/**
 * lock-manager.test.ts — Unit tests for the LockManager core class.
 *
 * Tests cover:
 * - Construction and initialization
 * - Atomic file operations (write-to-temp-then-rename)
 * - Cross-process coordination (O_EXCL locks, stale detection)
 * - Registry CRUD: save, load, delete claims and lock entries
 * - TTL-based expiration (isExpired, findExpired, cleanupExpired)
 * - Age-based sweep (sweepOlderThan)
 * - Disk sync and merge operations
 * - Statistics and lifecycle
 *
 * @module file-claiming/lock-manager.test
 */

import { existsSync, readFileSync, writeFileSync, mkdirSync, rmSync } from "node:fs";
import { join } from "node:path";
import {
  assert,
  assertRejects,
  createTempDir,
  cleanupTempDir,
  TEST_SESSION_ID,
  TEST_FILE_A,
  TEST_FILE_B,
} from "./test-utils.ts";

// ---------------------------------------------------------------------------
// Lazy-import the module under test
// ---------------------------------------------------------------------------

function getLockManager() {
  return require("../src/lock-manager");
}

function getTypes() {
  return require("../src/lock-types");
}

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

let tempDir: string;

function setup(): string {
  tempDir = createTempDir("lock-manager-test-");
  return tempDir;
}

function teardown(): void {
  if (tempDir) {
    cleanupTempDir(tempDir);
  }
}

// ---------------------------------------------------------------------------
// Test: Construction and initialization
// ---------------------------------------------------------------------------

async function testConstruction() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const mgr = new LockManager(dir);

  assert(
    mgr.getLockDir() === dir,
    `Lock directory matches: ${mgr.getLockDir()} === ${dir}`,
  );
  assert(
    mgr.getRegistryFilePath().endsWith("registry.json"),
    "Registry file path ends with registry.json",
  );
  assert(
    mgr.getCoordLockFilePath().endsWith("coord.lock"),
    "Coord lock file path ends with coord.lock",
  );

  // The directory already exists (createTempDir created it)
  assert(existsSync(dir), "Temp directory exists before init");
  await mgr.init();
  assert(existsSync(dir), "Directory still exists after init");

  // init is idempotent
  await mgr.init();
  assert(existsSync(dir), "Directory still exists after second init");

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: construction and initialization works");
}

// ---------------------------------------------------------------------------
// Test: Atomic file operations
// ---------------------------------------------------------------------------

async function testAtomicFileOperations() {
  const dir = setup();
  const { atomicWriteJson, atomicReadJson, fileExists } = getLockManager();
  const testFile = join(dir, "test.json");

  // Write and read
  const data = { key: "value", number: 42 };
  await atomicWriteJson(testFile, data);
  assert(existsSync(testFile), "File exists after write");
  assert(
    existsSync(testFile + ".tmp") === false,
    "Temp file was cleaned up after rename",
  );

  const loaded = await atomicReadJson<typeof data>(testFile);
  assert(loaded !== null, "File content is not null");
  assert(loaded!.key === "value", "Content matches: key");
  assert(loaded!.number === 42, "Content matches: number");

  // Read non-existent file
  const missing = await atomicReadJson<unknown>(join(dir, "missing.json"));
  assert(missing === null, "Missing file returns null");

  // fileExists
  assert(fileExists(testFile) === true, "fileExists returns true for existing file");
  assert(
    fileExists(join(dir, "ghost.json")) === false,
    "fileExists returns false for non-existing file",
  );

  teardown();
  console.log("✅ LockManager: atomic file operations work");
}

// ---------------------------------------------------------------------------
// Test: Registry save/load
// ---------------------------------------------------------------------------

async function testRegistrySaveLoad() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const { mockOwner } = await import("./test-utils.ts");

  const mgr = new LockManager(dir);
  await mgr.init();

  // Empty registry on first load
  const empty = await mgr.loadRegistry();
  assert(
    Object.keys(empty.claims).length === 0,
    "Empty registry has no claims",
  );
  assert(
    Object.keys(empty.locks).length === 0,
    "Empty registry has no locks",
  );

  // Save and load with claims and locks
  const claims: Record<string, any> = {
    "claim-1": {
      id: "claim-1",
      path: TEST_FILE_A,
      lockType: "write",
      status: "active",
      owner: mockOwner("agent", "test"),
      createdAt: new Date().toISOString(),
      updatedAt: new Date().toISOString(),
    },
  };
  const locks: Record<string, any[]> = {
    [TEST_FILE_A]: [
      {
        path: TEST_FILE_A,
        lockType: "write",
        claimId: "claim-1",
        owner: mockOwner("agent", "test"),
        acquiredAt: new Date().toISOString(),
      },
    ],
  };

  await mgr.saveRegistry(claims, locks);

  const loaded = await mgr.loadRegistry();
  assert(
    loaded.claims["claim-1"] !== undefined,
    "Saved claim is loadable",
  );
  assert(
    loaded.claims["claim-1"].path === TEST_FILE_A,
    "Loaded claim path matches",
  );
  assert(
    loaded.locks[TEST_FILE_A].length === 1,
    "Loaded lock entries match",
  );

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: registry save/load works");
}

// ---------------------------------------------------------------------------
// Test: Individual claim CRUD
// ---------------------------------------------------------------------------

async function testClaimCRUD() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const { mockOwner } = await import("./test-utils.ts");

  const mgr = new LockManager(dir);
  await mgr.init();

  const claim: any = {
    id: "crud-1",
    path: TEST_FILE_A,
    lockType: "write",
    status: "active",
    owner: mockOwner("agent", "test"),
    createdAt: new Date().toISOString(),
    updatedAt: new Date().toISOString(),
    expiresAt: new Date(Date.now() + 300_000).toISOString(),
  };

  // Save
  await mgr.saveClaim(claim);
  let loaded = await mgr.loadClaim("crud-1");
  assert(loaded !== undefined, "Claim loaded by ID");
  assert(loaded!.id === "crud-1", "Loaded claim ID matches");
  assert(loaded!.path === TEST_FILE_A, "Loaded claim path matches");

  // Load all
  const all = await mgr.loadAllClaims();
  assert(all.length === 1, "loadAllClaims returns 1 claim");

  // Load by path
  const byPath = await mgr.loadClaimsByPath(TEST_FILE_A);
  assert(byPath.length === 1, "loadClaimsByPath returns 1 claim");

  // Load by status
  const byStatus = await mgr.loadClaimsByStatus("active");
  assert(byStatus.length === 1, "loadClaimsByStatus('active') returns 1 claim");

  // Delete
  const deleted = await mgr.deleteClaim("crud-1");
  assert(deleted === true, "deleteClaim returns true");
  loaded = await mgr.loadClaim("crud-1");
  assert(loaded === undefined, "Deleted claim is undefined");

  // Delete non-existent
  const missing = await mgr.deleteClaim("nonexistent");
  assert(missing === false, "deleteClaim on non-existent returns false");

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: individual claim CRUD works");
}

// ---------------------------------------------------------------------------
// Test: Lock entry CRUD
// ---------------------------------------------------------------------------

async function testLockEntryCRUD() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const { mockOwner } = await import("./test-utils.ts");

  const mgr = new LockManager(dir);
  await mgr.init();

  const entry: any = {
    path: TEST_FILE_A,
    lockType: "write",
    claimId: "entry-1",
    owner: mockOwner("agent", "test"),
    acquiredAt: new Date().toISOString(),
  };

  // Save
  await mgr.saveLockEntry(entry);
  const loaded = await mgr.loadLockEntries(TEST_FILE_A);
  assert(loaded.length === 1, "lock entry saved and loaded");
  assert(loaded[0].claimId === "entry-1", "Loaded entry claimId matches");

  // Load all entries
  const all = await mgr.loadAllLockEntries();
  assert(Object.keys(all).length === 1, "All lock entries loaded");

  // Remove
  await mgr.removeLockEntry("entry-1", TEST_FILE_A);
  const afterRemove = await mgr.loadLockEntries(TEST_FILE_A);
  assert(afterRemove.length === 0, "Lock entry removed");

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: lock entry CRUD works");
}

// ---------------------------------------------------------------------------
// Test: TTL-based expiration
// ---------------------------------------------------------------------------

async function testExpiration() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const { mockOwner } = await import("./test-utils.ts");

  const mgr = new LockManager(dir);
  await mgr.init();

  const now = new Date().toISOString();
  const future = new Date(Date.now() + 300_000).toISOString();
  const past = new Date(Date.now() - 60_000).toISOString();

  // Active claim with future expiry — not expired
  const activeClaim: any = {
    id: "active-1",
    path: TEST_FILE_A,
    lockType: "write",
    status: "active",
    owner: mockOwner("agent", "test"),
    createdAt: now,
    updatedAt: now,
    expiresAt: future,
  };

  // Active claim with past expiry — expired
  const expiredClaim: any = {
    id: "expired-1",
    path: TEST_FILE_B,
    lockType: "write",
    status: "active",
    owner: mockOwner("agent", "test"),
    createdAt: now,
    updatedAt: now,
    expiresAt: past,
  };

  // Released claim (should not be expired)
  const releasedClaim: any = {
    id: "released-1",
    path: TEST_FILE_B,
    lockType: "read",
    status: "released",
    owner: mockOwner("agent", "test"),
    createdAt: now,
    updatedAt: now,
    expiresAt: past,
  };

  await mgr.saveClaim(activeClaim);
  await mgr.saveClaim(expiredClaim);
  await mgr.saveClaim(releasedClaim);

  // isExpired
  assert(mgr.isExpired(activeClaim) === false, "Active claim is not expired");
  assert(mgr.isExpired(expiredClaim) === true, "Expired claim is expired");
  assert(mgr.isExpired(releasedClaim) === false, "Released claim is not expired");

  // findExpired
  const expired = await mgr.findExpired();
  assert(expired.length === 1, "findExpired finds 1 expired claim");
  assert(expired[0].id === "expired-1", "findExpired found the right claim");

  // cleanupExpired
  const result = await mgr.cleanupExpired();
  assert(result.expiredCount === 1, "cleanupExpired reports 1 expired");
  assert(result.expiredClaims[0].id === "expired-1", "Cleanup expired right claim");

  // Verify status on disk
  const loaded = await mgr.loadClaim("expired-1");
  assert(loaded!.status === "expired", "Expired claim status updated on disk");

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: TTL-based expiration works");
}

// ---------------------------------------------------------------------------
// Test: Age-based sweep
// ---------------------------------------------------------------------------

async function testAgeBasedSweep() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const { mockOwner } = await import("./test-utils.ts");

  const mgr = new LockManager(dir);
  await mgr.init();

  const oldTime = new Date(Date.now() - 2 * 60 * 60 * 1000).toISOString();
  const recentTime = new Date().toISOString();

  // Old claim (no expiresAt — relies on age-based sweep)
  const oldClaim: any = {
    id: "old-1",
    path: TEST_FILE_A,
    lockType: "write",
    status: "active",
    owner: mockOwner("agent", "old-agent"),
    createdAt: oldTime,
    updatedAt: oldTime,
  };

  // Recent claim
  const recentClaim: any = {
    id: "recent-1",
    path: TEST_FILE_B,
    lockType: "read",
    status: "active",
    owner: mockOwner("agent", "recent-agent"),
    createdAt: recentTime,
    updatedAt: recentTime,
  };

  await mgr.saveClaim(oldClaim);
  await mgr.saveClaim(recentClaim);

  // Sweep older than 1 hour
  const swept = await mgr.sweepOlderThan(3_600_000);
  assert(swept === 1, "sweepOlderThan removes 1 old claim");

  // Verify old claim removed
  const loaded = await mgr.loadClaim("old-1");
  assert(loaded === undefined, "Old claim removed from disk");

  // Recent claim still present
  const recent = await mgr.loadClaim("recent-1");
  assert(recent !== undefined, "Recent claim still present");

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: age-based sweep works");
}

// ---------------------------------------------------------------------------
// Test: Cross-process coordination (coordination lock)
// ---------------------------------------------------------------------------

async function testCoordLock() {
  const dir = setup();
  const { LockManager } = getLockManager();

  const mgr1 = new LockManager(dir);
  const mgr2 = new LockManager(dir);
  await mgr1.init();
  await mgr2.init();

  // Acquire lock on mgr1
  const acquired1 = await mgr1.acquireCoordLock("test-1");
  assert(acquired1 === true, "mgr1 acquires coordination lock");

  // mgr2 should not be able to acquire (short timeout)
  const acquired2 = await mgr2.acquireCoordLock("test-2", 100);
  assert(acquired2 === false, "mgr2 cannot acquire while mgr1 holds it");

  // Release on mgr1
  await mgr1.releaseCoordLock();

  // Now mgr2 can acquire
  const acquired3 = await mgr2.acquireCoordLock("test-2", 1000);
  assert(acquired3 === true, "mgr2 acquires after mgr1 releases");

  await mgr2.releaseCoordLock();
  await mgr1.destroy();
  await mgr2.destroy();
  teardown();
  console.log("✅ LockManager: cross-process coordination works");
}

// ---------------------------------------------------------------------------
// Test: withCoordLock convenience
// ---------------------------------------------------------------------------

async function testWithCoordLock() {
  const dir = setup();
  const { LockManager } = getLockManager();

  const mgr = new LockManager(dir);
  await mgr.init();

  const result = await mgr.withCoordLock("test", async () => {
    return "hello from locked section";
  });
  assert(result === "hello from locked section", "withCoordLock returns function result");

  // Verify lock is released after execution
  const acquired = await mgr.acquireCoordLock("test-2", 100);
  assert(acquired === true, "Lock released after withCoordLock");

  await mgr.releaseCoordLock();
  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: withCoordLock convenience works");
}

// ---------------------------------------------------------------------------
// Test: Sync from/to disk
// ---------------------------------------------------------------------------

async function testSync() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const { mockOwner } = await import("./test-utils.ts");

  const mgr = new LockManager(dir);
  await mgr.init();

  // syncFromDisk on empty registry
  const syncResult = await mgr.syncFromDisk();
  assert(
    syncResult.diskClaims.length === 0,
    "syncFromDisk returns empty on fresh registry",
  );
  assert(syncResult.wasUpdated === false, "wasUpdated is false on empty");

  // Save a claim
  const claim: any = {
    id: "sync-1",
    path: TEST_FILE_A,
    lockType: "write",
    status: "active",
    owner: mockOwner("agent", "test"),
    createdAt: new Date().toISOString(),
    updatedAt: new Date().toISOString(),
  };
  await mgr.saveClaim(claim);

  // syncFromDisk now has data
  const syncResult2 = await mgr.syncFromDisk();
  assert(syncResult2.diskClaims.length === 1, "syncFromDisk finds 1 claim");
  assert(syncResult2.wasUpdated === true, "wasUpdated is true");

  // syncToDisk
  const newClaims: Record<string, any> = {
    ["sync-2"]: {
      id: "sync-2",
      path: TEST_FILE_B,
      lockType: "read",
      status: "active",
      owner: mockOwner("agent", "test"),
      createdAt: new Date().toISOString(),
      updatedAt: new Date().toISOString(),
    },
  };
  await mgr.syncToDisk(newClaims, {});
  const loaded = await mgr.loadClaim("sync-2");
  assert(loaded !== undefined, "syncToDisk persisted claim");

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: sync from/to disk works");
}

// ---------------------------------------------------------------------------
// Test: Merge from disk
// ---------------------------------------------------------------------------

async function testMerge() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const { mockOwner } = await import("./test-utils.ts");

  const mgr = new LockManager(dir);
  await mgr.init();

  // Save a disk claim
  const diskClaim: any = {
    id: "disk-1",
    path: TEST_FILE_A,
    lockType: "write",
    status: "active",
    owner: mockOwner("agent", "disk"),
    createdAt: new Date().toISOString(),
    updatedAt: new Date().toISOString(),
  };
  await mgr.saveClaim(diskClaim);

  // Merge with memory claims (memory wins on collision)
  const memoryClaims: Record<string, any> = {
    ["memory-1"]: {
      id: "memory-1",
      path: TEST_FILE_B,
      lockType: "read",
      status: "active",
      owner: mockOwner("agent", "memory"),
      createdAt: new Date().toISOString(),
      updatedAt: new Date().toISOString(),
    },
  };

  const merged = await mgr.mergeFromDisk(memoryClaims);
  assert(merged["disk-1"] !== undefined, "Disk claim present in merge");
  assert(merged["memory-1"] !== undefined, "Memory claim present in merge");
  assert(Object.keys(merged).length === 2, "Merge contains both claims");

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: merge from disk works");
}

// ---------------------------------------------------------------------------
// Test: Statistics
// ---------------------------------------------------------------------------

async function testStats() {
  const dir = setup();
  const { LockManager } = getLockManager();
  const { mockOwner } = await import("./test-utils.ts");

  const mgr = new LockManager(dir);
  await mgr.init();

  const statsBefore = await mgr.getStats();
  assert(statsBefore.totalClaims === 0, "Stats: no claims initially");
  assert(statsBefore.registryExists === false, "Stats: registry doesn't exist yet");

  // Add claims
  const claim: any = {
    id: "stats-1",
    path: TEST_FILE_A,
    lockType: "write",
    status: "active",
    owner: mockOwner("agent", "test"),
    createdAt: new Date().toISOString(),
    updatedAt: new Date().toISOString(),
  };
  await mgr.saveClaim(claim);

  const statsAfter = await mgr.getStats();
  assert(statsAfter.totalClaims === 1, "Stats: 1 claim");
  assert(statsAfter.activeClaims === 1, "Stats: 1 active");
  assert(statsAfter.registryExists === true, "Stats: registry exists");

  await mgr.destroy();
  teardown();
  console.log("✅ LockManager: statistics work");
}

// ---------------------------------------------------------------------------
// Test: Lifecycle (destroy)
// ---------------------------------------------------------------------------

async function testLifecycle() {
  const dir = setup();
  const { LockManager } = getLockManager();

  const mgr = new LockManager(dir);
  await mgr.init();

  // Acquire coord lock
  await mgr.acquireCoordLock("lifecycle-test");
  assert(mgr["hasCoordLock"] === true, "Coord lock held");

  // Destroy releases it
  await mgr.destroy();
  assert(mgr["hasCoordLock"] === false, "Coord lock released after destroy");

  console.log("✅ LockManager: lifecycle (destroy) works");
}

// ---------------------------------------------------------------------------
// Test: File locking via LockManager
// ---------------------------------------------------------------------------

async function testAcquireLockFile() {
  const dir = setup();
  const { acquireLockFile, releaseLockFile } = getLockManager();

  const lockFile = join(dir, "coord.lock");

  // Acquire
  const acquired = await acquireLockFile(lockFile, "test-owner");
  assert(acquired === true, "acquireLockFile returns true");
  assert(existsSync(lockFile), "Lock file exists after acquisition");

  // Release
  await releaseLockFile(lockFile);
  assert(existsSync(lockFile) === false, "Lock file removed after release");

  // Acquire again
  const reacquired = await acquireLockFile(lockFile, "test-owner", 100);
  assert(reacquired === true, "Re-acquire succeeds after release");

  await releaseLockFile(lockFile);
  teardown();
  console.log("✅ LockManager: acquire/release lock file works");
}

// ---------------------------------------------------------------------------
// Test: withLockFile convenience
// ---------------------------------------------------------------------------

async function testWithLockFile() {
  const dir = setup();
  const { withLockFile } = getLockManager();

  const lockFile = join(dir, "coord.lock");

  const result = await withLockFile(lockFile, "test", async () => {
    return 42;
  });
  assert(result === 42, "withLockFile returns function result");

  // Lock file should be cleaned up
  const exists = await import("node:fs").then((fs) => fs.existsSync(lockFile));
  assert(exists === false, "Lock file cleaned up after withLockFile");

  teardown();
  console.log("✅ LockManager: withLockFile convenience works");
}

// ---------------------------------------------------------------------------
// Test: createLockManager factory
// ---------------------------------------------------------------------------

async function testCreateLockManager() {
  const dir = setup();

  // We need to set config to use our dir
  const config = require("../src/config");
  config.setConfig({ lockDir: dir });
  config.getConfig(); // force read

  const { createLockManager } = getLockManager();

  // Override by passing explicit dir
  const mgr = await createLockManager(dir);
  assert(mgr.getLockDir() === dir, "Lock manager created with correct dir");
  await mgr.init(); // should be idempotent
  assert(mgr.getLockDir() === dir, "Lock manager retains dir after init");

  await mgr.destroy();
  config.resetConfig();
  teardown();
  console.log("✅ LockManager: createLockManager factory works");
}

// ---------------------------------------------------------------------------
// Test: Lock timeout
// ---------------------------------------------------------------------------

async function testLockTimeout() {
  const dir = setup();
  const { acquireLockFile, releaseLockFile } = getLockManager();

  const lockFile = join(dir, "coord.lock");

  // Hold lock from first owner
  const acquired = await acquireLockFile(lockFile, "owner-1");
  assert(acquired === true, "First owner acquires lock");

  // Second owner with very short timeout should fail
  const failed = await acquireLockFile(lockFile, "owner-2", 50);
  assert(failed === false, "Second owner times out");

  // Release
  await releaseLockFile(lockFile);

  // Second owner should succeed now
  const success = await acquireLockFile(lockFile, "owner-2", 100);
  assert(success === true, "Second owner acquires after release");

  await releaseLockFile(lockFile);
  teardown();
  console.log("✅ LockManager: lock timeout works");
}

// ---------------------------------------------------------------------------
// Test runner
// ---------------------------------------------------------------------------

async function runTests() {
  console.log("Running LockManager Unit Tests\n");

  const tests = [
    testConstruction,
    testAtomicFileOperations,
    testRegistrySaveLoad,
    testClaimCRUD,
    testLockEntryCRUD,
    testExpiration,
    testAgeBasedSweep,
    testCoordLock,
    testWithCoordLock,
    testSync,
    testMerge,
    testStats,
    testLifecycle,
    testAcquireLockFile,
    testWithLockFile,
    testCreateLockManager,
    testLockTimeout,
  ];

  try {
    for (const test of tests) {
      try {
        await test();
      } catch (err) {
        console.error(`\n❌ Test ${test.name} failed: ${err}`);
        throw err;
      }
    }
    console.log("\n✅ All LockManager unit tests passed!");
  } catch (err) {
    console.error(`\n❌ Test suite failed: ${err}`);
    process.exit(1);
  }
}

runTests();