Medios-Macina/MPV/mpv_ipc.py

"""MPV IPC client for cross-platform communication.

This module provides a cross-platform interface to communicate with mpv
using either named pipes (Windows) or Unix domain sockets (Linux/macOS).

This is the central hub for all Python-mpv IPC communication. The Lua script
should use the Python CLI, which uses this module to manage mpv connections.
"""

import json
import os
import platform
import socket
import subprocess
import sys
import time as _time
import shutil
from pathlib import Path
from typing import Any, Dict, Optional, List, BinaryIO, Tuple, cast

from SYS.logger import debug


# Fixed pipe name for persistent MPV connection across all Python sessions
FIXED_IPC_PIPE_NAME = "mpv-medeia-macina"
MPV_LUA_SCRIPT_PATH = str(Path(__file__).resolve().parent / "LUA" / "main.lua")


_LYRIC_PROCESS: Optional[subprocess.Popen] = None
_LYRIC_LOG_FH: Optional[Any] = None


_MPV_AVAILABILITY_CACHE: Optional[Tuple[bool, Optional[str]]] = None


def _check_mpv_availability() -> Tuple[bool, Optional[str]]:
    """Return (available, reason) for the mpv executable.

    This checks that:
    - `mpv` is present in PATH
    - `mpv --version` can run successfully

    Result is cached per-process to avoid repeated subprocess calls.
    """
    global _MPV_AVAILABILITY_CACHE
    if _MPV_AVAILABILITY_CACHE is not None:
        return _MPV_AVAILABILITY_CACHE

    mpv_path = shutil.which("mpv")
    if not mpv_path:
        _MPV_AVAILABILITY_CACHE = (False, "Executable 'mpv' not found in PATH")
        return _MPV_AVAILABILITY_CACHE

    try:
        result = subprocess.run(
            [mpv_path, "--version"],
            capture_output=True,
            text=True,
            timeout=2,
        )
        if result.returncode == 0:
            _MPV_AVAILABILITY_CACHE = (True, None)
            return _MPV_AVAILABILITY_CACHE
        _MPV_AVAILABILITY_CACHE = (False, f"MPV returned non-zero exit code: {result.returncode}")
        return _MPV_AVAILABILITY_CACHE
    except Exception as exc:
        _MPV_AVAILABILITY_CACHE = (False, f"Error running MPV: {exc}")
        return _MPV_AVAILABILITY_CACHE


def _windows_list_lyric_helper_pids(ipc_path: str) -> List[int]:
    """Return PIDs of `python -m MPV.lyric --ipc <ipc_path>` helpers (Windows only)."""
    if platform.system() != "Windows":
        return []
    try:
        ipc_path = str(ipc_path or "")
    except Exception:
        ipc_path = ""
    if not ipc_path:
        return []

    # Use CIM to query command lines; output as JSON for robust parsing.
    # Note: `ConvertTo-Json` returns a number for single item, array for many, or null.
    ps_script = (
        "$ipc = "
        + json.dumps(ipc_path)
        + "; "
        "Get-CimInstance Win32_Process | "
        "Where-Object { $_.CommandLine -and $_.CommandLine -match ' -m\\s+MPV\\.lyric(\\s|$)' -and $_.CommandLine -match ('--ipc\\s+' + [regex]::Escape($ipc)) } | "
        "Select-Object -ExpandProperty ProcessId | ConvertTo-Json -Compress"
    )

    try:
        out = subprocess.check_output(
            ["powershell", "-NoProfile", "-Command", ps_script],
            stdin=subprocess.DEVNULL,
            stderr=subprocess.DEVNULL,
            timeout=2,
            text=True,
        )
    except Exception:
        return []

    txt = (out or "").strip()
    if not txt or txt == "null":
        return []
    try:
        obj = json.loads(txt)
    except Exception:
        return []

    pids: List[int] = []
    if isinstance(obj, list):
        for v in obj:
            try:
                pids.append(int(v))
            except Exception:
                pass
    else:
        try:
            pids.append(int(obj))
        except Exception:
            pass

    # De-dupe and filter obvious junk.
    uniq: List[int] = []
    for pid in pids:
        if pid and pid > 0 and pid not in uniq:
            uniq.append(pid)
    return uniq


def _windows_kill_pids(pids: List[int]) -> None:
    if platform.system() != "Windows":
        return
    for pid in pids or []:
        try:
            subprocess.run(
                ["taskkill", "/PID", str(int(pid)), "/F"],
                stdin=subprocess.DEVNULL,
                stdout=subprocess.DEVNULL,
                stderr=subprocess.DEVNULL,
                timeout=2,
            )
        except Exception:
            continue


class MPVIPCError(Exception):
    """Raised when MPV IPC communication fails."""
    pass


class MPV:
    """High-level MPV controller for this app.

    Responsibilities:
    - Own the IPC pipe/socket path
    - Start MPV with the bundled Lua script
    - Query playlist and currently playing item via IPC

    This class intentionally stays "dumb": it does not implement app logic.
    App behavior is driven by cmdlet (e.g. `.pipe`) and the bundled Lua script.
    """

    def __init__(
        self,
        ipc_path: Optional[str] = None,
        lua_script_path: Optional[str | Path] = None,
        timeout: float = 5.0,
    ) -> None:

        ok, reason = _check_mpv_availability()
        if not ok:
            raise MPVIPCError(reason or "MPV unavailable")

        self.timeout = timeout
        self.ipc_path = ipc_path or get_ipc_pipe_path()

        if lua_script_path is None:
            lua_script_path = MPV_LUA_SCRIPT_PATH
        lua_path = Path(str(lua_script_path)).resolve()
        self.lua_script_path = str(lua_path)

    def client(self, silent: bool = False) -> "MPVIPCClient":
        return MPVIPCClient(socket_path=self.ipc_path, timeout=self.timeout, silent=bool(silent))

    def is_running(self) -> bool:
        client = self.client(silent=True)
        try:
            ok = client.connect()
            return bool(ok)
        finally:
            client.disconnect()

    def send(self, command: Dict[str, Any] | List[Any], silent: bool = False) -> Optional[Dict[str, Any]]:
        client = self.client(silent=bool(silent))
        try:
            if not client.connect():
                return None
            return client.send_command(command)
        except Exception as exc:
            if not silent:
                debug(f"MPV IPC error: {exc}")
            return None
        finally:
            client.disconnect()

    def get_property(self, name: str, default: Any = None) -> Any:
        resp = self.send({"command": ["get_property", name]})
        if resp and resp.get("error") == "success":
            return resp.get("data", default)
        return default

    def set_property(self, name: str, value: Any) -> bool:
        resp = self.send({"command": ["set_property", name, value]})
        return bool(resp and resp.get("error") == "success")

    def get_playlist(self, silent: bool = False) -> Optional[List[Dict[str, Any]]]:
        resp = self.send({"command": ["get_property", "playlist"], "request_id": 100}, silent=silent)
        if resp is None:
            return None
        if resp.get("error") == "success":
            data = resp.get("data", [])
            return data if isinstance(data, list) else []
        return []

    def get_now_playing(self) -> Optional[Dict[str, Any]]:
        if not self.is_running():
            return None

        playlist = self.get_playlist(silent=True) or []
        pos = self.get_property("playlist-pos", None)
        path = self.get_property("path", None)
        title = self.get_property("media-title", None)

        effective_path = _unwrap_memory_target(path) if isinstance(path, str) else path

        current_item: Optional[Dict[str, Any]] = None
        if isinstance(pos, int) and 0 <= pos < len(playlist):
            item = playlist[pos]
            current_item = item if isinstance(item, dict) else None
        else:
            for item in playlist:
                if isinstance(item, dict) and item.get("current") is True:
                    current_item = item
                    break

        return {
            "path": effective_path,
            "title": title,
            "playlist_pos": pos,
            "playlist_item": current_item,
        }

    def ensure_lua_loaded(self) -> None:
        try:
            script_path = self.lua_script_path
            if not script_path or not os.path.exists(script_path):
                return
            # Safe to call repeatedly; mpv will reload the script.
            self.send({"command": ["load-script", script_path], "request_id": 12}, silent=True)
        except Exception:
            return

    def ensure_lyric_loader_running(self) -> None:
        """Start (or keep) the Python lyric overlay helper.

        Uses the fixed IPC pipe name so it can follow playback.
        """
        global _LYRIC_PROCESS, _LYRIC_LOG_FH

        # Cross-session guard (Windows): avoid spawning multiple helpers across separate CLI runs.
        # Also clean up stale helpers when mpv isn't running anymore.
        if platform.system() == "Windows":
            try:
                existing = _windows_list_lyric_helper_pids(str(self.ipc_path))
                if existing:
                    if not self.is_running():
                        _windows_kill_pids(existing)
                        return
                    # If multiple exist, kill them and start fresh (prevents double overlays).
                    if len(existing) == 1:
                        return
                    _windows_kill_pids(existing)
            except Exception:
                pass

        try:
            if _LYRIC_PROCESS is not None and _LYRIC_PROCESS.poll() is None:
                return
        except Exception:
            pass

        try:
            if _LYRIC_PROCESS is not None:
                try:
                    _LYRIC_PROCESS.terminate()
                except Exception:
                    pass
        finally:
            _LYRIC_PROCESS = None
            try:
                if _LYRIC_LOG_FH is not None:
                    _LYRIC_LOG_FH.close()
            except Exception:
                pass
            _LYRIC_LOG_FH = None

        try:
            try:
                tmp_dir = Path(os.environ.get("TEMP") or os.environ.get("TMP") or ".")
            except Exception:
                tmp_dir = Path(".")
            log_path = str((tmp_dir / "medeia-mpv-lyric.log").resolve())

            # Ensure the module can be imported even when the app is launched from a different cwd.
            # Repo root = parent of the MPV package directory.
            try:
                repo_root = Path(__file__).resolve().parent.parent
            except Exception:
                repo_root = Path.cwd()

            cmd: List[str] = [
                sys.executable,
                "-m",
                "MPV.lyric",
                "--ipc",
                str(self.ipc_path),
                "--log",
                log_path,
            ]

            # Redirect helper stdout/stderr to the log file so we can see crashes/import errors.
            try:
                _LYRIC_LOG_FH = open(log_path, "a", encoding="utf-8", errors="replace")
            except Exception:
                _LYRIC_LOG_FH = None

            kwargs: Dict[str, Any] = {
                "stdin": subprocess.DEVNULL,
                "stdout": _LYRIC_LOG_FH or subprocess.DEVNULL,
                "stderr": _LYRIC_LOG_FH or subprocess.DEVNULL,
            }

            # Ensure immediate flushing to the log file.
            env = os.environ.copy()
            env["PYTHONUNBUFFERED"] = "1"
            try:
                existing_pp = env.get("PYTHONPATH")
                env["PYTHONPATH"] = str(repo_root) if not existing_pp else (str(repo_root) + os.pathsep + str(existing_pp))
            except Exception:
                pass
            kwargs["env"] = env

            # Make the current directory the repo root so `-m MPV.lyric` resolves reliably.
            kwargs["cwd"] = str(repo_root)
            if platform.system() == "Windows":
                kwargs["creationflags"] = 0x00000008  # DETACHED_PROCESS

            _LYRIC_PROCESS = subprocess.Popen(cmd, **kwargs)
            debug(f"Lyric loader started (log={log_path})")
        except Exception as exc:
            debug(f"Lyric loader failed to start: {exc}")

    def wait_for_ipc(self, retries: int = 20, delay_seconds: float = 0.2) -> bool:
        for _ in range(max(1, retries)):
            client = self.client(silent=True)
            try:
                if client.connect():
                    return True
            finally:
                client.disconnect()
            _time.sleep(delay_seconds)
        return False

    def kill_existing_windows(self) -> None:
        if platform.system() != "Windows":
            return
        try:
            subprocess.run(
                ["taskkill", "/IM", "mpv.exe", "/F"],
                stdin=subprocess.DEVNULL,
                stdout=subprocess.DEVNULL,
                stderr=subprocess.DEVNULL,
                timeout=2,
            )
        except Exception:
            return

    def start(
        self,
        *,
        extra_args: Optional[List[str]] = None,
        ytdl_raw_options: Optional[str] = None,
        http_header_fields: Optional[str] = None,
        detached: bool = True,
    ) -> None:
        cmd: List[str] = [
            "mpv",
            f"--input-ipc-server={self.ipc_path}",
            "--idle=yes",
            "--force-window=yes",
        ]

        # Always load the bundled Lua script at startup.
        if self.lua_script_path and os.path.exists(self.lua_script_path):
            cmd.append(f"--script={self.lua_script_path}")

        if ytdl_raw_options:
            cmd.append(f"--ytdl-raw-options={ytdl_raw_options}")
        if http_header_fields:
            cmd.append(f"--http-header-fields={http_header_fields}")
        if extra_args:
            cmd.extend([str(a) for a in extra_args if a])

        kwargs: Dict[str, Any] = {}
        if detached and platform.system() == "Windows":
            kwargs["creationflags"] = 0x00000008  # DETACHED_PROCESS

        debug("Starting MPV")
        subprocess.Popen(cmd, stdin=subprocess.DEVNULL, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, **kwargs)


def get_ipc_pipe_path() -> str:
    """Get the fixed IPC pipe/socket path for persistent MPV connection.
    
    Uses a fixed name so all playback sessions connect to the same MPV
    window/process instead of creating new instances.
    
    Returns:
        Path to IPC pipe (Windows) or socket (Linux/macOS)
    """
    system = platform.system()
    
    if system == "Windows":
        return f"\\\\.\\pipe\\{FIXED_IPC_PIPE_NAME}"
    elif system == "Darwin":  # macOS
        return f"/tmp/{FIXED_IPC_PIPE_NAME}.sock"
    else:  # Linux and others
        return f"/tmp/{FIXED_IPC_PIPE_NAME}.sock"


def _unwrap_memory_target(text: Optional[str]) -> Optional[str]:
    """Return the real target from a memory:// M3U payload if present."""
    if not isinstance(text, str) or not text.startswith("memory://"):
        return text
    for line in text.splitlines():
        line = line.strip()
        if not line or line.startswith('#') or line.startswith('memory://'):
            continue
        return line
    return text


class MPVIPCClient:
    """Client for communicating with mpv via IPC socket/pipe.
    
    This is the unified interface for all Python code to communicate with mpv.
    It handles platform-specific differences (Windows named pipes vs Unix sockets).
    """
    
    def __init__(self, socket_path: Optional[str] = None, timeout: float = 5.0, silent: bool = False):
        """Initialize MPV IPC client.
        
        Args:
            socket_path: Path to IPC socket/pipe. If None, uses the fixed persistent path.
            timeout: Socket timeout in seconds.
        """
        self.timeout = timeout
        self.socket_path = socket_path or get_ipc_pipe_path()
        self.sock: socket.socket | BinaryIO | None = None
        self.is_windows = platform.system() == "Windows"
        self.silent = bool(silent)
    
    def connect(self) -> bool:
        """Connect to mpv IPC socket.
        
        Returns:
            True if connection successful, False otherwise.
        """
        try:
            if self.is_windows:
                # Windows named pipes
                try:
                    # Try to open the named pipe
                    self.sock = open(self.socket_path, 'r+b', buffering=0)
                    return True
                except (OSError, IOError) as exc:
                    if not self.silent:
                        debug(f"Failed to connect to MPV named pipe: {exc}")
                    return False
            else:
                # Unix domain socket (Linux, macOS)
                if not os.path.exists(self.socket_path):
                    if not self.silent:
                        debug(f"IPC socket not found: {self.socket_path}")
                    return False

                af_unix = getattr(socket, "AF_UNIX", None)
                if af_unix is None:
                    if not self.silent:
                        debug("IPC AF_UNIX is not available on this platform")
                    return False

                self.sock = socket.socket(af_unix, socket.SOCK_STREAM)
                self.sock.settimeout(self.timeout)
                self.sock.connect(self.socket_path)
                return True
        except Exception as exc:
            if not self.silent:
                debug(f"Failed to connect to MPV IPC: {exc}")
            self.sock = None
            return False
    
    def send_command(self, command_data: Dict[str, Any] | List[Any]) -> Optional[Dict[str, Any]]:
        """Send a command to mpv and get response.
        
        Args:
            command_data: Command dict (e.g. {"command": [...]}) or list (e.g. ["loadfile", ...])
        
        Returns:
            Response dict with 'error' key (value 'success' on success), or None on error.
        """
        if not self.sock:
            if not self.connect():
                return None
        
        try:
            # Format command as JSON (mpv IPC protocol)
            request: Dict[str, Any]
            if isinstance(command_data, list):
                request = {"command": command_data}
            else:
                request = command_data
                
            # Add request_id if not present to match response
            if "request_id" not in request:
                request["request_id"] = int(_time.time() * 1000) % 100000
                
            payload = json.dumps(request) + "\n"
            
            # Debug: log the command being sent
            from SYS.logger import debug as _debug
            _debug(f"[IPC] Sending: {payload.strip()}")
            
            # Send command
            if self.is_windows:
                pipe = cast(BinaryIO, self.sock)
                pipe.write(payload.encode("utf-8"))
                pipe.flush()
            else:
                sock_obj = cast(socket.socket, self.sock)
                sock_obj.sendall(payload.encode("utf-8"))
            
            # Receive response
            # We need to read lines until we find the one with matching request_id
            # or until timeout/error. MPV might send events in between.
            start_time = _time.time()
            while _time.time() - start_time < self.timeout:
                response_data = b""
                if self.is_windows:
                    try:
                        pipe = cast(BinaryIO, self.sock)
                        response_data = pipe.readline()
                    except (OSError, IOError):
                        return None
                else:
                    try:
                        # This is simplistic for Unix socket (might not get full line)
                        # But for now assuming MPV sends line-buffered JSON
                        sock_obj = cast(socket.socket, self.sock)
                        chunk = sock_obj.recv(4096)
                        if not chunk:
                            break
                        response_data = chunk
                        # TODO: Handle partial lines if needed
                    except socket.timeout:
                        return None
                
                if not response_data:
                    break
                    
                try:
                    lines = response_data.decode('utf-8').strip().split('\n')
                    for line in lines:
                        if not line: continue
                        resp = json.loads(line)
                        
                        # Debug: log responses
                        from SYS.logger import debug as _debug
                        _debug(f"[IPC] Received: {line}")
                        
                        # Check if this is the response to our request
                        if resp.get("request_id") == request.get("request_id"):
                            return resp

                        # Handle async log messages/events for visibility
                        event_type = resp.get("event")
                        if event_type == "log-message":
                            level = resp.get("level", "info")
                            prefix = resp.get("prefix", "")
                            text = resp.get("text", "").strip()
                            debug(f"[MPV {level}] {prefix} {text}".strip())
                        elif event_type:
                            debug(f"[MPV event] {event_type}: {resp}")
                        elif "error" in resp and "request_id" not in resp:
                            debug(f"[MPV error] {resp}")
                except json.JSONDecodeError:
                    pass
                    
            return None
        except Exception as exc:
            debug(f"Error sending command to MPV: {exc}")
            self.disconnect()
            return None
    
    def disconnect(self) -> None:
        """Disconnect from mpv IPC socket."""
        if self.sock:
            try:
                self.sock.close()
            except Exception:
                pass
            self.sock = None
    
    def __del__(self) -> None:
        """Cleanup on object destruction."""
        self.disconnect()
    
    def __enter__(self):
        """Context manager entry."""
        self.connect()
        return self
    
    def __exit__(self, exc_type, exc_val, exc_tb):
        """Context manager exit."""
        self.disconnect()