"""
Output targets for streaming compositor.

Supports:
- Display window (preview)
- File output (recording)
- Stream output (RTMP, etc.) - future
- NVENC hardware encoding (auto-detected)
- CuPy GPU arrays (auto-converted to numpy for output)
"""

import numpy as np
import subprocess
from abc import ABC, abstractmethod
from typing import Tuple, Optional, List, Union
from pathlib import Path

# Try to import CuPy for GPU array support
try:
    import cupy as cp
    CUPY_AVAILABLE = True
except ImportError:
    cp = None
    CUPY_AVAILABLE = False


def ensure_numpy(frame: Union[np.ndarray, 'cp.ndarray']) -> np.ndarray:
    """Convert frame to numpy array if it's a CuPy array."""
    if CUPY_AVAILABLE and isinstance(frame, cp.ndarray):
        return cp.asnumpy(frame)
    return frame

# Cache NVENC availability check
_nvenc_available: Optional[bool] = None


def check_nvenc_available() -> bool:
    """Check if NVENC hardware encoding is available."""
    global _nvenc_available
    if _nvenc_available is not None:
        return _nvenc_available

    try:
        result = subprocess.run(
            ["ffmpeg", "-encoders"],
            capture_output=True,
            text=True,
            timeout=5
        )
        _nvenc_available = "h264_nvenc" in result.stdout
    except Exception:
        _nvenc_available = False

    return _nvenc_available


def get_encoder_params(codec: str, preset: str, crf: int) -> List[str]:
    """
    Get encoder-specific FFmpeg parameters.

    For NVENC (h264_nvenc, hevc_nvenc):
    - Uses -cq for constant quality (similar to CRF)
    - Presets: p1 (fastest) to p7 (slowest/best quality)
    - Mapping: fast->p4, medium->p5, slow->p6

    For libx264:
    - Uses -crf for constant rate factor
    - Presets: ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow
    """
    if codec in ("h264_nvenc", "hevc_nvenc"):
        # Map libx264 presets to NVENC presets
        nvenc_preset_map = {
            "ultrafast": "p1",
            "superfast": "p2",
            "veryfast": "p3",
            "faster": "p3",
            "fast": "p4",
            "medium": "p5",
            "slow": "p6",
            "slower": "p6",
            "veryslow": "p7",
        }
        nvenc_preset = nvenc_preset_map.get(preset, "p4")

        # NVENC quality: 0 (best) to 51 (worst), similar to CRF
        # CRF 18 = high quality, CRF 23 = good quality
        return [
            "-c:v", codec,
            "-preset", nvenc_preset,
            "-cq", str(crf),  # Constant quality mode
            "-rc", "vbr",     # Variable bitrate with quality target
        ]
    else:
        # Standard libx264 params
        return [
            "-c:v", codec,
            "-preset", preset,
            "-crf", str(crf),
        ]


class Output(ABC):
    """Abstract base class for output targets."""

    @abstractmethod
    def write(self, frame: np.ndarray, t: float):
        """Write a frame to the output."""
        pass

    @abstractmethod
    def close(self):
        """Close the output and clean up resources."""
        pass

    @property
    @abstractmethod
    def is_open(self) -> bool:
        """Check if output is still open/valid."""
        pass


class DisplayOutput(Output):
    """
    Display frames using mpv (handles Wayland properly).

    Useful for live preview. Press 'q' to quit.
    """

    def __init__(self, title: str = "Streaming Preview", size: Tuple[int, int] = None,
                 audio_source: str = None, fps: float = 30):
        self.title = title
        self.size = size
        self.audio_source = audio_source
        self.fps = fps
        self._is_open = True
        self._process = None
        self._audio_process = None

    def _start_mpv(self, frame_size: Tuple[int, int]):
        """Start mpv process for display."""
        import sys
        w, h = frame_size
        cmd = [
            "mpv",
            "--no-cache",
            "--demuxer=rawvideo",
            f"--demuxer-rawvideo-w={w}",
            f"--demuxer-rawvideo-h={h}",
            "--demuxer-rawvideo-mp-format=rgb24",
            f"--demuxer-rawvideo-fps={self.fps}",
            f"--title={self.title}",
            "-",
        ]
        print(f"Starting mpv: {' '.join(cmd)}", file=sys.stderr)
        self._process = subprocess.Popen(
            cmd,
            stdin=subprocess.PIPE,
            stderr=subprocess.PIPE,
        )

        # Start audio playback if we have an audio source
        if self.audio_source:
            audio_cmd = [
                "ffplay", "-nodisp", "-autoexit", "-loglevel", "quiet",
                str(self.audio_source)
            ]
            print(f"Starting audio: {self.audio_source}", file=sys.stderr)
            self._audio_process = subprocess.Popen(
                audio_cmd,
                stdout=subprocess.DEVNULL,
                stderr=subprocess.DEVNULL,
            )

    def write(self, frame: np.ndarray, t: float):
        """Display frame."""
        if not self._is_open:
            return

        # Convert GPU array to numpy if needed
        frame = ensure_numpy(frame)

        # Ensure frame is correct format
        if frame.dtype != np.uint8:
            frame = np.clip(frame, 0, 255).astype(np.uint8)
        if not frame.flags['C_CONTIGUOUS']:
            frame = np.ascontiguousarray(frame)

        # Start mpv on first frame
        if self._process is None:
            self._start_mpv((frame.shape[1], frame.shape[0]))

        # Check if mpv is still running
        if self._process.poll() is not None:
            self._is_open = False
            return

        try:
            self._process.stdin.write(frame.tobytes())
            self._process.stdin.flush()  # Prevent buffering
        except BrokenPipeError:
            self._is_open = False

    def close(self):
        """Close the display and audio."""
        if self._process:
            try:
                self._process.stdin.close()
            except:
                pass
            self._process.terminate()
            self._process.wait()
        if self._audio_process:
            self._audio_process.terminate()
            self._audio_process.wait()
        self._is_open = False

    @property
    def is_open(self) -> bool:
        if self._process and self._process.poll() is not None:
            self._is_open = False
        return self._is_open


class FileOutput(Output):
    """
    Write frames to a video file using ffmpeg.

    Automatically uses NVENC hardware encoding when available,
    falling back to libx264 CPU encoding otherwise.
    """

    def __init__(
        self,
        path: str,
        size: Tuple[int, int],
        fps: float = 30,
        codec: str = "auto",  # "auto", "h264_nvenc", "libx264"
        crf: int = 18,
        preset: str = "fast",
        audio_source: str = None,
    ):
        self.path = Path(path)
        self.size = size
        self.fps = fps
        self._is_open = True

        # Auto-detect NVENC
        if codec == "auto":
            codec = "h264_nvenc" if check_nvenc_available() else "libx264"
        self.codec = codec

        # Build ffmpeg command
        cmd = [
            "ffmpeg", "-y",
            "-f", "rawvideo",
            "-vcodec", "rawvideo",
            "-pix_fmt", "rgb24",
            "-s", f"{size[0]}x{size[1]}",
            "-r", str(fps),
            "-i", "-",
        ]

        # Add audio input if provided
        if audio_source:
            cmd.extend(["-i", str(audio_source)])
            # Explicitly map: video from input 0 (rawvideo), audio from input 1
            cmd.extend(["-map", "0:v", "-map", "1:a"])

        # Get encoder-specific params
        cmd.extend(get_encoder_params(codec, preset, crf))
        cmd.extend(["-pix_fmt", "yuv420p"])

        # Add audio codec if we have audio
        if audio_source:
            cmd.extend(["-c:a", "aac", "-b:a", "192k", "-shortest"])

        # Use fragmented mp4 for streamable output while writing
        if str(self.path).endswith('.mp4'):
            cmd.extend(["-movflags", "frag_keyframe+empty_moov+default_base_moof"])

        cmd.append(str(self.path))

        import sys
        print(f"FileOutput cmd: {' '.join(cmd)}", file=sys.stderr)
        self._process = subprocess.Popen(
            cmd,
            stdin=subprocess.PIPE,
            stderr=None,  # Show errors for debugging
        )

    def write(self, frame: np.ndarray, t: float):
        """Write frame to video file."""
        if not self._is_open or self._process.poll() is not None:
            self._is_open = False
            return

        # Convert GPU array to numpy if needed
        frame = ensure_numpy(frame)

        # Resize if needed
        if frame.shape[1] != self.size[0] or frame.shape[0] != self.size[1]:
            import cv2
            frame = cv2.resize(frame, self.size)

        # Ensure correct format
        if frame.dtype != np.uint8:
            frame = np.clip(frame, 0, 255).astype(np.uint8)
        if not frame.flags['C_CONTIGUOUS']:
            frame = np.ascontiguousarray(frame)

        try:
            self._process.stdin.write(frame.tobytes())
        except BrokenPipeError:
            self._is_open = False

    def close(self):
        """Close the video file."""
        if self._process:
            self._process.stdin.close()
            self._process.wait()
        self._is_open = False

    @property
    def is_open(self) -> bool:
        return self._is_open and self._process.poll() is None


class MultiOutput(Output):
    """
    Write to multiple outputs simultaneously.

    Useful for recording while showing preview.
    """

    def __init__(self, outputs: list):
        self.outputs = outputs

    def write(self, frame: np.ndarray, t: float):
        for output in self.outputs:
            if output.is_open:
                output.write(frame, t)

    def close(self):
        for output in self.outputs:
            output.close()

    @property
    def is_open(self) -> bool:
        return any(o.is_open for o in self.outputs)


class NullOutput(Output):
    """
    Discard frames (for benchmarking).
    """

    def __init__(self):
        self._is_open = True
        self.frame_count = 0

    def write(self, frame: np.ndarray, t: float):
        self.frame_count += 1

    def close(self):
        self._is_open = False

    @property
    def is_open(self) -> bool:
        return self._is_open


class PipeOutput(Output):
    """
    Pipe frames directly to mpv.

    Launches mpv with rawvideo demuxer and writes frames to stdin.
    """

    def __init__(self, size: Tuple[int, int], fps: float = 30, audio_source: str = None):
        self.size = size
        self.fps = fps
        self.audio_source = audio_source
        self._is_open = True
        self._process = None
        self._audio_process = None
        self._started = False

    def _start(self):
        """Start mpv and audio on first frame."""
        if self._started:
            return
        self._started = True

        import sys
        w, h = self.size

        # Start mpv
        cmd = [
            "mpv", "--no-cache",
            "--demuxer=rawvideo",
            f"--demuxer-rawvideo-w={w}",
            f"--demuxer-rawvideo-h={h}",
            "--demuxer-rawvideo-mp-format=rgb24",
            f"--demuxer-rawvideo-fps={self.fps}",
            "--title=Streaming",
            "-"
        ]
        print(f"Starting mpv: {w}x{h} @ {self.fps}fps", file=sys.stderr)
        self._process = subprocess.Popen(
            cmd,
            stdin=subprocess.PIPE,
            stderr=subprocess.DEVNULL,
        )

        # Start audio
        if self.audio_source:
            audio_cmd = [
                "ffplay", "-nodisp", "-autoexit", "-loglevel", "quiet",
                str(self.audio_source)
            ]
            print(f"Starting audio: {self.audio_source}", file=sys.stderr)
            self._audio_process = subprocess.Popen(
                audio_cmd,
                stdout=subprocess.DEVNULL,
                stderr=subprocess.DEVNULL,
            )

    def write(self, frame: np.ndarray, t: float):
        """Write frame to mpv."""
        if not self._is_open:
            return

        self._start()

        # Check mpv still running
        if self._process.poll() is not None:
            self._is_open = False
            return

        # Convert GPU array to numpy if needed
        frame = ensure_numpy(frame)

        # Resize if needed
        if frame.shape[1] != self.size[0] or frame.shape[0] != self.size[1]:
            import cv2
            frame = cv2.resize(frame, self.size)

        # Ensure correct format
        if frame.dtype != np.uint8:
            frame = np.clip(frame, 0, 255).astype(np.uint8)
        if not frame.flags['C_CONTIGUOUS']:
            frame = np.ascontiguousarray(frame)

        try:
            self._process.stdin.write(frame.tobytes())
            self._process.stdin.flush()
        except BrokenPipeError:
            self._is_open = False

    def close(self):
        """Close mpv and audio."""
        if self._process:
            try:
                self._process.stdin.close()
            except:
                pass
            self._process.terminate()
            self._process.wait()
        if self._audio_process:
            self._audio_process.terminate()
            self._audio_process.wait()
        self._is_open = False

    @property
    def is_open(self) -> bool:
        if self._process and self._process.poll() is not None:
            self._is_open = False
        return self._is_open


class HLSOutput(Output):
    """
    Write frames as HLS stream (m3u8 playlist + .ts segments).

    This enables true live streaming where the browser can poll
    for new segments as they become available.

    Automatically uses NVENC hardware encoding when available.
    """

    def __init__(
        self,
        output_dir: str,
        size: Tuple[int, int],
        fps: float = 30,
        segment_duration: float = 4.0,  # 4s segments for stability
        codec: str = "auto",  # "auto", "h264_nvenc", "libx264"
        crf: int = 23,
        preset: str = "fast",  # Better quality than ultrafast
        audio_source: str = None,
    ):
        self.output_dir = Path(output_dir)
        self.output_dir.mkdir(parents=True, exist_ok=True)
        self.size = size
        self.fps = fps
        self.segment_duration = segment_duration
        self._is_open = True

        # Auto-detect NVENC
        if codec == "auto":
            codec = "h264_nvenc" if check_nvenc_available() else "libx264"
        self.codec = codec

        # HLS playlist path
        self.playlist_path = self.output_dir / "stream.m3u8"

        # Build ffmpeg command for HLS output
        cmd = [
            "ffmpeg", "-y",
            "-f", "rawvideo",
            "-vcodec", "rawvideo",
            "-pix_fmt", "rgb24",
            "-s", f"{size[0]}x{size[1]}",
            "-r", str(fps),
            "-i", "-",
        ]

        # Add audio input if provided
        if audio_source:
            cmd.extend(["-i", str(audio_source)])
            cmd.extend(["-map", "0:v", "-map", "1:a"])

        # Keyframe interval - must be exactly segment_duration for clean cuts
        gop_size = int(fps * segment_duration)

        # Get encoder-specific params
        cmd.extend(get_encoder_params(codec, preset, crf))
        cmd.extend([
            "-pix_fmt", "yuv420p",
            # Force keyframes at exact intervals for clean segment boundaries
            "-g", str(gop_size),
            "-keyint_min", str(gop_size),
            "-sc_threshold", "0",  # Disable scene change detection
            "-force_key_frames", f"expr:gte(t,n_forced*{segment_duration})",
            # Reduce buffering for faster segment availability
            "-flush_packets", "1",
        ])

        # Add audio codec if we have audio
        if audio_source:
            cmd.extend(["-c:a", "aac", "-b:a", "128k"])

        # HLS specific options for smooth live streaming
        cmd.extend([
            "-f", "hls",
            "-hls_time", str(segment_duration),
            "-hls_list_size", "0",  # Keep all segments in playlist
            "-hls_flags", "independent_segments+append_list+split_by_time",
            "-hls_segment_type", "mpegts",
            "-hls_segment_filename", str(self.output_dir / "segment_%05d.ts"),
            str(self.playlist_path),
        ])

        import sys
        print(f"HLSOutput cmd: {' '.join(cmd)}", file=sys.stderr)
        self._process = subprocess.Popen(
            cmd,
            stdin=subprocess.PIPE,
            stderr=None,  # Show errors for debugging
        )

        # Track segments for status reporting
        self.segments_written = 0
        self._last_segment_check = 0

    def write(self, frame: np.ndarray, t: float):
        """Write frame to HLS stream."""
        if not self._is_open or self._process.poll() is not None:
            self._is_open = False
            return

        # Convert GPU array to numpy if needed
        frame = ensure_numpy(frame)

        # Resize if needed
        if frame.shape[1] != self.size[0] or frame.shape[0] != self.size[1]:
            import cv2
            frame = cv2.resize(frame, self.size)

        # Ensure correct format
        if frame.dtype != np.uint8:
            frame = np.clip(frame, 0, 255).astype(np.uint8)
        if not frame.flags['C_CONTIGUOUS']:
            frame = np.ascontiguousarray(frame)

        try:
            self._process.stdin.write(frame.tobytes())
        except BrokenPipeError:
            self._is_open = False

        # Periodically count segments
        if t - self._last_segment_check > 1.0:
            self._last_segment_check = t
            self.segments_written = len(list(self.output_dir.glob("segment_*.ts")))

    def close(self):
        """Close the HLS stream."""
        if self._process:
            self._process.stdin.close()
            self._process.wait()
        self._is_open = False

        # Final segment count
        self.segments_written = len(list(self.output_dir.glob("segment_*.ts")))

        # Mark playlist as ended (VOD mode)
        if self.playlist_path.exists():
            with open(self.playlist_path, "a") as f:
                f.write("#EXT-X-ENDLIST\n")

    @property
    def is_open(self) -> bool:
        return self._is_open and self._process.poll() is None


class IPFSHLSOutput(Output):
    """
    Write frames as HLS stream with segments uploaded to IPFS.

    Each segment is uploaded to IPFS as it's created, enabling distributed
    streaming where clients can fetch segments from any IPFS gateway.

    The m3u8 playlist is continuously updated with IPFS URLs and can be
    fetched via get_playlist() or the playlist_cid property.
    """

    def __init__(
        self,
        output_dir: str,
        size: Tuple[int, int],
        fps: float = 30,
        segment_duration: float = 4.0,
        codec: str = "auto",
        crf: int = 23,
        preset: str = "fast",
        audio_source: str = None,
        ipfs_gateway: str = "https://ipfs.io/ipfs",
    ):
        self.output_dir = Path(output_dir)
        self.output_dir.mkdir(parents=True, exist_ok=True)
        self.size = size
        self.fps = fps
        self.segment_duration = segment_duration
        self.ipfs_gateway = ipfs_gateway.rstrip("/")
        self._is_open = True

        # Auto-detect NVENC
        if codec == "auto":
            codec = "h264_nvenc" if check_nvenc_available() else "libx264"
        self.codec = codec

        # Track segment CIDs
        self.segment_cids: dict = {}  # segment_number -> cid
        self._last_segment_checked = -1
        self._playlist_cid: Optional[str] = None

        # Import IPFS client
        from ipfs_client import add_file, add_bytes
        self._ipfs_add_file = add_file
        self._ipfs_add_bytes = add_bytes

        # Local HLS paths
        self.local_playlist_path = self.output_dir / "stream.m3u8"

        # Build ffmpeg command for HLS output
        cmd = [
            "ffmpeg", "-y",
            "-f", "rawvideo",
            "-vcodec", "rawvideo",
            "-pix_fmt", "rgb24",
            "-s", f"{size[0]}x{size[1]}",
            "-r", str(fps),
            "-i", "-",
        ]

        # Add audio input if provided
        if audio_source:
            cmd.extend(["-i", str(audio_source)])
            cmd.extend(["-map", "0:v", "-map", "1:a"])

        # Keyframe interval
        gop_size = int(fps * segment_duration)

        # Get encoder-specific params
        cmd.extend(get_encoder_params(codec, preset, crf))
        cmd.extend([
            "-pix_fmt", "yuv420p",
            "-g", str(gop_size),
            "-keyint_min", str(gop_size),
            "-sc_threshold", "0",
            "-force_key_frames", f"expr:gte(t,n_forced*{segment_duration})",
            "-flush_packets", "1",
        ])

        # Add audio codec if we have audio
        if audio_source:
            cmd.extend(["-c:a", "aac", "-b:a", "128k"])

        # HLS options
        cmd.extend([
            "-f", "hls",
            "-hls_time", str(segment_duration),
            "-hls_list_size", "0",
            "-hls_flags", "independent_segments+append_list+split_by_time",
            "-hls_segment_type", "mpegts",
            "-hls_segment_filename", str(self.output_dir / "segment_%05d.ts"),
            str(self.local_playlist_path),
        ])

        import sys
        print(f"IPFSHLSOutput: starting ffmpeg", file=sys.stderr)
        self._process = subprocess.Popen(
            cmd,
            stdin=subprocess.PIPE,
            stderr=None,
        )

    def _upload_new_segments(self):
        """Check for new segments and upload them to IPFS."""
        import sys

        # Find all segments
        segments = sorted(self.output_dir.glob("segment_*.ts"))

        for seg_path in segments:
            # Extract segment number from filename
            seg_name = seg_path.stem  # segment_00000
            seg_num = int(seg_name.split("_")[1])

            # Skip if already uploaded
            if seg_num in self.segment_cids:
                continue

            # Skip if segment is still being written (check if file size is stable)
            try:
                size1 = seg_path.stat().st_size
                if size1 == 0:
                    continue  # Empty file, still being created

                import time
                time.sleep(0.1)
                size2 = seg_path.stat().st_size
                if size1 != size2:
                    continue  # File still being written
            except FileNotFoundError:
                continue

            # Upload to IPFS
            cid = self._ipfs_add_file(seg_path, pin=True)
            if cid:
                self.segment_cids[seg_num] = cid
                print(f"IPFS: segment_{seg_num:05d}.ts -> {cid}", file=sys.stderr)

                # Update playlist after each segment upload
                self._update_ipfs_playlist()

    def _update_ipfs_playlist(self):
        """Generate and upload IPFS-aware m3u8 playlist."""
        if not self.segment_cids:
            return

        import sys

        # Build m3u8 content with IPFS URLs
        lines = [
            "#EXTM3U",
            "#EXT-X-VERSION:3",
            f"#EXT-X-TARGETDURATION:{int(self.segment_duration) + 1}",
            "#EXT-X-MEDIA-SEQUENCE:0",
        ]

        # Add segments in order
        for seg_num in sorted(self.segment_cids.keys()):
            cid = self.segment_cids[seg_num]
            lines.append(f"#EXTINF:{self.segment_duration:.3f},")
            lines.append(f"{self.ipfs_gateway}/{cid}")

        playlist_content = "\n".join(lines) + "\n"

        # Upload playlist to IPFS
        cid = self._ipfs_add_bytes(playlist_content.encode("utf-8"), pin=True)
        if cid:
            self._playlist_cid = cid
            print(f"IPFS: playlist updated -> {cid} ({len(self.segment_cids)} segments)", file=sys.stderr)

    def write(self, frame: np.ndarray, t: float):
        """Write frame to HLS stream and upload segments to IPFS."""
        if not self._is_open or self._process.poll() is not None:
            self._is_open = False
            return

        # Convert GPU array to numpy if needed
        frame = ensure_numpy(frame)

        # Resize if needed
        if frame.shape[1] != self.size[0] or frame.shape[0] != self.size[1]:
            import cv2
            frame = cv2.resize(frame, self.size)

        # Ensure correct format
        if frame.dtype != np.uint8:
            frame = np.clip(frame, 0, 255).astype(np.uint8)
        if not frame.flags['C_CONTIGUOUS']:
            frame = np.ascontiguousarray(frame)

        try:
            self._process.stdin.write(frame.tobytes())
        except BrokenPipeError:
            self._is_open = False
            return

        # Check for new segments periodically (every second)
        current_segment = int(t / self.segment_duration)
        if current_segment > self._last_segment_checked:
            self._last_segment_checked = current_segment
            self._upload_new_segments()

    def close(self):
        """Close the HLS stream and finalize IPFS uploads."""
        import sys

        if self._process:
            self._process.stdin.close()
            self._process.wait()
        self._is_open = False

        # Upload any remaining segments
        self._upload_new_segments()

        # Generate final playlist with #EXT-X-ENDLIST
        if self.segment_cids:
            lines = [
                "#EXTM3U",
                "#EXT-X-VERSION:3",
                f"#EXT-X-TARGETDURATION:{int(self.segment_duration) + 1}",
                "#EXT-X-MEDIA-SEQUENCE:0",
                "#EXT-X-PLAYLIST-TYPE:VOD",
            ]

            for seg_num in sorted(self.segment_cids.keys()):
                cid = self.segment_cids[seg_num]
                lines.append(f"#EXTINF:{self.segment_duration:.3f},")
                lines.append(f"{self.ipfs_gateway}/{cid}")

            lines.append("#EXT-X-ENDLIST")
            playlist_content = "\n".join(lines) + "\n"

            cid = self._ipfs_add_bytes(playlist_content.encode("utf-8"), pin=True)
            if cid:
                self._playlist_cid = cid
                print(f"IPFS: final playlist -> {cid} ({len(self.segment_cids)} segments)", file=sys.stderr)

    @property
    def playlist_cid(self) -> Optional[str]:
        """Get the current playlist CID."""
        return self._playlist_cid

    @property
    def playlist_url(self) -> Optional[str]:
        """Get the full IPFS URL for the playlist."""
        if self._playlist_cid:
            return f"{self.ipfs_gateway}/{self._playlist_cid}"
        return None

    def get_playlist(self) -> str:
        """Get the current m3u8 playlist content with IPFS URLs."""
        if not self.segment_cids:
            return "#EXTM3U\n"

        lines = [
            "#EXTM3U",
            "#EXT-X-VERSION:3",
            f"#EXT-X-TARGETDURATION:{int(self.segment_duration) + 1}",
            "#EXT-X-MEDIA-SEQUENCE:0",
        ]

        for seg_num in sorted(self.segment_cids.keys()):
            cid = self.segment_cids[seg_num]
            lines.append(f"#EXTINF:{self.segment_duration:.3f},")
            lines.append(f"{self.ipfs_gateway}/{cid}")

        if not self._is_open:
            lines.append("#EXT-X-ENDLIST")

        return "\n".join(lines) + "\n"

    @property
    def is_open(self) -> bool:
        return self._is_open and self._process.poll() is None