#!/usr/bin/env node
import { resolveMCPRoot } from '#mcp/root'
import { MCP_VERSION, startServer } from '#mcp/server'
import { readToolPolicyFromEnv } from '#mcp/tool/policy'
import { resolveCORSOrigins } from '#mcp/transport/origins'

if (process.argv.includes('--version')) {
  process.stdout.write(`${MCP_VERSION}\n`)
  process.exit(0)
}

if (process.argv.includes('--help') || process.argv.includes('-h')) {
  process.stdout.write(
    `openpencil-mcp-http\n\n` +
      `Start the OpenPencil MCP server.\n\n` +
      `On macOS/Linux, the server listens on a Unix domain socket by default\n` +
      `with optional TCP for browser clients. On Windows, only TCP is available.\n\n` +
      `Options:\n` +
      `  --help, -h    Show this help message\n` +
      `  --version     Print the version\n\n` +
      `Environment variables:\n` +
      `  PORT                         TCP port (default: 7600, set to 0 to disable TCP)\n` +
      `  OPENPENCIL_MCP_SOCKET        Override Unix socket path (recorded in the discovery file)\n` +
      `  OPENPENCIL_MCP_DISCOVERY_PATH Override discovery file (mcp.json) location; defaults to the\n` +
      `                               platform path. Parent dir created 0o700. Mainly for test isolation.\n` +
      `  OPENPENCIL_MCP_TCP           Deprecated — TCP is controlled by PORT (>0 = on, 0 = off)\n` +
      `  OPENPENCIL_MCP_AUTH_TOKEN    Bearer token for MCP and RPC auth\n` +
      `  OPENPENCIL_MCP_ROOT          Allowed directory for file-scoped tools (default: home directory on Windows, current working directory elsewhere)\n` +
      `  OPENPENCIL_MCP_EVAL           Set to 1 to enable the eval tool\n` +
      `  OPENPENCIL_MCP_DISABLED_TOOLS Comma-separated tool names to omit\n` +
      `  OPENPENCIL_MCP_SCOPE         "selection" to let clients read only the selected layers\n` +
      `                               (default: "document")\n` +
      `  OPENPENCIL_MCP_CORS_ORIGIN   Allowed CORS origins, comma-separated.\n` +
      `                               Defaults to the desktop app origin, since the app\n` +
      `                               webview is the only view that calls this server.\n` +
      `  OPENPENCIL_MCP_APP_TIMEOUT_MS  If set, close the server and remove its discovery\n` +
      `                               file after no app is attached for this many ms. The\n` +
      `                               grace period starts at startup and after disconnects.\n` +
      `                               Unset/0 disables it (default) — do not set this for\n` +
      `                               manual/CLI use, since nothing may ever register.\n`
  )
  process.exit(0)
}

const rawPortText = (process.env.PORT ?? '7600').trim()
// Reject non-digit strings (including hex like "0x50" and partially-numeric like
// "7600abc") — Number.parseInt would silently parse these, masking misconfig.
if (!/^\d+$/.test(rawPortText)) {
  process.stderr.write(`Error: PORT must be an integer in 0–65535, got "${process.env.PORT}"\n`)
  process.exit(1)
}
const rawPort = Number.parseInt(rawPortText, 10)
// Validate PORT: must be an integer in 0–65535. 0 means "disable TCP".
if (rawPort < 0 || rawPort > 65535) {
  process.stderr.write(`Error: PORT must be an integer in 0–65535, got "${process.env.PORT}"\n`)
  process.exit(1)
}
const port = rawPort
// OPENPENCIL_MCP_TCP is accepted for backward compat but has no effect —
// the PORT value alone determines whether TCP is enabled (PORT=0 is the kill switch).
const withTcp = port > 0

const MAX_APP_TIMEOUT_MS = 2_147_483_647
const rawAppTimeoutText = process.env.OPENPENCIL_MCP_APP_TIMEOUT_MS?.trim()
let appAttachTimeoutMs: number | undefined
if (rawAppTimeoutText) {
  if (!/^\d+$/.test(rawAppTimeoutText)) {
    process.stderr.write(
      `Error: OPENPENCIL_MCP_APP_TIMEOUT_MS must be a non-negative integer, got "${rawAppTimeoutText}"\n`
    )
    process.exit(1)
  }
  appAttachTimeoutMs = Number.parseInt(rawAppTimeoutText, 10)
  if (!Number.isSafeInteger(appAttachTimeoutMs) || appAttachTimeoutMs > MAX_APP_TIMEOUT_MS) {
    process.stderr.write(
      `Error: OPENPENCIL_MCP_APP_TIMEOUT_MS must be an integer in 0–${MAX_APP_TIMEOUT_MS}, got "${rawAppTimeoutText}"\n`
    )
    process.exit(1)
  }
}

const toolPolicy = readToolPolicyFromEnv()

const handle = await startServer({
  httpPort: withTcp ? port : 0,
  withTcp,
  socketPath: process.env.OPENPENCIL_MCP_SOCKET?.trim() || null,
  enableEval: toolPolicy.allowEval,
  disabledTools: toolPolicy.disabledTools,
  scope: toolPolicy.scope,
  mcpRoot: resolveMCPRoot(process.env.OPENPENCIL_MCP_ROOT),
  // Auth token: undefined → auto-generate, empty string → disable auth,
  // non-empty → use trimmed value. Whitespace-only is rejected to prevent a
  // silent fallback to an auto-generated token when the operator intended to
  // set an explicit one.
  authToken: (() => {
    const raw = process.env.OPENPENCIL_MCP_AUTH_TOKEN
    if (raw === undefined) return undefined
    if (raw === '') return null
    const trimmed = raw.trim()
    if (!trimmed) {
      process.stderr.write(
        'Error: OPENPENCIL_MCP_AUTH_TOKEN is whitespace-only. Set a real token, or use an empty string to disable auth.\n'
      )
      process.exit(1)
    }
    return trimmed
  })(),
  corsOrigin: resolveCORSOrigins(process.env.OPENPENCIL_MCP_CORS_ORIGIN),
  appAttachTimeoutMs
})

const readyMarker = process.env.OPENPENCIL_MCP_READY_MARKER
if (readyMarker && /^open-pencil-ready:[a-f0-9-]{36}$/.test(readyMarker)) {
  process.stderr.write(`${readyMarker}\n`)
}

process.stderr.write(`OpenPencil MCP server\n`)
if (handle.socketPath) process.stderr.write(`  Socket: ${handle.socketPath}\n`)
if (handle.httpPort) process.stderr.write(`  HTTP:   http://127.0.0.1:${handle.httpPort}\n`)

// Graceful shutdown on signals
const shutdown = async () => {
  process.stderr.write('\nShutting down MCP server...\n')
  await handle.close()
  process.exit(0)
}

process.on('SIGINT', () => void shutdown().catch(() => process.exit(1)))
process.on('SIGTERM', () => void shutdown().catch(() => process.exit(1)))