import { FormSectionCard, FormSectionGrid } from "@repo/rdx-ui/components";
import {
  Button,
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
  Spinner,
} from "@repo/shadcn-ui/components";
import {
  DownloadIcon,
  ExternalLinkIcon,
  EyeIcon,
  PrinterIcon,
  ZoomInIcon,
  ZoomOutIcon,
} from "lucide-react";
import { useEffect, useMemo, useRef, useState } from "react";

const DEFAULT_ZOOM_OPTIONS = [50, 75, 100, 125, 150];
const FIT_ZOOM_VALUE = "fit";
const PDF_PAGE_WIDTH = 794;
const PDF_PAGE_HEIGHT = 1123;

type PDFViewerProps = {
  src?: string | null;
  title?: string;
  description?: string;
  className?: string;
  loading?: boolean;
  error?: string | null;
  defaultZoom?: number | "fit";
  zoomOptions?: number[];
  onOpen?: () => void;
  onDownload?: () => void;
  onPrint?: () => void;
};

const clampZoom = (value: number, zoomOptions: number[]) => {
  const min = Math.min(...zoomOptions);
  const max = Math.max(...zoomOptions);

  return Math.min(Math.max(value, min), max);
};

export function PDFViewer({
  src,
  title = "Vista previa",
  description = "Documento PDF embebido en la pantalla.",
  className,
  loading = false,
  error = null,
  defaultZoom = FIT_ZOOM_VALUE,
  zoomOptions = DEFAULT_ZOOM_OPTIONS,
  onOpen,
  onDownload,
  onPrint,
}: PDFViewerProps) {
  const viewportRef = useRef<HTMLDivElement | null>(null);
  const [fitZoom, setFitZoom] = useState(100);
  const [zoom, setZoom] = useState<string>(() =>
    defaultZoom === FIT_ZOOM_VALUE ? FIT_ZOOM_VALUE : String(clampZoom(defaultZoom, zoomOptions))
  );

  const resolvedSrc = useMemo(() => {
    if (!src) {
      return null;
    }

    const separator = src.includes("#") ? "&" : "#";
    return `${src}${separator}toolbar=0&navpanes=0&scrollbar=1&view=FitH`;
  }, [src]);

  useEffect(() => {
    if (zoom !== FIT_ZOOM_VALUE) {
      return;
    }

    const element = viewportRef.current;
    if (!element) {
      return;
    }

    const updateFitZoom = () => {
      const styles = window.getComputedStyle(element);
      const paddingX =
        Number.parseFloat(styles.paddingLeft) + Number.parseFloat(styles.paddingRight);
      const paddingY =
        Number.parseFloat(styles.paddingTop) + Number.parseFloat(styles.paddingBottom);
      const availableWidth = Math.max(element.clientWidth - paddingX, 320);
      const availableHeight = Math.max(element.clientHeight - paddingY, 320);
      const widthScale = availableWidth / PDF_PAGE_WIDTH;
      const heightScale = availableHeight / PDF_PAGE_HEIGHT;
      const nextScale = Math.min(widthScale, heightScale, 1);
      setFitZoom(Math.max(Math.round(nextScale * 100), 25));
    };

    updateFitZoom();

    const observer = new ResizeObserver(() => updateFitZoom());
    observer.observe(element);
    window.addEventListener("resize", updateFitZoom);

    return () => {
      observer.disconnect();
      window.removeEventListener("resize", updateFitZoom);
    };
  }, [zoom]);

  const effectiveZoom = zoom === FIT_ZOOM_VALUE ? fitZoom : Number(zoom);
  const zoomScale = effectiveZoom / 100;
  const minZoom = Math.min(...zoomOptions);
  const maxZoom = Math.max(...zoomOptions);

  const handleOpen = () => {
    if (onOpen) {
      onOpen();
      return;
    }

    if (src) {
      window.open(src, "_blank", "noopener,noreferrer");
    }
  };

  const handleDownload = () => {
    if (onDownload) {
      onDownload();
      return;
    }

    if (!src) {
      return;
    }

    const link = document.createElement("a");
    link.href = src;
    link.download = "";
    link.click();
  };

  const handlePrint = () => {
    if (onPrint) {
      onPrint();
      return;
    }

    if (src) {
      window.open(src, "_blank", "noopener,noreferrer");
    }
  };

  return (
    <FormSectionCard
      actions={
        <div className="flex flex-wrap items-center gap-2">
          <Button
            disabled={loading || !src || (zoom !== FIT_ZOOM_VALUE && Number(zoom) <= minZoom)}
            onClick={() =>
              setZoom((current) => {
                if (current === FIT_ZOOM_VALUE) {
                  return String(Math.max(fitZoom - 25, minZoom));
                }

                return String(clampZoom(Number(current) - 25, zoomOptions));
              })
            }
            size="icon-sm"
            type="button"
            variant="outline"
          >
            <ZoomOutIcon className="size-4" />
          </Button>

          <Select onValueChange={setZoom} value={zoom}>
            <SelectTrigger className="w-24 bg-background">
              <SelectValue placeholder="Zoom" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value={FIT_ZOOM_VALUE}>Ajustar</SelectItem>
              {zoomOptions.map((option) => (
                <SelectItem key={option} value={String(option)}>
                  {option}%
                </SelectItem>
              ))}
            </SelectContent>
          </Select>

          <Button
            disabled={loading || !src || (zoom !== FIT_ZOOM_VALUE && Number(zoom) >= maxZoom)}
            onClick={() =>
              setZoom((current) => {
                if (current === FIT_ZOOM_VALUE) {
                  return String(clampZoom(fitZoom + 25, zoomOptions));
                }

                return String(clampZoom(Number(current) + 25, zoomOptions));
              })
            }
            size="icon-sm"
            type="button"
            variant="outline"
          >
            <ZoomInIcon className="size-4" />
          </Button>

          <Button disabled={loading || !src} onClick={handleOpen} type="button" variant="outline">
            <ExternalLinkIcon className="mr-2 size-4" />
            Abrir PDF
          </Button>

          <Button
            disabled={loading || !src}
            onClick={handleDownload}
            type="button"
            variant="outline"
          >
            <DownloadIcon className="mr-2 size-4" />
            Descargar
          </Button>

          <Button
            disabled={loading || !src}
            onClick={handlePrint}
            size="icon-sm"
            type="button"
            variant="outline"
          >
            <PrinterIcon className="size-4" />
          </Button>
        </div>
      }
      className="shadow-sm"
      contentClassName="space-y-5"
      description={description}
      icon={<EyeIcon className="size-5" />}
      title={title}
    >
      <FormSectionGrid className="gap-y-6 md:grid-cols-1">
        <div className="flex-1 overflow-auto bg-muted p-4 md:p-5" ref={viewportRef}>
          {loading ? (
            <div className="flex h-full min-h-[480px] items-center justify-center rounded-xl border border-dashed bg-background/80">
              <div className="flex items-center gap-3 text-sm text-muted-foreground">
                <Spinner className="size-4" />
                Cargando vista previa del PDF...
              </div>
            </div>
          ) : null}

          {!loading && error ? (
            <div className="flex h-full min-h-[480px] items-center justify-center rounded-xl border border-dashed bg-background/80 px-6 text-center">
              <div className="space-y-2">
                <p className="font-medium text-foreground">No se pudo cargar la vista previa</p>
                <p className="text-sm text-muted-foreground">{error}</p>
              </div>
            </div>
          ) : null}

          {!(loading || error) && resolvedSrc ? (
            <div className="mx-auto flex min-h-full justify-center">
              <div
                className="origin-top rounded-xl border bg-red-500 shadow-sm transition-transform"
                style={{
                  transform: `scale(${zoomScale})`,
                  transformOrigin: "top center",
                  width: `${PDF_PAGE_WIDTH}px`,
                }}
              >
                <iframe
                  className="w-full rounded-xl bg-amber-500"
                  src={resolvedSrc}
                  style={{ height: `${PDF_PAGE_HEIGHT}px` }}
                  title={title}
                />
              </div>
            </div>
          ) : null}

          {loading || error || resolvedSrc ? null : (
            <div className="flex h-full min-h-[480px] items-center justify-center rounded-xl border border-dashed bg-background/80 px-6 text-center">
              <div className="space-y-2">
                <p className="font-medium text-foreground">Vista previa no disponible</p>
                <p className="text-sm text-muted-foreground">
                  El PDF de la proforma todavía no está listo para mostrarse.
                </p>
              </div>
            </div>
          )}
        </div>
      </FormSectionGrid>
    </FormSectionCard>
  );
}