/**
 * Contract-identity ACCEPTANCE §5 (core half) — the shared stamp record:
 * header form, frontmatter-safe serialization, and the tolerant parser that
 * gates read the stamp back with.
 */
import { describe, expect, it } from "vitest";

import type { ContractDomain } from "./preimage.js";
import {
  type ContractStampRecord,
  formatStampHeader,
  parseContractStamp,
  serializeContractStamp,
} from "./stamp.js";

const FCID = "a3f9e21b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b785";
const DOMAINS: Record<ContractDomain, string> = {
  components: "1".repeat(64),
  tokens: "2".repeat(64),
  canonicalMap: "3".repeat(64),
  policy: "4".repeat(64),
};
const RECORD: ContractStampRecord = { contractVersion: 12, fcid: FCID, domains: DOMAINS };

describe("formatStampHeader", () => {
  it("prefixes the shared pin formatter's output — never a second pin format", () => {
    expect(formatStampHeader(RECORD)).toBe("fragments contract v12 · a3f9e21");
  });
});

describe("serializeContractStamp", () => {
  it("renders plain header lines with the literal header form on the first line", () => {
    expect(serializeContractStamp(RECORD)).toBe(
      [
        "contract: fragments contract v12 · a3f9e21",
        `contract-fcid: ${FCID}`,
        `contract-domains: components=${DOMAINS.components} tokens=${DOMAINS.tokens} canonicalMap=${DOMAINS.canonicalMap} policy=${DOMAINS.policy}`,
      ].join("\n")
    );
  });

  it("omits the domains line when sub-hashes are unknown", () => {
    const serialized = serializeContractStamp({ contractVersion: 12, fcid: FCID });
    expect(serialized).not.toContain("contract-domains:");
    expect(serialized.split("\n")).toHaveLength(2);
  });
});

describe("parseContractStamp", () => {
  it("round-trips serialize → parse, with and without domains", () => {
    expect(parseContractStamp(serializeContractStamp(RECORD))).toEqual(RECORD);
    expect(parseContractStamp(serializeContractStamp({ contractVersion: 12, fcid: FCID }))).toEqual(
      { contractVersion: 12, fcid: FCID }
    );
  });

  it("finds the stamp inside a rendered agent-context-shaped file", () => {
    const rendered = `---
generated_by: fragments-sdk@0.0.0
preset: universal
last_init: 2026-06-09T00:00:00.000Z
${serializeContractStamp(RECORD)}
---

# Agent context for this project

Prefer canonical components over raw HTML elements.
`;
    expect(parseContractStamp(rendered)).toEqual(RECORD);
  });

  it("returns null when the stamp is absent or malformed — never throws", () => {
    expect(parseContractStamp("")).toBeNull();
    expect(parseContractStamp("# Just markdown\n\ncontract talk, no stamp\n")).toBeNull();
    // Header without the fcid line (and vice versa) is not a stamp.
    expect(parseContractStamp("contract: fragments contract v12 · a3f9e21\n")).toBeNull();
    expect(parseContractStamp(`contract-fcid: ${FCID}\n`)).toBeNull();
    // Short fcid in the header must prefix the full fcid.
    expect(
      parseContractStamp(`contract: fragments contract v12 · 0000000\ncontract-fcid: ${FCID}\n`)
    ).toBeNull();
    // Truncated full fcid.
    expect(
      parseContractStamp(
        `contract: fragments contract v12 · a3f9e21\ncontract-fcid: ${FCID.slice(0, 40)}\n`
      )
    ).toBeNull();
    // Malformed domains line poisons the whole stamp.
    expect(
      parseContractStamp(
        `${serializeContractStamp({ contractVersion: 12, fcid: FCID })}\ncontract-domains: components=zzz\n`
      )
    ).toBeNull();
    expect(
      parseContractStamp(
        `${serializeContractStamp({ contractVersion: 12, fcid: FCID })}\ncontract-domains: components=${DOMAINS.components}\n`
      )
    ).toBeNull();
  });
});