"""
Port Configuration and Status API Router

Endpoints for port configuration, status querying, and process management.
"""

import json
import os
import platform
import subprocess
import time
from pathlib import Path

from fastapi import APIRouter, HTTPException
from fastapi.responses import JSONResponse
from pydantic import BaseModel, Field, field_validator

router = APIRouter(prefix="/api/ports", tags=["ports"])

# Config file path
_CONFIG_DIR = Path(__file__).parent.parent.parent
_PORTS_CONFIG_FILE = _CONFIG_DIR / "ports_config.json"


class PortConfig(BaseModel):
    """Port configuration model."""

    fastapi_port: int = Field(default=2048, ge=1024, le=65535)
    camoufox_debug_port: int = Field(default=9222, ge=1024, le=65535)
    stream_proxy_port: int = Field(default=3120, ge=0, le=65535)
    stream_proxy_enabled: bool = True

    @field_validator("fastapi_port", "camoufox_debug_port")
    @classmethod
    def validate_required_port(cls, v: int) -> int:
        if v < 1024:
            raise ValueError("Port must be >= 1024")
        return v


class ProcessInfo(BaseModel):
    """Information about a process."""

    pid: int
    name: str


class PortStatus(BaseModel):
    """Status of a port."""

    port: int
    port_type: str
    in_use: bool
    processes: list[ProcessInfo] = []


class KillRequest(BaseModel):
    """Request to kill a process."""

    pid: int = Field(..., ge=1, description="PID of the process to terminate")
    confirm: bool = Field(default=False, description="Confirm termination")


def _load_port_config() -> PortConfig:
    """Load port config from file or environment."""
    # Environment variables take priority
    config = PortConfig(
        fastapi_port=int(os.environ.get("DEFAULT_FASTAPI_PORT", "2048")),
        camoufox_debug_port=int(os.environ.get("DEFAULT_CAMOUFOX_PORT", "9222")),
        stream_proxy_port=int(os.environ.get("STREAM_PORT", "3120")),
        stream_proxy_enabled=os.environ.get("STREAM_PORT", "3120") != "0",
    )

    # Override with saved config if exists
    if _PORTS_CONFIG_FILE.exists():
        try:
            data = json.loads(_PORTS_CONFIG_FILE.read_text(encoding="utf-8"))
            config = PortConfig(**data)
        except Exception:
            pass

    return config


def _save_port_config(config: PortConfig) -> None:
    """Save port config to file."""
    _PORTS_CONFIG_FILE.write_text(
        json.dumps(config.model_dump(), ensure_ascii=False, indent=2),
        encoding="utf-8",
    )


def _find_processes_on_port(port: int) -> list[ProcessInfo]:
    """Find processes listening on a port."""
    processes: list[ProcessInfo] = []
    system = platform.system()

    try:
        if system in ("Linux", "Darwin"):
            cmd = f"lsof -ti tcp:{port} -sTCP:LISTEN"
            result = subprocess.run(
                cmd, shell=True, capture_output=True, text=True, timeout=5
            )
            if result.returncode == 0 and result.stdout.strip():
                pids = [
                    int(p) for p in result.stdout.strip().splitlines() if p.isdigit()
                ]
                for pid in pids:
                    name = _get_process_name(pid)
                    processes.append(ProcessInfo(pid=pid, name=name))

        elif system == "Windows":
            cmd = "netstat -ano -p TCP"
            result = subprocess.run(
                cmd,
                shell=True,
                capture_output=True,
                text=True,
                timeout=10,
                creationflags=subprocess.CREATE_NO_WINDOW,  # type: ignore[attr-defined]
            )
            if result.returncode == 0:
                for line in result.stdout.strip().splitlines():
                    parts = line.split()
                    if (
                        len(parts) >= 5
                        and parts[0].upper() == "TCP"
                        and parts[3].upper() == "LISTENING"
                    ):
                        local_addr = parts[1]
                        if local_addr.endswith(f":{port}"):
                            pid_str = parts[4]
                            if pid_str.isdigit():
                                pid = int(pid_str)
                                name = _get_process_name(pid)
                                processes.append(ProcessInfo(pid=pid, name=name))

    except Exception:
        pass

    # Deduplicate by PID
    seen_pids: set[int] = set()
    unique_processes: list[ProcessInfo] = []
    for p in processes:
        if p.pid not in seen_pids:
            seen_pids.add(p.pid)
            unique_processes.append(p)

    return unique_processes


def _get_process_name(pid: int) -> str:
    """Get process name by PID."""
    system = platform.system()

    try:
        if system == "Linux":
            result = subprocess.run(
                ["ps", "-p", str(pid), "-o", "comm="],
                capture_output=True,
                text=True,
                timeout=3,
            )
            if result.returncode == 0 and result.stdout.strip():
                return result.stdout.strip()

        elif system == "Darwin":
            result = subprocess.run(
                ["ps", "-p", str(pid), "-o", "comm="],
                capture_output=True,
                text=True,
                timeout=3,
            )
            if result.returncode == 0 and result.stdout.strip():
                return result.stdout.strip()

        elif system == "Windows":
            result = subprocess.run(
                ["tasklist", "/NH", "/FO", "CSV", "/FI", f"PID eq {pid}"],
                capture_output=True,
                text=True,
                timeout=3,
                creationflags=subprocess.CREATE_NO_WINDOW,  # type: ignore[attr-defined]
            )
            if result.returncode == 0 and result.stdout.strip():
                parts = result.stdout.strip().split('","')
                if parts:
                    return parts[0].strip('"')

    except Exception:
        pass

    return "Unknown"


def _kill_process(pid: int) -> tuple[bool, str]:
    """Kill a process by PID. Returns (success, message)."""
    system = platform.system()

    try:
        if system in ("Linux", "Darwin"):
            # Try SIGTERM first
            subprocess.run(["kill", "-TERM", str(pid)], capture_output=True, timeout=3)
            time.sleep(0.5)

            # Check if still alive
            check = subprocess.run(
                ["kill", "-0", str(pid)], capture_output=True, text=True
            )
            if check.returncode != 0:
                return True, f"Process {pid} terminated (SIGTERM)"

            # Force kill
            subprocess.run(["kill", "-KILL", str(pid)], capture_output=True, timeout=3)
            time.sleep(0.2)

            # Verify
            check = subprocess.run(
                ["kill", "-0", str(pid)], capture_output=True, text=True
            )
            if check.returncode != 0:
                return True, f"Process {pid} force terminated (SIGKILL)"
            else:
                return False, f"Unable to terminate process {pid}"

        elif system == "Windows":
            result = subprocess.run(
                ["taskkill", "/PID", str(pid), "/T", "/F"],
                capture_output=True,
                text=True,
                timeout=5,
                creationflags=subprocess.CREATE_NO_WINDOW,  # type: ignore[attr-defined]
            )
            if result.returncode == 0:
                return True, f"Process {pid} terminated"
            else:
                return False, f"Unable to terminate process {pid}: {result.stderr}"

    except Exception as e:
        return False, f"Error terminating process: {e}"

    return False, "Unsupported OS"


@router.get("/config")
async def get_port_config() -> JSONResponse:
    """Get port configuration."""
    config = _load_port_config()
    return JSONResponse(content=config.model_dump())


@router.post("/config")
async def update_port_config(config: PortConfig) -> JSONResponse:
    """
    Update port configuration.

    Note: Changes will take effect on next server restart.
    """
    _save_port_config(config)
    return JSONResponse(
        content={
            "success": True,
            "config": config.model_dump(),
            "message": "Configuration saved. Changes will take effect on next restart.",
        }
    )


@router.get("/status")
async def get_port_status() -> JSONResponse:
    """Get port occupation status."""
    config = _load_port_config()

    statuses: list[PortStatus] = []

    # Check FastAPI port
    fastapi_processes = _find_processes_on_port(config.fastapi_port)
    statuses.append(
        PortStatus(
            port=config.fastapi_port,
            port_type="FastAPI",
            in_use=len(fastapi_processes) > 0,
            processes=fastapi_processes,
        )
    )

    # Check Camoufox debug port
    camoufox_processes = _find_processes_on_port(config.camoufox_debug_port)
    statuses.append(
        PortStatus(
            port=config.camoufox_debug_port,
            port_type="Camoufox Debug",
            in_use=len(camoufox_processes) > 0,
            processes=camoufox_processes,
        )
    )

    # Check Stream proxy port (if enabled)
    if config.stream_proxy_enabled and config.stream_proxy_port > 0:
        stream_processes = _find_processes_on_port(config.stream_proxy_port)
        statuses.append(
            PortStatus(
                port=config.stream_proxy_port,
                port_type="Stream Proxy",
                in_use=len(stream_processes) > 0,
                processes=stream_processes,
            )
        )

    return JSONResponse(content={"ports": [s.model_dump() for s in statuses]})


@router.post("/kill")
async def kill_process(request: KillRequest) -> JSONResponse:
    """
    Terminate process with specified PID.

    Security validation:
    - Requires confirm=true
    - PID must belong to a process on a configured port
    """
    if not request.confirm:
        raise HTTPException(
            status_code=400,
            detail="Please set confirm=true to confirm process termination",
        )

    # Security: Validate PID belongs to a tracked port
    config = _load_port_config()
    tracked_pids: set[int] = set()

    # Collect PIDs from all configured ports
    for port in [config.fastapi_port, config.camoufox_debug_port]:
        for proc in _find_processes_on_port(port):
            tracked_pids.add(proc.pid)

    # Also check stream proxy port if enabled
    if config.stream_proxy_enabled and config.stream_proxy_port > 0:
        for proc in _find_processes_on_port(config.stream_proxy_port):
            tracked_pids.add(proc.pid)

    if request.pid not in tracked_pids:
        raise HTTPException(
            status_code=403,
            detail=f"Security validation failed: PID {request.pid} does not belong to a configured port. Only processes running on FastAPI ({config.fastapi_port}), Camoufox ({config.camoufox_debug_port}) or Stream Proxy ({config.stream_proxy_port}) ports can be terminated.",
        )

    success, message = _kill_process(request.pid)

    return JSONResponse(
        content={"success": success, "message": message, "pid": request.pid},
        status_code=200 if success else 500,
    )