const test = require('node:test');
const assert = require('node:assert/strict');
const { EventEmitter } = require('node:events');
const fs = require('node:fs');
const os = require('node:os');
const path = require('node:path');
const FolderMonitor = require('../lib/folder-monitor');
const { classifyProcessedCandidates, planAtomicAdmissions } = require('../lib/automation-control');

function createWatcherHarness() {
  const calls = [];
  const timers = createManualTimers();
  const watch = (folderPath, options) => {
    const watcher = new EventEmitter();
    watcher.close = async () => {};
    calls.push({ folderPath, options, watcher });
    return watcher;
  };
  return { calls, monitor: new FolderMonitor({ watch, ...timers }) };
}

function createManualTimers() {
  const intervals = new Set();
  const timeouts = new Set();
  const intervalDelays = [];
  return {
    setIntervalFn(callback, delay) {
      intervals.add(callback);
      intervalDelays.push(delay);
      return callback;
    },
    clearIntervalFn(callback) {
      intervals.delete(callback);
    },
    setTimeoutFn(callback) {
      timeouts.add(callback);
      return callback;
    },
    clearTimeoutFn(callback) {
      timeouts.delete(callback);
    },
    async runInterval() {
      for (const callback of [...intervals]) await callback();
    },
    async runTimeouts() {
      for (const callback of [...timeouts]) {
        timeouts.delete(callback);
        await callback();
      }
    },
    intervalDelays
  };
}

function createSilentWatch() {
  return () => {
    const watcher = new EventEmitter();
    watcher.close = async () => {};
    return watcher;
  };
}

function createScanHarness({ files = [] } = {}) {
  const events = { newFiles: [], statuses: [] };
  const timers = createManualTimers();
  const stats = new Map(files.map((file) => [file.path, { mtimeMs: file.mtimeMs }]));
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    walkFolder: async () => files.map(({ path: filePath, name, size }) => ({ path: filePath, name, size })),
    access: async () => {},
    stat: async (filePath) => stats.get(filePath),
    now: () => 1234,
    ...timers
  });
  monitor.on('new-files', (paths) => events.newFiles.push(paths));
  monitor.on('status', (status) => events.statuses.push(status));
  return { monitor, events, runInterval: timers.runInterval };
}

function createDeferredScanHarness() {
  let calls = 0;
  let releaseFirstScan;
  const timers = createManualTimers();
  const firstScan = new Promise((resolve) => { releaseFirstScan = resolve; });
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    access: async () => {},
    stat: async () => ({ mtimeMs: 1 }),
    walkFolder: async () => {
      calls++;
      if (calls === 1) await firstScan;
      return [];
    },
    ...timers
  });
  monitor.start({ folderPath: 'C:\\incoming', reconcileIntervalMinutes: 5 });
  return { monitor, releaseFirstScan, scanCalls: () => calls };
}

function createReachabilityHarness(initiallyReachable) {
  let reachable = initiallyReachable;
  let calls = 0;
  const statusEvents = [];
  const timers = createManualTimers();
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    access: async () => {
      if (!reachable) throw new Error('unreachable');
    },
    walkFolder: async () => {
      calls++;
      return [];
    },
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('status', (status) => statusEvents.push(status));
  return {
    monitor,
    setReachable(value) { reachable = value; },
    statusEvents,
    scanCalls: () => calls,
    runInterval: timers.runInterval
  };
}

test('existing files are included only on the first start of the same watch scope', () => {
  const { calls, monitor } = createWatcherHarness();
  const settings = { folderPath: 'C:\\incoming', includeExisting: true, recursive: false };
  monitor.start(settings);
  monitor.start(settings);
  assert.equal(calls[0].options.ignoreInitial, false);
  assert.equal(calls[1].options.ignoreInitial, true);
});

test('existing files remain ignored unless the option is enabled', () => {
  const { calls, monitor } = createWatcherHarness();
  monitor.start({ folderPath: 'C:\\incoming', includeExisting: false, recursive: false });
  monitor.start({ folderPath: 'C:\\incoming', includeExisting: true, recursive: false });
  assert.equal(calls[0].options.ignoreInitial, true);
  assert.equal(calls[1].options.ignoreInitial, false);
});

test('a changed folder or filter creates a new initial scope', () => {
  const { calls, monitor } = createWatcherHarness();
  monitor.start({ folderPath: 'C:\\incoming', includeExisting: true, recursive: false, extensions: 'mp4' });
  monitor.start({ folderPath: 'D:\\incoming', includeExisting: true, recursive: false, extensions: 'mp4' });
  monitor.start({ folderPath: 'D:\\incoming', includeExisting: true, recursive: false, extensions: 'mkv' });
  assert.deepEqual(calls.map(call => call.options.ignoreInitial), [false, false, false]);
});

test('initial scan completion is exposed so the one-time option can be persisted as consumed', () => {
  const { calls, monitor } = createWatcherHarness();
  let completed = 0;
  monitor.on('initial-scan-complete', () => { completed++; });
  monitor.start({ folderPath: 'C:\\incoming', includeExisting: true, recursive: false });
  calls[0].watcher.emit('ready');
  calls[0].watcher.emit('ready');
  assert.equal(completed, 1);
});

test('dry scan returns every descriptor with a disjoint filter classification without emitting files', async () => {
  const { monitor, events } = createScanHarness({
    files: [
      { path: 'C:\\incoming\\a.mkv', name: 'a.mkv', size: 10, mtimeMs: 1 },
      { path: 'C:\\incoming\\b.txt', name: 'b.txt', size: 10, mtimeMs: 2 }
    ]
  });
  monitor.start({ folderPath: 'C:\\incoming', extensions: 'mkv', filterMode: 'include', recursive: true, reconcileIntervalMinutes: 5 });
  const result = await monitor.scan({ emitFiles: false, trigger: 'test' });
  assert.deepEqual(result.files, [
    { path: 'C:\\incoming\\a.mkv', name: 'a.mkv', size: 10, mtimeMs: 1, filterMatched: true, filterReason: 'matched' },
    { path: 'C:\\incoming\\b.txt', name: 'b.txt', size: 10, mtimeMs: 2, filterMatched: false, filterReason: 'extension' }
  ]);
  assert.equal(result.files.length, 2);
  assert.equal(result.files.filter(file => file.filterMatched).length, 1);
  assert.equal(events.newFiles.length, 0);
});

test('productive full scans emit every classified descriptor without consuming watcher duplicate reservations', async () => {
  const { monitor, events } = createScanHarness({
    files: [
      { path: 'C:\\incoming\\a.mkv', name: 'a.mkv', size: 10, mtimeMs: 1 },
      { path: 'C:\\incoming\\b.txt', name: 'b.txt', size: 10, mtimeMs: 2 }
    ]
  });
  monitor.start({ folderPath: 'C:\\incoming', extensions: 'mkv', filterMode: 'include', recursive: true, skipDuplicates: true, reconcileIntervalMinutes: 5 });

  await monitor.scan({ emitFiles: true, trigger: 'startup' });
  await monitor.scan({ emitFiles: true, trigger: 'interval' });

  assert.deepEqual(events.newFiles.map(files => files.map(file => ({ name: file.name, filterMatched: file.filterMatched }))), [
    [{ name: 'a.mkv', filterMatched: true }, { name: 'b.txt', filterMatched: false }],
    [{ name: 'a.mkv', filterMatched: true }, { name: 'b.txt', filterMatched: false }]
  ]);
  assert.equal(monitor.status().seenCount, 0);
});

test('reconciliation intervals accept only finite numeric positive-list values', () => {
  const cases = [
    [1, 60000],
    [5, 300000],
    [15, 900000],
    [30, 1800000],
    [60, 3600000],
    [-1, 300000],
    [Number.POSITIVE_INFINITY, 300000],
    ['1', 300000],
    ['15', 300000],
    [2, 300000],
    [undefined, 300000]
  ];

  for (const [reconcileIntervalMinutes, expectedDelay] of cases) {
    const timers = createManualTimers();
    const monitor = new FolderMonitor({ watch: createSilentWatch(), ...timers });
    monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes });
    assert.equal(timers.intervalDelays[0], expectedDelay, String(reconcileIntervalMinutes));
    monitor.stop();
  }
});

test('status owns monitoring start and next reconciliation timestamps across pause resume and intervals', async () => {
  let now = 1000;
  const timers = createManualTimers();
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    access: async () => {},
    walkFolder: async () => [],
    stat: async () => ({ mtimeMs: 1 }),
    now: () => now,
    ...timers
  });

  monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  assert.equal(monitor.status().startedAt, 1000);
  assert.equal(monitor.status().nextReconcileAt, 301000);
  now = 2000;
  await monitor.scan({ emitFiles: true, trigger: 'startup' });
  assert.equal(monitor.status().startedAt, 1000);
  assert.equal(monitor.status().nextReconcileAt, 301000);
  await monitor.pause();
  assert.equal(monitor.status().startedAt, null);
  assert.equal(monitor.status().nextReconcileAt, null);
  now = 4000;
  await monitor.resume({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  assert.equal(monitor.status().startedAt, 4000);
  assert.equal(monitor.status().nextReconcileAt, 304000);
  now = 304000;
  await timers.runInterval();
  assert.equal(monitor.status().startedAt, 4000);
  assert.equal(monitor.status().lastScanAt, 304000);
  assert.equal(monitor.status().nextReconcileAt, 604000);
});

test('paused configuration keeps watcher and interval closed while allowing a read-only scan', async () => {
  const timers = createManualTimers();
  let watcherStarts = 0;
  const monitor = new FolderMonitor({
    watch: () => {
      watcherStarts++;
      return createSilentWatch()();
    },
    access: async () => {},
    walkFolder: async () => [{ path: 'C:\\watch\\a.mkv', name: 'a.mkv', size: 1 }],
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });

  const result = monitor.configure({ folderPath: 'C:\\watch', extensions: 'mkv', reconcileIntervalMinutes: 5 });
  const scan = await monitor.scan({ emitFiles: false, trigger: 'test' });
  const productive = await monitor.scan({ emitFiles: true, trigger: 'manual' });

  assert.deepEqual(result, { includesExisting: false, paused: true });
  assert.equal(watcherStarts, 0);
  assert.equal(timers.intervalDelays.length, 0);
  assert.equal(monitor.status().paused, true);
  assert.equal(monitor.status().folderPath, 'C:\\watch');
  assert.deepEqual(scan.files.map(file => file.name), ['a.mkv']);
  assert.equal(productive.cancelled, true);
});

test('overlapping reconcile requests serialize and collapse to one follow-up scan', async () => {
  const { monitor, releaseFirstScan, scanCalls } = createDeferredScanHarness();
  const first = monitor.scan({ emitFiles: true, trigger: 'interval' });
  const second = monitor.scan({ emitFiles: true, trigger: 'reconnect' });
  const third = monitor.scan({ emitFiles: true, trigger: 'manual' });
  releaseFirstScan();
  await Promise.all([first, second, third]);
  assert.equal(scanCalls(), 2);
});

test('disconnect preserves configuration and reconnect performs one immediate scan', async () => {
  const { monitor, setReachable, statusEvents, scanCalls, runInterval } = createReachabilityHarness(false);
  monitor.start({ folderPath: 'Z:\\watch', reconcileIntervalMinutes: 5 });
  await runInterval();
  assert.equal(statusEvents.at(-1).reachable, false);
  assert.equal(monitor.status().folderPath, 'Z:\\watch');
  setReachable(true);
  await runInterval();
  assert.equal(statusEvents.at(-1).reachable, true);
  assert.equal(scanCalls(), 1);
});

test('reachable reconciliation intervals scan the configured folder', async () => {
  const { monitor, runInterval, scanCalls } = createReachabilityHarness(true);
  monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  await runInterval();
  await runInterval();
  assert.equal(scanCalls(), 2);
});

test('pause stops watcher and reconciliation until explicit resume', async () => {
  const { monitor, runInterval, scanCalls } = createReachabilityHarness(true);
  monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  await monitor.pause();
  await runInterval();
  assert.equal(scanCalls(), 0);
  assert.equal(monitor.status().paused, true);
  await monitor.resume({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  assert.equal(scanCalls(), 1);
  assert.equal(monitor.status().paused, false);
});

test('resume can activate watcher and interval before a separately gated reconciliation', async () => {
  const { monitor, scanCalls } = createReachabilityHarness(true);
  const settings = { folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 };
  monitor.start(settings);
  await monitor.pause();

  const result = await monitor.resume(settings, { reconcile: false });

  assert.equal(scanCalls(), 0);
  assert.equal(result.reconciled, false);
  assert.equal(monitor.status().running, true);
  assert.equal(monitor.status().paused, false);
});

test('repeated pause emits one status change and keeps reconciliation stopped', async () => {
  const { monitor, statusEvents, runInterval, scanCalls } = createReachabilityHarness(true);
  monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  const statusCountBeforePause = statusEvents.length;

  await monitor.pause();
  await monitor.pause();
  await runInterval();

  assert.equal(statusEvents.length, statusCountBeforePause + 1);
  assert.equal(statusEvents.at(-1).paused, true);
  assert.equal(scanCalls(), 0);
});

test('stop emits an immutable non-running status snapshot', () => {
  const { monitor } = createWatcherHarness();
  const statuses = [];
  monitor.on('status', (status) => statuses.push(status));
  monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  const statusCount = statuses.length;
  monitor.stop();
  assert.equal(statuses.length, statusCount + 1);
  assert.equal(statuses.at(-1).running, false);
  assert.equal(Object.isFrozen(statuses.at(-1)), true);
});

test('pause invalidates a running scan before it can publish late state or files', async () => {
  let releaseWalk;
  let markWalkStarted;
  const walkPending = new Promise((resolve) => { releaseWalk = resolve; });
  const walkStarted = new Promise((resolve) => { markWalkStarted = resolve; });
  const timers = createManualTimers();
  const statuses = [];
  const newFiles = [];
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    access: async () => {},
    walkFolder: async () => {
      markWalkStarted();
      await walkPending;
      return [{ path: 'C:\\watch\\late.mkv', name: 'late.mkv', size: 1 }];
    },
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('status', (status) => statuses.push(status));
  monitor.on('new-files', (files) => newFiles.push(files));
  monitor.start({ folderPath: 'C:\\watch', extensions: 'mkv', skipDuplicates: true, reconcileIntervalMinutes: 5 });
  const scan = monitor.scan({ emitFiles: true, trigger: 'manual' });
  await walkStarted;
  await monitor.pause();
  const statusCountAfterPause = statuses.length;
  releaseWalk();
  const result = await scan;
  assert.equal(result.cancelled, true);
  assert.equal(statuses.length, statusCountAfterPause);
  assert.deepEqual(newFiles, []);
  assert.equal(monitor.status().scanning, false);
});

test('stop cancels a running scan and its pending follow-up', async () => {
  let releaseWalk;
  let markWalkStarted;
  let walkCalls = 0;
  const walkPending = new Promise((resolve) => { releaseWalk = resolve; });
  const walkStarted = new Promise((resolve) => { markWalkStarted = resolve; });
  const timers = createManualTimers();
  const statuses = [];
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    access: async () => {},
    walkFolder: async () => {
      walkCalls++;
      if (walkCalls === 1) {
        markWalkStarted();
        await walkPending;
      }
      return [];
    },
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('status', (status) => statuses.push(status));
  monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  const first = monitor.scan({ emitFiles: true, trigger: 'interval' });
  await walkStarted;
  const followUp = monitor.scan({ emitFiles: true, trigger: 'manual' });
  monitor.stop();
  const statusCountAfterStop = statuses.length;
  releaseWalk();
  const results = await Promise.all([first, followUp]);
  assert.equal(walkCalls, 1);
  assert.equal(results.every((result) => result.cancelled === true), true);
  assert.equal(statuses.length, statusCountAfterStop);
});

test('late watcher add callbacks are ignored after pause', async () => {
  const timers = createManualTimers();
  const watchers = [];
  const newFiles = [];
  const monitor = new FolderMonitor({
    watch: () => {
      const watcher = new EventEmitter();
      watcher.close = async () => {};
      watchers.push(watcher);
      return watcher;
    },
    access: async () => {},
    walkFolder: async () => [],
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('new-files', (files) => newFiles.push(files));
  monitor.start({ folderPath: 'C:\\watch', extensions: 'mkv', reconcileIntervalMinutes: 5 });
  await monitor.pause();
  watchers[0].emit('add', 'C:\\watch\\late.mkv');
  await timers.runTimeouts();
  assert.deepEqual(newFiles, []);
});

test('resume full scan redelivers candidates while watcher duplicate history remains reserved', async () => {
  const timers = createManualTimers();
  const watchers = [];
  const newFiles = [];
  const monitor = new FolderMonitor({
    watch: () => {
      const watcher = new EventEmitter();
      watcher.close = async () => {};
      watchers.push(watcher);
      return watcher;
    },
    access: async () => {},
    walkFolder: async () => [{ path: 'C:\\watch\\same.mkv', name: 'same.mkv', size: 1 }],
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('new-files', (files) => newFiles.push(files));
  const settings = { folderPath: 'C:\\watch', extensions: 'mkv', skipDuplicates: true, reconcileIntervalMinutes: 5 };
  monitor.start(settings);
  watchers[0].emit('add', 'C:\\watch\\same.mkv');
  await timers.runTimeouts();
  await monitor.pause();
  await monitor.resume(settings);
  watchers[1].emit('add', 'C:\\watch\\same.mkv');
  await timers.runTimeouts();
  assert.deepEqual(newFiles.map(files => files.map(file => typeof file === 'string' ? file : file.path)), [
    ['C:\\watch\\same.mkv'],
    ['C:\\watch\\same.mkv']
  ]);
  assert.equal(monitor.status().seenCount, 1);
});

test('watcher add paused before batch timeout is emitted exactly once by resume scan', async () => {
  const timers = createManualTimers();
  const watchers = [];
  const newFiles = [];
  const filePath = 'C:\\watch\\pending.mkv';
  const monitor = new FolderMonitor({
    watch: () => {
      const watcher = new EventEmitter();
      watcher.close = async () => {};
      watchers.push(watcher);
      return watcher;
    },
    access: async () => {},
    walkFolder: async () => [{ path: filePath, name: 'pending.mkv', size: 1 }],
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('new-files', (files) => newFiles.push(files));
  const settings = { folderPath: 'C:\\watch', extensions: 'mkv', skipDuplicates: true, reconcileIntervalMinutes: 5 };
  monitor.start(settings);
  watchers[0].emit('add', filePath);
  assert.deepEqual(newFiles, []);
  await monitor.pause();
  assert.deepEqual(newFiles, []);
  await monitor.resume(settings);
  assert.deepEqual(newFiles.map(files => files.map(file => typeof file === 'string' ? file : file.path)), [[filePath]]);
  assert.equal(monitor.status().seenCount, 0);
});

test('synchronous pause during watcher delivery keeps its reservation while resume scan redelivers the candidate', async () => {
  const timers = createManualTimers();
  const watchers = [];
  const newFiles = [];
  const filePath = 'C:\\watch\\delivered.mkv';
  let pausePromise;
  const monitor = new FolderMonitor({
    watch: () => {
      const watcher = new EventEmitter();
      watcher.close = async () => {};
      watchers.push(watcher);
      return watcher;
    },
    access: async () => {},
    walkFolder: async () => [{ path: filePath, name: 'delivered.mkv', size: 1 }],
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('new-files', (files) => {
    newFiles.push(files);
    pausePromise = monitor.pause();
  });
  const settings = { folderPath: 'C:\\watch', extensions: 'mkv', skipDuplicates: true, reconcileIntervalMinutes: 5 };
  monitor.start(settings);
  watchers[0].emit('add', filePath);
  await timers.runTimeouts();
  await pausePromise;
  assert.deepEqual(newFiles, [[filePath]]);
  await monitor.resume(settings);
  assert.deepEqual(newFiles.map(files => files.map(file => typeof file === 'string' ? file : file.path)), [[filePath], [filePath]]);
  assert.equal(monitor.status().seenCount, 1);
});

test('pause rollback never deletes historical seen state from a dedupe-off batch', async () => {
  const timers = createManualTimers();
  const watchers = [];
  const newFiles = [];
  const filePath = 'C:\\watch\\historical.mkv';
  let discoverExisting = false;
  const monitor = new FolderMonitor({
    watch: () => {
      const watcher = new EventEmitter();
      watcher.close = async () => {};
      watchers.push(watcher);
      return watcher;
    },
    access: async () => {},
    walkFolder: async () => discoverExisting ? [{ path: filePath, name: 'historical.mkv', size: 1 }] : [],
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('new-files', (files) => newFiles.push(files));
  const dedupeOn = { folderPath: 'C:\\watch', extensions: 'mkv', skipDuplicates: true, reconcileIntervalMinutes: 5 };
  const dedupeOff = { ...dedupeOn, skipDuplicates: false };
  monitor.start(dedupeOn);
  watchers[0].emit('add', filePath);
  await timers.runTimeouts();
  assert.deepEqual(newFiles, [[filePath]]);
  await monitor.pause();
  await monitor.resume(dedupeOff);
  watchers[1].emit('add', filePath);
  assert.deepEqual(newFiles, [[filePath]]);
  await monitor.pause();
  await monitor.resume(dedupeOn);
  watchers[2].emit('add', filePath);
  await timers.runTimeouts();
  assert.deepEqual(newFiles, [[filePath]]);
  assert.equal(monitor.status().seenCount, 1);
});

test('dry scan leaves the public status byte-identical and does not consume reconnect state', async () => {
  let reachable = false;
  const timers = createManualTimers();
  const statuses = [];
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    access: async () => {
      if (!reachable) throw new Error('offline');
    },
    walkFolder: async () => [],
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('status', (status) => statuses.push(status));
  monitor.start({ folderPath: 'Z:\\watch', reconcileIntervalMinutes: 5 });
  await monitor.scan({ emitFiles: true, trigger: 'interval' });
  reachable = true;
  const before = JSON.stringify(monitor.status());
  const statusCount = statuses.length;
  const dry = await monitor.scan({ emitFiles: false, trigger: 'test' });
  assert.equal(dry.reachable, true);
  assert.equal(JSON.stringify(monitor.status()), before);
  assert.equal(statuses.length, statusCount);
  const productive = await monitor.scan({ emitFiles: true, trigger: 'reconnect' });
  assert.equal(productive.reconnected, true);
});

test('walk failure clears scan state, sanitizes the error and preserves one follow-up', async () => {
  let releaseFailure;
  let walkCalls = 0;
  const failurePending = new Promise((resolve) => { releaseFailure = resolve; });
  const timers = createManualTimers();
  const statuses = [];
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    access: async () => {},
    walkFolder: async () => {
      walkCalls++;
      if (walkCalls === 1) {
        await failurePending;
        throw new Error('token=secret-value at C:\\private\\file.mkv');
      }
      return [];
    },
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('status', (status) => statuses.push(status));
  monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  const first = monitor.scan({ emitFiles: true, trigger: 'interval' });
  const second = monitor.scan({ emitFiles: true, trigger: 'reconnect' });
  const third = monitor.scan({ emitFiles: true, trigger: 'manual' });
  releaseFailure();
  await Promise.all([first, second, third]);
  assert.equal(walkCalls, 2);
  assert.equal(statuses.some((status) => status.error === 'Ordnerscan fehlgeschlagen'), true);
  assert.equal(statuses.some((status) => status.error.includes('secret-value') || status.error.includes('C:\\private')), false);
  assert.equal(monitor.status().scanning, false);
});

test('new-files listener failure terminates the productive scan with a sanitized error', async () => {
  const { monitor } = createScanHarness({
    files: [{ path: 'C:\\watch\\a.mkv', name: 'a.mkv', size: 1, mtimeMs: 1 }]
  });
  monitor.on('new-files', () => {
    throw new Error('apiKey=listener-secret');
  });
  monitor.start({ folderPath: 'C:\\watch', extensions: 'mkv', reconcileIntervalMinutes: 5 });
  const result = await monitor.scan({ emitFiles: true, trigger: 'manual' });
  assert.equal(result.error, 'Ordnerscan fehlgeschlagen');
  assert.equal(monitor.status().error, 'Ordnerscan fehlgeschlagen');
  assert.equal(monitor.status().error.includes('listener-secret'), false);
  assert.equal(monitor.status().scanning, false);
});

test('interval callback contains unexpected scan rejection', async () => {
  const timers = createManualTimers();
  const statuses = [];
  const monitor = new FolderMonitor({
    watch: createSilentWatch(),
    access: async () => {},
    walkFolder: async () => [],
    stat: async () => ({ mtimeMs: 1 }),
    ...timers
  });
  monitor.on('status', (status) => statuses.push(status));
  monitor.start({ folderPath: 'C:\\watch', reconcileIntervalMinutes: 5 });
  monitor.scan = async () => { throw new Error('token=interval-secret'); };
  await assert.doesNotReject(() => timers.runInterval());
  assert.equal(statuses.at(-1).error, 'Ordnerscan fehlgeschlagen');
  assert.equal(statuses.at(-1).error.includes('interval-secret'), false);
});

test('real temporary folder recovers a file-atomic deferral with default duplicate protection', async () => {
  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'mhu-automation-folder-'));
  const detached = `${root}-detached`;
  const timers = createManualTimers();
  const queuedPaths = new Set();
  const admissions = [];
  let currentJobCount = 14998;
  try {
    fs.mkdirSync(path.join(root, 'nested'));
    const fourJobPath = path.join(root, 'four-jobs.mkv');
    const twoJobPath = path.join(root, 'nested', 'two-jobs.mkv');
    fs.writeFileSync(fourJobPath, Buffer.from('four'));
    fs.writeFileSync(path.join(root, 'ignored.txt'), Buffer.from('ignored'));
    fs.writeFileSync(twoJobPath, Buffer.from('two'));
    fs.writeFileSync(path.join(root, 'nested', 'excluded.mp4'), Buffer.from('excluded'));
    fs.utimesSync(fourJobPath, new Date('2020-01-01T00:00:00.000Z'), new Date('2020-01-01T00:00:00.000Z'));
    fs.utimesSync(twoJobPath, new Date('2020-01-02T00:00:00.000Z'), new Date('2020-01-02T00:00:00.000Z'));
    const monitor = new FolderMonitor({ watch: createSilentWatch(), ...timers });
    monitor.on('new-files', (files) => {
      const descriptors = files.map(file => typeof file === 'string' ? {
        path: file,
        name: path.basename(file),
        mtimeMs: fs.statSync(file).mtimeMs
      } : file).filter(file => file.filterMatched !== false);
      const processed = classifyProcessedCandidates({ candidates: descriptors, queuePaths: [...queuedPaths] });
      const unprocessed = new Set(processed.unprocessedPaths);
      const candidates = descriptors
        .filter(file => unprocessed.has(file.path))
        .map(file => ({ ...file, eligibleJobCount: file.name === 'four-jobs.mkv' ? 4 : 2 }));
      const plan = planAtomicAdmissions({ candidates, currentJobCount, queueLimitJobs: 15000 });
      for (const filePath of plan.admittedPaths) queuedPaths.add(filePath);
      currentJobCount += plan.plannedJobs;
      admissions.push({
        trigger: monitor.status().lastScanTrigger,
        admittedPaths: plan.admittedPaths,
        deferredPaths: plan.deferredPaths,
        currentJobCount
      });
    });
    monitor.start({
      folderPath: root,
      recursive: true,
      extensions: 'mkv',
      filterMode: 'include',
      skipDuplicates: true,
      reconcileIntervalMinutes: 5
    });

    const first = await monitor.scan({ emitFiles: true, trigger: 'startup' });
    assert.deepEqual(first.files.filter(file => file.filterMatched).map(file => file.name).sort(), ['four-jobs.mkv', 'two-jobs.mkv']);
    assert.equal(first.files.every((file) => Number.isFinite(file.mtimeMs)), true);
    assert.deepEqual(admissions[0], {
      trigger: 'startup',
      admittedPaths: [twoJobPath],
      deferredPaths: [fourJobPath],
      currentJobCount: 15000
    });

    currentJobCount = 14996;
    await timers.runInterval();
    assert.deepEqual(admissions[1], {
      trigger: 'interval',
      admittedPaths: [fourJobPath],
      deferredPaths: [],
      currentJobCount: 15000
    });

    fs.renameSync(root, detached);
    await timers.runInterval();
    assert.equal(monitor.status().reachable, false);
    assert.equal(admissions.length, 2);

    fs.renameSync(detached, root);
    await timers.runInterval();
    assert.equal(monitor.status().reachable, true);
    assert.equal(admissions.at(-1).trigger, 'reconnect');
    assert.deepEqual(admissions.at(-1).admittedPaths, []);

    await timers.runInterval();
    assert.equal(admissions.filter(entry => entry.trigger === 'reconnect').length, 1);
    assert.equal(admissions.at(-1).trigger, 'interval');
    assert.deepEqual([...queuedPaths].sort(), [fourJobPath, twoJobPath].sort());
    await monitor.pause();
  } finally {
    if (fs.existsSync(detached)) fs.renameSync(detached, root);
    fs.rmSync(root, { recursive: true, force: true });
  }
});