/**
 * Tests for .claude/helpers/memory.js
 *
 * Run: node --test tests/helpers/memory.test.js
 *
 * Coverage gaps addressed:
 *  - loadMemory: missing file, corrupted JSON, valid file
 *  - saveMemory: directory creation, JSON format
 *  - commands.get: with key, without key, missing key
 *  - commands.set: missing key arg, _updated timestamp, overwrite
 *  - commands.delete: missing key arg, non-existent key
 *  - commands.keys: filters _-prefixed meta keys
 *  - commands.clear: resets to empty object
 *  - Error handling: corrupted JSON masked silently
 */

'use strict'

const { describe, it, before, after, beforeEach } = require('node:test')
const assert = require('node:assert/strict')
const fs = require('node:fs')
const path = require('node:path')
const os = require('node:os')

// Helper to load the module with a custom CWD so MEMORY_FILE points to a tmp dir
function loadModule(cwd) {
  // Clear require cache so MEMORY_DIR/MEMORY_FILE are re-evaluated each time
  const modPath = require.resolve('../../.claude/helpers/memory.js')
  delete require.cache[modPath]
  const origCwd = process.cwd
  process.cwd = () => cwd
  try {
    const mod = require('../../.claude/helpers/memory.js')
    return mod
  } finally {
    process.cwd = origCwd
    delete require.cache[modPath]
  }
}

describe('memory.js', () => {
  let tmpDir
  let commands
  let memoryFile

  before(() => {
    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'mem-test-'))
    memoryFile = path.join(tmpDir, '.claude-flow', 'data', 'memory.json')
  })

  after(() => {
    fs.rmSync(tmpDir, { recursive: true, force: true })
  })

  beforeEach(() => {
    // Reset memory file before each test
    const dir = path.dirname(memoryFile)
    if (fs.existsSync(dir)) fs.rmSync(dir, { recursive: true })
    commands = loadModule(tmpDir)
  })

  // ── loadMemory ─────────────────────────────────────────────────────────────

  describe('loadMemory (via commands.get)', () => {
    it('returns {} when memory file does not exist', () => {
      const result = commands.get(undefined)
      assert.deepEqual(result, {})
    })

    it('returns {} and does not throw when file contains corrupted JSON', () => {
      const dir = path.dirname(memoryFile)
      fs.mkdirSync(dir, { recursive: true })
      fs.writeFileSync(memoryFile, '{ not valid json !!!')
      // Should not throw; silently returns {}
      const result = commands.get(undefined)
      assert.deepEqual(result, {})
    })

    it('parses and returns stored memory when file is valid JSON', () => {
      const dir = path.dirname(memoryFile)
      fs.mkdirSync(dir, { recursive: true })
      fs.writeFileSync(memoryFile, JSON.stringify({ foo: 'bar' }, null, 2))
      const result = commands.get('foo')
      assert.equal(result, 'bar')
    })

    // EDGE CASE: empty file (0 bytes) should not crash
    it('returns {} when file is empty', () => {
      const dir = path.dirname(memoryFile)
      fs.mkdirSync(dir, { recursive: true })
      fs.writeFileSync(memoryFile, '')
      const result = commands.get(undefined)
      assert.deepEqual(result, {})
    })
  })

  // ── saveMemory (via commands.set) ──────────────────────────────────────────

  describe('saveMemory (via commands.set)', () => {
    it('creates the data directory if it does not exist', () => {
      commands.set('k', 'v')
      assert.ok(fs.existsSync(path.dirname(memoryFile)))
    })

    it('writes pretty-printed JSON to disk', () => {
      commands.set('hello', 'world')
      const raw = fs.readFileSync(memoryFile, 'utf-8')
      const parsed = JSON.parse(raw)
      assert.equal(parsed.hello, 'world')
      // Pretty-printed → contains newlines
      assert.ok(raw.includes('\n'))
    })
  })

  // ── commands.get ───────────────────────────────────────────────────────────

  describe('commands.get', () => {
    it('returns the whole memory object when no key is provided', () => {
      commands.set('a', 1)
      commands.set('b', 2)
      const result = commands.get(undefined)
      assert.equal(result.a, 1)
      assert.equal(result.b, 2)
    })

    it('returns undefined for a key that was never set', () => {
      const result = commands.get('nonexistent')
      assert.equal(result, undefined)
    })

    it('returns the value for an existing key', () => {
      commands.set('mykey', 'myvalue')
      const result = commands.get('mykey')
      assert.equal(result, 'myvalue')
    })
  })

  // ── commands.set ───────────────────────────────────────────────────────────

  describe('commands.set', () => {
    it('returns undefined and does not write when key is missing', () => {
      const result = commands.set(undefined, 'value')
      assert.equal(result, undefined)
      assert.ok(!fs.existsSync(memoryFile))
    })

    it('writes a _updated ISO timestamp alongside the value', () => {
      const before = Date.now()
      commands.set('ts-test', 'v')
      const after = Date.now()
      const raw = JSON.parse(fs.readFileSync(memoryFile, 'utf-8'))
      const ts = new Date(raw._updated).getTime()
      assert.ok(ts >= before && ts <= after + 100)
    })

    it('overwrites an existing key without losing other keys', () => {
      commands.set('x', 'first')
      commands.set('y', 'other')
      commands.set('x', 'second')
      assert.equal(commands.get('x'), 'second')
      assert.equal(commands.get('y'), 'other')
    })
  })

  // ── commands.delete ────────────────────────────────────────────────────────

  describe('commands.delete', () => {
    it('logs error and does not write when key is missing', () => {
      const result = commands.delete(undefined)
      assert.equal(result, undefined)
      assert.ok(!fs.existsSync(memoryFile))
    })

    it('removes an existing key from memory', () => {
      commands.set('to-remove', 'val')
      commands.delete('to-remove')
      assert.equal(commands.get('to-remove'), undefined)
    })

    it('is a no-op and does not throw when deleting a non-existent key', () => {
      commands.set('keep', 'val')
      assert.doesNotThrow(() => commands.delete('ghost'))
      assert.equal(commands.get('keep'), 'val')
    })
  })

  // ── commands.keys ──────────────────────────────────────────────────────────

  describe('commands.keys', () => {
    it('returns only user-defined keys, excluding _-prefixed meta keys', () => {
      commands.set('alpha', 1)
      commands.set('beta', 2)
      const keys = commands.keys()
      assert.ok(keys.includes('alpha'))
      assert.ok(keys.includes('beta'))
      assert.ok(!keys.includes('_updated'), '_updated must be filtered out')
    })

    it('returns an empty array when memory is empty', () => {
      const keys = commands.keys()
      assert.deepEqual(keys, [])
    })
  })

  // ── commands.clear ─────────────────────────────────────────────────────────

  describe('commands.clear', () => {
    it('replaces all memory with an empty object', () => {
      commands.set('a', 1)
      commands.set('b', 2)
      commands.clear()
      assert.deepEqual(commands.get(undefined), {})
    })

    it('does not throw when memory is already empty', () => {
      assert.doesNotThrow(() => commands.clear())
    })
  })
})