/// <reference no-default-lib="true" />
/// <reference lib="esnext" />
/// <reference lib="dom" />
import {
  useStatusBar,
  openInTheSameTab,
  encodeTitleURI,
} from "../scrapbox-userscript-std/dom.ts";
import type { Scrapbox, SearchedTitle } from "https://raw.githubusercontent.com/scrapbox-jp/types/0.0.8/mod.ts";
declare const scrapbox: Scrapbox;

const id = "next-action";
let initialized: Promise<void>;
const dummyImage = "/assets/img/favicon/apple-touch-icon.png";

export function setup(projects: string[]) {
  const selector = `head style[data-userscript-name="${id}"]`;
  document.querySelector(selector)?.remove?.();
  const style = document.createElement("style");
  style.dataset.userscriptName = id;
  style.textContent = `a#${id}.tool-btn:hover {
  text-decoration: none;
}
a#${id}.tool-btn::before {
  position: absolute;
  content: "\\f0ae";
  font: 900 20px/46px "Font Awesome 5 Free";
}
a#${id}.tool-btn img {
  opacity: 0;
}
a#${id}.tool-btn ~ ul a::before {
  position: absolute;
  font-family: "Font Awesome 5 Free";
  font-weight: 900;
}
a#${id}.tool-btn ~ ul img {
  opacity: 0;
  margin-right: 0;
}`;
  document.head.append(style);
  
  if (!document.getElementById(id)) {
    scrapbox.PageMenu.addMenu({
      title: id,
      image: dummyImage,
      onClick: async () => {
        initialized ??= load(projects);
        await initialized;
      },
    });
  }
}

async function load(projects: string[]) {
  scrapbox.PageMenu(id).removeAllItems();
  const { render, dispose } = useStatusBar();
  let count = 0;
  
  try {
    for (const project of projects) {
      render(
        { type: "spinner" },
        { type: "text", text: `Searching "/${project}" for next actions...`},
      );
      for await (const title of listNextActions(project)) {
        count++;
        scrapbox.PageMenu(id).addItem({
          title,
          onClick: () => {
            const path = `https://scrapbox.io/${
              project
            }/${encodeTitleURI(title)}`;
            if (project !== scrapbox.Project.name) {       
              window.open(path);
              return;
            }
            openInTheSameTab(path);
          },
        });
      }
      if (project === projects[projects.length - 1]) continue;
      scrapbox.PageMenu(id).addSeparator();
    }
    
    render(
      { type: "check-circle" },
      { type: "text", text: `Found ${count} actions.`},
    );
  } catch(e: unknown) {
    render(
      { type: "exclamation-triangle" },
      { type: "text", text: e instanceof Error ?
        `${e.name} ${e.message}` :
        `Unknown error! (see developper console)`,
      },
    );
    console.error(e);
  } finally {
    setTimeout(() => dispose(), 1000);
  }
}
async function* listNextActions(project: string, filter?: RegExp) {
  filter ??= /^(?:⬜(?:[^p]*|p[^-]*))|🔳/;
  
  if (project === scrapbox.Project.name) {
    for (const { title, exists } of scrapbox.Project.pages) {
      if (!filter.test(title)) continue;
      yield title;
    }
    return;
  }
  
  const titles = new Set<string>();
  for await (const title of getLinks(project)) {
    if (!titles.has(title) && filter.test(title)) {
      titles.add(title);
      yield title;
    }
  }
}

async function* getLinks(project: string) {
  const path = `/api/pages/${project}/search/titles`;
  let followingId = null;
  
  do {
    const path_ = `${path}${
      followingId ? `?followingId=${followingId}` : ""
    }` as string;
    const res = await fetch(path_);
    followingId = res.headers.get("X-following-id");
    
    const pages = (await res.json()) as SearchedTitle[];
    for (const { title, links } of pages) {
      yield title;
      for (const link of links) {
        yield link;
      }
    }
    
    if (!followingId) break; // 空文字列の場合もある
  } while (true)
}