import { describe, expect, it } from "vitest";
import {
  emptyArtifact,
  serializeArtifact,
  type Artifact,
  type Proposal,
} from "../src/model";

const agent = {
  kind: "agent" as const,
  id: "claude",
  agent: { sdk: "@cline/sdk", model: "sonnet", sessionId: "s1" },
};

describe("Proposal model (spec §6.3, INV-13)", () => {
  it("serializes proposals with stable field order and survives a round-trip", () => {
    const a = emptyArtifact("docs/x.md");
    a.anchors["a_1"] = {
      fingerprint: { text: "old text", before: "", after: "", lineHint: 0 },
    };
    const p: Proposal = {
      id: "pr_1",
      anchorId: "a_1",
      replacement: "new text",
      author: agent,
      createdAt: "2026-06-10T00:00:00.000Z",
      turnId: "turn-1",
      instruction: "tighten",
    };
    a.proposals.push(p);
    const reloaded = JSON.parse(serializeArtifact(a)) as Artifact;
    expect(reloaded.proposals).toHaveLength(1);
    expect(reloaded.proposals[0]).toEqual(p);
    // optional fields are OMITTED (not null) when absent
    const bare: Proposal = {
      id: "pr_2", anchorId: "a_1", replacement: "r", author: agent,
      createdAt: "2026-06-10T00:00:00.000Z",
    };
    a.proposals.push(bare);
    const again = JSON.parse(serializeArtifact(a)) as Artifact;
    expect("turnId" in again.proposals[1]).toBe(false);
    expect("instruction" in again.proposals[1]).toBe(false);
    // serialization is byte-stable (INV-2)
    expect(serializeArtifact(again)).toBe(serializeArtifact(a));
  });
});