import express from 'express'
import cors from 'cors'
import fs from 'node:fs'
import fsp from 'node:fs/promises'
import path from 'node:path'
import { fileURLToPath } from 'node:url'
import { execFile } from 'node:child_process'
import { promisify } from 'node:util'

const execFileAsync = promisify(execFile)
const __filename = fileURLToPath(import.meta.url)
const __dirname = path.dirname(__filename)

const app = express()
app.use(cors())
app.use(express.json({ limit: '1mb' }))

const WORKSPACE_DIR = path.join(process.env.HOME || '', '.openclaw/workspace')
const MEMORY_DIR = path.join(WORKSPACE_DIR, 'memory')
const MAIN_MEMORY_FILE = path.join(WORKSPACE_DIR, 'MEMORY.md')
const DIST_DIR = path.join(__dirname, 'dist')
const DAILY_MEMORY_PATTERN = /^\d{4}-\d{2}-\d{2}\.md$/

const APPWRITE_ENDPOINT = process.env.APPWRITE_SELF_HOSTED_URL || process.env.APPWRITE_LOCAL_ENDPOINT
const APPWRITE_PROJECT_ID = process.env.APPWRITE_SELF_HOSTED_PROJECT_ID || process.env.APPWRITE_LOCAL_PROJECT_ID
const APPWRITE_KEY = process.env.APPWRITE_SELF_HOSTED_API_KEY || process.env.APPWRITE_LOCAL_API_KEY
const APPWRITE_DATABASE_ID = process.env.APPWRITE_MEMORY_DATABASE_ID || 'freecastle'
const APPWRITE_COLLECTION_ID = process.env.APPWRITE_MEMORY_COLLECTION_ID || 'memory_files'

const APPWRITE_ENV = {
  ...process.env,
  APPWRITE_ENDPOINT,
  APPWRITE_PROJECT_ID,
  APPWRITE_KEY,
}

if (!fs.existsSync(MEMORY_DIR)) {
  fs.mkdirSync(MEMORY_DIR, { recursive: true })
}

function todayDateStamp() {
  return new Date().toISOString().split('T')[0]
}

function currentTimeStamp() {
  return new Date().toTimeString().slice(0, 5)
}

function isValidDailyMemoryFilename(filename) {
  return typeof filename === 'string' && DAILY_MEMORY_PATTERN.test(filename)
}

function isValidMemoryFilename(filename) {
  return filename === 'MEMORY.md' || isValidDailyMemoryFilename(filename)
}

function resolveDailyMemoryPath(filename) {
  if (!isValidDailyMemoryFilename(filename)) return null
  const resolvedPath = path.resolve(MEMORY_DIR, filename)
  const memoryDirPrefix = `${path.resolve(MEMORY_DIR)}${path.sep}`
  return resolvedPath.startsWith(memoryDirPrefix) ? resolvedPath : null
}

function resolveMemoryPath(filename) {
  if (filename === 'MEMORY.md') return MAIN_MEMORY_FILE
  return resolveDailyMemoryPath(filename)
}

function kindForFilename(filename) {
  return filename === 'MEMORY.md' ? 'main' : 'daily'
}

function readUtf8File(filePath) {
  return fs.readFileSync(filePath, 'utf8')
}

function wordCount(content) {
  return content.trim().split(/\s+/).filter(Boolean).length
}

function getEntryCount(content) {
  if (!content) return 0
  return content.split('\n').filter((line) => line.trim().startsWith('- [')).length
}

function formatDateLabel(filename) {
  const match = filename.match(/^(\d{4})-(\d{2})-(\d{2})\.md$/)
  if (!match) return filename
  const [, year, month, day] = match
  const date = new Date(`${year}-${month}-${day}T12:00:00`)
  return date.toLocaleDateString(undefined, {
    weekday: 'short',
    year: 'numeric',
    month: 'short',
    day: 'numeric',
  })
}

async function runAppwrite(args) {
  const { stdout } = await execFileAsync('appwrite', args, {
    env: APPWRITE_ENV,
    maxBuffer: 10 * 1024 * 1024,
  })
  return stdout?.trim() || ''
}

async function runAppwriteJson(args) {
  const stdout = await runAppwrite([...args, '--json'])
  return stdout ? JSON.parse(stdout) : null
}

async function getDocument(documentId) {
  try {
    return await runAppwriteJson([
      'databases', 'get-document',
      '--database-id', APPWRITE_DATABASE_ID,
      '--collection-id', APPWRITE_COLLECTION_ID,
      '--document-id', documentId,
    ])
  } catch (error) {
    const stderr = `${error.stderr || ''}${error.stdout || ''}${error.message || ''}`
    if (/document_not_found|404|not found|could not be found/i.test(stderr)) return null
    throw error
  }
}

async function listDocuments() {
  const result = await runAppwriteJson([
    'databases', 'list-documents',
    '--database-id', APPWRITE_DATABASE_ID,
    '--collection-id', APPWRITE_COLLECTION_ID,
  ])
  return result?.documents || []
}

async function upsertDocument(filename, content) {
  const data = JSON.stringify({
    filename,
    kind: kindForFilename(filename),
    content,
  })

  const existing = await getDocument(filename)
  if (existing) {
    return runAppwriteJson([
      'databases', 'update-document',
      '--database-id', APPWRITE_DATABASE_ID,
      '--collection-id', APPWRITE_COLLECTION_ID,
      '--document-id', filename,
      '--data', data,
    ])
  }

  return runAppwriteJson([
    'databases', 'create-document',
    '--database-id', APPWRITE_DATABASE_ID,
    '--collection-id', APPWRITE_COLLECTION_ID,
    '--document-id', filename,
    '--data', data,
  ])
}

async function syncFileToAppwrite(filename) {
  const filePath = resolveMemoryPath(filename)
  if (!filePath || !fs.existsSync(filePath)) return null
  const content = await fsp.readFile(filePath, 'utf8')
  return upsertDocument(filename, content)
}

async function syncWorkspaceToAppwrite() {
  const filenames = [
    'MEMORY.md',
    ...fs.readdirSync(MEMORY_DIR).filter(isValidDailyMemoryFilename).sort(),
  ]

  for (const filename of filenames) {
    await syncFileToAppwrite(filename)
  }
}

let syncPromise = syncWorkspaceToAppwrite().catch((error) => {
  console.error('Initial Appwrite sync failed:', error)
})

async function ensureSync() {
  await syncPromise
}

async function readMemoryDocument(filename) {
  const doc = await getDocument(filename)
  if (doc?.content != null) {
    return doc
  }

  await syncFileToAppwrite(filename)
  return getDocument(filename)
}

function buildFileMeta(doc) {
  const content = doc.content || ''
  const mtimeMs = doc.$updatedAt ? new Date(doc.$updatedAt).getTime() : Date.now()
  return {
    filename: doc.filename,
    mtimeMs,
    size: Buffer.byteLength(content, 'utf8'),
    wordCount: wordCount(content),
    entryCount: getEntryCount(content),
    dateLabel: formatDateLabel(doc.filename),
  }
}

app.get('/api/health', async (req, res) => {
  try {
    await ensureSync()
    await runAppwrite(['databases', 'get-collection', '--database-id', APPWRITE_DATABASE_ID, '--collection-id', APPWRITE_COLLECTION_ID])
    res.json({
      ok: true,
      appwrite: true,
      memoryDir: fs.existsSync(MEMORY_DIR),
      mainMemory: fs.existsSync(MAIN_MEMORY_FILE),
    })
  } catch (error) {
    res.status(500).json({ ok: false, error: error.message })
  }
})

app.get('/api/meta', async (req, res) => {
  try {
    await ensureSync()
    const docs = await listDocuments()
    const mainDoc = docs.find((doc) => doc.filename === 'MEMORY.md')
    const dailyDocs = docs
      .filter((doc) => isValidDailyMemoryFilename(doc.filename))
      .sort((a, b) => String(b.filename).localeCompare(String(a.filename)))

    const mainMemory = mainDoc ? {
      exists: true,
      mtimeMs: new Date(mainDoc.$updatedAt).getTime(),
      size: Buffer.byteLength(mainDoc.content || '', 'utf8'),
      wordCount: wordCount(mainDoc.content || ''),
      entryCount: getEntryCount(mainDoc.content || ''),
    } : null

    const dailyFiles = dailyDocs.map(buildFileMeta)
    const summary = dailyFiles.reduce((acc, file) => {
      acc.dailyFileCount += 1
      acc.totalDailyEntries += file.entryCount
      acc.totalDailyWords += file.wordCount
      return acc
    }, { dailyFileCount: 0, totalDailyEntries: 0, totalDailyWords: 0 })

    res.json({ mainMemory, dailyFiles, summary })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.get('/api/memories', async (req, res) => {
  try {
    await ensureSync()
    const docs = await listDocuments()
    const files = docs
      .map((doc) => doc.filename)
      .filter(isValidDailyMemoryFilename)
      .sort()
      .reverse()
    res.json(files)
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.get('/api/memories/:filename', async (req, res) => {
  try {
    const { filename } = req.params
    if (!isValidDailyMemoryFilename(filename)) {
      return res.status(400).json({ error: 'Invalid memory filename' })
    }
    await ensureSync()
    const doc = await readMemoryDocument(filename)
    if (!doc) return res.status(404).json({ error: 'File not found' })
    return res.json({ content: doc.content || '' })
  } catch (error) {
    return res.status(500).json({ error: error.message })
  }
})

app.get('/api/main-memory', async (req, res) => {
  try {
    await ensureSync()
    const doc = await readMemoryDocument('MEMORY.md')
    if (!doc) return res.status(404).json({ error: 'MEMORY.md not found' })
    res.json({ content: doc.content || '' })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

async function writeThrough(filename, content) {
  const filePath = resolveMemoryPath(filename)
  if (!filePath) throw new Error('Invalid memory filename')
  await fsp.writeFile(filePath, content, 'utf8')
  await upsertDocument(filename, content)
}

app.put('/api/main-memory', async (req, res) => {
  try {
    const { content } = req.body
    if (typeof content !== 'string') {
      return res.status(400).json({ error: 'Content is required' })
    }
    await ensureSync()
    await writeThrough('MEMORY.md', content)
    res.json({ success: true })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.put('/api/memories/:filename', async (req, res) => {
  try {
    const { filename } = req.params
    if (!isValidDailyMemoryFilename(filename)) {
      return res.status(400).json({ error: 'Invalid memory filename' })
    }
    const { content } = req.body
    if (typeof content !== 'string') {
      return res.status(400).json({ error: 'Content is required' })
    }
    await ensureSync()
    await writeThrough(filename, content)
    res.json({ success: true })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.get('/api/search', async (req, res) => {
  const query = typeof req.query.q === 'string' ? req.query.q.trim().toLowerCase() : ''
  if (!query || query.length < 2) {
    return res.json({ query, results: [], total: 0 })
  }

  try {
    await ensureSync()
    const docs = (await listDocuments())
      .filter((doc) => isValidDailyMemoryFilename(doc.filename))
      .sort((a, b) => String(b.filename).localeCompare(String(a.filename)))

    const results = []
    for (const doc of docs) {
      const content = doc.content || ''
      const lower = content.toLowerCase()
      if (!lower.includes(query)) continue

      const lines = content.split('\n')
      const matchingLines = lines
        .map((line) => line.trim())
        .filter((line) => line.toLowerCase().includes(query))
        .slice(0, 5)

      const firstMatchIdx = lower.indexOf(query)
      const windowStart = Math.max(0, firstMatchIdx - 80)
      const windowEnd = Math.min(content.length, firstMatchIdx + 120)
      const snippet = content.slice(windowStart, windowEnd).replace(/\n/g, ' ')

      results.push({
        filename: doc.filename,
        dateLabel: formatDateLabel(doc.filename),
        entryCount: getEntryCount(content),
        wordCount: wordCount(content),
        matchCount: (lower.match(new RegExp(query.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'), 'g')) || []).length,
        snippet: `${windowStart > 0 ? '…' : ''}${snippet}${windowEnd < content.length ? '…' : ''}`,
        matchingLines,
      })
    }

    results.sort((a, b) => b.matchCount - a.matchCount)
    res.json({ query, results, total: results.length })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.post('/api/log', async (req, res) => {
  const message = typeof req.body?.message === 'string' ? req.body.message.trim() : ''
  if (!message) {
    return res.status(400).json({ error: 'Message is required' })
  }

  try {
    await ensureSync()
    const filename = `${todayDateStamp()}.md`
    const filePath = resolveDailyMemoryPath(filename)
    const existing = filePath && fs.existsSync(filePath) ? await fsp.readFile(filePath, 'utf8') : ''
    const prefix = existing && !existing.endsWith('\n') ? '\n' : ''
    const content = `${existing}${prefix}- [${currentTimeStamp()}] ${message}\n`
    await writeThrough(filename, content)
    res.json({ success: true, mode: 'appwrite' })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.get('/api/review', async (req, res) => {
  try {
    const { stdout, stderr } = await execFileAsync('claw-mem', ['review'])
    const output = `${stdout || ''}${stderr || ''}`
    const REVIEW_PATTERN = /^  File: (.+\.md)$/gm
    const files = []
    let match
    while ((match = REVIEW_PATTERN.exec(output)) !== null) {
      const filename = path.basename(match[1].trim())
      if (isValidDailyMemoryFilename(filename)) {
        const doc = await readMemoryDocument(filename)
        if (doc) {
          files.push({
            filename,
            dateLabel: formatDateLabel(filename),
            wordCount: wordCount(doc.content || ''),
            entryCount: getEntryCount(doc.content || ''),
            content: doc.content || '',
          })
        }
      }
    }
    res.json({
      files,
      hasCandidates: files.length > 0,
      instructions: files.length > 0
        ? 'Read each file, distill key learnings into MEMORY.md, then prune.'
        : 'All memory files are recent. Check back in a few days.',
    })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.get('/api/review-count', async (req, res) => {
  try {
    const { stdout, stderr } = await execFileAsync('claw-mem', ['review'])
    const output = `${stdout || ''}${stderr || ''}`
    const REVIEW_PATTERN = /^  File: (.+\.md)$/gm
    let count = 0
    let match
    while ((match = REVIEW_PATTERN.exec(output)) !== null) {
      const filename = path.basename(match[1].trim())
      if (isValidDailyMemoryFilename(filename)) count++
    }
    res.json({ count })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.post('/api/prune', async (req, res) => {
  try {
    const { stdout, stderr } = await execFileAsync('claw-mem', ['prune'])
    const output = `${stdout || ''}${stderr || ''}`
    const countMatch = output.match(/(\d+)\s+file/i) || output.match(/pruned\s+(\d+)/i)
    res.json({ success: true, prunedCount: countMatch ? Number.parseInt(countMatch[1], 10) : null, output })
  } catch (error) {
    res.status(500).json({ error: error.message || 'Prune failed', output: `${error.stdout || ''}${error.stderr || ''}` })
  }
})

app.post('/api/distill', async (req, res) => {
  const { note, sourceFilename } = req.body || {}
  if (typeof note !== 'string' || !note.trim()) {
    return res.status(400).json({ error: 'Distilled note is required' })
  }

  try {
    await ensureSync()
    const mainDoc = await readMemoryDocument('MEMORY.md')
    if (!mainDoc) return res.status(404).json({ error: 'MEMORY.md not found' })

    const existing = mainDoc.content || ''
    const dateStr = todayDateStamp()
    const sourceTag = sourceFilename ? ` (from ${sourceFilename})` : ''
    const distillEntry = `\n- **[${dateStr}]**${sourceTag} ${note.trim()}\n`
    await writeThrough('MEMORY.md', `${existing}${distillEntry}`)
    res.json({ success: true, appended: distillEntry.trim() })
  } catch (error) {
    res.status(500).json({ error: error.message })
  }
})

app.use(express.static(DIST_DIR))
app.get(/.*/, (req, res) => {
  res.sendFile(path.join(DIST_DIR, 'index.html'))
})

const PORT = Number(process.env.PORT) || 3333

if (import.meta.url === `file://${process.argv[1]}`) {
  app.listen(PORT, '0.0.0.0', () => {
    console.log(`Freeclaw Memory Cloud running on port ${PORT}`)
  })
}

export { app, isValidDailyMemoryFilename, resolveDailyMemoryPath }