"""System metrics ingestion."""
import subprocess
import logging
from datetime import datetime, timezone

import psutil

from ..models import MetricSnapshot

logger = logging.getLogger(__name__)


class SystemMetricsIngestor:
    """Collect system metrics."""

    def get_snapshot(self) -> MetricSnapshot:
        """Capture current system metrics."""
        try:
            cpu = psutil.cpu_percent(interval=0.1)
            memory = psutil.virtual_memory()
            disk = psutil.disk_usage("/")
            load = psutil.getloadavg()
            net = psutil.net_io_counters()
            
            # Top processes by CPU
            processes = []
            for proc in psutil.process_iter(["pid", "name", "cpu_percent", "memory_percent"]):
                try:
                    processes.append({
                        "pid": proc.info["pid"],
                        "name": proc.info["name"],
                        "cpu": proc.info["cpu_percent"],
                        "memory": proc.info["memory_percent"],
                    })
                except (psutil.NoSuchProcess, psutil.AccessDenied):
                    pass
            
            # Sort by CPU, take top 10
            processes.sort(key=lambda p: p.get("cpu", 0) or 0, reverse=True)
            
            return MetricSnapshot(
                timestamp=datetime.now(timezone.utc),
                cpu_percent=cpu,
                memory_percent=memory.percent,
                disk_percent=disk.percent,
                load_avg=load,
                network_bytes_in=net.bytes_sent,
                network_bytes_out=net.bytes_recv,
                top_processes=processes[:10],
            )
        except Exception as e:
            logger.error("Failed to collect metrics: %s", e)
            return MetricSnapshot(timestamp=datetime.now(timezone.utc))

    def get_process_info(self, pattern: str) -> list[dict]:
        """Get processes matching a name pattern."""
        processes = []
        for proc in psutil.process_iter(["pid", "name", "cpu_percent", "memory_percent", "create_time", "status"]):
            try:
                if pattern.lower() in (proc.info["name"] or "").lower():
                    processes.append({
                        "pid": proc.info["pid"],
                        "name": proc.info["name"],
                        "cpu": proc.info["cpu_percent"],
                        "memory": proc.info["memory_percent"],
                        "status": proc.info["status"],
                        "created": datetime.fromtimestamp(
                            proc.info["create_time"], tz=timezone.utc
                        ).isoformat() if proc.info["create_time"] else "unknown",
                    })
            except (psutil.NoSuchProcess, psutil.AccessDenied):
                pass
        return processes

    def get_disk_io(self) -> dict:
        """Get disk I/O counters."""
        try:
            counters = psutil.disk_io_counters()
            if counters:
                return {
                    "read_count": counters.read_count,
                    "write_count": counters.write_count,
                    "read_bytes": counters.read_bytes,
                    "write_bytes": counters.write_bytes,
                    "read_time": counters.read_time,
                    "write_time": counters.write_time,
                }
        except Exception as e:
            logger.warning("Failed to get disk IO: %s", e)
        return {}

    def get_open_files_summary(self) -> dict:
        """Get summary of open file descriptors."""
        try:
            import resource
            soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
            return {"soft_limit": soft, "hard_limit": hard}
        except Exception:
            return {}