import { mkdir, readFile, writeFile } from "node:fs/promises";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";

const packageRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
const schemaDirectory = resolve(packageRoot, "protocol/schemas");
const outputPath = resolve(
  packageRoot,
  "src/protocol/generated/schema-bundle.ts",
);
const schemaNames = [
  "identity",
  "capabilities",
  "command",
  "provider-descriptor",
  "provider-event",
  "workspace-diff",
  "workspace-file-reference",
  "semantic-tool",
  "usage",
  "stop-reason",
  "terminal",
  "question-set",
  "question-response",
  "question-adapter-fixture",
  "request",
  "result",
  "event",
  "fixture",
];

const schemas = await Promise.all(
  schemaNames.map(async (name) => ({
    name,
    value: JSON.parse(
      await readFile(resolve(schemaDirectory, `${name}.schema.json`), "utf8"),
    ),
  })),
);

const identifier = (name) =>
  name.replace(/-([a-z])/g, (_match, letter) => letter.toUpperCase());
const declarations = schemas
  .map(
    ({ name, value }) =>
      `export const ${identifier(name)}Schema = ${JSON.stringify(value, null, 2)} as const;`,
  )
  .join("\n\n");
const bundle = schemaNames
  .map((name) => `  ${JSON.stringify(name)}: ${identifier(name)}Schema,`)
  .join("\n");
const generated = `// Generated by scripts/generate-protocol-schema-module.mjs. Do not edit.\n\n${declarations}\n\nexport const prpSchemaBundle = {\n${bundle}\n} as const;\n`;

if (process.argv.includes("--check")) {
  const current = await readFile(outputPath, "utf8").catch(() => "");
  if (current !== generated) {
    process.stderr.write(
      "Generated PRP schema module is stale. Run pnpm generate:protocol-types.\n",
    );
    process.exitCode = 1;
  } else {
    process.stdout.write(
      "Generated PRP schema module matches the JSON Schema sources.\n",
    );
  }
} else {
  await mkdir(dirname(outputPath), { recursive: true });
  await writeFile(outputPath, generated);
  process.stdout.write("Generated PRP schema module.\n");
}