'use client'

import { ImageIcon, Loader2, Search, X } from 'lucide-react'
import { useCallback, useEffect, useRef, useState } from 'react'
import { Badge } from '@/components/ui/badge'
import { Button } from '@/components/ui/button'
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from '@/components/ui/dialog'
import { Input } from '@/components/ui/input'
import { cn } from '@/lib/utils'

interface CatalogImagePickerProps {
  value: string
  onChange: (name: string) => void
  /** Filter: 'header' | 'teaser' | 'all' */
  type?: 'header' | 'teaser' | 'all'
  disabled?: boolean
  label?: string
}

const PAGE_SIZE = 80

export function CatalogImagePicker({
  value,
  onChange,
  type = 'all',
  disabled,
  label,
}: CatalogImagePickerProps) {
  const [open, setOpen] = useState(false)
  const [search, setSearch] = useState('')
  const [debounced, setDebounced] = useState('')
  const [images, setImages] = useState<string[]>([])
  const [total, setTotal] = useState(0)
  const [loading, setLoading] = useState(false)
  const [offset, setOffset] = useState(0)
  const [hasMore, setHasMore] = useState(true)
  const scrollRef = useRef<HTMLDivElement>(null)

  // Debounce search
  useEffect(() => {
    const t = setTimeout(() => setDebounced(search.trim()), 250)
    return () => clearTimeout(t)
  }, [search])

  const fetchImages = useCallback(
    async (nextOffset: number, replace: boolean) => {
      setLoading(true)
      try {
        const params = new URLSearchParams({
          limit: String(PAGE_SIZE),
          offset: String(nextOffset),
          type,
        })
        if (debounced) params.set('search', debounced)
        const res = await fetch(`/api/admin/catalog/images?${params}`)
        if (!res.ok) throw new Error()
        const data = await res.json()
        const fetched: string[] = data.images ?? []
        setTotal(data.total ?? 0)
        setHasMore(nextOffset + fetched.length < (data.total ?? 0))
        setImages((prev) => (replace ? fetched : [...prev, ...fetched]))
        setOffset(nextOffset + fetched.length)
      } catch {
        // ignore
      } finally {
        setLoading(false)
      }
    },
    [debounced, type],
  )

  // Reset and fetch on open / search change
  // biome-ignore lint/correctness/useExhaustiveDependencies: explicitly chosen here, see surrounding code
  useEffect(() => {
    if (!open) return
    setImages([])
    setOffset(0)
    setHasMore(true)
    fetchImages(0, true)
    if (scrollRef.current) scrollRef.current.scrollTop = 0
  }, [open, debounced, fetchImages])

  const handleScroll = useCallback(() => {
    const el = scrollRef.current
    if (!el || loading || !hasMore) return
    if (el.scrollTop + el.clientHeight >= el.scrollHeight - 300) {
      fetchImages(offset, false)
    }
  }, [loading, hasMore, offset, fetchImages])

  const handleSelect = (name: string) => {
    onChange(name)
    setOpen(false)
  }

  const handleClear = () => {
    onChange('')
    setOpen(false)
  }

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <DialogTrigger asChild>
        <Button
          type="button"
          variant="outline"
          disabled={disabled}
          className="h-auto w-full justify-start gap-2 px-3 py-2"
        >
          {value ? (
            <CatalogImageThumb name={value} size={40} />
          ) : (
            <div className="flex h-10 w-16 items-center justify-center rounded bg-muted">
              <ImageIcon className="h-4 w-4 text-muted-foreground" />
            </div>
          )}
          <div className="min-w-0 text-left">
            <p className="text-xs font-medium truncate">
              {label ||
                (type === 'header'
                  ? 'Headline image'
                  : type === 'teaser'
                    ? 'Teaser image'
                    : 'Image')}
            </p>
            <p className="text-[11px] text-muted-foreground truncate font-mono">
              {value || 'None selected'}
            </p>
          </div>
        </Button>
      </DialogTrigger>
      <DialogContent className="max-w-4xl">
        <DialogHeader>
          <DialogTitle>
            {type === 'header'
              ? 'Select Headline Image'
              : type === 'teaser'
                ? 'Select Teaser Image'
                : 'Select Catalog Image'}
          </DialogTitle>
        </DialogHeader>

        <div className="flex items-center gap-2">
          <div className="relative flex-1">
            <Search className="absolute left-2.5 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
            <Input
              placeholder="Search by filename..."
              value={search}
              onChange={(e) => setSearch(e.target.value)}
              className="pl-9 pr-9"
              autoFocus
            />
            {search && (
              <button
                type="button"
                onClick={() => setSearch('')}
                className="absolute right-2.5 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground"
              >
                <X className="h-4 w-4" />
              </button>
            )}
          </div>
          <Badge variant="secondary" className="shrink-0 tabular-nums">
            {total} images
          </Badge>
          <Button type="button" variant="outline" size="sm" onClick={handleClear}>
            Clear
          </Button>
        </div>

        <div
          ref={scrollRef}
          onScroll={handleScroll}
          className="h-[480px] overflow-y-auto rounded-md border bg-muted/20 p-2"
        >
          {images.length === 0 && !loading && (
            <p className="py-16 text-center text-sm text-muted-foreground">No images found</p>
          )}
          <div className="grid grid-cols-[repeat(auto-fill,minmax(180px,1fr))] gap-2">
            {images.map((name) => (
              <button
                key={name}
                type="button"
                onClick={() => handleSelect(name)}
                className={cn(
                  'group relative flex flex-col overflow-hidden rounded-md border bg-card transition-colors hover:border-primary hover:shadow-sm',
                  value === name && 'border-primary ring-2 ring-primary/30',
                )}
                title={name}
              >
                <div className="flex h-24 items-center justify-center bg-gradient-to-b from-muted/30 to-muted/60 p-1">
                  <CatalogImageThumb name={name} size={80} />
                </div>
                <div className="border-t bg-background/95 px-2 py-1">
                  <p className="truncate font-mono text-[10px] text-muted-foreground group-hover:text-foreground">
                    {name}
                  </p>
                </div>
              </button>
            ))}
          </div>
          {loading && (
            <div className="flex items-center justify-center py-4">
              <Loader2 className="h-4 w-4 animate-spin text-muted-foreground" />
            </div>
          )}
        </div>
      </DialogContent>
    </Dialog>
  )
}

// ── Thumbnail with gif/png fallback ─────────────────────────────

function CatalogImageThumb({ name, size = 60 }: { name: string; size?: number }) {
  const [error, setError] = useState(0)

  // Reset error state when name changes
  // biome-ignore lint/correctness/useExhaustiveDependencies: explicitly chosen here, see surrounding code
  useEffect(() => setError(0), [name])

  if (!name || error >= 2) {
    return (
      <div
        className="flex items-center justify-center rounded bg-muted"
        style={{ width: size, height: size * 0.6 }}
      >
        <ImageIcon className="h-4 w-4 text-muted-foreground" />
      </div>
    )
  }

  // Try .png first, fallback to .gif
  const src =
    error === 0 ? `/swf/c_images/catalogue/${name}.png` : `/swf/c_images/catalogue/${name}.gif`

  return (
    <img
      src={src}
      alt={name}
      className="object-contain"
      style={{ imageRendering: 'pixelated', maxWidth: size, maxHeight: size * 0.75 }}
      onError={() => setError((e) => e + 1)}
    />
  )
}