"use client";

import * as React from "react";
import { WebViewerInstance } from "@pdftron/webviewer";
import {
  Dialog,
  DialogTrigger,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogDescription,
  DialogFooter,
} from "@/components/ui/dialog";
import { Building2, FileIcon, Loader2 } from "lucide-react";
import { Button } from "@/components/ui/button";

// 인터페이스
interface Attachment {
  id: number;
  fileName: string;
  filePath: string;
  fileType?: string;
}

interface Version {
  id: number;
  stage: string;
  revision: string;
  uploaderType: string;
  uploaderName: string | null;
  comment: string | null;
  status: string | null;
  planDate: string | null;
  actualDate: string | null;
  approvedDate: string | null;
  DocumentSubmitDate: Date;
  attachments: Attachment[];
  selected?: boolean;
}

type ViewDocumentDialogProps = {
  versions: Version[];
};

export function ViewDocumentDialog({ versions }: ViewDocumentDialogProps) {
  const [open, setOpen] = React.useState(false);

  return (
    <>
      <Button
        size="sm"
        className="border-blue-200"
        variant="outline"
        onClick={() => setOpen((prev) => !prev)}
      >
        문서 보기
      </Button>
      {open && (
        <DocumentViewer open={open} setOpen={setOpen} versions={versions} />
      )}
    </>
  );
}

const DocumentViewer: React.FC<{
  open: boolean;
  setOpen: React.Dispatch<React.SetStateAction<boolean>>;
  versions: Version[];
}> = ({ open, setOpen, versions }) => {
  const [instance, setInstance] = React.useState<null | WebViewerInstance>(
    null
  );
  const [viwerLoading, setViewerLoading] = React.useState<boolean>(true);
  const [fileSetLoading, setFileSetLoading] = React.useState<boolean>(true);
  const viewer = React.useRef<HTMLDivElement>(null);
  const initialized = React.useRef(false);
  const isCancelled = React.useRef(false); // 초기화 중단용 flag

  const cleanupHtmlStyle = () => {
    const htmlElement = document.documentElement;

    // 기존 style 속성 가져오기
    const originalStyle = htmlElement.getAttribute("style") || "";

    // "color-scheme: light" 또는 "color-scheme: dark" 찾기
    const colorSchemeStyle = originalStyle
      .split(";")
      .map((s) => s.trim())
      .find((s) => s.startsWith("color-scheme:"));

    // 새로운 스타일 적용 (color-scheme만 유지)
    if (colorSchemeStyle) {
      htmlElement.setAttribute("style", colorSchemeStyle + ";");
    } else {
      htmlElement.removeAttribute("style"); // color-scheme도 없으면 style 속성 자체 삭제
    }

    console.log("html style 삭제");
  };

  React.useEffect(() => {
    if (open && !initialized.current) {
      initialized.current = true;
      isCancelled.current = false; // 다시 열릴 때는 false로 리셋

      requestAnimationFrame(() => {
        if (viewer.current) {
          import("@pdftron/webviewer").then(({ default: WebViewer }) => {
            console.log(isCancelled.current);
            if (isCancelled.current) {
              console.log("📛 WebViewer 초기화 취소됨 (Dialog 닫힘)");

              return;
            }

            WebViewer(
              {
                path: "/pdftronWeb",
                licenseKey:
                  "demo:1739264618684:616161d7030000000091db1c97c6f386d41d3506ab5b507381ef2ee2bd",
                fullAPI: true,
                css: "/globals.css",
              },
              viewer.current as HTMLDivElement
            ).then(async (instance: WebViewerInstance) => {
              setInstance(instance);
              instance.UI.enableFeatures([instance.UI.Feature.MultiTab]);
              instance.UI.disableElements([
                "addTabButton",
                "multiTabsEmptyPage",
              ]);
              setViewerLoading(false);
            });
          });
        }
      });
    }

    return () => {
      // cleanup 시에는 중단 flag 세움
      if (instance) {
        instance.UI.dispose();
      }
      setTimeout(() => cleanupHtmlStyle(), 500);
    };
  }, [open]);

  React.useEffect(() => {
    const loadDocument = async () => {
      if (instance && versions.length > 0) {
        const { UI } = instance;

        const optionsArray: any[] = [];

        versions.forEach((c) => {
          const { attachments } = c;
          attachments.forEach((c2) => {
            const { fileName, filePath, fileType } = c2;

            const fileTypeCur = fileType ?? "";

            const options = {
              filename: fileName,
              ...(fileTypeCur.includes("xlsx") && {
                officeOptions: {
                  formatOptions: {
                    applyPageBreaksToSheet: true,
                  },
                },
              }),
            };

            optionsArray.push({
              filePath,
              options,
            });
          });
        });

        const tabIds = [];

        for (const option of optionsArray) {
          const { filePath, options } = option;
          const response = await fetch(filePath);
          const blob = await response.blob();

          const tab = await UI.TabManager.addTab(blob, options);
          tabIds.push(tab); // 탭 ID 저장
        }

        if (tabIds.length > 0) {
          await UI.TabManager.setActiveTab(tabIds[0]);
        }

        setFileSetLoading(false);
      }
    };
    loadDocument();
  }, [instance, versions]);

  return (
    <Dialog
      open={open}
      onOpenChange={async (val) => {
        console.log({ val, fileSetLoading });
        if (!val && fileSetLoading) {
          return;
        }

        if (instance) {
          try {
            await instance.UI.dispose();
            setInstance(null); // 상태도 초기화
          } catch (e) {
            console.warn("dispose error", e);
          }
        }

        // cleanupHtmlStyle()
        setViewerLoading(false);
        setOpen((prev) => !prev);
        await setTimeout(() => cleanupHtmlStyle(), 1000);
      }}
    >
      <DialogContent className="w-[90vw] h-[90vh]" style={{ maxWidth: "none" }}>
        <DialogHeader className="h-[38px]">
          <DialogTitle>문서 미리보기</DialogTitle>
          <DialogDescription>첨부파일 미리보기</DialogDescription>
        </DialogHeader>
        <div
          ref={viewer}
          style={{ height: "calc(90vh - 20px - 38px - 1rem - 48px)" }}
        >
          {viwerLoading && (
            <div className="flex flex-col items-center justify-center py-12">
              <Loader2 className="h-8 w-8 text-blue-500 animate-spin mb-4" />
              <p className="text-sm text-muted-foreground">
                문서 뷰어 로딩 중...
              </p>
            </div>
          )}
        </div>
      </DialogContent>
    </Dialog>
  );
};