"""
Pydantic schemas for system stats module
"""
from pydantic import Field
from typing import Optional, List
from datetime import datetime
from src.shared.base import BaseSchema


class CpuStats(BaseSchema):
    """CPU usage statistics"""

    usage_percent: float = Field(
        ...,
        description="CPU usage percentage (0-100)",
        ge=0,
        le=100
    )

    cores: int = Field(
        ...,
        description="Number of CPU cores"
    )

    load_1m: Optional[float] = Field(
        default=None,
        description="1-minute load average"
    )

    load_5m: Optional[float] = Field(
        default=None,
        description="5-minute load average"
    )

    load_15m: Optional[float] = Field(
        default=None,
        description="15-minute load average"
    )


class MemoryStats(BaseSchema):
    """Memory usage statistics"""

    usage_percent: float = Field(
        ...,
        description="Memory usage percentage (0-100)",
        ge=0,
        le=100
    )

    total_bytes: int = Field(
        ...,
        description="Total memory in bytes"
    )

    used_bytes: int = Field(
        ...,
        description="Used memory in bytes"
    )

    available_bytes: int = Field(
        ...,
        description="Available memory in bytes"
    )


class DiskStats(BaseSchema):
    """Disk usage statistics for a single mount point"""

    mount_point: str = Field(
        ...,
        description="Mount point path"
    )

    device: str = Field(
        ...,
        description="Device name (e.g., /dev/sda1)"
    )

    fstype: str = Field(
        ...,
        description="Filesystem type (e.g., ext4, xfs)"
    )

    usage_percent: float = Field(
        ...,
        description="Disk usage percentage (0-100)",
        ge=0,
        le=100
    )

    total_bytes: int = Field(
        ...,
        description="Total disk space in bytes"
    )

    used_bytes: int = Field(
        ...,
        description="Used disk space in bytes"
    )

    free_bytes: int = Field(
        ...,
        description="Free disk space in bytes"
    )


class NetworkStats(BaseSchema):
    """Network I/O statistics"""

    bytes_sent: int = Field(
        ...,
        description="Total bytes sent"
    )

    bytes_recv: int = Field(
        ...,
        description="Total bytes received"
    )

    bytes_total: int = Field(
        ...,
        description="Total bytes (sent + received)"
    )


class GpuStats(BaseSchema):
    """GPU/VRAM statistics (if available)"""

    available: bool = Field(
        ...,
        description="Whether GPU stats are available"
    )

    name: Optional[str] = Field(
        default=None,
        description="GPU name"
    )

    usage_percent: Optional[float] = Field(
        default=None,
        description="VRAM usage percentage (0-100)"
    )

    total_bytes: Optional[int] = Field(
        default=None,
        description="Total VRAM in bytes"
    )

    used_bytes: Optional[int] = Field(
        default=None,
        description="Used VRAM in bytes"
    )

    free_bytes: Optional[int] = Field(
        default=None,
        description="Free VRAM in bytes"
    )


class SystemStatsResponse(BaseSchema):
    """Response model for system stats"""

    cpu: CpuStats = Field(
        ...,
        description="CPU statistics"
    )

    memory: MemoryStats = Field(
        ...,
        description="Memory statistics"
    )

    disks: List[DiskStats] = Field(
        ...,
        description="Disk statistics for all mounted filesystems"
    )

    network: NetworkStats = Field(
        ...,
        description="Network I/O statistics"
    )

    gpu: GpuStats = Field(
        ...,
        description="GPU/VRAM statistics"
    )

    hostname: str = Field(
        ...,
        description="System hostname"
    )

    queried_at: datetime = Field(
        ...,
        description="UTC timestamp when stats were collected"
    )