// Hook timing budget enforcement.
//
// Two thresholds are measured per hook:
//
// - WALL_CLOCK_P95_MS = 200 — total round-trip including Node ESM cold-start.
//   The cold-start alone is 60-120ms on Intel Mac, so 100ms is unrealistic
//   for any subprocess-based hook. 200ms gives headroom for shared CI noise.
//
// - LOGIC_TIME_P95_MS = 50 — pure work (regex evaluation + JSONL/state I/O)
//   measured by a fixture-runner that imports lib.mjs once and exercises
//   the hook's hot path inline. This is the meaningful hook-perf assertion;
//   ESM cold-start is not something the plugin can optimize.
//
// p95 = the 4th value of 5 sorted iterations. Failing once triggers a single
// retry to absorb transient OS noise; a second failure is treated as a real
// signal (real perf regression or threshold needs tuning).

import { test } from 'node:test';
import assert from 'node:assert/strict';
import { execSync } from 'child_process';
import {
  mkdtempSync, mkdirSync, writeFileSync, readFileSync, existsSync,
  unlinkSync, rmSync, appendFileSync,
} from 'fs';
import { join } from 'path';
import { tmpdir } from 'os';
import { nowIso, nowEpoch } from '../hooks/scripts/lib.mjs';

const SCRIPTS_DIR = join(import.meta.dirname, '..', 'hooks', 'scripts');
const WALL_CLOCK_P95_MS = 200;
const LOGIC_TIME_P95_MS = 50;
const ITERATIONS = 5;

function setupDir() {
  const dir = mkdtempSync(join(tmpdir(), 'ia-perf-'));
  mkdirSync(join(dir, 'state'), { recursive: true });
  return dir;
}

function p95(samples) {
  return [...samples].sort((a, b) => a - b)[3];
}

// --- Wall-clock measurement (subprocess spawn) ---

function runWallClock(scriptName, stdinJson, dataDir) {
  const t0 = performance.now();
  execSync(`node ${join(SCRIPTS_DIR, scriptName)}`, {
    input: JSON.stringify(stdinJson),
    env: { ...process.env, CLAUDE_PLUGIN_DATA: dataDir },
    encoding: 'utf8',
    timeout: 5000,
  });
  return performance.now() - t0;
}

function measureWallClock(scriptName, stdinTemplate) {
  const samples = [];
  for (let i = 0; i < ITERATIONS; i++) {
    const dir = setupDir();
    try {
      const sid = `perf-${i}`;
      // Pre-seed state for hooks that read it (tool-tracker, session-end)
      writeFileSync(
        join(dir, 'state', `${sid}.json`),
        JSON.stringify({ start_epoch: nowEpoch(), start_iso: nowIso(), tool_count: 0, edit_count: 0 })
      );
      samples.push(runWallClock(scriptName, { ...stdinTemplate, session_id: sid }, dir));
    } finally {
      rmSync(dir, { recursive: true, force: true });
    }
  }
  return samples;
}

// --- Logic-time fixtures (no subprocess, single import of lib.mjs) ---
//
// These mirror each hook's hot path in pure inline code so we can measure
// regex + I/O cost without paying the ~80ms ESM cold-start tax. The pattern
// list intentionally mirrors the size class of prompt-analyzer's full
// pattern set (~25 regexes) so the benchmark stays representative.

const samplePatterns = [
  /\bI\s+can'?t\s+do\s+this\s+without\b/i,
  /\bwhat\s+should\s+I\b/i,
  /\bI\s+need\s+you\s+to\b/i,
  /\bonly\s+you\s+understand\b/i,
  /\b(?:always|never|every|all)\s+the\s+time\b/i,
  /\bdefinitely\s+(?:should|will|need)\b/i,
  /\babsolutely\s+(?:right|correct)\b/i,
  /\bI\s+am\s+(?:tired|exhausted|drained)\b/i,
  /\blate\s+night\b/i,
  /\b(?:can'?t|cannot)\s+sleep\b/i,
  /\bI\s+(?:wish|want)\s+(?:I|you)\s+could\b/i,
  /\bdo\s+you\s+think\b/i,
  /\bare\s+you\s+sure\b/i,
  /\bright\?$/i,
  /\bagree\?$/i,
  /\bam\s+I\s+(?:right|wrong)\b/i,
  /\bplease\s+confirm\b/i,
  /\bI\s+keep\s+(?:thinking|coming\s+back)\b/i,
  /\bI\s+(?:can'?t|cannot)\s+stop\b/i,
  /\bone\s+more\s+(?:thing|question)\b/i,
  /\bjust\s+one\s+more\b/i,
  /\bI'?ve\s+been\s+thinking\b/i,
  /\bwhy\s+did\s+I\b/i,
  /\bI\s+messed\s+up\b/i,
  /\bI\s+made\s+a\s+mistake\b/i,
];

function logicSessionStart(dir, sid) {
  const stateFile = join(dir, 'state', `${sid}.json`);
  const sessionsLog = join(dir, 'sessions.jsonl');
  const iso = nowIso();
  const epoch = nowEpoch();
  const state = { start_epoch: epoch, start_iso: iso, tool_count: 0, edit_count: 0 };
  writeFileSync(stateFile, JSON.stringify(state));
  appendFileSync(
    sessionsLog,
    JSON.stringify({ session_id: sid, start: iso, hour: new Date().getUTCHours(), is_late_night: false }) + '\n'
  );
}

function logicPromptAnalyzer(dir, sid, prompt) {
  const stateFile = join(dir, 'state', `${sid}.json`);
  const state = existsSync(stateFile) ? JSON.parse(readFileSync(stateFile, 'utf8')) : {};
  let depHit = 0, valHit = 0;
  for (const p of samplePatterns) { if (p.test(prompt)) { valHit = 1; break; } }
  state.dep_flags = (state.dep_flags || 0) + depHit;
  state.val_flags = (state.val_flags || 0) + valHit;
  writeFileSync(stateFile, JSON.stringify(state));
}

function logicToolTracker(dir, sid, toolName) {
  const stateFile = join(dir, 'state', `${sid}.json`);
  const eventsLog = join(dir, 'events.jsonl');
  const state = existsSync(stateFile) ? JSON.parse(readFileSync(stateFile, 'utf8')) : {};
  state.tool_count = (state.tool_count || 0) + 1;
  if (toolName === 'Edit' || toolName === 'Write') state.edit_count = (state.edit_count || 0) + 1;
  appendFileSync(
    eventsLog,
    JSON.stringify({ ts: nowIso(), session_id: sid, tool_name: toolName }) + '\n'
  );
  writeFileSync(stateFile, JSON.stringify(state));
}

function logicSessionEnd(dir, sid) {
  const stateFile = join(dir, 'state', `${sid}.json`);
  const sessionsLog = join(dir, 'sessions.jsonl');
  if (!existsSync(stateFile)) return;
  const state = JSON.parse(readFileSync(stateFile, 'utf8'));
  appendFileSync(
    sessionsLog,
    JSON.stringify({
      session_id: sid,
      start: state.start_iso,
      end: nowIso(),
      duration_min: 0,
      tool_count: state.tool_count || 0,
      edit_count: state.edit_count || 0,
      flags: { dependency: 0, escalation: 0, fatigue: 0, validation: state.val_flags || 0, pushback: 0 },
    }) + '\n'
  );
  unlinkSync(stateFile);
}

function measureLogicTime(fn, ...extraArgs) {
  const samples = [];
  for (let i = 0; i < ITERATIONS; i++) {
    const dir = setupDir();
    const sid = `perf-${i}`;
    try {
      writeFileSync(
        join(dir, 'state', `${sid}.json`),
        JSON.stringify({ start_epoch: nowEpoch(), start_iso: nowIso(), tool_count: 0, edit_count: 0 })
      );
      const t0 = performance.now();
      fn(dir, sid, ...extraArgs);
      samples.push(performance.now() - t0);
    } finally {
      rmSync(dir, { recursive: true, force: true });
    }
  }
  return samples;
}

function assertWithRetry(measure, threshold, label) {
  let samples = measure();
  let p = p95(samples);
  if (p > threshold) {
    samples = measure();
    p = p95(samples);
  }
  assert.ok(
    p <= threshold,
    `${label} p95 = ${p.toFixed(1)}ms exceeds ${threshold}ms (samples: ${samples.map(s => s.toFixed(1)).join(', ')})`
  );
}

// --- Wall-clock tests (4) ---

test('session-start.mjs wall-clock p95 within 200ms', () => {
  assertWithRetry(
    () => measureWallClock('session-start.mjs', { cwd: '/tmp' }),
    WALL_CLOCK_P95_MS,
    'session-start wall-clock'
  );
});

test('prompt-analyzer.mjs wall-clock p95 within 200ms', () => {
  assertWithRetry(
    () => measureWallClock('prompt-analyzer.mjs', { prompt: 'are you sure I should do this? right?', cwd: '/tmp' }),
    WALL_CLOCK_P95_MS,
    'prompt-analyzer wall-clock'
  );
});

test('tool-tracker.mjs wall-clock p95 within 200ms', () => {
  assertWithRetry(
    () => measureWallClock('tool-tracker.mjs', { tool_name: 'Edit', cwd: '/tmp' }),
    WALL_CLOCK_P95_MS,
    'tool-tracker wall-clock'
  );
});

test('session-end.mjs wall-clock p95 within 200ms', () => {
  assertWithRetry(
    () => measureWallClock('session-end.mjs', { cwd: '/tmp' }),
    WALL_CLOCK_P95_MS,
    'session-end wall-clock'
  );
});

// --- Logic-time tests (4) ---

test('session-start logic-time p95 within 50ms', () => {
  assertWithRetry(
    () => measureLogicTime(logicSessionStart),
    LOGIC_TIME_P95_MS,
    'session-start logic-time'
  );
});

test('prompt-analyzer logic-time p95 within 50ms', () => {
  assertWithRetry(
    () => measureLogicTime(logicPromptAnalyzer, 'are you sure I should do this? right?'),
    LOGIC_TIME_P95_MS,
    'prompt-analyzer logic-time'
  );
});

test('tool-tracker logic-time p95 within 50ms', () => {
  assertWithRetry(
    () => measureLogicTime(logicToolTracker, 'Edit'),
    LOGIC_TIME_P95_MS,
    'tool-tracker logic-time'
  );
});

test('session-end logic-time p95 within 50ms', () => {
  assertWithRetry(
    () => measureLogicTime(logicSessionEnd),
    LOGIC_TIME_P95_MS,
    'session-end logic-time'
  );
});