保存</Text>
        </View>

        {/* 预览：Image + CSS filter 所见即所得（不依赖 Canvas ctx.filter） */}
        <View className='edit-canvas-wrap'>
          <Image
            className='edit-preview-img'
            src={sticker ? sticker.src : ''}
            mode='aspectFit'
            style={{ filter: previewFilter }}
          />
        </View>

        {/* 快速操作 */}
        <View className='edit-tools surface-card mt-20'>
          <View className='edit-row'>
            <Text className='edit-label'>快速操作</Text>
            <View className='edit-quick-actions'>
              <View className='quick-btn' onTap={handleCrop}>
                <Text>裁剪</Text>
              </View>
              <View className='quick-btn' onTap={handleSketch}>
                <Text>转线稿</Text>
              </View>
            </View>
          </View>

          {/* 亮度 */}
          <View className='edit-row slider-row'>
            <Text className='edit-label'>亮度</Text>
            <TouchSlider
              id='slider-brightness'
              value={brightness}
              min={-100}
              max={100}
              onChange={setBrightness}
              format={(v) => (v > 0 ? `+${v}` : `${v}`)}
            />
          </View>

          {/* 色相 */}
          <View className='edit-row slider-row'>
            <Text className='edit-label'>色相</Text>
            <TouchSlider
              id='slider-hue'
              value={hue}
              min={-180}
              max={180}
              onChange={setHue}
              format={(v) => (v > 0 ? `+${v}` : `${v}`)}
            />
          </View>

          {/* 对比度 */}
          <View className='edit-row slider-row'>
            <Text className='edit-label'>对比度</Text>
            <TouchSlider
              id='slider-contrast'
              value={contrast}
              min={-100}
              max={100}
              onChange={setContrast}
              format={(v) => (v > 0 ? `+${v}` : `${v}`)}
            />
          </View>
        </View>

        <View style={{ flex: 1 }} />

        <BottomActionBar className='edit-footer'>
          <View className='btn-secondary' onTap={() => Taro.navigateBack()}>
            <Text>取消</Text>
          </View>
          <View className='btn-primary' onTap={handleSave}>
            <Text>保存</Text>
          </View>
        </BottomActionBar>

        <View className='safe-bottom-placeholder' />

        {loading && (
          <View className='edit-loading'>
            <Text className='edit-loading-text'>处理中…</Text>
          </View>
        )}
      </View>
    </View>
  )
}