clarc/src/cli.ts

#!/usr/bin/env bun

// PTY wrapper for claude CLI

// Check for Bun runtime (only fails when running bundled .js with Node)
if (typeof Bun === "undefined") {
  console.error("claude-remote requires Bun to run.");
  console.error("Install Bun: https://bun.sh");
  process.exit(1);
}

import type { IPty } from "bun-pty";
import { spawn } from "bun-pty";
import type { ClientMessage, ServerMessage } from "./types";

interface Args {
  server: string;
  secret: string;
  claudeArgs: string[];
}

function parseArgs(): Args {
  const args = process.argv.slice(2);

  // Read config from env vars first
  let server = process.env.CLAUDE_REMOTE_SERVER || "ws://localhost:7200/ws";
  let secret = process.env.CLAUDE_REMOTE_SECRET || "";
  const claudeArgs: string[] = [];

  let i = 0;
  while (i < args.length) {
    if (args[i] === "--server" && i + 1 < args.length) {
      server = args[i + 1] as string;
      i += 2;
    } else if (args[i] === "--secret" && i + 1 < args.length) {
      secret = args[i + 1] as string;
      i += 2;
    } else if (args[i] === "--help" || args[i] === "-h") {
      // Run claude --help synchronously and append our section
      const result = Bun.spawnSync(["claude", "--help"]);
      if (result.success) {
        process.stdout.write(result.stdout);
        console.log("");
        console.log("Remote:");
        console.log(
          "  --server <url>                                    WebSocket server URL (env: CLAUDE_REMOTE_SERVER)",
        );
        console.log(
          "  --secret <secret>                                 Authentication secret (env: CLAUDE_REMOTE_SECRET)",
        );
        console.log("");
      } else {
        console.error("Failed to run 'claude --help'. Is claude installed?");
      }
      process.exit(result.exitCode ?? 0);
    } else if (args[i] === "--") {
      // -- separator is optional, just skip it
      claudeArgs.push(...args.slice(i + 1));
      break;
    } else {
      claudeArgs.push(args[i] as string);
      i++;
    }
  }

  if (!secret) {
    console.error(
      "No secret configured. Set CLAUDE_REMOTE_SECRET or use --secret",
    );
    process.exit(1);
  }

  return { server, secret, claudeArgs };
}

function getTerminalSize(): { cols: number; rows: number } {
  if (process.stdout.isTTY) {
    return {
      cols: process.stdout.columns || 80,
      rows: process.stdout.rows || 24,
    };
  }
  return { cols: 80, rows: 24 };
}

function tryParseHookEvent(
  line: string,
): { type: string; [key: string]: unknown } | null {
  // Look for lines that are valid JSON objects
  const trimmed = line.trim();
  if (!trimmed.startsWith("{") || !trimmed.endsWith("}")) {
    return null;
  }

  try {
    const parsed = JSON.parse(trimmed);
    // Check if it has a type field
    if (typeof parsed === "object" && parsed !== null && "type" in parsed) {
      return parsed as { type: string; [key: string]: unknown };
    }
    return null;
  } catch {
    return null;
  }
}

async function main() {
  const args = parseArgs();

  let pty: IPty | null = null;
  let ws: WebSocket | null = null;
  let isExiting = false;
  let reconnectTimer: Timer | null = null;
  let reconnectDelay = 1000; // Start at 1s, back off exponentially
  const maxReconnectDelay = 30000; // Cap at 30s
  const disposables: Array<{ dispose: () => void }> = [];
  let lineBuffer = "";

  const cleanup = () => {
    if (isExiting) return;
    isExiting = true;

    if (reconnectTimer) {
      clearTimeout(reconnectTimer);
    }
    for (const d of disposables) {
      d.dispose();
    }
    if (process.stdin.isTTY) {
      process.stdin.setRawMode(false);
    }
    if (pty) {
      pty.kill();
    }
    if (ws) {
      ws.close();
    }
    process.exit(0);
  };

  process.on("SIGINT", cleanup);
  process.on("SIGTERM", cleanup);
  process.on("SIGCONT", () => {
    // Restore terminal state after being resumed from suspension
    if (process.stdin.isTTY) {
      process.stdin.setRawMode(true);
    }
    process.stdin.resume();
    if (pty) {
      // Resume child process first
      process.kill(pty.pid, "SIGCONT");
      // Give child time to wake up, then trigger redraw
      setTimeout(() => {
        if (pty && !isExiting) {
          const { cols, rows } = getTerminalSize();
          pty.resize(cols, rows);
          process.kill(pty.pid, "SIGWINCH"); // Tell child window changed
        }
      }, 50);
    }
  });

  // Spawn PTY only after WebSocket connects
  const spawnClaude = () => {
    const { cols, rows } = getTerminalSize();

    pty = spawn("claude", args.claudeArgs, {
      name: "xterm-256color",
      cols,
      rows,
      cwd: process.cwd(),
      env: process.env as Record<string, string>,
    });

    // Set stdin to raw mode if TTY
    if (process.stdin.isTTY) {
      process.stdin.setRawMode(true);
    }

    // Forward local stdin to PTY
    process.stdin.on("data", (data: Buffer) => {
      // ctrl+z in raw mode - suspend child and self
      if (data.length === 1 && data[0] === 0x1a) {
        if (pty) {
          process.kill(pty.pid, "SIGTSTP");
        }
        process.kill(process.pid, "SIGTSTP");
        return;
      }
      if (pty) {
        pty.write(data.toString());
      }
    });

    // Forward PTY output to stdout AND WebSocket
    disposables.push(
      pty.onData((data: string) => {
        process.stdout.write(data);

        if (ws && ws.readyState === WebSocket.OPEN) {
          // Send output to server
          const outputMsg: ClientMessage = { type: "output", data };
          ws.send(JSON.stringify(outputMsg));

          // Buffer data and process complete lines for hook events
          lineBuffer += data;
          const lines = lineBuffer.split("\n");
          // Keep the last incomplete line in the buffer
          lineBuffer = lines.pop() || "";

          // Process each complete line for hook events
          for (const line of lines) {
            const event = tryParseHookEvent(line);
            if (event && (event.type === "state" || event.type === "stats")) {
              // Send state or stats event to server
              if (event.type === "state") {
                const stateMsg: ClientMessage = {
                  type: "state",
                  state: event.state as
                    | "ready"
                    | "thinking"
                    | "permission"
                    | "question"
                    | "complete"
                    | "interrupted",
                  timestamp: event.timestamp as number,
                };
                ws.send(JSON.stringify(stateMsg));
              } else if (event.type === "stats") {
                const statsMsg: ClientMessage = {
                  type: "stats",
                  prompts: event.prompts as number,
                  completions: event.completions as number,
                  tools: event.tools as number,
                  compressions: event.compressions as number,
                  thinking_seconds: event.thinking_seconds as number,
                  work_seconds: event.work_seconds as number,
                  mode: event.mode as "normal" | "auto_accept" | "plan",
                  model: (event.model as string) || null,
                  prompts_changed_at: event.prompts_changed_at as number,
                  completions_changed_at:
                    event.completions_changed_at as number,
                  tool_timestamps: event.tool_timestamps as number[],
                  session_start: event.session_start as number,
                  idle_since: (event.idle_since as number) || null,
                };
                ws.send(JSON.stringify(statsMsg));
              }
            }
          }
        }
      }),
    );

    // Handle PTY exit
    disposables.push(
      pty.onExit((event) => {
        if (ws && !isExiting) {
          const msg: ClientMessage = { type: "exit", code: event.exitCode };
          ws.send(JSON.stringify(msg));
        }
        cleanup();
      }),
    );

    // Handle terminal resize
    process.stdout.on("resize", () => {
      if (pty && process.stdout.isTTY) {
        const newCols = process.stdout.columns || 80;
        const newRows = process.stdout.rows || 24;
        pty.resize(newCols, newRows);

        if (ws && ws.readyState === WebSocket.OPEN) {
          const msg: ClientMessage = {
            type: "resize",
            cols: newCols,
            rows: newRows,
          };
          ws.send(JSON.stringify(msg));
        }
      }
    });
  };

  // Connect to server first, then spawn claude
  const connect = () => {
    if (isExiting) return;

    ws = new WebSocket(args.server);

    ws.onopen = () => {
      if (!ws) return;

      // Reset backoff on successful connection
      reconnectDelay = 1000;

      const command = `claude ${args.claudeArgs.join(" ")}`;
      const msg: ClientMessage = {
        type: "auth",
        secret: args.secret,
        cwd: process.cwd(),
        command,
      };
      ws.send(JSON.stringify(msg));
    };

    ws.onmessage = (event) => {
      try {
        const msg: ServerMessage = JSON.parse(event.data);

        if (msg.type === "authenticated") {
          console.debug(`Connected to ${args.server}`);
          // Only spawn claude after authenticated
          if (!pty) {
            spawnClaude();
          }
        } else if (msg.type === "input") {
          if (pty) {
            pty.write(msg.data);
          }
        } else if (msg.type === "resize") {
          if (pty) {
            pty.resize(msg.cols, msg.rows);
          }
        } else if (msg.type === "ping") {
          // Acknowledge ping (keep-alive)
        }
      } catch (err) {
        console.error("Failed to parse server message:", err);
      }
    };

    ws.onerror = () => {
      // Error details come through onclose, suppress here
    };

    ws.onclose = () => {
      if (isExiting) return;

      const hadPty = pty !== null;

      if (hadPty) {
        console.error(
          `Disconnected from server (retry in ${reconnectDelay / 1000}s)`,
        );
      } else {
        console.error(
          `Waiting for server at ${args.server} (retry in ${reconnectDelay / 1000}s)`,
        );
      }

      // Exponential backoff for reconnection
      reconnectTimer = setTimeout(() => {
        connect();
      }, reconnectDelay);

      reconnectDelay = Math.min(reconnectDelay * 2, maxReconnectDelay);
    };
  };

  console.error(`Connecting to ${args.server}...`);
  connect();
}

main().catch((err) => {
  console.error("Fatal error:", err);
  process.exit(1);
});