import os
import logging
from functools import partial
from pathlib import Path
from typing import Iterator, Optional, Union

from .general import SysCommand
from .networking import list_interfaces, enrich_iface_types
from .exceptions import SysCallError
from .output import log

__packages__ = [
	"mesa",
	"xf86-video-amdgpu",
	"xf86-video-ati",
	"xf86-video-nouveau",
	"xf86-video-vmware",
	"libva-mesa-driver",
	"libva-intel-driver",
	"intel-media-driver",
	"vulkan-radeon",
	"vulkan-intel",
	"nvidia",
]

AVAILABLE_GFX_DRIVERS = {
	# Sub-dicts are layer-2 options to be selected
	# and lists are a list of packages to be installed
	"All open-source (default)": [
		"mesa",
		"xf86-video-amdgpu",
		"xf86-video-ati",
		"xf86-video-nouveau",
		"xf86-video-vmware",
		"libva-mesa-driver",
		"libva-intel-driver",
		"intel-media-driver",
		"vulkan-radeon",
		"vulkan-intel",
	],
	"AMD / ATI (open-source)": [
		"mesa",
		"xf86-video-amdgpu",
		"xf86-video-ati",
		"libva-mesa-driver",
		"vulkan-radeon",
	],
	"Intel (open-source)": [
		"mesa",
		"libva-intel-driver",
		"intel-media-driver",
		"vulkan-intel",
	],
	"Nvidia (open kernel module for newer GPUs, Turing+)": ["nvidia-open"],
	"Nvidia (open-source nouveau driver)": [
		"mesa",
		"xf86-video-nouveau",
		"libva-mesa-driver"
	],
	"Nvidia (proprietary)": ["nvidia"],
	"VMware / VirtualBox (open-source)": ["mesa", "xf86-video-vmware"],
}

CPUINFO = Path("/proc/cpuinfo")
MEMINFO = Path("/proc/meminfo")


def cpuinfo() -> Iterator[dict[str, str]]:
	"""Yields information about the CPUs of the system."""
	cpu = {}

	with CPUINFO.open() as file:
		for line in file:
			if not (line := line.strip()):
				yield cpu
				cpu = {}
				continue

			key, value = line.split(":", maxsplit=1)
			cpu[key.strip()] = value.strip()


def meminfo(key: Optional[str] = None) -> Union[dict[str, int], Optional[int]]:
	"""Returns a dict with memory info if called with no args
	or the value of the given key of said dict.
	"""
	with MEMINFO.open() as file:
		mem_info = {
			(columns := line.strip().split())[0].rstrip(':'): int(columns[1])
			for line in file
		}

	if key is None:
		return mem_info

	return mem_info.get(key)


def has_wifi() -> bool:
	return 'WIRELESS' in enrich_iface_types(list_interfaces().values()).values()


def has_cpu_vendor(vendor_id: str) -> bool:
	return any(cpu.get("vendor_id") == vendor_id for cpu in cpuinfo())


has_amd_cpu = partial(has_cpu_vendor, "AuthenticAMD")


has_intel_cpu = partial(has_cpu_vendor, "GenuineIntel")


def has_uefi() -> bool:
	return os.path.isdir('/sys/firmware/efi')


def graphics_devices() -> dict:
	cards = {}
	for line in SysCommand("lspci"):
		if b' VGA ' in line or b' 3D ' in line:
			_, identifier = line.split(b': ', 1)
			cards[identifier.strip().decode('UTF-8')] = line
	return cards


def has_nvidia_graphics() -> bool:
	return any('nvidia' in x.lower() for x in graphics_devices())


def has_amd_graphics() -> bool:
	return any('amd' in x.lower() for x in graphics_devices())


def has_intel_graphics() -> bool:
	return any('intel' in x.lower() for x in graphics_devices())


def cpu_vendor() -> Optional[str]:
	for cpu in cpuinfo():
		return cpu.get("vendor_id")

	return None


def cpu_model() -> Optional[str]:
	for cpu in cpuinfo():
		return cpu.get("model name")

	return None


def sys_vendor() -> Optional[str]:
	with open(f"/sys/devices/virtual/dmi/id/sys_vendor") as vendor:
		return vendor.read().strip()


def product_name() -> Optional[str]:
	with open(f"/sys/devices/virtual/dmi/id/product_name") as product:
		return product.read().strip()


def mem_available() -> Optional[int]:
	return meminfo('MemAvailable')


def mem_free() -> Optional[int]:
	return meminfo('MemFree')


def mem_total() -> Optional[int]:
	return meminfo('MemTotal')


def virtualization() -> Optional[str]:
	try:
		return str(SysCommand("systemd-detect-virt")).strip('\r\n')
	except SysCallError as error:
		log(f"Could not detect virtual system: {error}", level=logging.DEBUG)

	return None


def is_vm() -> bool:
	try:
		return b"none" not in b"".join(SysCommand("systemd-detect-virt")).lower()
	except SysCallError as error:
		log(f"System is not running in a VM: {error}", level=logging.DEBUG)
	return None

# TODO: Add more identifiers