import { generateKeyPairSync, sign, verify } from 'node:crypto';
import { chmod, mkdir, readFile, writeFile } from 'node:fs/promises';
import { join } from 'node:path';

import { canonicalJsonDigest, canonicalValueBytes, byteDigest } from '../../src/security/canonical-digest.ts';
import { computeProductionInputRoot } from '../../src/security/production-input-root.ts';

const digest = (character: string) => character.repeat(64);

export interface ReleaseFixture {
  distDir: string;
  signedManifestPath: string;
  sbomPath: string;
  trustPolicyPath: string;
  verifierModulePath: string;
  verifySignedReleaseEnvelope(input: { signedRelease: any; trustPolicy: any; now: string; protectedState: any }): any;
  protectedState: {
    latestLedgerHeadHash: string;
    latestLedgerRevision: number;
    currentManifestDigest: string | null;
    publisherFence: number;
  };
  manifestDigest: string;
  buildId: string;
  expiresAt: string;
  signFor(input: {
    buildId: string;
    distDir: string;
    predecessorManifestDigest: string | null;
    publisherFence: number;
    issuedAt?: string;
    expiresAt?: string;
    outputPath: string;
  }): Promise<{ manifestDigest: string; signedManifestPath: string }>;
}

export async function createReleaseFixture(root: string): Promise<ReleaseFixture> {
  const distDir = join(root, 'dist');
  await mkdir(join(distDir, 'assets'), { recursive: true });
  await writeFile(join(distDir, 'index.html'), '<!doctype html><title>Portfolio</title>\n');
  await writeFile(join(distDir, 'assets/app.js'), 'console.log("portfolio");\n');
  const sbomPath = join(root, 'sbom.cdx.json');
  await writeFile(sbomPath, '{"bomFormat":"CycloneDX","specVersion":"1.6"}\n');

  const keys = generateKeyPairSync('ed25519');
  const publicKeyPem = keys.publicKey.export({ type: 'spki', format: 'pem' }).toString();
  const trustPolicyPath = join(root, 'release-trust.json');
  await writeFile(trustPolicyPath, canonicalValueBytes({
    keyId: 'release-test-key', issuerEpoch: 7, scope: 'portfolio-release-signing/v1', publicKeyPem,
  }));

  const verifierModulePath = join(root, 'real-release-verifier.mjs');
  await writeFile(verifierModulePath, `
import { createHash, verify } from 'node:crypto';

function canonical(value) {
  if (value === null || typeof value !== 'object') return JSON.stringify(value);
  if (Array.isArray(value)) return '[' + value.map(canonical).join(',') + ']';
  return '{' + Object.keys(value).sort().map((key) => JSON.stringify(key) + ':' + canonical(value[key])).join(',') + '}';
}
function digest(schema, value) {
  return createHash('sha256').update(canonical({ schema, value })).digest('hex');
}
function fail(message) { throw new Error(message); }

export function verifySignedReleaseEnvelope({ signedRelease, trustPolicy, now, protectedState }) {
  if (signedRelease?.schema !== 'portfolio-signed-release-manifest/v1') fail('bad envelope schema');
  if (signedRelease.signature?.algorithm !== 'Ed25519' || signedRelease.signature?.encoding !== 'base64url-nopad') fail('bad signature metadata');
  if (signedRelease.signature?.keyId !== trustPolicy.keyId || signedRelease.signature?.issuerEpoch !== trustPolicy.issuerEpoch || signedRelease.signature?.scope !== trustPolicy.scope) fail('untrusted signer');
  const signature = Buffer.from(signedRelease.signature.value, 'base64url');
  if (signature.length !== 64 || !verify(null, Buffer.from(canonical(signedRelease.payload)), trustPolicy.publicKeyPem, signature)) fail('invalid release signature');
  const manifestDigest = digest('portfolio-candidate-release-manifest/v1', signedRelease.payload);
  if (manifestDigest !== signedRelease.payloadDigest) fail('candidate digest mismatch');
  const candidate = signedRelease.payload;
  if (candidate.latestLedgerHeadHash !== protectedState.latestLedgerHeadHash || candidate.latestLedgerRevision !== protectedState.latestLedgerRevision) fail('stale ledger');
  if (candidate.releaseManifest.currentManifestDigest !== protectedState.currentManifestDigest) fail('stale predecessor');
  if (Date.parse(now) >= Date.parse(candidate.releaseManifest.expiresAt)) fail('expired release');
  return {
    schema: 'portfolio-verified-release-admission/v1',
    manifestDigest,
    manifestPayload: candidate.releaseManifest,
    expiresAt: candidate.releaseManifest.expiresAt,
    predecessorManifestDigest: candidate.releaseManifest.currentManifestDigest,
    latestLedgerHeadHash: candidate.latestLedgerHeadHash,
    latestLedgerRevision: candidate.latestLedgerRevision,
    expectedFence: protectedState.publisherFence + 1,
    signatureVerified: true,
  };
}
`);
  await chmod(verifierModulePath, 0o500);

  const protectedState = {
    latestLedgerHeadHash: digest('9'), latestLedgerRevision: 11, currentManifestDigest: null, publisherFence: 0,
  };

  const verifySignedReleaseEnvelope = ({ signedRelease, trustPolicy, now, protectedState: state }: { signedRelease: any; trustPolicy: any; now: string; protectedState: any }) => {
    if (signedRelease?.schema !== 'portfolio-signed-release-manifest/v1') throw new Error('bad envelope schema');
    if (signedRelease.signature?.keyId !== trustPolicy.keyId || signedRelease.signature?.issuerEpoch !== trustPolicy.issuerEpoch ||
        signedRelease.signature?.scope !== trustPolicy.scope) throw new Error('untrusted signer');
    const signature = Buffer.from(signedRelease.signature.value, 'base64url');
    if (signature.length !== 64 || !verify(null, canonicalValueBytes(signedRelease.payload), trustPolicy.publicKeyPem, signature)) throw new Error('invalid release signature');
    const manifestDigest = canonicalJsonDigest('portfolio-candidate-release-manifest/v1', signedRelease.payload);
    if (manifestDigest !== signedRelease.payloadDigest) throw new Error('candidate digest mismatch');
    const candidate = signedRelease.payload;
    if (candidate.latestLedgerHeadHash !== state.latestLedgerHeadHash || candidate.latestLedgerRevision !== state.latestLedgerRevision) throw new Error('stale ledger');
    if (candidate.releaseManifest.currentManifestDigest !== state.currentManifestDigest) throw new Error('stale predecessor');
    if (Date.parse(now) >= Date.parse(candidate.releaseManifest.expiresAt)) throw new Error('expired release');
    return {
      schema: 'portfolio-verified-release-admission/v1', manifestDigest, manifestPayload: candidate.releaseManifest,
      expiresAt: candidate.releaseManifest.expiresAt, predecessorManifestDigest: candidate.releaseManifest.currentManifestDigest,
      latestLedgerHeadHash: candidate.latestLedgerHeadHash, latestLedgerRevision: candidate.latestLedgerRevision,
      expectedFence: state.publisherFence + 1, signatureVerified: true,
    };
  };

  const signFor = async (input: {
    buildId: string;
    distDir: string;
    predecessorManifestDigest: string | null;
    publisherFence: number;
    issuedAt?: string;
    expiresAt?: string;
    outputPath: string;
  }) => {
    const artifactPaths = ['assets/app.js', 'index.html'];
    const artifacts = await Promise.all(artifactPaths.map(async (path) => {
      const bytes = await readFile(join(input.distDir, path));
      return { path, sha256: byteDigest(bytes), bytes: bytes.length, encoding: 'identity' as const };
    }));
    const inputDigests = {
      PortfolioContent: digest('a'), PublicAssetManifest: digest('b'), PreparedAssetSet: digest('c'), SiteConfig: digest('d'),
    };
    const issuedAt = input.issuedAt ?? '2026-09-02T00:00:00Z';
    const expiresAt = input.expiresAt ?? '2026-09-03T00:00:00Z';
    const releaseManifest = {
      schema: 'portfolio-release-manifest/v1' as const,
      launchMode: 'private-source-initial-launch' as const,
      buildId: input.buildId,
      inputDigests,
      productionInputRoot: computeProductionInputRoot({
        portfolioContentDigest: inputDigests.PortfolioContent,
        publicAssetManifestDigest: inputDigests.PublicAssetManifest,
        preparedAssetSetDigest: inputDigests.PreparedAssetSet,
        siteConfigDigest: inputDigests.SiteConfig,
      }),
      artifacts,
      deployFiles: artifactPaths,
      sourceCommit: digest('e'), sourceTree: digest('f'), approvedRecordRoot: digest('1'), approvedAssetRoot: digest('2'),
      approvalProofSetDigest: digest('3'), approvalProjectionAttestationDigest: digest('4'), scanEvidenceDigest: digest('5'),
      policyVersions: { approval: '1', privacy: '1', release: '1' }, toolVersions: { node: '22.22.1' },
      predecessorManifestDigest: input.predecessorManifestDigest,
      currentManifestDigest: input.predecessorManifestDigest,
      issuedAt, expiresAt, minimumBoundExpiry: expiresAt,
    };
    const candidate = {
      schema: 'portfolio-candidate-release-manifest/v1',
      releaseManifest,
      latestLedgerHeadHash: protectedState.latestLedgerHeadHash,
      latestLedgerRevision: protectedState.latestLedgerRevision,
      sourceClosureDigest: digest('6'), publicRefMap: [], lfsOids: [], releaseArchives: [],
      buildProvenanceDigest: digest('7'), privacyPolicyDigest: digest('8'), toolImageDigests: [digest('0')],
    };
    const payloadDigest = canonicalJsonDigest('portfolio-candidate-release-manifest/v1', candidate);
    const signature = sign(null, canonicalValueBytes(candidate), keys.privateKey).toString('base64url');
    const signedRelease = {
      schema: 'portfolio-signed-release-manifest/v1', payload: candidate, payloadDigest,
      signature: {
        algorithm: 'Ed25519', encoding: 'base64url-nopad', keyId: 'release-test-key', issuerEpoch: 7,
        scope: 'portfolio-release-signing/v1', value: signature,
      },
    };
    await writeFile(input.outputPath, canonicalValueBytes(signedRelease));
    return { manifestDigest: payloadDigest, signedManifestPath: input.outputPath };
  };

  const signedManifestPath = join(root, 'signed-release.json');
  const initial = await signFor({ buildId: 'release-a', distDir, predecessorManifestDigest: null, publisherFence: 0, outputPath: signedManifestPath });
  return {
    distDir, signedManifestPath, sbomPath, trustPolicyPath, verifierModulePath, verifySignedReleaseEnvelope, protectedState,
    manifestDigest: initial.manifestDigest, buildId: 'release-a', expiresAt: '2026-09-03T00:00:00Z', signFor,
  };
}

export async function initializeReleaseRoot(root: string, state?: Partial<ReleaseFixture['protectedState']>): Promise<void> {
  await mkdir(join(root, 'control'), { recursive: true });
  await writeFile(join(root, '.portfolio-release-root'), 'portfolio-release-root/v1\n');
  await writeFile(join(root, 'control/state.json'), canonicalValueBytes({
    schema: 'portfolio-release-control-state/v1',
    currentManifestDigest: state?.currentManifestDigest ?? null,
    currentReleaseId: null,
    publisherFence: state?.publisherFence ?? 0,
    latestLedgerHeadHash: state?.latestLedgerHeadHash ?? digest('9'),
    latestLedgerRevision: state?.latestLedgerRevision ?? 11,
    activeTransaction: null,
  }));
}