import { useCallback, useEffect, useState } from 'react'
import Cropper, { type Area } from 'react-easy-crop'
import { ImagePlus, X } from 'lucide-react'
import { getCroppedImage } from '../utils/cropImage'
import { useT } from '../i18n/useT'
import styles from './ImageCropper.module.css'

interface ImageCropperProps {
  value: string | null
  onChange: (value: string | null) => void
  /** Crop aspect ratio. Defaults to square (1). */
  aspect?: number
  /**
   * Output format. When omitted, follows the uploaded file
   * (PNG stays PNG with transparent padding; other images become JPEG with white padding).
   */
  outputFormat?: 'jpeg' | 'png'
  /** Fill color for JPEG and for crop areas outside the image. */
  fillColor?: string
  /** Minimum zoom. Values below 1 shrink the image inside the crop frame. */
  minZoom?: number
  maxZoom?: number
  accept?: string
  uploadLabel?: string
  hint?: string
  changeLabel?: string
  /** Smaller upload/preview frame for narrow grid columns. */
  compact?: boolean
}

function isPngSource(file: File): boolean {
  return (
    file.type === 'image/png' ||
    file.name.toLowerCase().endsWith('.png')
  )
}

function isPngDataUrl(src: string): boolean {
  return /^data:image\/png/i.test(src)
}

export function ImageCropper({
  value,
  onChange,
  aspect = 1,
  outputFormat,
  fillColor,
  minZoom = 0.4,
  maxZoom = 3,
  accept = 'image/*',
  uploadLabel,
  hint,
  changeLabel,
  compact = false,
}: ImageCropperProps) {
  const t = useT()
  const resolvedUploadLabel = uploadLabel ?? t('products.form.thumbnailUpload')
  const resolvedHint = hint ?? t('products.form.thumbnailHint')
  const resolvedChangeLabel = changeLabel ?? t('products.form.thumbnailChange')
  const [imageSrc, setImageSrc] = useState<string | null>(null)
  const [sourceIsPng, setSourceIsPng] = useState(false)
  const [crop, setCrop] = useState({ x: 0, y: 0 })
  const [zoom, setZoom] = useState(1)
  const [croppedArea, setCroppedArea] = useState<Area | null>(null)

  const resolvedFormat: 'jpeg' | 'png' =
    outputFormat ?? (sourceIsPng ? 'png' : 'jpeg')
  const resolvedFillColor =
    fillColor ?? (resolvedFormat === 'jpeg' ? '#ffffff' : undefined)
  const useTransparentPad = resolvedFormat === 'png' && !resolvedFillColor

  useEffect(() => {
    setCrop({ x: 0, y: 0 })
    setZoom(1)
    setCroppedArea(null)
  }, [aspect])

  const onCropComplete = useCallback((_: Area, pixels: Area) => {
    setCroppedArea(pixels)
  }, [])

  function handleFile(e: React.ChangeEvent<HTMLInputElement>) {
    const file = e.target.files?.[0]
    if (!file) return
    const png = isPngSource(file)
    setSourceIsPng(png)
    const reader = new FileReader()
    reader.onload = () => {
      setImageSrc(reader.result as string)
      setCrop({ x: 0, y: 0 })
      setZoom(1)
      setCroppedArea(null)
    }
    reader.readAsDataURL(file)
    e.target.value = ''
  }

  async function applyCrop() {
    if (!imageSrc || !croppedArea) return
    const format: 'jpeg' | 'png' =
      outputFormat ?? (isPngDataUrl(imageSrc) || sourceIsPng ? 'png' : 'jpeg')
    const fill = fillColor ?? (format === 'jpeg' ? '#ffffff' : undefined)
    const cropped = await getCroppedImage(imageSrc, croppedArea, format, fill)
    onChange(cropped)
    setImageSrc(null)
    setZoom(1)
    setCrop({ x: 0, y: 0 })
  }

  function cancelCrop() {
    setImageSrc(null)
    setZoom(1)
    setCrop({ x: 0, y: 0 })
  }

  function removeThumbnail() {
    onChange(null)
  }

  const isPortrait = aspect < 1
  const maxHeight = isPortrait ? 'min(360px, 42vh)' : 'min(280px, 36vh)'
  const frameStyle: React.CSSProperties = compact
    ? {
        aspectRatio: String(aspect),
        width: '100%',
        height: 'auto',
        minHeight: 0,
      }
    : {
        aspectRatio: String(aspect),
        width: `min(100%, calc(${maxHeight} * ${aspect}))`,
        height: 'auto',
        maxHeight,
        minHeight: 0,
        marginInline: 'auto',
        alignSelf: 'center',
      }

  const cropSurfaceStyle: React.CSSProperties = useTransparentPad
    ? { ...frameStyle }
    : { ...frameStyle, background: resolvedFillColor ?? '#1e293b' }

  return (
    <div className={`${styles.wrapper} ${compact ? styles.compact : ''}`}>
      {value && !imageSrc && (
        <div className={styles.preview} style={frameStyle}>
          <img src={value} alt={resolvedUploadLabel} className={styles.previewImg} />
          <button
            type="button"
            className={styles.removeBtn}
            onClick={removeThumbnail}
            aria-label={t('products.form.thumbnailRemove')}
          >
            <X size={16} />
          </button>
        </div>
      )}

      {!value && !imageSrc && (
        <label className={styles.uploadZone} style={frameStyle}>
          <ImagePlus size={compact ? 20 : 28} />
          <span>{resolvedUploadLabel}</span>
          <span className={styles.hint}>{resolvedHint}</span>
          <input type="file" accept={accept} onChange={handleFile} hidden />
        </label>
      )}

      {imageSrc && (
        <div className={styles.cropPanel}>
          <div
            className={`${styles.cropArea} ${useTransparentPad ? styles.cropAreaTransparent : ''}`}
            style={cropSurfaceStyle}
          >
            <Cropper
              key={String(aspect)}
              image={imageSrc}
              crop={crop}
              zoom={zoom}
              minZoom={minZoom}
              maxZoom={maxZoom}
              aspect={aspect}
              onCropChange={setCrop}
              onZoomChange={setZoom}
              onCropComplete={onCropComplete}
              restrictPosition={minZoom >= 1}
              style={{
                containerStyle: useTransparentPad
                  ? { background: 'transparent' }
                  : { background: resolvedFillColor ?? '#1e293b' },
              }}
            />
          </div>
          <div className={styles.cropControls}>
            <label className={styles.zoomLabel}>
              {t('products.form.zoom')}
              <input
                type="range"
                min={minZoom}
                max={maxZoom}
                step={0.05}
                value={zoom}
                onChange={(e) => setZoom(Number(e.target.value))}
              />
            </label>
            <div className={styles.cropActions}>
              <button type="button" className={styles.cancelBtn} onClick={cancelCrop}>
                {t('products.form.cancel')}
              </button>
              <button
                type="button"
                className={styles.applyBtn}
                onClick={() => void applyCrop()}
                disabled={!croppedArea}
              >
                {t('products.form.applyCrop')}
              </button>
            </div>
          </div>
        </div>
      )}

      {value && !imageSrc && (
        <label className={styles.changeBtn}>
          {resolvedChangeLabel}
          <input type="file" accept={accept} onChange={handleFile} hidden />
        </label>
      )}
    </div>
  )
}