import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";
import { describe, expect, it } from "vitest";
import { createDistillationReceipt, writeDistillationReceipt } from "./distillation-receipt.js";

describe("distillation receipt", () => {
  it("allows open-weight teacher provenance", () => {
    const receipt = createDistillationReceipt({
      dataset: "math_train_sample.json",
      output: "distill.json",
      teacherModel: "qwen3:4b",
      provider: "ollama",
      teacherKind: "open-weight",
      samples: 10,
      now: new Date("2026-06-27T00:00:00.000Z"),
    });

    expect(receipt.schema).toBe("fable.distillation.receipt.v1");
    expect(receipt.decision).toBe("ok");
    expect(receipt.reasons).toEqual([]);
  });

  it("flags closed or unknown teachers for review", () => {
    const closed = createDistillationReceipt({ dataset: "x", output: "y", teacherModel: "claude", provider: "openrouter", teacherKind: "closed-frontier" });
    const unknown = createDistillationReceipt({ dataset: "x", output: "y", teacherModel: "mystery", provider: "other" });

    expect(closed.decision).toBe("needs-review");
    expect(closed.reasons.join("\n")).toContain("closed-frontier teacher output");
    expect(unknown.decision).toBe("needs-review");
    expect(unknown.reasons.join("\n")).toContain("teacher kind unknown");
  });

  it("writes a JSON receipt", () => {
    const dir = fs.mkdtempSync(path.join(os.tmpdir(), "distill-receipt-"));
    const file = path.join(dir, "receipt.json");
    writeDistillationReceipt(file, createDistillationReceipt({ dataset: "x", output: "y", teacherModel: "qwen", provider: "ollama", teacherKind: "open-weight" }));

    expect(fs.readFileSync(file, "utf-8")).toContain("fable.distillation.receipt.v1");
  });
});