import { getPage, readLinksBulk, getProject } from "../scrapbox-userscript-std/rest.ts";
import { Page, UnixTime } from "../scrapbox-jp%2Ftypes/rest.ts";
import { useStatusBar } from "../scrapbox-userscript-std/mod.ts";
import { pool, Result, sort } from "../async-lib/mod.ts";

export type ExportPage = Pick<Page, "id" | "title" | "created" | "updated" | "lines">;
export interface ExportData {
  name: string;
  displayName: string;
  exported: UnixTime;
  pages: ExportPage[];
}

export const createExport = async (
  project: string,
  threshold = 100,
): Promise<ExportData> => {
  const { render, dispose } = useStatusBar();
  render(
    { type: "spinner"},
    { type: "text", text: `Loading pages from "${project}"` },
  );
  
  try {
    const result = await getProject(project);
    if (!result.ok) throw result.value;
    const { name, displayName } = result.value;
    
    const reader = await readLinksBulk(project);
    if ("name" in reader) throw reader;
    
    const pages: ExportPage[] = [];
    const { render, dispose } = useStatusBar();
    
    try {
      for await (const titles of reader) {
        const reader = sort([...pool(
          threshold,
          titles,
          async (page) => {
            const result = await getPage(project, page.title);
            if (!result.ok) {
              console.error(result.value);
              throw result.value;
            }
            const { id, title, created, updated, lines } = result.value;
            pages.push({ id, title, created, updated, lines });
            return `[${pages.length}] ${title}`;
          },
        )]);
        let animationId: number | undefined;
        for await (const result of reader) {
          if (!result.success) continue;
          if (animationId !== undefined) cancelAnimationFrame(animationId);
          animationId = requestAnimationFrame(
            () => render({ type: "text", text: result.value })
          );
        }
      }
    } finally {
      dispose();
    }
    const exported = (new Date()).getTime() / 1000;
    render(
      { type: "check-circle" },
      { type: "text", text: `Exported ${pages.length} pages from /${name}`}
    );
    return { name, displayName, exported, pages };
  } catch(e) {
    render(
      { type: "exclamation-triangle" },
      {
        type: "text",
        text: typeof e === "object" && "name" in e && "message" in e ?
          `${e.name} ${e.message}` :
          "Unexpected error! (see developer console)",
      },
    );
    throw e;
  } finally {
    setTimeout(() => dispose(), 1000);
  }
};