#!/usr/bin/env bun
import type { App, LogLine } from '@types'
import { loadGitignore } from '@gitignore'
import { program } from 'commander'
import { createHash } from 'crypto'
import { existsSync, mkdirSync, readFileSync, readdirSync, statSync, unlinkSync, writeFileSync } from 'fs'
import color from 'kleur'
import { dirname, join, relative } from 'path'

const HOST = `http://localhost:${process.env.PORT ?? 3000}`

interface FileInfo {
  hash: string
  mtime: string
  size: number
}

interface Manifest {
  files: Record<string, FileInfo>
  name: string
}

const STATE_ICONS: Record<string, string> = {
  running: color.green('●'),
  starting: color.yellow('◎'),
  stopped: color.gray('◯'),
  invalid: color.red('◌'),
}

function makeUrl(path: string): string {
  return `${HOST}${path}`
}

async function get<T>(url: string): Promise<T | undefined> {
  try {
    const res = await fetch(makeUrl(url))
    if (!res.ok) throw new Error(`${res.status} ${res.statusText}`)
    return await res.json()
  } catch (error) {
    console.error(error)
  }
}

async function post<T, B = unknown>(url: string, body?: B): Promise<T | undefined> {
  try {
    const res = await fetch(makeUrl(url), {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body),
    })
    if (!res.ok) throw new Error(`${res.status} ${res.statusText}`)
    return await res.json()
  } catch (error) {
    console.error(error)
  }
}

async function put(url: string, body: Buffer | Uint8Array): Promise<boolean> {
  try {
    const res = await fetch(makeUrl(url), {
      method: 'PUT',
      body: body as BodyInit,
    })
    if (!res.ok) throw new Error(`${res.status} ${res.statusText}`)
    return true
  } catch (error) {
    console.error(error)
    return false
  }
}

async function download(url: string): Promise<Buffer | undefined> {
  try {
    const fullUrl = makeUrl(url)
    const res = await fetch(fullUrl)
    if (!res.ok) throw new Error(`${res.status} ${res.statusText}`)
    return Buffer.from(await res.arrayBuffer())
  } catch (error) {
    console.error(error)
  }
}

async function del(url: string): Promise<boolean> {
  try {
    const res = await fetch(makeUrl(url), {
      method: 'DELETE',
    })
    if (!res.ok) throw new Error(`${res.status} ${res.statusText}`)
    return true
  } catch (error) {
    console.error(error)
    return false
  }
}

function computeHash(content: Buffer | string): string {
  return createHash('sha256').update(content).digest('hex')
}

function generateLocalManifest(appPath: string, appName: string): Manifest {
  const files: Record<string, FileInfo> = {}
  const gitignore = loadGitignore(appPath)

  function walkDir(dir: string) {
    if (!existsSync(dir)) return

    const entries = readdirSync(dir, { withFileTypes: true })

    for (const entry of entries) {
      const fullPath = join(dir, entry.name)
      const relativePath = relative(appPath, fullPath)

      if (gitignore.shouldExclude(relativePath)) continue

      if (entry.isDirectory()) {
        walkDir(fullPath)
      } else if (entry.isFile()) {
        const content = readFileSync(fullPath)
        const stats = statSync(fullPath)

        files[relativePath] = {
          hash: computeHash(content),
          mtime: stats.mtime.toISOString(),
          size: stats.size,
        }
      }
    }
  }

  walkDir(appPath)

  return {
    name: appName,
    files,
  }
}

async function infoApp(name: string) {
  const app: App | undefined = await get(`/api/apps/${name}`)
  if (!app) {
    console.error(`App not found: ${name}`)
    return
  }

  const icon = STATE_ICONS[app.state] ?? '◯'
  console.log(`${icon} ${color.bold(app.name)}`)
  console.log(`  State:   ${app.state}`)
  if (app.port) {
    console.log(`  Port:    ${app.port}`)
    console.log(`  URL:     http://localhost:${app.port}`)
  }
  if (app.started) {
    const uptime = Date.now() - app.started
    const seconds = Math.floor(uptime / 1000) % 60
    const minutes = Math.floor(uptime / 60000) % 60
    const hours = Math.floor(uptime / 3600000)
    const parts = []
    if (hours) parts.push(`${hours}h`)
    if (minutes) parts.push(`${minutes}m`)
    parts.push(`${seconds}s`)
    console.log(`  Uptime:  ${parts.join(' ')}`)
  }
  if (app.error) console.log(`  Error:   ${color.red(app.error)}`)
}

async function listApps() {
  const apps: App[] | undefined = await get('/api/apps')
  if (!apps) return

  for (const app of apps) {
    console.log(`${STATE_ICONS[app.state] ?? '◯'} ${app.name}`)
  }
}

const startApp = async (app: string) => {
  await post(`/api/apps/${app}/start`)
}

const stopApp = async (app: string) => {
  await post(`/api/apps/${app}/stop`)
}

const restartApp = async (app: string) => {
  await post(`/api/apps/${app}/restart`)
}

const printLog = (line: LogLine) =>
  console.log(`${new Date(line.time).toLocaleTimeString()} ${line.text}`)

async function logApp(name: string, options: { follow?: boolean }) {
  if (options.follow) {
    await tailLogs(name)
    return
  }

  const logs: LogLine[] | undefined = await get(`/api/apps/${name}/logs`)
  if (!logs) {
    console.error(`App not found: ${name}`)
    return
  }
  if (logs.length === 0) {
    console.log('No logs yet')
    return
  }
  for (const line of logs) {
    printLog(line)
  }
}

async function tailLogs(name: string) {
  const url = makeUrl(`/api/apps/${name}/logs/stream`)
  const res = await fetch(url)
  if (!res.ok) {
    console.error(`App not found: ${name}`)
    return
  }
  if (!res.body) return

  const reader = res.body.getReader()
  const decoder = new TextDecoder()
  let buffer = ''

  while (true) {
    const { done, value } = await reader.read()
    if (done) break

    buffer += decoder.decode(value, { stream: true })
    const lines = buffer.split('\n\n')
    buffer = lines.pop() ?? ''

    for (const line of lines) {
      if (line.startsWith('data: ')) {
        const data = JSON.parse(line.slice(6)) as LogLine
        printLog(data)
      }
    }
  }
}

async function openApp(name: string) {
  const app: App | undefined = await get(`/api/apps/${name}`)
  if (!app) {
    console.error(`App not found: ${name}`)
    return
  }
  if (app.state !== 'running') {
    console.error(`App is not running: ${name}`)
    return
  }
  const url = `http://localhost:${app.port}`
  console.log(`Opening ${url}`)
  Bun.spawn(['open', url])
}

async function getApp(name: string) {
  console.log(`Fetching ${color.bold(name)} from server...`)

  const manifest: Manifest | undefined = await get(`/api/sync/apps/${name}/manifest`)
  if (!manifest) {
    console.error(`App not found: ${name}`)
    return
  }

  const appPath = join(process.cwd(), name)
  if (existsSync(appPath)) {
    console.error(`Directory already exists: ${name}`)
    return
  }

  mkdirSync(appPath, { recursive: true })

  const files = Object.keys(manifest.files)
  console.log(`Downloading ${files.length} files...`)

  for (const file of files) {
    const content = await download(`/api/sync/apps/${name}/files/${file}`)
    if (!content) {
      console.error(`Failed to download: ${file}`)
      continue
    }

    const fullPath = join(appPath, file)
    const dir = dirname(fullPath)

    if (!existsSync(dir)) {
      mkdirSync(dir, { recursive: true })
    }

    writeFileSync(fullPath, content)
  }

  console.log(color.green(`✓ Downloaded ${name}`))
}

function isApp(): boolean {
  try {
    const pkg = JSON.parse(readFileSync(join(process.cwd(), 'package.json'), 'utf-8'))
    return !!pkg?.scripts?.toes
  } catch (e) {
    return false
  }
}

async function pushApp() {
  if (!isApp()) {
    console.error('Not a toes app. Use `toes get <app>` to grab one.')
    return
  }

  const appName = process.cwd().split('/').pop()
  if (!appName) {
    console.error('Could not determine app name from current directory')
    return
  }

  console.log(`Pushing ${color.bold(appName)} to server...`)

  const localManifest = generateLocalManifest(process.cwd(), appName)
  const remoteManifest: Manifest | undefined = await get(`/api/sync/apps/${appName}/manifest`)

  if (!remoteManifest) {
    console.error('App not found on server')
    return
  }

  const localFiles = new Set(Object.keys(localManifest.files))
  const remoteFiles = new Set(Object.keys(remoteManifest.files))

  // Files to upload (new or changed)
  const toUpload: string[] = []
  for (const file of localFiles) {
    const local = localManifest.files[file]!
    const remote = remoteManifest.files[file]
    if (!remote || local.hash !== remote.hash) {
      toUpload.push(file)
    }
  }

  // Files to delete (in remote but not local)
  const toDelete: string[] = []
  for (const file of remoteFiles) {
    if (!localFiles.has(file)) {
      toDelete.push(file)
    }
  }

  if (toUpload.length === 0 && toDelete.length === 0) {
    console.log('Already up to date')
    return
  }

  if (toUpload.length > 0) {
    console.log(`Uploading ${toUpload.length} files...`)
    for (const file of toUpload) {
      const content = readFileSync(join(process.cwd(), file))
      const success = await put(`/api/sync/apps/${appName}/files/${file}`, content)
      if (success) {
        console.log(`  ${color.green('↑')} ${file}`)
      } else {
        console.log(`  ${color.red('✗')} ${file}`)
      }
    }
  }

  if (toDelete.length > 0) {
    console.log(`Deleting ${toDelete.length} files on server...`)
    for (const file of toDelete) {
      const success = await del(`/api/sync/apps/${appName}/files/${file}`)
      if (success) {
        console.log(`  ${color.red('✗')} ${file}`)
      } else {
        console.log(`  ${color.red('Failed to delete')} ${file}`)
      }
    }
  }

  console.log(color.green('✓ Push complete'))
}

async function pullApp() {
  if (!isApp()) {
    console.error('Not a toes app. Use `toes get <app>` to grab one.')
    return
  }

  const appName = process.cwd().split('/').pop()
  if (!appName) {
    console.error('Could not determine app name from current directory')
    return
  }

  console.log(`Pulling ${color.bold(appName)} from server...`)

  const remoteManifest: Manifest | undefined = await get(`/api/sync/apps/${appName}/manifest`)
  if (!remoteManifest) {
    console.error('App not found on server')
    return
  }

  const localManifest = generateLocalManifest(process.cwd(), appName)

  const localFiles = new Set(Object.keys(localManifest.files))
  const remoteFiles = new Set(Object.keys(remoteManifest.files))

  // Files to download (new or changed)
  const toDownload: string[] = []
  for (const file of remoteFiles) {
    const remote = remoteManifest.files[file]!
    const local = localManifest.files[file]
    if (!local || remote.hash !== local.hash) {
      toDownload.push(file)
    }
  }

  // Files to delete (in local but not remote)
  const toDelete: string[] = []
  for (const file of localFiles) {
    if (!remoteFiles.has(file)) {
      toDelete.push(file)
    }
  }

  if (toDownload.length === 0 && toDelete.length === 0) {
    console.log('Already up to date')
    return
  }

  if (toDownload.length > 0) {
    console.log(`Downloading ${toDownload.length} files...`)
    for (const file of toDownload) {
      const content = await download(`/api/sync/apps/${appName}/files/${file}`)
      if (!content) {
        console.log(`  ${color.red('✗')} ${file}`)
        continue
      }

      const fullPath = join(process.cwd(), file)
      const dir = dirname(fullPath)

      if (!existsSync(dir)) {
        mkdirSync(dir, { recursive: true })
      }

      writeFileSync(fullPath, content)
      console.log(`  ${color.green('↓')} ${file}`)
    }
  }

  if (toDelete.length > 0) {
    console.log(`Deleting ${toDelete.length} local files...`)
    for (const file of toDelete) {
      const fullPath = join(process.cwd(), file)
      unlinkSync(fullPath)
      console.log(`  ${color.red('✗')} ${file}`)
    }
  }

  console.log(color.green('✓ Pull complete'))
}

program
  .name('toes')
  .version('0.0.1', '-v, --version')

program
  .command('info')
  .description('Show info for an app')
  .argument('<name>', 'app name')
  .action(infoApp)

program
  .command('list')
  .description('List all apps')
  .action(listApps)

program
  .command('start')
  .description('Start an app')
  .argument('<name>', 'app name')
  .action(startApp)

program
  .command('stop')
  .description('Stop an app')
  .argument('<name>', 'app name')
  .action(stopApp)

program
  .command('restart')
  .description('Restart an app')
  .argument('<name>', 'app name')
  .action(restartApp)

program
  .command('logs')
  .description('Show logs for an app')
  .argument('<name>', 'app name')
  .option('-f, --follow', 'follow log output')
  .action(logApp)

program
  .command('log', { hidden: true })
  .argument('<name>', 'app name')
  .option('-f, --follow', 'follow log output')
  .action(logApp)

program
  .command('open')
  .description('Open an app in browser')
  .argument('<name>', 'app name')
  .action(openApp)

program
  .command('get')
  .description('Download an app from server')
  .argument('<name>', 'app name')
  .action(getApp)

program
  .command('push')
  .description('Push local changes to server')
  .action(pushApp)

program
  .command('pull')
  .description('Pull changes from server')
  .action(pullApp)

program.parse()