feat: add lockfile to prevent concurrent instances (#30)

src/takopi/cli.py

@@ -14,6 +14,7 @@ from .backends import EngineBackend
 from .bridge import BridgeConfig, run_main_loop
 from .config import ConfigError, load_telegram_config
 from .engines import get_backend, get_engine_config, list_backends
+from .lockfile import LockError, LockHandle, acquire_lock, token_fingerprint
 from .logging import setup_logging
 from .onboarding import check_setup, render_setup_guide
 from .router import AutoRouter, RunnerEntry
@@ -32,6 +33,46 @@ def _version_callback(value: bool) -> None:
         _print_version_and_exit()
 
 
+def load_and_validate_config(
+    path: str | Path | None = None,
+) -> tuple[dict, Path, str, int]:
+    config, config_path = load_telegram_config(path)
+    try:
+        token = config["bot_token"]
+    except KeyError:
+        raise ConfigError(f"Missing key `bot_token` in {config_path}.") from None
+    if not isinstance(token, str) or not token.strip():
+        raise ConfigError(
+            f"Invalid `bot_token` in {config_path}; expected a non-empty string."
+        ) from None
+    try:
+        chat_id_value = config["chat_id"]
+    except KeyError:
+        raise ConfigError(f"Missing key `chat_id` in {config_path}.") from None
+    if isinstance(chat_id_value, bool) or not isinstance(chat_id_value, int):
+        raise ConfigError(
+            f"Invalid `chat_id` in {config_path}; expected an integer."
+        ) from None
+    return config, config_path, token.strip(), chat_id_value
+
+
+def acquire_config_lock(config_path: Path, token: str) -> LockHandle:
+    try:
+        return acquire_lock(
+            config_path=config_path,
+            token_fingerprint=token_fingerprint(token),
+        )
+    except LockError as exc:
+        lines = str(exc).splitlines()
+        if lines:
+            typer.echo(lines[0], err=True)
+            if len(lines) > 1:
+                typer.echo("\n".join(lines[1:]), err=True)
+        else:
+            typer.echo("error: unknown error", err=True)
+        raise typer.Exit(code=1) from exc
+
+
 def _default_engine_for_setup(override: str | None) -> str:
     if override:
         return override
@@ -139,28 +180,13 @@ def _parse_bridge_config(
     *,
     final_notify: bool,
     default_engine_override: str | None,
+    config: dict,
+    config_path: Path,
+    token: str,
+    chat_id: int,
 ) -> BridgeConfig:
     startup_pwd = os.getcwd()
 
-    config, config_path = load_telegram_config()
-    try:
-        token = config["bot_token"]
-    except KeyError:
-        raise ConfigError(f"Missing key `bot_token` in {config_path}.") from None
-    if not isinstance(token, str) or not token.strip():
-        raise ConfigError(
-            f"Invalid `bot_token` in {config_path}; expected a non-empty string."
-        ) from None
-    try:
-        chat_id_value = config["chat_id"]
-    except KeyError:
-        raise ConfigError(f"Missing key `chat_id` in {config_path}.") from None
-    if isinstance(chat_id_value, bool) or not isinstance(chat_id_value, int):
-        raise ConfigError(
-            f"Invalid `chat_id` in {config_path}; expected an integer."
-        ) from None
-    chat_id = chat_id_value
-
     backends = list_backends()
     default_engine = _resolve_default_engine(
         override=default_engine_override,
@@ -201,25 +227,38 @@ def _run_auto_router(
     *, default_engine_override: str | None, final_notify: bool, debug: bool
 ) -> None:
     setup_logging(debug=debug)
+    lock_handle: LockHandle | None = None
     try:
         default_engine = _default_engine_for_setup(default_engine_override)
         backend = get_backend(default_engine)
     except ConfigError as e:
-        typer.echo(str(e), err=True)
+        typer.echo(f"error: {e}", err=True)
         raise typer.Exit(code=1)
     setup = check_setup(backend)
     if not setup.ok:
         render_setup_guide(setup)
         raise typer.Exit(code=1)
     try:
+        config, config_path, token, chat_id = load_and_validate_config()
+        lock_handle = acquire_config_lock(config_path, token)
         cfg = _parse_bridge_config(
             final_notify=final_notify,
             default_engine_override=default_engine_override,
+            config=config,
+            config_path=config_path,
+            token=token,
+            chat_id=chat_id,
         )
-    except ConfigError as e:
-        typer.echo(str(e), err=True)
-        raise typer.Exit(code=1)
         anyio.run(run_main_loop, cfg)
+    except ConfigError as e:
+        typer.echo(f"error: {e}", err=True)
+        raise typer.Exit(code=1)
+    except KeyboardInterrupt:
+        logger.info("[shutdown] interrupted")
+        raise typer.Exit(code=130)
+    finally:
+        if lock_handle is not None:
+            lock_handle.release()
 
 
 app = typer.Typer(

src/takopi/lockfile.py

@@ -0,0 +1,152 @@
+from __future__ import annotations
+
+import hashlib
+import json
+import logging
+import os
+from dataclasses import dataclass
+from pathlib import Path
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass(frozen=True)
+class LockInfo:
+    pid: int | None
+    token_fingerprint: str | None
+
+
+class LockError(RuntimeError):
+    def __init__(
+        self,
+        *,
+        path: Path,
+        state: str,
+    ) -> None:
+        self.path = path
+        self.state = state
+        super().__init__(_format_lock_message(path, state))
+
+
+@dataclass
+class LockHandle:
+    path: Path
+
+    def release(self) -> None:
+        try:
+            self.path.unlink(missing_ok=True)
+        except OSError as exc:
+            logger.warning("[lock] failed to remove lock file %s: %s", self.path, exc)
+
+    def __enter__(self) -> "LockHandle":
+        return self
+
+    def __exit__(self, exc_type, exc, tb) -> None:
+        self.release()
+
+
+def token_fingerprint(token: str) -> str:
+    digest = hashlib.sha256(token.encode("utf-8")).hexdigest()
+    return digest[:10]
+
+
+def lock_path_for_config(config_path: Path) -> Path:
+    return config_path.with_suffix(".lock")
+
+
+def acquire_lock(
+    *, config_path: Path, token_fingerprint: str | None = None
+) -> LockHandle:
+    cfg_path = config_path.expanduser().resolve()
+    lock_path = lock_path_for_config(cfg_path)
+    try:
+        lock_path.parent.mkdir(parents=True, exist_ok=True)
+        existing = _read_lock_info(lock_path)
+        if existing:
+            if (
+                token_fingerprint
+                and existing.token_fingerprint
+                and existing.token_fingerprint != token_fingerprint
+            ):
+                _write_lock_info(
+                    lock_path,
+                    pid=os.getpid(),
+                    token_fingerprint=token_fingerprint,
+                )
+                return LockHandle(path=lock_path)
+            if _pid_running(existing.pid):
+                raise LockError(path=lock_path, state="running") from None
+        _write_lock_info(
+            lock_path,
+            pid=os.getpid(),
+            token_fingerprint=token_fingerprint,
+        )
+    except OSError as exc:
+        raise LockError(path=lock_path, state=str(exc)) from exc
+
+    return LockHandle(path=lock_path)
+
+
+def _read_lock_info(path: Path) -> LockInfo | None:
+    try:
+        raw = path.read_text(encoding="utf-8")
+    except FileNotFoundError:
+        return None
+    except OSError:
+        return None
+    try:
+        data = json.loads(raw)
+    except json.JSONDecodeError:
+        return None
+    if not isinstance(data, dict):
+        return None
+    pid = data.get("pid")
+    if isinstance(pid, bool) or not isinstance(pid, int):
+        pid = None
+    token_hint = data.get("token_fingerprint")
+    if not isinstance(token_hint, str):
+        token_hint = None
+    return LockInfo(
+        pid=pid,
+        token_fingerprint=token_hint,
+    )
+
+
+def _write_lock_info(path: Path, *, pid: int, token_fingerprint: str | None) -> None:
+    payload = {"pid": pid, "token_fingerprint": token_fingerprint}
+    path.write_text(
+        json.dumps(payload, indent=2, sort_keys=True) + "\n", encoding="utf-8"
+    )
+
+
+def _pid_running(pid: int | None) -> bool:
+    if pid is None or pid <= 0:
+        return False
+    try:
+        os.kill(pid, 0)
+    except ProcessLookupError:
+        return False
+    except PermissionError:
+        return True
+    except OSError:
+        return False
+    return True
+
+
+def _format_lock_message(path: Path, state: str) -> str:
+    if state != "running":
+        return f"error: lock failed: {state}"
+    header = "error: already running"
+    display_path = _display_lock_path(path)
+    lines = [header, f"remove {display_path} if stale"]
+    return "\n".join(lines)
+
+
+def _display_lock_path(path: Path) -> str:
+    home = Path.home()
+    try:
+        resolved = path.expanduser().resolve()
+        rel = resolved.relative_to(home)
+        return f"~/{rel}"
+    except (ValueError, OSError):
+        return str(path)

tests/test_exec_bridge.py

@@ -29,32 +29,26 @@ def _patch_config(monkeypatch, config):
     monkeypatch.setattr(
         cli,
         "load_telegram_config",
-        lambda: (config, Path("takopi.toml")),
+        lambda *args, **kwargs: (config, Path("takopi.toml")),
     )
 
 
-def test_parse_bridge_config_rejects_empty_token(monkeypatch) -> None:
+def test_load_and_validate_config_rejects_empty_token(monkeypatch) -> None:
     from takopi import cli
 
     _patch_config(monkeypatch, {"bot_token": "   ", "chat_id": 123})
 
     with pytest.raises(cli.ConfigError, match="bot_token"):
-        cli._parse_bridge_config(
-            final_notify=True,
-            default_engine_override=None,
-        )
+        cli.load_and_validate_config()
 
 
-def test_parse_bridge_config_rejects_string_chat_id(monkeypatch) -> None:
+def test_load_and_validate_config_rejects_string_chat_id(monkeypatch) -> None:
     from takopi import cli
 
     _patch_config(monkeypatch, {"bot_token": "token", "chat_id": "123"})
 
     with pytest.raises(cli.ConfigError, match="chat_id"):
-        cli._parse_bridge_config(
-            final_notify=True,
-            default_engine_override=None,
-        )
+        cli.load_and_validate_config()
 
 
 def test_codex_extract_resume_finds_command() -> None:

tests/test_lockfile.py

@@ -0,0 +1,82 @@
+import json
+import os
+
+import pytest
+
+import takopi.lockfile as lockfile
+
+
+def test_lockfile_creates_and_cleans_up(tmp_path) -> None:
+    config_path = tmp_path / "takopi.toml"
+    config_path.write_text("ok", encoding="utf-8")
+
+    handle = lockfile.acquire_lock(
+        config_path=config_path,
+        token_fingerprint="deadbeef",
+    )
+    try:
+        assert lockfile.lock_path_for_config(config_path).exists()
+    finally:
+        handle.release()
+
+    assert not lockfile.lock_path_for_config(config_path).exists()
+
+
+def test_lockfile_refuses_running_pid(tmp_path) -> None:
+    config_path = tmp_path / "takopi.toml"
+    config_path.write_text("ok", encoding="utf-8")
+
+    handle = lockfile.acquire_lock(
+        config_path=config_path,
+        token_fingerprint="deadbeef",
+    )
+    try:
+        with pytest.raises(lockfile.LockError) as exc:
+            lockfile.acquire_lock(
+                config_path=config_path,
+                token_fingerprint="deadbeef",
+            )
+        message = str(exc.value).lower()
+        assert "already running" in message
+        assert str(lockfile.lock_path_for_config(config_path)) in str(exc.value)
+    finally:
+        handle.release()
+
+
+def test_lockfile_replaces_dead_pid(tmp_path, monkeypatch) -> None:
+    config_path = tmp_path / "takopi.toml"
+    config_path.write_text("ok", encoding="utf-8")
+    lock_path = lockfile.lock_path_for_config(config_path)
+    payload = {"pid": 424242, "token_fingerprint": "deadbeef"}
+    lock_path.write_text(json.dumps(payload), encoding="utf-8")
+
+    monkeypatch.setattr(lockfile, "_pid_running", lambda pid: False)
+
+    handle = lockfile.acquire_lock(
+        config_path=config_path,
+        token_fingerprint="deadbeef",
+    )
+    try:
+        updated = json.loads(lock_path.read_text(encoding="utf-8"))
+        assert updated["pid"] == os.getpid()
+        assert updated["token_fingerprint"] == "deadbeef"
+    finally:
+        handle.release()
+
+
+def test_lockfile_replaces_token_mismatch(tmp_path) -> None:
+    config_path = tmp_path / "takopi.toml"
+    config_path.write_text("ok", encoding="utf-8")
+    lock_path = lockfile.lock_path_for_config(config_path)
+    payload = {"pid": os.getpid(), "token_fingerprint": "other"}
+    lock_path.write_text(json.dumps(payload), encoding="utf-8")
+
+    handle = lockfile.acquire_lock(
+        config_path=config_path,
+        token_fingerprint="deadbeef",
+    )
+    try:
+        updated = json.loads(lock_path.read_text(encoding="utf-8"))
+        assert updated["token_fingerprint"] == "deadbeef"
+    finally:
+        handle.release()