import { readFileSync } from 'node:fs';

const read = (path) => readFileSync(new URL(`../${path}`, import.meta.url), 'utf8');
const semver = /^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?(?:\+[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?$/;
const contract = JSON.parse(read('contracts/api-contract.json'));
const fail = (message) => {
  console.error(`API contract check failed: ${message}`);
  process.exit(1);
};

if (typeof contract.version !== 'string' || !semver.test(contract.version)) {
  fail('contracts/api-contract.json must contain a SemVer version.');
}

const apiMajor = Number(contract.version.split('.')[0]);
const openapi = read('docs/openapi.yaml');
const openapiVersion = /^info:\s*\r?\n(?:.*\r?\n)*?\s+version:\s*([^\s#]+)/m.exec(openapi)?.[1];
if (openapiVersion !== contract.version) fail(`OpenAPI version ${openapiVersion ?? '(missing)'} differs from ${contract.version}.`);

const backend = read('server/src/WebDrop.Api/ApiContract.cs');
const backendVersion = /const string Version = "([^"]+)"/.exec(backend)?.[1];
if (backendVersion !== contract.version) fail(`backend version ${backendVersion ?? '(missing)'} differs from ${contract.version}.`);

const frontend = read('web/src/core-bridge/contract.ts');
const supportedMajor = Number(/SUPPORTED_API_CONTRACT_MAJOR\s*=\s*(\d+)/.exec(frontend)?.[1]);
if (supportedMajor !== apiMajor) {
  fail(`backend contract is ${contract.version}; frontend still supports API major ${supportedMajor || '(missing)'}. Update web/src/core-bridge/contract.ts.`);
}

const tag = process.argv[2];
if (tag !== undefined) {
  if (!tag.startsWith('v')) fail(`release tag ${tag} must start with v.`);
  const releaseVersion = tag.slice(1);
  if (!semver.test(releaseVersion) || releaseVersion.includes('+')) {
    fail(`release tag ${tag} must be a SemVer version usable as an OCI image tag (expected vMAJOR.MINOR.PATCH[-prerelease]).`);
  }
}

console.log(`API contract ${contract.version}: backend, OpenAPI, and frontend major ${supportedMajor} agree.`);