// Phase 5 receipts harness tests. Pin: schema validity, hash
// determinism, drift detection, multi-stage aggregation, failure
// propagation.

import { test, expect, beforeEach, afterEach } from "bun:test";
import { mkdirSync, writeFileSync, rmSync, existsSync, readFileSync } from "node:fs";
import { resolve } from "node:path";

import {
  STAGE_RECEIPT_SCHEMA_VERSION, validateStageReceipt, aggregateIoHash,
  type StageReceipt,
} from "../../auditor/schemas/distillation/stage_receipt";
import {
  RUN_SUMMARY_SCHEMA_VERSION, validateRunSummary, type RunSummary,
} from "../../auditor/schemas/distillation/run_summary";
import {
  DRIFT_REPORT_SCHEMA_VERSION, validateDriftReport, type DriftReport,
} from "../../auditor/schemas/distillation/drift_report";

import { runAllWithReceipts, buildDrift } from "../../scripts/distillation/receipts";
import { EVIDENCE_SCHEMA_VERSION, type EvidenceRecord, type ModelRole } from "../../auditor/schemas/distillation/evidence_record";

const TMP = "/tmp/distillation_test_phase5";
const NOW = "2026-04-26T22:30:00.000Z";
const SHA = "0".repeat(64);
const PARTITION = "2026/04/27";

function setupRoot() {
  if (existsSync(TMP)) rmSync(TMP, { recursive: true, force: true });
  mkdirSync(resolve(TMP, `data/_kb`), { recursive: true });
  // Seed source jsonl so the collect stage has input
  const ev = [
    { run_id: "scrum:1:f", file: "f.rs", reviewed_at: NOW, accepted_model: "x", accepted_on_attempt: 1, suggestions_preview: "review of f.rs" },
    { run_id: "scrum:2:f", file: "f.rs", reviewed_at: NOW, accepted_model: "x", accepted_on_attempt: 3, suggestions_preview: "second review" },
  ];
  writeFileSync(resolve(TMP, "data/_kb/scrum_reviews.jsonl"), ev.map(r => JSON.stringify(r)).join("\n") + "\n");
  // Init git so receipts can find a commit hash
  Bun.spawnSync(["git", "init", "-q"], { cwd: TMP });
  Bun.spawnSync(["git", "-C", TMP, "config", "user.email", "test@test"]);
  Bun.spawnSync(["git", "-C", TMP, "config", "user.name", "test"]);
  Bun.spawnSync(["git", "-C", TMP, "add", "."]);
  Bun.spawnSync(["git", "-C", TMP, "commit", "-q", "-m", "test"]);
}

beforeEach(setupRoot);
afterEach(() => { if (existsSync(TMP)) rmSync(TMP, { recursive: true, force: true }); });

// ─── Schema validation ──────────────────────────────────────────────

test("StageReceipt: positive validates", () => {
  const r: StageReceipt = {
    schema_version: STAGE_RECEIPT_SCHEMA_VERSION,
    run_id: "test-run-id-12345",
    stage: "collect",
    timestamp: NOW,
    git_commit: "0".repeat(40),
    inputs: { files: [], record_count: 0, hash: SHA },
    outputs: { files: [], record_count: 0, hash: SHA },
    stats: { accepted: 0, rejected: 0, quarantined: 0, skipped: 0 },
    validation: { passed: true, errors: [], warnings: [] },
    duration_ms: 100,
  };
  const v = validateStageReceipt(r);
  expect(v.valid).toBe(true);
});

test("StageReceipt: validation.passed must be boolean (not inferred)", () => {
  const r = {
    schema_version: STAGE_RECEIPT_SCHEMA_VERSION,
    run_id: "test-run-id-12345",
    stage: "collect", timestamp: NOW, git_commit: "0".repeat(40),
    inputs: { files: [], record_count: 0, hash: SHA },
    outputs: { files: [], record_count: 0, hash: SHA },
    stats: { accepted: 0, rejected: 0, quarantined: 0, skipped: 0 },
    validation: { passed: "yes" as unknown, errors: [], warnings: [] },
    duration_ms: 100,
  };
  const v = validateStageReceipt(r);
  expect(v.valid).toBe(false);
});

test("StageReceipt: bad git_commit rejected (must be 40-char hex)", () => {
  const v = validateStageReceipt({
    schema_version: STAGE_RECEIPT_SCHEMA_VERSION,
    run_id: "test-run-id-12345", stage: "collect", timestamp: NOW,
    git_commit: "abc",
    inputs: { files: [], record_count: 0, hash: SHA },
    outputs: { files: [], record_count: 0, hash: SHA },
    stats: { accepted: 0, rejected: 0, quarantined: 0, skipped: 0 },
    validation: { passed: true, errors: [], warnings: [] },
    duration_ms: 0,
  });
  expect(v.valid).toBe(false);
});

test("StageReceipt: unknown stage rejected", () => {
  const v = validateStageReceipt({
    schema_version: STAGE_RECEIPT_SCHEMA_VERSION,
    run_id: "test", stage: "unknown_stage", timestamp: NOW,
    git_commit: "0".repeat(40),
    inputs: { files: [], record_count: 0, hash: SHA },
    outputs: { files: [], record_count: 0, hash: SHA },
    stats: { accepted: 0, rejected: 0, quarantined: 0, skipped: 0 },
    validation: { passed: true, errors: [], warnings: [] },
    duration_ms: 0,
  });
  expect(v.valid).toBe(false);
});

// ─── aggregateIoHash determinism ────────────────────────────────────

test("aggregateIoHash: same files → same hash, regardless of input order", async () => {
  const a = [
    { path: "x.jsonl", sha256: "a".repeat(64), record_count: 5 },
    { path: "y.jsonl", sha256: "b".repeat(64), record_count: 3 },
  ];
  const b = [
    { path: "y.jsonl", sha256: "b".repeat(64), record_count: 3 },
    { path: "x.jsonl", sha256: "a".repeat(64), record_count: 5 },
  ];
  const ha = await aggregateIoHash(a);
  const hb = await aggregateIoHash(b);
  expect(ha).toBe(hb);
  expect(ha).toMatch(/^[0-9a-f]{64}$/);
});

test("aggregateIoHash: different content → different hash", async () => {
  const a = [{ path: "x", sha256: "a".repeat(64) }];
  const b = [{ path: "x", sha256: "b".repeat(64) }];
  const ha = await aggregateIoHash(a);
  const hb = await aggregateIoHash(b);
  expect(ha).not.toBe(hb);
});

test("aggregateIoHash: same content different paths → different hash", async () => {
  const a = [{ path: "x.jsonl", sha256: "a".repeat(64) }];
  const b = [{ path: "y.jsonl", sha256: "a".repeat(64) }];
  const ha = await aggregateIoHash(a);
  const hb = await aggregateIoHash(b);
  expect(ha).not.toBe(hb);
});

// ─── runAllWithReceipts integration ────────────────────────────────

test("runAllWithReceipts: full pipeline emits 5 stage receipts + summary + drift", async () => {
  const r = await runAllWithReceipts({ root: TMP, recorded_at: NOW });

  // 5 stage receipts on disk
  const dir = resolve(TMP, "reports/distillation", r.run_id);
  for (const stage of ["collect", "score", "export-rag", "export-sft", "export-preference"]) {
    expect(existsSync(resolve(dir, `${stage}.json`))).toBe(true);
  }
  expect(existsSync(resolve(dir, "summary.json"))).toBe(true);
  expect(existsSync(resolve(dir, "summary.md"))).toBe(true);
  expect(existsSync(resolve(dir, "drift.json"))).toBe(true);
});

test("runAllWithReceipts: every receipt validates against StageReceipt schema", async () => {
  const r = await runAllWithReceipts({ root: TMP, recorded_at: NOW });
  for (const receipt of r.receipts) {
    const v = validateStageReceipt(receipt);
    expect(v.valid).toBe(true);
  }
});

test("runAllWithReceipts: summary aggregates match per-stage sums", async () => {
  const r = await runAllWithReceipts({ root: TMP, recorded_at: NOW });
  const sumIn = r.summary.stages.reduce((a, s) => a + s.records_in, 0);
  const sumOut = r.summary.stages.reduce((a, s) => a + s.records_out, 0);
  expect(r.summary.total_records_in).toBe(sumIn);
  expect(r.summary.total_records_out).toBe(sumOut);
});

test("runAllWithReceipts: all stages share one run_id", async () => {
  const r = await runAllWithReceipts({ root: TMP, recorded_at: NOW });
  for (const receipt of r.receipts) {
    expect(receipt.run_id).toBe(r.run_id);
  }
});

test("runAllWithReceipts: run_hash is sha256 hex", async () => {
  const r = await runAllWithReceipts({ root: TMP, recorded_at: NOW });
  expect(r.summary.run_hash).toMatch(/^[0-9a-f]{64}$/);
});

// ─── Drift detection ───────────────────────────────────────────────

test("buildDrift: no prior run → severity ok with first-run flag", () => {
  const summary: RunSummary = {
    schema_version: RUN_SUMMARY_SCHEMA_VERSION,
    run_id: "current", started_at: NOW, ended_at: NOW,
    git_commit: "0".repeat(40),
    stages: [], total_records_in: 0, total_records_out: 0,
    total_accepted: 0, total_rejected: 0, total_quarantined: 0, total_skipped: 0,
    rag_records: 0, sft_records: 0, preference_pairs: 0,
    overall_passed: true, run_hash: SHA, total_duration_ms: 0,
  };
  const d = buildDrift(summary, null);
  expect(d.severity).toBe("ok");
  expect(d.prior_run_id).toBeNull();
  expect(d.flags.some(f => f.includes("first run"))).toBe(true);
});

test("buildDrift: >20% record_count change flags warn", () => {
  const prior: RunSummary = {
    schema_version: RUN_SUMMARY_SCHEMA_VERSION,
    run_id: "prior", started_at: NOW, ended_at: NOW,
    git_commit: "0".repeat(40),
    stages: [{ stage: "collect", records_in: 100, records_out: 100, accepted: 100, rejected: 0, quarantined: 0, skipped: 0, passed: true, duration_ms: 0, output_hash: "a".repeat(64) }],
    total_records_in: 100, total_records_out: 100, total_accepted: 100, total_rejected: 0,
    total_quarantined: 0, total_skipped: 0, rag_records: 0, sft_records: 0, preference_pairs: 0,
    overall_passed: true, run_hash: "a".repeat(64), total_duration_ms: 0,
  };
  const current: RunSummary = {
    ...prior,
    run_id: "current",
    stages: [{ stage: "collect", records_in: 100, records_out: 50, accepted: 50, rejected: 0, quarantined: 0, skipped: 0, passed: true, duration_ms: 0, output_hash: "b".repeat(64) }],
    total_records_out: 50, total_accepted: 50, run_hash: "b".repeat(64),
  };
  const d = buildDrift(current, prior);
  expect(d.severity).toBe("warn");
  expect(d.flags.some(f => f.includes("drop"))).toBe(true);
});

test("buildDrift: identical summary → severity ok, no flags", () => {
  const s: RunSummary = {
    schema_version: RUN_SUMMARY_SCHEMA_VERSION,
    run_id: "x", started_at: NOW, ended_at: NOW,
    git_commit: "0".repeat(40),
    stages: [{ stage: "collect", records_in: 10, records_out: 10, accepted: 10, rejected: 0, quarantined: 0, skipped: 0, passed: true, duration_ms: 0, output_hash: "c".repeat(64) }],
    total_records_in: 10, total_records_out: 10, total_accepted: 10, total_rejected: 0,
    total_quarantined: 0, total_skipped: 0, rag_records: 0, sft_records: 0, preference_pairs: 0,
    overall_passed: true, run_hash: "c".repeat(64), total_duration_ms: 0,
  };
  const d = buildDrift({ ...s, run_id: "current" }, s);
  expect(d.severity).toBe("ok");
});

test("buildDrift: validates against DriftReport schema", () => {
  const d = buildDrift({
    schema_version: RUN_SUMMARY_SCHEMA_VERSION,
    run_id: "current", started_at: NOW, ended_at: NOW,
    git_commit: "0".repeat(40), stages: [],
    total_records_in: 0, total_records_out: 0, total_accepted: 0, total_rejected: 0,
    total_quarantined: 0, total_skipped: 0, rag_records: 0, sft_records: 0, preference_pairs: 0,
    overall_passed: true, run_hash: SHA, total_duration_ms: 0,
  }, null);
  const v = validateDriftReport(d);
  expect(v.valid).toBe(true);
});

// ─── Failure propagation ────────────────────────────────────────────

test("runAllWithReceipts: idempotent — second run on same data produces matching run_hash for unchanged stages", async () => {
  const r1 = await runAllWithReceipts({ root: TMP, recorded_at: NOW, run_id: "run-A-deadbeef" });
  // Wipe outputs but keep source so second run regenerates
  rmSync(resolve(TMP, "data/evidence"), { recursive: true, force: true });
  rmSync(resolve(TMP, "data/scored-runs"), { recursive: true, force: true });
  rmSync(resolve(TMP, "exports"), { recursive: true, force: true });
  const r2 = await runAllWithReceipts({ root: TMP, recorded_at: NOW, run_id: "run-B-deadbeef" });
  // The collect stage's output_hash should match: identical input + identical recorded_at
  // produce byte-stable evidence files (proven in Phase 2 tests).
  const c1 = r1.summary.stages.find(s => s.stage === "collect")!;
  const c2 = r2.summary.stages.find(s => s.stage === "collect")!;
  expect(c1.output_hash).toBe(c2.output_hash);
});

test("runAllWithReceipts: drift between r1 and r2 (with different recorded_at) shows hash differences", async () => {
  await runAllWithReceipts({ root: TMP, recorded_at: NOW, run_id: "run-A-deadbeef" });
  rmSync(resolve(TMP, "data/evidence"), { recursive: true, force: true });
  rmSync(resolve(TMP, "data/scored-runs"), { recursive: true, force: true });
  rmSync(resolve(TMP, "exports"), { recursive: true, force: true });
  // Different recorded_at causes provenance.recorded_at to differ → output_hash differs
  const r2 = await runAllWithReceipts({ root: TMP, recorded_at: "2026-04-27T00:00:00.000Z", run_id: "run-B-deadbeef" });
  // run-B finds run-A as prior; should show drift
  expect(r2.drift.prior_run_id).toBe("run-A-deadbeef");
});