/**
 * Config schema test — locks in the [E00-S04-T01] TypeBox/Ajv configuration
 * schema for the workspace.
 *
 * Acceptance criteria covered (each test fails without the committed state):
 *   - "configuration schema is defined with TypeBox/Ajv" → the new
 *     `packages/config` package (`@personal-blog/config`) pins the
 *     golden-tuple runtime deps exactly (`@sinclair/typebox@0.34.52`,
 *     `ajv@8.20.0` — Technology-Stack §5.2/§7), its `src/schema.ts` defines
 *     `configSchema` with TypeBox (`Type.Object`), and its `src/validate.ts`
 *     compiles that schema with Ajv (`new Ajv({ allErrors: true })` +
 *     `.compile(configSchema)`) and exports `validateConfig`; the package
 *     boundary re-exports both. Mutation probes prove the assertions are
 *     non-vacuous (dropping a field, relaxing a constraint, replacing
 *     TypeBox/Ajv with a hand-rolled object all fail).
 *   - "schema covers the validated config fields" → the schema defines the
 *     four validated config fields with their constraints: `host` (string,
 *     default `0.0.0.0`), `port` (integer 1–65535, default `3000`),
 *     `databaseUrl` (optional non-empty string — the local non-container path
 *     has no database), `sessionSecret` (required, ≥ 32 chars — the story's
 *     secret field, EPPP_SESSION_SECRET, Security-and-Operations §32/§26),
 *     and the object is closed (`additionalProperties: false`).
 *   - the issue's test plan — "validate a full config against the
 *     TypeBox/Ajv schema" → the deterministic probe imports the committed
 *     `src/schema.ts` (Node type stripping, no build step) and validates a
 *     full config through Ajv, plus the negative cases (missing required
 *     field naming `sessionSecret`, secret too short, unknown property, port
 *     out of range / not an integer, empty `databaseUrl`); when the package
 *     is built (CI builds it first) the probe additionally exercises the
 *     compiled `validateConfig` boundary exactly as the later configuration
 *     adapter will consume it.
 *
 * Run: `node --test tests/config-schema.test.mjs`
 * (node:test — built into Node >= 18; no dependencies, lockfile untouched.)
 */

import test from 'node:test';
import assert from 'node:assert/strict';
import { readFileSync, existsSync, writeFileSync, rmSync } from 'node:fs';
import { spawnSync } from 'node:child_process';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const REPO_ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');

const read = (relPath) => readFileSync(path.join(REPO_ROOT, relPath), 'utf8');

/** The committed config package under test. */
const CONFIG_DIR = 'packages/config';
const MANIFEST_PATH = `${CONFIG_DIR}/package.json`;
const SCHEMA_SRC = `${CONFIG_DIR}/src/schema.ts`;
const VALIDATE_SRC = `${CONFIG_DIR}/src/validate.ts`;
const INDEX_SRC = `${CONFIG_DIR}/src/index.ts`;

/** The root test glob (root `scripts.test`, E00-S01-T12) that runs every suite. */
const ROOT_TEST_GLOB = 'tests/**/*.test.mjs';

/** The CI job that gates the config-schema criterion on every PR. */
const CI_JOB = 'config-schema';

/** Golden-tuple pins for the configuration schema (Technology-Stack §5.2/§7). */
const GOLDEN_TYPEBOX = '0.34.52';
const GOLDEN_AJV = '8.20.0';

// ---------------------------------------------------------------------------
// Static assertions on the committed config package
// ---------------------------------------------------------------------------

/**
 * Asserts the schema is defined with TypeBox and covers the validated config
 * fields with their documented constraints. Fails fast on any deviation; the
 * mutation probes below prove the assertions are non-vacuous.
 */
function assertSchemaShape(src) {
  // Defined with TypeBox: the schema object is built by Type.Object from the
  // @sinclair/typebox `Type` factory (never a hand-rolled plain object).
  assert.match(
    src,
    /import \{ Type, type Static \} from '@sinclair\/typebox'/,
    'the schema module must import Type (and the Static type) from @sinclair/typebox',
  );
  assert.match(
    src,
    /export const configSchema = Type\.Object\(/,
    'the schema must be defined with TypeBox (Type.Object) — not a hand-rolled object',
  );

  // The validated config fields, each with its documented constraint.
  assert.match(
    src,
    /host: Type\.Optional\(Type\.String\(\{ default: '0\.0\.0\.0' \}\)\)/,
    'the schema must cover the host field (optional string, default 0.0.0.0 — the bind address)',
  );
  assert.match(
    src,
    /port: Type\.Optional\(Type\.Integer\(\{ minimum: 1, maximum: 65535, default: 3000 \}\)\)/,
    'the schema must cover the port field (optional integer 1-65535, default 3000)',
  );
  assert.match(
    src,
    /databaseUrl: Type\.Optional\(Type\.String\(\{ minLength: 1 \}\)\)/,
    'the schema must cover the databaseUrl field (optional non-empty string)',
  );
  assert.match(
    src,
    /sessionSecret: Type\.String\(\{ minLength: 32 \}\)/,
    'the schema must cover the sessionSecret field (required string, at least 32 chars — never Type.Optional)',
  );
  assert.match(
    src,
    /additionalProperties: false/,
    'the schema must close the object (additionalProperties: false) so unexpected settings are rejected',
  );
}

/** Asserts the validator compiles the schema with Ajv and exports validateConfig. */
function assertValidateShape(src) {
  assert.match(
    src,
    /import \{ Ajv \} from 'ajv'/,
    'the validator module must import Ajv (the golden-tuple validator)',
  );
  assert.match(
    src,
    /new Ajv\(\{ allErrors: true \}\)/,
    'the validator must create the Ajv instance with allErrors (report every violation)',
  );
  assert.match(
    src,
    /\.compile\(configSchema\)/,
    'the validator must compile the TypeBox configSchema with Ajv',
  );
  assert.match(
    src,
    /export function validateConfig/,
    'the validator module must export the validateConfig entry point',
  );
}

// ---------------------------------------------------------------------------
// Criterion tests
// ---------------------------------------------------------------------------

test('the config package exists, pins the golden-tuple runtime deps exactly, and builds with tsc', () => {
  const manifest = JSON.parse(read(MANIFEST_PATH));
  assert.equal(manifest.name, '@personal-blog/config');
  assert.equal(
    manifest.dependencies?.['@sinclair/typebox'],
    GOLDEN_TYPEBOX,
    `@sinclair/typebox must be pinned exactly to the golden tuple (${GOLDEN_TYPEBOX})`,
  );
  assert.match(
    manifest.dependencies?.['@sinclair/typebox'],
    /^\d+\.\d+\.\d+$/,
    'the @sinclair/typebox pin must be exact (no ^ / ~ / range)',
  );
  assert.equal(
    manifest.dependencies?.ajv,
    GOLDEN_AJV,
    `ajv must be pinned exactly to the golden tuple (${GOLDEN_AJV})`,
  );
  assert.match(
    manifest.dependencies?.ajv,
    /^\d+\.\d+\.\d+$/,
    'the ajv pin must be exact (no ^ / ~ / range)',
  );
  // The CI job and the local build path compile the package with tsc.
  assert.equal(manifest.scripts?.build, 'tsc -p tsconfig.json');
  assert.equal(manifest.scripts?.typecheck, 'tsc -p tsconfig.json --noEmit');
});

test('the configuration schema is defined with TypeBox and covers the validated config fields', () => {
  assert.ok(existsSync(path.join(REPO_ROOT, SCHEMA_SRC)), `committed ${SCHEMA_SRC} must exist`);
  assertSchemaShape(read(SCHEMA_SRC));
});

test('the schema is validated with Ajv: validate.ts compiles configSchema and exports validateConfig', () => {
  assert.ok(existsSync(path.join(REPO_ROOT, VALIDATE_SRC)), `committed ${VALIDATE_SRC} must exist`);
  assertValidateShape(read(VALIDATE_SRC));
});

test('the package boundary re-exports the schema and the validator', () => {
  const src = read(INDEX_SRC);
  assert.match(src, /export \{ configSchema \} from '\.\/schema\.js'/, 'the boundary must re-export configSchema');
  assert.match(src, /export type \{ Config \} from '\.\/schema\.js'/, 'the boundary must re-export the Config type');
  assert.match(src, /export \{ validateConfig \} from '\.\/validate\.js'/, 'the boundary must re-export validateConfig');
  assert.match(src, /export type \{ ConfigValidationResult \} from '\.\/validate\.js'/, 'the boundary must re-export the ConfigValidationResult type');
});

test('the config-schema criterion is enforced in CI', () => {
  // Picked up by the root test command (root `scripts.test` glob).
  const scripts = JSON.parse(read('package.json')).scripts ?? {};
  assert.equal(
    scripts.test,
    `node --test "${ROOT_TEST_GLOB}"`,
    `root scripts.test must run the "${ROOT_TEST_GLOB}" glob so this suite runs with the rest`,
  );
  // And a dedicated CI job gates it on every PR.
  const workflow = read('.gitea/workflows/ci.yml');
  assert.ok(
    workflow.includes(`node --test tests/config-schema.test.mjs`),
    `CI must run the config-schema suite (job "${CI_JOB}") on every PR`,
  );
  assert.ok(
    workflow.includes(`pnpm --filter @personal-blog/config build`),
    'the CI job must build the config package (the probe exercises the compiled boundary)',
  );
});

// ---------------------------------------------------------------------------
// Mutation probes — the static assertions are non-vacuous
// ---------------------------------------------------------------------------

test('removing a validated config field from the schema fails the coverage assertion (mutation probe)', () => {
  const mutated = read(SCHEMA_SRC).replace(
    /sessionSecret: Type\.String\(\{ minLength: 32 \}\),\n/,
    '',
  );
  assert.notEqual(mutated, read(SCHEMA_SRC), 'the mutation must actually remove the sessionSecret field');
  assert.throws(() => assertSchemaShape(mutated), /sessionSecret/);
});

test('making the secret optional fails the coverage assertion (mutation probe)', () => {
  const mutated = read(SCHEMA_SRC).replace(
    'sessionSecret: Type.String({ minLength: 32 })',
    'sessionSecret: Type.Optional(Type.String({ minLength: 32 }))',
  );
  assert.notEqual(mutated, read(SCHEMA_SRC), 'the mutation must actually make sessionSecret optional');
  assert.throws(() => assertSchemaShape(mutated), /never Type\.Optional/);
});

test('relaxing the secret length fails the coverage assertion (mutation probe)', () => {
  const mutated = read(SCHEMA_SRC).replace('minLength: 32', 'minLength: 8');
  assert.notEqual(mutated, read(SCHEMA_SRC), 'the mutation must actually relax the minLength');
  assert.throws(() => assertSchemaShape(mutated), /at least 32 chars/);
});

test('opening the object fails the coverage assertion (mutation probe)', () => {
  // Replace every occurrence (the docstring mentions the keyword too) so the
  // committed schema code itself is the mutation target.
  const mutated = read(SCHEMA_SRC).replace(/additionalProperties: false/g, 'additionalProperties: true');
  assert.notEqual(mutated, read(SCHEMA_SRC), 'the mutation must actually open the object');
  assert.throws(() => assertSchemaShape(mutated), /additionalProperties: false/);
});

test('replacing TypeBox with a hand-rolled object fails the TypeBox assertion (mutation probe)', () => {
  const mutated = read(SCHEMA_SRC)
    .replace("import { Type, type Static } from '@sinclair/typebox';", '// no TypeBox')
    .replace('export const configSchema = Type.Object(', 'export const configSchema = {');
  assert.notEqual(mutated, read(SCHEMA_SRC), 'the mutation must actually drop TypeBox');
  assert.throws(() => assertSchemaShape(mutated), /must import Type/);
});

test('dropping the Ajv compile fails the validator assertion (mutation probe)', () => {
  const mutated = read(VALIDATE_SRC)
    .replace("import { Ajv } from 'ajv';", '// no Ajv')
    .replace('const validateConfigValue = ajv.compile(configSchema);', 'const validateConfigValue = () => true;');
  assert.notEqual(mutated, read(VALIDATE_SRC), 'the mutation must actually drop the Ajv compile');
  assert.throws(() => assertValidateShape(mutated), /Ajv|compile/);
});

// ---------------------------------------------------------------------------
// Deterministic behavioral probe — the issue's test plan: validate a full
// config against the TypeBox/Ajv schema
// ---------------------------------------------------------------------------

/**
 * How the current Node executes TypeScript sources: `default` (>= 23.6, type
 * stripping on by default), `strip-types-flag` (>= 22.6 via
 * `--experimental-strip-types`) or `null` (cannot run .ts at all). The
 * workspace pins engines.node to 24.x, where type stripping is stable.
 */
function tsExecMode() {
  const [major, minor] = process.versions.node.split('.').map(Number);
  if (major > 23 || (major === 23 && minor >= 6)) return 'default';
  if (major === 22 && minor >= 6) return 'strip-types-flag';
  return null;
}

const TS_STRIPPING = tsExecMode() !== null;

/**
 * The probe source: imports the committed `src/schema.ts` (type-stripped,
 * no build step) and validates a full config plus the negative cases through
 * Ajv — the issue's test plan. When the package is built (`dist/` present,
 * as in the CI job), it additionally exercises the compiled
 * `validateConfig` boundary exactly as the later configuration adapter will.
 * Written to a temp file inside `packages/config/` so `@sinclair/typebox` and
 * `ajv` resolve through the package's own dependency links, then removed.
 */
const PROBE_SOURCE = `
import { configSchema } from './src/schema.ts';
import { Ajv } from 'ajv';
import { existsSync } from 'node:fs';

const validate = new Ajv({ allErrors: true }).compile(configSchema);
const errorsOf = (value) => {
  validate(value);
  return (validate.errors ?? []).map((error) => error.message ?? 'invalid');
};

const FULL = {
  host: '0.0.0.0',
  port: 3000,
  databaseUrl: 'postgres://eppp:eppp@db:5432/eppp',
  sessionSecret: 's'.repeat(32),
};

const result = {
  // The issue's test plan: "validate a full config against the TypeBox/Ajv
  // schema" — a full config is valid.
  fullValid: validate(FULL),
  // host/port/databaseUrl are optional (port and host carry defaults; the
  // local non-container path has no database), so a config with only the
  // required secret is valid too.
  defaultsValid: validate({ sessionSecret: 's'.repeat(32) }),
  // The required field is enforced and the error names it (E00-S04-T02 will
  // format these as field-specific startup errors).
  missingSecretErrors: errorsOf({ host: '0.0.0.0', port: 3000 }),
  shortSecretErrors: errorsOf({ ...FULL, sessionSecret: 'short' }),
  // The object is closed: an unexpected setting is rejected loudly.
  unknownPropertyErrors: errorsOf({ ...FULL, extra: true }),
  // Port is an integer in 1-65535.
  portTooHighErrors: errorsOf({ ...FULL, port: 65536 }),
  portNotIntegerErrors: errorsOf({ ...FULL, port: '3000' }),
  // databaseUrl must be non-empty when present.
  emptyDatabaseUrlErrors: errorsOf({ ...FULL, databaseUrl: '' }),
};

// Compiled boundary (built by the CI job): the committed validateConfig.
if (existsSync('./dist/index.js')) {
  const { validateConfig } = await import('./dist/index.js');
  result.boundaryFullValid = validateConfig(FULL).valid;
  result.boundaryMissingSecretErrors = validateConfig({ host: '0.0.0.0', port: 3000 }).errors;
  result.boundaryUnknownPropertyErrors = validateConfig({ ...FULL, extra: true }).errors;
}

console.log('CONFIG_SCHEMA_PROBE_RESULT ' + JSON.stringify(result));
`;

test('a full config validates against the committed TypeBox/Ajv schema, and violations are rejected (deterministic probe)', { skip: !TS_STRIPPING }, () => {
  // The issue's test plan: "validate a full config against the TypeBox/Ajv
  // schema". The probe runs the committed schema.ts through Ajv (Node type
  // stripping, no build step) from inside packages/config so the golden-tuple
  // deps resolve through the package's own links.
  const probeFile = path.join(REPO_ROOT, CONFIG_DIR, `.config-schema-probe-${process.pid}.mjs`);
  const args =
    tsExecMode() === 'strip-types-flag'
      ? ['--experimental-strip-types', path.basename(probeFile)]
      : [path.basename(probeFile)];
  try {
    writeFileSync(probeFile, PROBE_SOURCE);
    const run = spawnSync(process.execPath, args, {
      cwd: path.join(REPO_ROOT, CONFIG_DIR),
      encoding: 'utf8',
      timeout: 60_000,
    });
    assert.equal(
      run.status,
      0,
      `the probe must exit 0 (status ${run.status}):\n${(run.stderr || run.stdout || '').trim()}`,
    );
    const match = run.stdout.match(/CONFIG_SCHEMA_PROBE_RESULT (\{.*\})/);
    assert.ok(match, `the probe must print CONFIG_SCHEMA_PROBE_RESULT:\n${run.stdout.trim()}`);
    const result = JSON.parse(match[1]);

    // The issue's test plan: a full config validates.
    assert.equal(result.fullValid, true, 'a full config must validate against the TypeBox/Ajv schema');
    assert.equal(result.defaultsValid, true, 'host/port/databaseUrl are optional (defaults; no-database path)');

    // The required field is enforced and the error names it.
    assert.ok(
      result.missingSecretErrors.some((msg) => /required property 'sessionSecret'/.test(msg)),
      `missing sessionSecret must be rejected naming the field (got: ${JSON.stringify(result.missingSecretErrors)})`,
    );
    assert.ok(
      result.shortSecretErrors.some((msg) => /fewer than 32/.test(msg)),
      `a short sessionSecret must be rejected (got: ${JSON.stringify(result.shortSecretErrors)})`,
    );

    // The object is closed and the numeric/string constraints hold.
    assert.ok(
      result.unknownPropertyErrors.some((msg) => /additional properties/.test(msg)),
      `an unknown property must be rejected (got: ${JSON.stringify(result.unknownPropertyErrors)})`,
    );
    assert.ok(
      result.portTooHighErrors.some((msg) => /<= 65535/.test(msg)),
      `a port above 65535 must be rejected (got: ${JSON.stringify(result.portTooHighErrors)})`,
    );
    assert.ok(
      result.portNotIntegerErrors.some((msg) => /integer/.test(msg)),
      `a non-integer port must be rejected (got: ${JSON.stringify(result.portNotIntegerErrors)})`,
    );
    assert.ok(
      result.emptyDatabaseUrlErrors.some((msg) => /fewer than 1/.test(msg)),
      `an empty databaseUrl must be rejected (got: ${JSON.stringify(result.emptyDatabaseUrlErrors)})`,
    );

    // When the package is built (the CI job builds it), the compiled
    // validateConfig boundary behaves identically.
    if (existsSync(path.join(REPO_ROOT, CONFIG_DIR, 'dist', 'index.js'))) {
      assert.equal(result.boundaryFullValid, true, 'validateConfig must accept a full config');
      assert.ok(
        result.boundaryMissingSecretErrors.some((msg) => /required property 'sessionSecret'/.test(msg)),
        `validateConfig must reject a missing secret naming the field (got: ${JSON.stringify(result.boundaryMissingSecretErrors)})`,
      );
      assert.ok(
        result.boundaryUnknownPropertyErrors.some((msg) => /additional properties/.test(msg)),
        `validateConfig must reject an unknown property (got: ${JSON.stringify(result.boundaryUnknownPropertyErrors)})`,
      );
    }
  } finally {
    rmSync(probeFile, { force: true });
  }
});