import { build, stop } from "https://deno.land/x/esbuild@v0.24.0/mod.js";
import ts from "npm:typescript";

// from https://github.com/Microsoft/TypeScript/issues/6387#issuecomment-169739615
function error(diagnostics: ts.Diagnostic[]): void {
  diagnostics.forEach((diagnostic) => {
    let message = "Error";
    if (diagnostic.file) {
      const { line, character } = diagnostic.file.getLineAndCharacterOfPosition(
        diagnostic.start || 0
      );
      message += ` ${diagnostic.file.fileName} (${line + 1},${character + 1})`;
    }
    message +=
      ": " + ts.flattenDiagnosticMessageText(diagnostic.messageText, "\n");
    console.log(message);
  });
}

async function readConfigFile(configFileName: string) {
  const configFileText = await Deno.readTextFile(configFileName);
  const result = ts.parseConfigFileTextToJson(configFileName, configFileText);
  if (result.error) {
    error([result.error]);
    Deno.exit(1);
  }

  const config = ts.parseJsonConfigFileContent(
    result.config,
    ts.sys,
    await Deno.realPath(".")
  );
  if (config.errors.length > 0) {
    error(config.errors);
    Deno.exit(1);
  }
  return config;
}

async function buildDTS() {
  const config = await readConfigFile("./tsconfig.json");
  const emitted = ts
    .createProgram(config.fileNames, {
      ...config.options,
      emitDeclarationOnly: true,
    })
    .emit();
  if (emitted.diagnostics.length > 0) {
    error(emitted.diagnostics.slice());
    Deno.exit(1);
  }
}

async function buildESM() {
  await build({
    bundle: true,
    minify: true,
    keepNames: true,
    target: "es2017", // Required because OBS ships with a really old version of Chrome
    entryPoints: ["./domutil.ts"],
    outfile: "./dist/domutil.js",
    format: "esm",
    sourcemap: true,
  });
  await stop();
}

await Promise.all([buildDTS(), buildESM()]);