import { writeFile } from "node:fs/promises";
import { resolve } from "node:path";

import openapiTS, { astToString, COMMENT_HEADER } from "openapi-typescript";

const schemaUrl = process.env.OPENAPI_SCHEMA_URL ?? "http://127.0.0.1:8000/openapi.json";
const outputPath = resolve("src/api/schema.generated.ts");
const requiredPaths = ["/api/v1/demo/status", "/api/v1/demo/search"];

const response = await fetch(schemaUrl, {
  headers: { Accept: "application/json" },
  signal: AbortSignal.timeout(10_000),
});

if (!response.ok) {
  throw new Error(`OpenAPI schema request failed with HTTP ${response.status}`);
}

const schema = await response.json();
if (typeof schema !== "object" || schema === null || !("paths" in schema)) {
  throw new Error("OpenAPI response does not contain a paths object");
}

const paths = schema.paths;
if (typeof paths !== "object" || paths === null) {
  throw new Error("OpenAPI paths value is invalid");
}

for (const path of requiredPaths) {
  if (!(path in paths)) {
    throw new Error(`Required API path is missing: ${path}`);
  }
}

const ast = await openapiTS(schema, {
  alphabetize: true,
  immutable: true,
});
await writeFile(outputPath, `${COMMENT_HEADER}${astToString(ast)}`, "utf8");

console.log(`Generated ${outputPath} from ${schemaUrl}`);