// The recommended way to use this for now is through `silverbullet bundle:build` until
// we fork out PlugOS as a whole

import { Manifest } from "../types.ts";
import { YAML } from "../../common/deps.ts";
import {
  compile,
  CompileOptions,
  esbuild,
  sandboxCompileModule,
} from "../compile.ts";
import { cacheDir, flags, path } from "../deps.ts";

import { bundleAssets } from "../asset_bundle/builder.ts";

export async function bundle(
  manifestPath: string,
  options: CompileOptions = {},
): Promise<Manifest<any>> {
  const rootPath = path.dirname(manifestPath);
  const manifest = YAML.parse(
    await Deno.readTextFile(manifestPath),
  ) as Manifest<any>;

  if (!manifest.name) {
    throw new Error(`Missing 'name' in ${manifestPath}`);
  }

  // Dependencies
  for (
    const [name, moduleSpec] of Object.entries(manifest.dependencies || {})
  ) {
    manifest.dependencies![name] = await sandboxCompileModule(moduleSpec);
  }

  // Assets
  const assetsBundle = await bundleAssets(
    path.resolve(rootPath),
    manifest.assets as string[] || [],
  );
  manifest.assets = assetsBundle.toJSON();

  // Imports
  // Imports currently only "import" dependencies at this point, importing means: assume they're preloaded so we don't need to bundle them
  const plugCache = path.join(cacheDir()!, "plugos");
  await Deno.mkdir(plugCache, { recursive: true });
  const imports: Manifest<any>[] = [];
  for (const manifestUrl of manifest.imports || []) {
    // Safe file name
    const cachedManifestPath = manifestUrl.replaceAll(/[^a-zA-Z0-9]/g, "_");
    try {
      if (options.reload) {
        throw new Error("Forced reload");
      }
      // Try to just load from the cache
      const cachedManifest = JSON.parse(
        await Deno.readTextFile(path.join(plugCache, cachedManifestPath)),
      ) as Manifest<any>;
      imports.push(cachedManifest);
    } catch {
      // Otherwise, download and cache
      console.log("Caching plug", manifestUrl, "to", plugCache);
      const cachedManifest = await (await fetch(manifestUrl))
        .json() as Manifest<any>;
      await Deno.writeTextFile(
        path.join(plugCache, cachedManifestPath),
        JSON.stringify(cachedManifest),
      );
      imports.push(cachedManifest);
    }
  }

  // Functions
  for (const def of Object.values(manifest.functions || {})) {
    if (!def.path) {
      continue;
    }
    let jsFunctionName = "default",
      filePath = path.join(rootPath, def.path);
    if (filePath.indexOf(":") !== -1) {
      [filePath, jsFunctionName] = filePath.split(":");
    }

    def.code = await compile(
      filePath,
      jsFunctionName,
      {
        ...options,
        imports: [
          manifest,
          ...imports,
          // This is mostly for testing
          ...options.imports || [],
        ],
      },
    );
    delete def.path;
  }
  return manifest;
}

async function buildManifest(
  manifestPath: string,
  distPath: string,
  options: CompileOptions = {},
) {
  const generatedManifest = await bundle(manifestPath, options);
  const outFile = manifestPath.substring(
    0,
    manifestPath.length - path.extname(manifestPath).length,
  ) + ".json";
  const outPath = path.join(distPath, path.basename(outFile));
  console.log("Emitting bundle to", outPath);
  await Deno.writeTextFile(outPath, JSON.stringify(generatedManifest, null, 2));
  return { generatedManifest, outPath };
}

export async function bundleRun(
  manifestFiles: string[],
  dist: string,
  watch: boolean,
  options: CompileOptions = {},
) {
  // console.log("Args", arguments);
  let building = false;
  async function buildAll() {
    if (building) {
      return;
    }
    console.log("Building", manifestFiles);
    building = true;
    Deno.mkdirSync(dist, { recursive: true });
    for (const plugManifestPath of manifestFiles) {
      const manifestPath = plugManifestPath as string;
      try {
        await buildManifest(
          manifestPath,
          dist,
          options,
        );
      } catch (e) {
        console.error(`Error building ${manifestPath}:`, e);
      }
    }
    console.log("Done building plugs.");
    building = false;
  }

  await buildAll();

  if (watch) {
    console.log("Watching for changes...");
    const watcher = Deno.watchFs(manifestFiles.map((p) => path.dirname(p)));
    for await (const event of watcher) {
      if (event.paths.length > 0) {
        if (event.paths[0].endsWith(".json")) {
          continue;
        }
      }
      console.log("Change detected, rebuilding...");
      buildAll();
    }
  }
}

if (import.meta.main) {
  const args = flags.parse(Deno.args, {
    boolean: ["debug", "watch", "reload", "info"],
    string: ["dist", "importmap"],
    alias: { w: "watch" },
  });

  if (args._.length === 0) {
    console.log(
      "Usage: plugos-bundle [--debug] [--reload] [--dist <path>] [--info] [--importmap import_map.json] [--exclude=package1,package2] <manifest.plug.yaml> <manifest2.plug.yaml> ...",
    );
    Deno.exit(1);
  }

  if (!args.dist) {
    args.dist = path.resolve(".");
  }

  await bundleRun(
    args._ as string[],
    args.dist,
    args.watch,
    {
      debug: args.debug,
      reload: args.reload,
      info: args.info,
      importMap: args.importmap
        ? new URL(args.importmap, `file://${Deno.cwd()}/`)
        : undefined,
    },
  );
  esbuild.stop();
}