const { randomBytes, createHash } = require("node:crypto");
const { spawnSync } = require("node:child_process");
const path = require("node:path");
const cryptoService = require("../../../src/services/crypto");
const {
  checkSyntheticSample,
  runSyntheticContract,
} = require("../../../../scripts/qa/check-sensitive-recovery-contract.cjs");

describe("K0 synthetic sensitive recovery contract", () => {
  let config;
  let plaintext;
  let encrypted;

  beforeEach(() => {
    config = { fieldEncryptionKey: randomBytes(32).toString("base64") };
    plaintext = `synthetic-only-${randomBytes(16).toString("hex")}`;
    encrypted = cryptoService.encryptStringOrThrow(config, plaintext);
  });

  // Boolean assertions keep failed tests from printing fixture values/digests.
  function expectNoFixture(output, additional = []) {
    const key = Buffer.from(config.fieldEncryptionKey, "base64");
    const forbidden = [
      plaintext, encrypted, config.fieldEncryptionKey, key.toString("hex"),
      createHash("sha256").update(key).digest("hex"),
      createHash("sha256").update(config.fieldEncryptionKey).digest("hex"),
      ...encrypted.split(":").slice(1), ...additional,
    ];
    expect(forbidden.some((value) => output.includes(value))).toBe(false);
  }

  it("round-trips with the actual production crypto exports and only reports status", () => {
    const report = checkSyntheticSample(config, encrypted, plaintext);
    expect(report).toEqual({ status: "PASS", reason: "SYNTHETIC_MATCH" });
    expectNoFixture(JSON.stringify(report));
  });

  it.each([
    ["no config", undefined], ["no key", {}],
    ["null", { fieldEncryptionKey: null }], ["empty", { fieldEncryptionKey: "" }],
    ["whitespace", { fieldEncryptionKey: "  " }],
    ["wrong type", { fieldEncryptionKey: 32 }],
    ["unparseable", { fieldEncryptionKey: "%%%" }],
    ["short", { fieldEncryptionKey: Buffer.alloc(31).toString("base64") }],
    ["long", { fieldEncryptionKey: Buffer.alloc(33).toString("base64") }],
  ])("stops for an unavailable or invalid key: %s", (_label, candidate) => {
    expect(checkSyntheticSample(candidate, encrypted, plaintext)).toEqual({
      status: "STOP", reason: "KEY_UNAVAILABLE_OR_INVALID",
    });
  });

  it("stops for a different but valid 32-byte key", () => {
    const wrongKey = Buffer.from(config.fieldEncryptionKey, "base64");
    wrongKey[0] ^= 1;
    const report = checkSyntheticSample({ fieldEncryptionKey: wrongKey.toString("base64") }, encrypted, plaintext);
    expect(report).toEqual({ status: "STOP", reason: "DECRYPTION_FAILED" });
    expectNoFixture(JSON.stringify(report), [wrongKey.toString("base64")]);
  });

  it.each([["iv", 1], ["tag", 2], ["ciphertext", 3]])("stops after tampering with %s", (_label, index) => {
    const parts = encrypted.split(":");
    const value = Buffer.from(parts[index], "base64url");
    value[0] ^= 1;
    parts[index] = value.toString("base64url");
    const tampered = parts.join(":");
    const report = checkSyntheticSample(config, tampered, plaintext);
    expect(report).toEqual({ status: "STOP", reason: "DECRYPTION_FAILED" });
    expectNoFixture(JSON.stringify(report), [tampered]);
  });

  it.each([["empty", ""], ["null", null], ["absent", undefined]])("marks %s fields NOT_TESTED", (_label, value) => {
    expect(checkSyntheticSample(config, value, plaintext)).toEqual({ status: "NOT_TESTED", reason: "EMPTY_FIELD" });
  });

  it("does not let an empty field hide a missing key", () => {
    expect(checkSyntheticSample({}, "", plaintext)).toEqual({ status: "STOP", reason: "KEY_UNAVAILABLE_OR_INVALID" });
  });

  it.each([
    ["legacy plaintext", "synthetic-unencrypted"], ["unknown version", "v2:a:b:c"],
    ["missing parts", "v1:a:b"], ["extra parts", "v1:a:b:c:d"],
    ["empty parts", "v1:::"], ["invalid encoding", "v1:%%:%%:%%"],
    ["wrong type", 123],
  ])("stops instead of treating a null decryption as success: %s", (_label, payload) => {
    expect(checkSyntheticSample(config, payload, plaintext)).toEqual({ status: "STOP", reason: "INVALID_PAYLOAD" });
  });

  it("requires the synthetic expectation and detects a plaintext mismatch", () => {
    expect(checkSyntheticSample(config, encrypted)).toEqual({ status: "STOP", reason: "SYNTHETIC_EXPECTATION_REQUIRED" });
    const report = checkSyntheticSample(config, encrypted, "different-synthetic-value");
    expect(report).toEqual({ status: "STOP", reason: "PLAINTEXT_MISMATCH" });
    expectNoFixture(JSON.stringify(report));
  });

  it("drops raw exceptions, does not log, and never uses the logging decrypt branch", () => {
    const marker = `synthetic-error-${randomBytes(8).toString("hex")}`;
    const spies = ["log", "warn", "error", "info", "debug"].map((name) => vi.spyOn(console, name).mockImplementation(() => {}));
    const safe = vi.spyOn(cryptoService, "decryptStringSafe").mockImplementation(() => { throw new Error(marker); });
    try {
      const throwingConfig = { get fieldEncryptionKey() { throw new Error(marker); } };
      const report = checkSyntheticSample(throwingConfig, encrypted, plaintext);
      expect(report).toEqual({ status: "STOP", reason: "DECRYPTION_FAILED" });
      expectNoFixture(JSON.stringify(report), [marker]);
      expect(runSyntheticContract().status).toBe("PASS");
      expect(safe).not.toHaveBeenCalled();
      expect(spies.every((spy) => spy.mock.calls.length === 0)).toBe(true);
    } finally {
      safe.mockRestore();
      spies.forEach((spy) => spy.mockRestore());
    }
  });

  it("keeps real custody and real-data decryption untested after the synthetic matrix passes", () => {
    const report = runSyntheticContract();
    expect(report.status).toBe("PASS");
    expect(report.checks).toHaveLength(7);
    expect(report.checks.every((check) => check.matched)).toBe(true);
    expect(report).toMatchObject({ scope: "K0_SYNTHETIC_ONLY", originalKeySource: "UNKNOWN", custody: "NOT_TESTED", realDataDecryption: "NOT_TESTED" });
  });

  it("CLI ignores ambient key inputs and produces only the fixed aggregate contract", () => {
    const script = path.resolve(__dirname, "../../../../scripts/qa/check-sensitive-recovery-contract.cjs");
    const child = spawnSync(process.execPath, [script], {
      encoding: "utf8",
      env: { FIELD_ENCRYPTION_KEY: config.fieldEncryptionKey, DATABASE_URL: "synthetic-unused" },
    });
    expect(child.status).toBe(0);
    expect(child.stderr.length).toBe(0);
    expectNoFixture(child.stdout + child.stderr);
    const report = JSON.parse(child.stdout);
    expect(Object.keys(report).sort()).toEqual(["checks", "custody", "originalKeySource", "realDataDecryption", "scope", "status"]);
    expect(report.status).toBe("PASS");
    expect(report.checks.every((check) => Object.keys(check).sort().join(",") === "category,matched,reason,status")).toBe(true);
  });

  it("CLI rejects arbitrary arguments without echoing them", () => {
    const script = path.resolve(__dirname, "../../../../scripts/qa/check-sensitive-recovery-contract.cjs");
    const child = spawnSync(process.execPath, [script, plaintext], { encoding: "utf8", env: {} });
    expect(child.status).toBe(1);
    expect(child.stderr.length).toBe(0);
    expectNoFixture(child.stdout + child.stderr);
    expect(JSON.parse(child.stdout)).toEqual({ scope: "K0_SYNTHETIC_ONLY", status: "FAIL", reason: "ARGUMENTS_NOT_ALLOWED" });
  });
});