import type {
  CompleteEvent,
  IndexEvent,
  QueryProviderEvent,
} from "$sb/app_event.ts";
import {
  editor,
  index,
  markdown,
  space,
} from "$sb/silverbullet-syscall/mod.ts";

import { events, mq } from "$sb/plugos-syscall/mod.ts";

import { applyQuery } from "$sb/lib/query.ts";
import { invokeFunction } from "$sb/silverbullet-syscall/system.ts";
import type { Message } from "$sb/types.ts";
import { sleep } from "../../common/async_util.ts";
import { cacheFileListing } from "../federation/federation.ts";
import type { PageMeta } from "../../web/types.ts";

// Key space:
//   meta: => metaJson

export async function pageQueryProvider({
  query,
}: QueryProviderEvent): Promise<any[]> {
  return applyQuery(query, await space.listPages());
}

export async function deletePage() {
  const pageName = await editor.getCurrentPage();
  if (
    !await editor.confirm(`Are you sure you would like to delete ${pageName}?`)
  ) {
    return;
  }
  console.log("Navigating to index page");
  await editor.navigate("");
  console.log("Deleting page from space");
  await space.deletePage(pageName);
}

export async function copyPage() {
  const oldName = await editor.getCurrentPage();
  const newName = await editor.prompt(`New page title:`, `${oldName} (copy)`);

  if (!newName) {
    return;
  }

  try {
    // This throws an error if the page does not exist, which we expect to be the case
    await space.getPageMeta(newName);
    // So when we get to this point, we error out
    throw new Error(
      `Page ${newName} already exists, cannot rename to existing page.`,
    );
  } catch (e: any) {
    if (e.message === "Not found") {
      // Expected not found error, so we can continue
    } else {
      await editor.flashNotification(e.message, "error");
      throw e;
    }
  }

  const text = await editor.getText();

  console.log("Writing new page to space");
  await space.writePage(newName, text);

  console.log("Navigating to new page");
  await editor.navigate(newName);
}

export async function newPageCommand() {
  const allPages = await space.listPages();
  let pageName = `Untitled`;
  let i = 1;
  while (allPages.find((p) => p.name === pageName)) {
    pageName = `Untitled ${i}`;
    i++;
  }
  await editor.navigate(pageName);
}

export async function reindexCommand() {
  await editor.flashNotification("Performing full page reindex...");
  await reindexSpace();
  await editor.flashNotification("Done with page index!");
}

// Completion
export async function pageComplete(completeEvent: CompleteEvent) {
  const match = /\[\[([^\]@:\{}]*)$/.exec(completeEvent.linePrefix);
  if (!match) {
    return null;
  }
  let allPages: PageMeta[] = await space.listPages();
  const prefix = match[1];
  if (prefix.startsWith("!")) {
    // Federation prefix, let's first see if we're matching anything from federation that is locally synced
    const prefixMatches = allPages.filter((pageMeta) =>
      pageMeta.name.startsWith(prefix)
    );
    if (prefixMatches.length === 0) {
      // Ok, nothing synced in via federation, let's see if this URI is complete enough to try to fetch index.json
      if (prefix.includes("/")) {
        // Yep
        const domain = prefix.split("/")[0];
        // Cached listing
        allPages = (await cacheFileListing(domain)).filter((fm) =>
          fm.name.endsWith(".md")
        ).map((fm) => ({
          ...fm,
          name: fm.name.slice(0, -3),
        }));
      }
    }
  }
  return {
    from: completeEvent.pos - match[1].length,
    options: allPages.map((pageMeta) => {
      return {
        label: pageMeta.name,
        boost: pageMeta.lastModified,
        type: "page",
      };
    }),
  };
}

export async function reindexSpace() {
  console.log("Clearing page index...");
  await index.clearPageIndex();
  // Executed this way to not have to embed the search plug code here
  await invokeFunction("client", "search.clearIndex");
  const pages = await space.listPages();

  // Queue all page names to be indexed
  await mq.batchSend("indexQueue", pages.map((page) => page.name));

  // Now let's wait for the processing to finish
  let queueStats = await mq.getQueueStats("indexQueue");
  while (queueStats.queued > 0 || queueStats.processing > 0) {
    sleep(1000);
    queueStats = await mq.getQueueStats("indexQueue");
  }
  // And notify the user
  console.log("Indexing completed!");
}

export async function processIndexQueue(messages: Message[]) {
  for (const message of messages) {
    const name: string = message.body;
    console.log(`Indexing page ${name}`);
    const text = await space.readPage(name);
    // console.log("Going to parse markdown");
    const parsed = await markdown.parseMarkdown(text);
    // console.log("Dispatching ;age:index");
    await events.dispatchEvent("page:index", {
      name,
      tree: parsed,
    });
  }
}

export async function clearPageIndex(page: string) {
  // console.log("Clearing page index for page", page);
  await index.clearPageIndexForPage(page);
}

export async function parseIndexTextRepublish({ name, text }: IndexEvent) {
  // console.log("Reindexing", name);
  await events.dispatchEvent("page:index", {
    name,
    tree: await markdown.parseMarkdown(text),
  });
}