import type { RawImageDataSource, SystemLabelTemplate, SystemTemplateElementBase } from '../print/types/printer'
import { resolveMediaUrlForApp, storedValueLooksLikeImagePath } from '../resolveMediaUrl'
import { sortElementsForPreview } from './normalizePreviewTemplate'
import QRCode from 'qrcode'

const NUTRITION_FIXED_ITEMS = [
  { key: 'fat', label: 'Total Fat' },
  { key: 'saturatedFat', label: 'Saturated Fat' },
  { key: 'transFat', label: 'Trans Fat' },
  { key: 'cholesterol', label: 'Cholesterol' },
  { key: 'sodium', label: 'Sodium' },
  { key: 'carbs', label: 'Total Carbohydrates' },
  { key: 'dietaryFiber', label: 'Dietary Fiber' },
  { key: 'totalSugar', label: 'Total Sugar' },
  { key: 'protein', label: 'Protein' },
  { key: 'vitaminA', label: 'Vitamin A' },
  { key: 'vitaminC', label: 'Vitamin C' },
  { key: 'calcium', label: 'Calcium' },
  { key: 'iron', label: 'Iron' },
]

/** 与 Web LabelCanvas.unitToPx 一致：cm 用 37.8px/inch，保证与后台模板坐标系一致 */
const PX_PER_CM = 37.8
const PX_PER_INCH = 96

function toCanvasPx(value: number, unit: string): number {
  const u = String(unit || 'inch').toLowerCase()
  if (u === 'mm') return (value / 25.4) * PX_PER_INCH
  if (u === 'cm') return value * PX_PER_CM
  if (u === 'px') return value
  return value * PX_PER_INCH
}

function cfgStr(config: Record<string, any>, keys: string[], fallback = ''): string {
  for (const k of keys) {
    const v = config?.[k]
    if (v != null && v !== '') return String(v)
  }
  return fallback
}

/** 前缀在正文前；若正文已以前缀开头则不再重复拼接 */
function applyConfigPrefix(config: Record<string, any>, body: string): string {
  const prefix = String(config.prefix ?? config.Prefix ?? '')
  if (!prefix) return body
  const b = body ?? ''
  if (b.startsWith(prefix)) return b
  return `${prefix}${b}`
}

function readFontSize(config: Record<string, any>): number {
  const n = Number(config.fontSize ?? config.FontSize ?? 14)
  return Math.max(6, Math.round(Number.isFinite(n) ? n : 14))
}

function readTextAlign(config: Record<string, any>): string {
  return String(config.textAlign ?? config.TextAlign ?? 'left').toLowerCase()
}

function readFillColor(config: Record<string, any>): string {
  return String(config.color ?? config.Color ?? '#111827')
}

/** 按元素框宽度估算每行最大字符数（等宽近似，兼容中英文） */
function maxCharsPerLine(innerWidthPx: number, fontSize: number): number {
  if (innerWidthPx <= 4) return 8
  const approx = Math.max(0.45, Math.min(0.75, 0.55))
  /** 下限 8：避免过窄估算时按 4 字硬切把英文单词拦腰截断（如 All|ergens） */
  return Math.max(8, Math.floor(innerWidthPx / (fontSize * approx)))
}

/**
 * 优先在空格处断行，长词再按字符切分；避免固定宽度硬切破坏英文单词与「标签: 值」可读性。
 */
function wrapSingleLogicalLine(line: string, maxChars: number): string[] {
  const limit = Math.max(8, maxChars)
  const s = String(line)
  if (s.length <= limit) return [s]

  const words = s.split(/(\s+)/)
  const out: string[] = []
  let cur = ''

  const pushLongToken = (token: string) => {
    for (let i = 0; i < token.length; i += limit) {
      out.push(token.slice(i, i + limit))
    }
  }

  for (const w of words) {
    if (/^\s+$/.test(w)) {
      cur += w
      continue
    }
    if (!w) continue

    const trimmedRight = cur.replace(/\s+$/, '')
    const candidate = trimmedRight ? `${trimmedRight} ${w}` : w
    if (candidate.length <= limit) {
      cur = candidate
    } else {
      if (trimmedRight) out.push(trimmedRight)
      cur = ''
      if (w.length > limit) {
        pushLongToken(w)
      } else {
        cur = w
      }
    }
  }
  const tail = cur.replace(/\s+$/, '')
  if (tail) out.push(tail)
  return out.length ? out : ['']
}

function wrapTextToWidth(text: string, maxChars: number): string[] {
  const lines = String(text).split(/\r?\n/)
  const out: string[] = []
  for (const line of lines) {
    out.push(...wrapSingleLogicalLine(line, maxChars))
  }
  return out.length ? out : ['']
}

function previewTextForElement(element: SystemTemplateElementBase): string {
  const type = String(element.type || '').toUpperCase()
  const config = element.config || {}
  if (type === 'QRCODE') {
    return cfgStr(config, ['data', 'Data', 'value', 'Value'])
  }
  if (type === 'BARCODE') {
    // 平台模板条码值常见键：data / barcodeData（含大小写变体）
    return cfgStr(config, ['data', 'Data', 'barcodeData', 'BarcodeData', 'value', 'Value'])
  }
  const vst = String(element.valueSourceType || '').toUpperCase()
  const inputType = String(config.inputType ?? config.InputType ?? '').toLowerCase()
  const hasDict = !!(config.multipleOptionId ?? config.MultipleOptionId)
  if (vst === 'PRINT_INPUT' && (inputType === 'options' || hasDict)) {
    const rawSel = config.selectedOptionValues ?? config.SelectedOptionValues
    const arr = Array.isArray(rawSel) ? rawSel.map((x: unknown) => String(x)) : []
    const txt = cfgStr(config, ['text', 'Text'], '')
    if (arr.length > 0 && txt.trim()) return txt
    if (arr.length > 0) {
      const joined = arr.join(', ')
      return applyConfigPrefix(config, joined)
    }
    const hint = txt.trim() || 'Select below'
    return applyConfigPrefix(config, hint)
  }
  if (vst === 'PRINT_INPUT' && !(inputType === 'options' || hasDict)) {
    let body = cfgStr(config, ['text', 'Text'], '')
    if (!body.trim()) body = cfgStr(config, ['value', 'Value'], '')
    if (!body.trim()) body = cfgStr(config, ['format', 'Format', 'placeholder', 'Placeholder'], '')
    const unit = String(config.unit ?? config.Unit ?? '').trim()
    if (unit && body.trim() && !body.endsWith(unit)) body = `${body}${unit}`
    return applyConfigPrefix(config, body)
  }
  const body = cfgStr(config, [
    'text',
    'Text',
    'format',
    'Format',
    'content',
    'Content',
    'value',
    'Value',
    'displayText',
    'displayValue',
    'defaultValue',
    'placeholder',
  ])
  return applyConfigPrefix(config, body)
}

function isGraphicOnlyType(type: string): boolean {
  return type === 'IMAGE' || type === 'LOGO' || type === 'BARCODE' || type === 'QRCODE'
}

function previewExportPixelRatio(): number {
  try {
    const pr = uni.getSystemInfoSync().pixelRatio
    return Math.min(2.5, Math.max(1, typeof pr === 'number' && pr > 0 ? pr : 2))
  } catch {
    return 2
  }
}

function barcodeModulesFromValue(value: string): number[] {
  const s = String(value || '').trim()
  if (!s) return []
  const modules: number[] = []
  // quiet + start（轻量预览编码：保证视觉稳定，非扫描级编码）
  modules.push(1, 0, 1, 0, 1, 0, 1, 0)
  for (let i = 0; i < s.length; i++) {
    const code = s.charCodeAt(i) & 0xff
    // 用 5bit 模块 + 分隔位，避免在窄宽度里“整块发黑”。
    const key = (code ^ (i * 13) ^ (s.length * 7)) & 0x1f
    for (let b = 4; b >= 0; b--) modules.push((key >> b) & 1)
    modules.push(0)
  }
  // stop
  modules.push(1, 0, 1, 1, 0, 1, 0, 1)
  return modules
}

function drawBarcodeLikePreview(
  ctx: UniApp.CanvasContext,
  x: number,
  y: number,
  w: number,
  h: number,
  value: string,
  options?: { orientation?: string; showText?: boolean }
): void {
  const bw = Math.max(40, w || 140)
  const bh = Math.max(28, h || 56)
  const showText = options?.showText !== false
  const pad = 2
  const modules = barcodeModulesFromValue(value)
  const orientation = String(options?.orientation || 'horizontal').toLowerCase()
  const isVertical = orientation === 'vertical'

  ctx.setFillStyle('#ffffff')
  ctx.fillRect(x, y, bw, bh)
  if (!modules.length) return

  const txt = String(value || '').trim()
  ctx.setFillStyle('#111827')

  if (!isVertical) {
    const textH = showText && txt ? Math.max(10, Math.round(bh * 0.2)) : 0
    const barH = Math.max(10, bh - textH - pad * 2)
    const innerW = Math.max(8, bw - pad * 2)
    const moduleW = innerW / modules.length
    let cursor = x + pad
    for (let i = 0; i < modules.length; i++) {
      if (modules[i] === 1) {
        const rw = Math.max(0.7, moduleW * 0.86)
        ctx.fillRect(cursor, y + pad, rw, barH)
      }
      cursor += moduleW
    }
    if (showText && txt) {
      ctx.setFontSize(Math.max(9, Math.min(12, Math.round(textH * 0.8))))
      ctx.setTextAlign('center')
      ctx.fillText(txt, x + bw / 2, y + bh - 2)
      ctx.setTextAlign('left')
    }
    return
  }

  // vertical：条码在左，data 竖排在右
  const textBandW = showText && txt ? Math.max(10, Math.round(bw * 0.18)) : 0
  const barW = Math.max(10, bw - textBandW - pad * 2)
  const innerH = Math.max(10, bh - pad * 2)
  const moduleH = innerH / modules.length
  let cursorY = y + pad
  for (let i = 0; i < modules.length; i++) {
    if (modules[i] === 1) {
      const rh = Math.max(0.7, moduleH * 0.86)
      ctx.fillRect(x + pad, cursorY, barW, rh)
    }
    cursorY += moduleH
  }
  if (showText && txt) {
    const font = Math.max(9, Math.min(11, Math.floor(textBandW * 0.75)))
    const cx = x + bw - textBandW / 2
    const cy = y + bh / 2
    const anyCtx = ctx as any
    if (typeof anyCtx.save === 'function' && typeof anyCtx.rotate === 'function') {
      anyCtx.save()
      anyCtx.translate(cx, cy)
      // 竖排文本按模板端习惯：从下到上
      anyCtx.rotate(-Math.PI / 2)
      ctx.setFontSize(font)
      ctx.setTextAlign('center')
      ctx.fillText(txt, 0, Math.min(font * 0.35, 4))
      ctx.setTextAlign('left')
      anyCtx.restore()
    } else {
      // 低端环境兜底：不旋转能力时退化为逐字竖排
      let ty = y + pad + font
      ctx.setFontSize(font)
      ctx.setTextAlign('center')
      for (let i = 0; i < txt.length; i++) {
        ctx.fillText(txt[i], cx, ty)
        ty += font + 1
        if (ty > y + bh - 1) break
      }
      ctx.setTextAlign('left')
    }
  }
}

function drawQrCodePreview(
  ctx: UniApp.CanvasContext,
  x: number,
  y: number,
  w: number,
  h: number,
  value: string,
  errorLevelRaw?: string,
): void {
  const text = String(value || '').trim()
  const bw = Math.max(24, w || 96)
  const bh = Math.max(24, h || 96)
  if (!text) return

  let matrixSize = 0
  let moduleData: Uint8Array | number[] = []
  try {
    const lv = String(errorLevelRaw || 'M').trim().toUpperCase()
    const level = lv === 'L' || lv === 'M' || lv === 'Q' || lv === 'H' ? lv : 'M'
    const qr = QRCode.create(text, { errorCorrectionLevel: level })
    matrixSize = Number(qr?.modules?.size || 0)
    moduleData = (qr?.modules?.data as Uint8Array | number[]) || []
  } catch {
    matrixSize = 0
    moduleData = []
  }
  if (!matrixSize || !moduleData.length) return

  const pad = Math.max(1, Math.floor(Math.min(bw, bh) * 0.06))
  const side = Math.max(12, Math.min(bw, bh) - pad * 2)
  const cell = Math.max(1, Math.floor(side / matrixSize))
  const drawSide = cell * matrixSize
  const ox = x + Math.floor((bw - drawSide) / 2)
  const oy = y + Math.floor((bh - drawSide) / 2)

  ctx.setFillStyle('#ffffff')
  ctx.fillRect(x, y, bw, bh)
  ctx.setFillStyle('#111827')
  for (let r = 0; r < matrixSize; r++) {
    for (let c = 0; c < matrixSize; c++) {
      const idx = r * matrixSize + c
      const dark = Number((moduleData as any)[idx]) === 1
      if (!dark) continue
      ctx.fillRect(ox + c * cell, oy + r * cell, cell, cell)
    }
  }
}

function nutritionFixedField(cfg: Record<string, any>, key: string, field: 'value' | 'unit'): string {
  const directKey = field === 'value' ? key : `${key}Unit`
  const direct = cfg[directKey]
  if (direct != null && String(direct).trim() !== '') return String(direct).trim()
  const rows = Array.isArray(cfg.fixedNutrients) ? (cfg.fixedNutrients as Array<Record<string, unknown>>) : []
  const row = rows.find((item) => String(item.key ?? '').trim() === key)
  return String(row?.[field] ?? '').trim()
}

function nutritionExtraRows(cfg: Record<string, any>): Array<{ name: string; value: string; unit: string }> {
  const raw = cfg.extraNutrients
  if (!Array.isArray(raw)) return []
  return raw.map((item) => {
    const row = (item || {}) as Record<string, unknown>
    return {
      name: String(row.name ?? '').trim(),
      value: String(row.value ?? '').trim(),
      unit: String(row.unit ?? '').trim(),
    }
  })
}

function nutritionValueWithLessThan(value: string, unit: string): string {
  const v = String(value || '').trim()
  const u = String(unit || '').trim()
  if (!v && !u) return ''
  return `<${v}${u ? ` ${u}` : ''}`
}

/** 与屏幕预览 / 位图打印共用绘制逻辑（坐标系：设计宽 cw × ch，ctx 已 scale） */
function runLabelPreviewCanvasDraw(
  canvasId: string,
  componentInstance: any,
  template: SystemLabelTemplate,
  cw: number,
  ch: number,
  scale: number
): Promise<void> {
  const sorted = sortElementsForPreview(template.elements || [])

  return new Promise((resolve) => {
    const ctx = uni.createCanvasContext(canvasId, componentInstance)
    ctx.setFillStyle('#ffffff')
    ctx.scale(scale, scale)
    ctx.fillRect(0, 0, cw, ch)

    const drawRest = (index: number) => {
      if (index >= sorted.length) {
        ctx.draw(false, () => resolve())
        return
      }

      const el = sorted[index]
      const type = String(el.type || '').toUpperCase()
      const config = el.config || {}
      const x = Number(el.x) || 0
      const y = Number(el.y) || 0
      const w = Math.max(0, Number(el.width) || 0)
      const h = Math.max(0, Number(el.height) || 0)

      const next = () => drawRest(index + 1)

      if (type === 'IMAGE' || type === 'LOGO') {
        const src = resolveMediaUrlForApp(cfgStr(config, ['src', 'url', 'Src', 'Url']))
        if (src) {
          uni.getImageInfo({
            src,
            success: (info) => {
              try {
                ctx.drawImage(info.path, x, y, w || info.width, h || info.height)
              } catch (_) {
                ctx.setStrokeStyle('#cccccc')
                ctx.setLineWidth(1)
                ctx.strokeRect(x, y, w || 80, h || 40)
              }
              next()
            },
            fail: () => {
              ctx.setStrokeStyle('#cccccc')
              ctx.strokeRect(x, y, w || 80, h || 40)
              next()
            },
          })
          return
        }
        next()
        return
      }

      if (type === 'NUTRITION') {
        const bw = Math.max(40, w || 120)
        const bh = Math.max(36, h || 96)
        const pad = 3
        const rightX = x + bw - pad
        const maxY = y + bh - 2
        const titleSize = Math.max(11, Math.min(18, Number(config.nutritionTitleFontSize ?? config.NutritionTitleFontSize ?? 16) || 16))
        const bodySize = Math.max(8, Math.min(11, Math.floor(titleSize * 0.72)))
        let cursorY = y + pad

        const servingsPerContainer = String(config.servingsPerContainer ?? config.ServingsPerContainer ?? '').trim()
        const servingSize = String(config.servingSize ?? config.ServingSize ?? '').trim()
        const calories = String(config.calories ?? config.Calories ?? nutritionFixedField(config, 'calories', 'value') ?? '').trim()
        const rows = [
          ...NUTRITION_FIXED_ITEMS.map((item) => {
            const value = nutritionFixedField(config, item.key, 'value')
            const unit = nutritionFixedField(config, item.key, 'unit')
            if (!value) return null
            return { label: item.label, value: nutritionValueWithLessThan(value, unit) }
          }).filter(Boolean) as Array<{ label: string; value: string }>,
          ...nutritionExtraRows(config)
            .filter((r) => r.value)
            .map((r) => ({
              label: r.name || 'Other',
              value: nutritionValueWithLessThan(r.value, r.unit),
            })),
        ]

        const drawPair = (label: string, value: string, fs: number, bold = false): boolean => {
          const f = Math.max(8, Math.round(fs))
          const lh = f + 2
          if (cursorY + lh > maxY) return false
          ctx.setFillStyle('#111827')
          ctx.setFontSize(f)
          ctx.setTextAlign('left')
          ctx.fillText(label, x + pad, cursorY + f)
          if (bold) ctx.fillText(label, x + pad + 0.5, cursorY + f)
          if (value) {
            ctx.setTextAlign('right')
            ctx.fillText(value, rightX, cursorY + f)
            if (bold) ctx.fillText(value, rightX + 0.5, cursorY + f)
            ctx.setTextAlign('left')
          }
          cursorY += lh
          return true
        }

        ctx.setFillStyle('#ffffff')
        ctx.fillRect(x, y, bw, bh)
        ctx.setStrokeStyle('#111827')
        ctx.setLineWidth(1)
        ctx.strokeRect(x, y, bw, bh)

        if (cursorY + titleSize + 2 <= maxY) {
          ctx.setFillStyle('#111827')
          ctx.setFontSize(Math.round(titleSize))
          ctx.setTextAlign('left')
          ctx.fillText('Nutrition Facts', x + pad, cursorY + Math.round(titleSize))
          cursorY += Math.round(titleSize) + 2
          ctx.setLineWidth(1)
          ctx.beginPath()
          ctx.moveTo(x + pad, cursorY)
          ctx.lineTo(rightX, cursorY)
          ctx.stroke()
          cursorY += 2
        }

        if (calories) drawPair('Calories', nutritionValueWithLessThan(calories, ''), Math.max(bodySize, 9), true)
        if (servingsPerContainer) drawPair('Servings Per Container', servingsPerContainer, bodySize)
        if (servingSize) drawPair('Serving Size', servingSize, bodySize)
        for (const row of rows) {
          if (!drawPair(row.label, row.value, bodySize, true)) break
        }

        next()
        return
      }

      if (type === 'QRCODE' || type === 'BARCODE') {
        const d = previewTextForElement(el)
        const drawQrBarcodePlaceholder = () => {
          ctx.setFillStyle('#f3f4f6')
          ctx.fillRect(x, y, w || 60, h || 60)
          ctx.setStrokeStyle('#9ca3af')
          ctx.setLineWidth(1)
          ctx.strokeRect(x, y, w || 60, h || 60)
          ctx.setFillStyle('#374151')
          ctx.setFontSize(10)
          const label = type === 'QRCODE' ? 'QR' : 'BC'
          ctx.fillText(label, x + 4, y + 14)
          if (d) {
            const short = d.length > 12 ? `${d.slice(0, 10)}…` : d
            ctx.fillText(short, x + 4, y + 28)
          }
        }

        if (type === 'BARCODE' && d) {
          const orientation = cfgStr(config, ['orientation', 'Orientation'], 'horizontal')
          const showText = String(config.showText ?? config.ShowText ?? 'true').toLowerCase() !== 'false'
          drawBarcodeLikePreview(ctx, x, y, w || 140, h || 56, d, { orientation, showText })
          next()
          return
        }

        if (type === 'QRCODE' && d && !storedValueLooksLikeImagePath(d)) {
          drawQrCodePreview(ctx, x, y, w || 96, h || 96, d, cfgStr(config, ['errorLevel', 'ErrorLevel'], 'M'))
          next()
          return
        }

        // 管理端可把二维码默认值存为上传图片路径，须按位图绘制而非占位符文本
        if (type === 'QRCODE' && d && storedValueLooksLikeImagePath(d)) {
          const src = resolveMediaUrlForApp(d)
          if (src) {
            uni.getImageInfo({
              src,
              success: (info) => {
                try {
                  const dw = w || info.width
                  const dh = h || info.height
                  ctx.drawImage(info.path, x, y, dw, dh)
                } catch (_) {
                  drawQrBarcodePlaceholder()
                }
                next()
              },
              fail: () => {
                drawQrBarcodePlaceholder()
                next()
              },
            })
            return
          }
        }

        drawQrBarcodePlaceholder()
        next()
        return
      }

      const line = String(el.border || '').toLowerCase()
      if (line === 'line' || line === 'solid') {
        ctx.setStrokeStyle('#111827')
        ctx.setLineWidth(1)
        ctx.strokeRect(x, y, w, h)
      } else if (line === 'dotted') {
        ctx.setStrokeStyle('#9ca3af')
        ctx.setLineWidth(1)
        if (typeof (ctx as any).setLineDash === 'function') {
          ;(ctx as any).setLineDash([3, 3], 0)
          ctx.strokeRect(x, y, w, h)
          ;(ctx as any).setLineDash([], 0)
        } else {
          ctx.strokeRect(x, y, w, h)
        }
      }

      const text = previewTextForElement(el)
      if (text && !isGraphicOnlyType(type)) {
        const fontSize = readFontSize(config)
        const color = readFillColor(config)
        ctx.setFillStyle(color)
        ctx.setFontSize(fontSize)
        const fontWeight = String(config.fontWeight ?? config.FontWeight ?? 'normal').toLowerCase()
        if (typeof (ctx as any).setFontWeight === 'function') {
          ;(ctx as any).setFontWeight(fontWeight === 'bold' || fontWeight === '700' ? 'bold' : 'normal')
        }
        const align = readTextAlign(config)
        const pad = 2
        const innerW = Math.max(0, w - pad * 2)
        const innerH = Math.max(fontSize, h - pad * 2)
        let tx = x + pad
        if (align === 'center') tx = x + w / 2
        else if (align === 'right') tx = x + w - pad
        ctx.setTextAlign(align === 'center' ? 'center' : align === 'right' ? 'right' : 'left')
        const lineHeight = fontSize + Math.max(2, Math.round(fontSize * 0.15))
        const maxChars = maxCharsPerLine(innerW, fontSize)
        const lines = wrapTextToWidth(text, maxChars)
        const maxLines =
          innerH >= fontSize ? Math.max(1, Math.floor(innerH / lineHeight)) : lines.length
        const startY = y + pad + fontSize
        lines.slice(0, maxLines).forEach((ln, li) => {
          ctx.fillText(ln, tx, startY + li * lineHeight)
        })
        ctx.setTextAlign('left')
      }

      next()
    }

    drawRest(0)
  })
}

/**
 * 将模板绘制到 canvas，并导出临时路径供 <image> 展示。
 */
export function renderLabelPreviewToTempPath(
  canvasId: string,
  componentInstance: any,
  template: SystemLabelTemplate,
  maxDisplayWidthPx = 720
): Promise<string> {
  const unit = template.unit || 'inch'
  const cw = Math.max(40, Math.round(toCanvasPx(Number(template.width) || 2, unit)))
  const ch = Math.max(40, Math.round(toCanvasPx(Number(template.height) || 2, unit)))
  const scale = Math.min(1, maxDisplayWidthPx / cw)
  const outW = Math.max(1, Math.round(cw * scale))
  const outH = Math.max(1, Math.round(ch * scale))
  const exportPr = previewExportPixelRatio()

  return runLabelPreviewCanvasDraw(canvasId, componentInstance, template, cw, ch, scale).then(
    () =>
      new Promise<string>((resolve, reject) => {
        setTimeout(() => {
          uni.canvasToTempFilePath(
            {
              canvasId,
              width: outW,
              height: outH,
              destWidth: Math.round(outW * exportPr),
              destHeight: Math.round(outH * exportPr),
              success: (res) => resolve(res.tempFilePath),
              fail: (err) => reject(new Error(err.errMsg || 'canvasToTempFilePath failed')),
            },
            componentInstance
          )
        }, 120)
      })
  )
}

/**
 * 打印专用：与屏幕预览相同走 canvasToTempFilePath（已验证能出图），再由 printImageForCurrentPrinter 用原生 Bitmap 解码光栅化。
 * 避免 canvasGetImageData 在部分机型/页面上下文中返回空或错位，导致 BLE 发出“空标签”仍回调成功。
 */
export function renderLabelPreviewCanvasToTempPathForPrint(
  canvasId: string,
  componentInstance: any,
  template: SystemLabelTemplate,
  layout: { cw: number, ch: number, outW: number, outH: number, scale: number }
): Promise<string> {
  const { cw, ch, outW, outH, scale } = layout
  return runLabelPreviewCanvasDraw(canvasId, componentInstance, template, cw, ch, scale).then(
    () =>
      new Promise<string>((resolve, reject) => {
        setTimeout(() => {
          uni.canvasToTempFilePath(
            {
              canvasId,
              x: 0,
              y: 0,
              width: outW,
              height: outH,
              destWidth: outW,
              destHeight: outH,
              fileType: 'png',
              quality: 1,
              success: (res) => resolve(res.tempFilePath),
              fail: (err) => reject(new Error(err.errMsg || 'canvasToTempFilePath for print failed')),
            },
            componentInstance
          )
        }, 150)
      })
  )
}

/**
 * 与 `shouldRasterPrintViaCanvasImageData()` 配套：内置 UPOS 等机型不走 Bitmap int[]，与 Test Print 一致用 canvasGetImageData。
 */
export function renderLabelPreviewCanvasImageDataForPrint(
  canvasId: string,
  componentInstance: any,
  template: SystemLabelTemplate,
  layout: { cw: number, ch: number, outW: number, outH: number, scale: number }
): Promise<RawImageDataSource> {
  const { cw, ch, outW, outH, scale } = layout
  return runLabelPreviewCanvasDraw(canvasId, componentInstance, template, cw, ch, scale).then(
    () =>
      new Promise<RawImageDataSource>((resolve, reject) => {
        setTimeout(() => {
          uni.canvasGetImageData(
            {
              canvasId,
              x: 0,
              y: 0,
              width: outW,
              height: outH,
              success: (res: any) => {
                resolve({
                  width: outW,
                  height: outH,
                  data: res.data,
                })
              },
              fail: (err: any) => {
                reject(new Error(err?.errMsg || 'canvasGetImageData for print failed'))
              },
            },
            componentInstance
          )
        }, 150)
      })
  )
}

/**
 * 按打印机最大宽度（dots）与 DPI 计算栅格尺寸；宽为 8 的倍数，与 Test Print / rasterizeImageData 一致。
 */
export function getLabelPrintRasterLayout(
  template: SystemLabelTemplate,
  maxWidthDots: number,
  printDpi = 203
): { cw: number, ch: number, outW: number, outH: number, scale: number } {
  const unit = template.unit || 'inch'
  const cw = Math.max(40, Math.round(toCanvasPx(Number(template.width) || 2, unit)))
  const ch = Math.max(40, Math.round(toCanvasPx(Number(template.height) || 2, unit)))
  const designDpi = 96
  const idealW = Math.round(cw * (printDpi / designDpi))
  const cap = Math.max(8, Math.round(maxWidthDots || 576))
  let outW = Math.max(8, Math.min(cap, idealW))
  outW -= outW % 8
  if (outW < 8) outW = 8
  const scale = outW / cw
  const outH = Math.max(1, Math.round(ch * scale))
  return { cw, ch, outW, outH, scale }
}

export function getPreviewCanvasCssSize(template: SystemLabelTemplate, maxDisplayWidthPx = 720): {
  width: number
  height: number
} {
  const unit = template.unit || 'inch'
  const cw = Math.max(40, Math.round(toCanvasPx(Number(template.width) || 2, unit)))
  const ch = Math.max(40, Math.round(toCanvasPx(Number(template.height) || 2, unit)))
  const scale = Math.min(1, maxDisplayWidthPx / cw)
  return {
    width: Math.max(1, Math.round(cw * scale)),
    height: Math.max(1, Math.round(ch * scale)),
  }
}