"""Health check endpoints."""

import os
import platform
import psutil
from datetime import datetime
from fastapi import APIRouter, Depends
from sqlalchemy.orm import Session
from sqlalchemy import text

from app.dependencies import get_db, get_current_user, get_current_superuser
from app.config import settings
from app.models.user import User


router = APIRouter()

# Store app start time
APP_START_TIME = datetime.utcnow()


def get_system_info() -> dict:
    """Get detailed system information."""
    # Memory info
    memory = psutil.virtual_memory()

    # Disk info
    disk = psutil.disk_usage('/')

    # CPU info
    cpu_percent = psutil.cpu_percent(interval=0.1)

    return {
        "memory": {
            "total_gb": round(memory.total / (1024**3), 2),
            "used_gb": round(memory.used / (1024**3), 2),
            "available_gb": round(memory.available / (1024**3), 2),
            "percent": memory.percent
        },
        "disk": {
            "total_gb": round(disk.total / (1024**3), 2),
            "used_gb": round(disk.used / (1024**3), 2),
            "free_gb": round(disk.free / (1024**3), 2),
            "percent": disk.percent
        },
        "cpu": {
            "percent": cpu_percent,
            "cores": psutil.cpu_count()
        },
        "platform": {
            "system": platform.system(),
            "release": platform.release(),
            "python": platform.python_version()
        }
    }


@router.get("")
def health_check(db: Session = Depends(get_db)):
    """
    Health check endpoint that verifies database connectivity.
    Public endpoint for monitoring services.

    Returns:
        Dictionary with health status and database connectivity
    """
    try:
        # Test database connection
        db.execute(text("SELECT 1"))
        db_status = "connected"
    except Exception as e:
        db_status = f"error: {str(e)}"

    # Calculate uptime
    uptime_seconds = (datetime.utcnow() - APP_START_TIME).total_seconds()

    return {
        "status": "healthy" if db_status == "connected" else "unhealthy",
        "app": settings.APP_NAME,
        "version": settings.APP_VERSION,
        "database": db_status,
        "uptime_seconds": int(uptime_seconds)
    }


@router.get("/detailed")
def health_check_detailed(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_superuser)
):
    """
    Detailed health check with system information.
    Requires superuser authentication.

    Returns:
        Dictionary with detailed health status and system info
    """
    # Basic health check
    try:
        db.execute(text("SELECT 1"))
        db_status = "connected"
    except Exception as e:
        db_status = f"error: {str(e)}"

    # Calculate uptime
    uptime_seconds = (datetime.utcnow() - APP_START_TIME).total_seconds()
    days, remainder = divmod(int(uptime_seconds), 86400)
    hours, remainder = divmod(remainder, 3600)
    minutes, seconds = divmod(remainder, 60)

    return {
        "status": "healthy" if db_status == "connected" else "unhealthy",
        "app": settings.APP_NAME,
        "version": settings.APP_VERSION,
        "database": db_status,
        "uptime": {
            "seconds": int(uptime_seconds),
            "formatted": f"{days}d {hours}h {minutes}m {seconds}s"
        },
        "started_at": APP_START_TIME.isoformat(),
        "system": get_system_info(),
        "environment": {
            "debug": settings.DEBUG,
            "log_level": settings.LOG_LEVEL
        }
    }