"use client"

import { useEffect, useState, useCallback, useRef } from "react"
import { TransformWrapper, TransformComponent } from "react-zoom-pan-pinch"
import type { AssetResponse } from "@/lib/types"
import { getTokens } from "@/lib/auth"
import { MetadataSidebar } from "./metadata-sidebar"
import { Button } from "@/components/ui/button"
import { Skeleton } from "@/components/ui/skeleton"
import {
  XIcon,
  ZoomInIcon,
  ZoomOutIcon,
  Maximize2Icon,
  InfoIcon,
  ChevronLeftIcon,
  ChevronRightIcon,
} from "lucide-react"

interface ImageViewerProps {
  assets: AssetResponse[]
  initialIndex: number
  onClose: () => void
}

export function ImageViewer({ assets, initialIndex, onClose }: ImageViewerProps) {
  const [index, setIndex] = useState(initialIndex)
  const [src, setSrc] = useState<string | null>(null)
  const [sidebarOpen, setSidebarOpen] = useState(false)
  const prevBlobRef = useRef<string | null>(null)

  const asset = assets[index]
  const hasPrev = index > 0
  const hasNext = index < assets.length - 1

  useEffect(() => {
    if (prevBlobRef.current) URL.revokeObjectURL(prevBlobRef.current)
    setSrc(null)

    const { access } = getTokens()
    fetch(`/api/v1/assets/${asset.id}/file`, {
      headers: access ? { Authorization: `Bearer ${access}` } : {},
    })
      .then((r) => (r.ok ? r.blob() : Promise.reject()))
      .then((blob) => {
        const url = URL.createObjectURL(blob)
        prevBlobRef.current = url
        setSrc(url)
      })
      .catch(() => {})

    return () => {
      if (prevBlobRef.current) {
        URL.revokeObjectURL(prevBlobRef.current)
        prevBlobRef.current = null
      }
    }
  }, [asset.id])

  const goPrev = useCallback(() => {
    if (hasPrev) setIndex((i) => i - 1)
  }, [hasPrev])

  const goNext = useCallback(() => {
    if (hasNext) setIndex((i) => i + 1)
  }, [hasNext])

  useEffect(() => {
    function onKey(e: KeyboardEvent) {
      if (e.key === "Escape") onClose()
      if (e.key === "ArrowLeft") goPrev()
      if (e.key === "ArrowRight") goNext()
    }
    window.addEventListener("keydown", onKey)
    return () => window.removeEventListener("keydown", onKey)
  }, [onClose, goPrev, goNext])

  return (
    <div className="fixed inset-0 z-50 flex bg-black">
      {/* Main image area */}
      <div className="relative flex flex-1 items-center justify-center">
        <TransformWrapper
          key={asset.id}
          initialScale={1}
          minScale={0.5}
          maxScale={10}
          centerOnInit
          wheel={{ step: 0.1 }}
        >
          {({ zoomIn, zoomOut, resetTransform }) => (
            <>
              {/* Toolbar */}
              <div className="absolute top-0 right-0 left-0 z-10 flex items-center justify-between p-3">
                <div />
                <div className="flex items-center gap-1">
                  <ToolbarButton onClick={() => zoomIn()} icon={<ZoomInIcon />} />
                  <ToolbarButton onClick={() => zoomOut()} icon={<ZoomOutIcon />} />
                  <ToolbarButton onClick={() => resetTransform()} icon={<Maximize2Icon />} />
                  <ToolbarButton
                    onClick={() => setSidebarOpen(!sidebarOpen)}
                    icon={<InfoIcon />}
                    active={sidebarOpen}
                  />
                  <ToolbarButton onClick={onClose} icon={<XIcon />} />
                </div>
              </div>

              {/* Image */}
              <TransformComponent
                wrapperStyle={{ width: "100%", height: "100%" }}
                contentStyle={{
                  width: "100%",
                  height: "100%",
                  display: "flex",
                  alignItems: "center",
                  justifyContent: "center",
                }}
              >
                {src ? (
                  <img
                    src={src}
                    alt=""
                    className="max-h-full max-w-full object-contain"
                    draggable={false}
                  />
                ) : (
                  <Skeleton className="h-96 w-96 rounded-lg" />
                )}
              </TransformComponent>
            </>
          )}
        </TransformWrapper>

        {/* Navigation arrows */}
        {hasPrev && (
          <button
            onClick={goPrev}
            className="absolute left-3 top-1/2 -translate-y-1/2 rounded-full bg-black/50 p-2 text-white transition-colors hover:bg-black/70"
          >
            <ChevronLeftIcon className="h-6 w-6" />
          </button>
        )}
        {hasNext && (
          <button
            onClick={goNext}
            className="absolute right-3 top-1/2 -translate-y-1/2 rounded-full bg-black/50 p-2 text-white transition-colors hover:bg-black/70"
          >
            <ChevronRightIcon className="h-6 w-6" />
          </button>
        )}
      </div>

      {/* Metadata sidebar */}
      {sidebarOpen && (
        <MetadataSidebar
          asset={asset}
          onClose={() => setSidebarOpen(false)}
        />
      )}
    </div>
  )
}

function ToolbarButton({
  onClick,
  icon,
  active,
}: {
  onClick: () => void
  icon: React.ReactNode
  active?: boolean
}) {
  return (
    <Button
      variant="ghost"
      size="icon"
      onClick={onClick}
      className={`h-8 w-8 text-white hover:bg-white/20 ${active ? "bg-white/20" : ""}`}
    >
      <span className="h-4 w-4">{icon}</span>
    </Button>
  )
}