from __future__ import annotations

import locale
import random
import re
import subprocess
import tempfile
import time
import winreg
from dataclasses import dataclass
from pathlib import Path
from typing import Iterable

import requests

from .config import ConnectivityCheck


class WifiCommandError(RuntimeError):
    """Raised when a Windows networking command fails."""


@dataclass(slots=True)
class WifiStatus:
    interface_name: str | None
    description: str | None
    state: str | None
    ssid: str | None

    @property
    def is_connected(self) -> bool:
        state = (self.state or "").lower()
        return "connected" in state or "已连接" in state or "已連線" in state


def test_connectivity(checks: Iterable[ConnectivityCheck], timeout_seconds: int = 3) -> bool:
    for check in checks:
        try:
            response = requests.get(
                check.url,
                timeout=timeout_seconds,
                allow_redirects=check.allow_redirects,
            )
        except requests.RequestException:
            continue
        if response.status_code != check.expected_status:
            continue
        if check.require_final_url_match and _normalize_url(response.url) != _normalize_url(check.url):
            continue
        if check.expected_text is not None and check.expected_text not in response.text:
            continue
        if check.expected_status == 204 and response.content:
            continue
        return True
    return False


def get_wifi_status(preferred_interface_name: str | None = None) -> WifiStatus:
    output = run_command(["netsh", "wlan", "show", "interfaces"])
    blocks = [block.strip() for block in re.split(r"(?:\r?\n){2,}", output) if block.strip()]
    parsed_blocks = [_parse_key_value_block(block) for block in blocks]

    candidate = None
    if preferred_interface_name:
        preferred = preferred_interface_name.casefold()
        for block in parsed_blocks:
            if (block.get("name") or "").casefold() == preferred:
                candidate = block
                break

    if candidate is None:
        for block in parsed_blocks:
            state = (block.get("state") or "").lower()
            if "connected" in state or "disconnected" in state or "已" in state:
                candidate = block
                break

    if candidate is None:
        return WifiStatus(interface_name=None, description=None, state=None, ssid=None)

    return WifiStatus(
        interface_name=candidate.get("name"),
        description=candidate.get("description"),
        state=candidate.get("state"),
        ssid=candidate.get("ssid"),
    )


def restart_adapter(interface_name: str) -> None:
    run_command(["netsh", "interface", "set", "interface", interface_name, "disable"])
    time.sleep(2)
    run_command(["netsh", "interface", "set", "interface", interface_name, "enable"])


def disconnect_wifi(interface_name: str | None = None) -> None:
    command = ["netsh", "wlan", "disconnect"]
    if interface_name:
        command.append(f"interface={interface_name}")
    run_command(command)


def connect_wifi(
    profile_name: str,
    interface_name: str | None = None,
    *,
    ssid: str | None = None,
    auto_create_open_profile: bool = False,
) -> None:
    command = ["netsh", "wlan", "connect", f"name={profile_name}"]
    if ssid:
        command.append(f"ssid={ssid}")
    if interface_name:
        command.append(f"interface={interface_name}")
    try:
        run_command(command)
    except WifiCommandError as exc:
        if auto_create_open_profile and _is_missing_profile_error(str(exc), profile_name):
            create_open_wifi_profile(
                profile_name=profile_name,
                ssid=ssid or profile_name,
                interface_name=interface_name,
            )
            run_command(command)
            return
        if _is_missing_profile_error(str(exc), profile_name):
            available_profiles = list_wifi_profiles(interface_name)
            profiles_display = ", ".join(available_profiles) if available_profiles else "<none>"
            target = interface_name or "<default>"
            raise WifiCommandError(
                f'Windows WLAN profile "{profile_name}" is missing on interface {target}. '
                f"Available profiles: {profiles_display}",
            ) from exc
        raise


def list_wifi_profiles(interface_name: str | None = None) -> list[str]:
    command = ["netsh", "wlan", "show", "profiles"]
    if interface_name:
        command.append(f"interface={interface_name}")
    output = run_command(command)

    profiles: list[str] = []
    for raw_line in output.splitlines():
        line = raw_line.strip()
        if not line or ":" not in line:
            continue
        key, value = line.split(":", 1)
        key_lower = key.casefold()
        if "profile" not in key_lower and "配置文件" not in key_lower and "設定檔" not in key_lower:
            continue
        name = value.strip()
        if not name or name == "<None>":
            continue
        profiles.append(name)
    return profiles


def create_open_wifi_profile(
    profile_name: str,
    ssid: str,
    interface_name: str | None = None,
    *,
    connection_mode: str = "auto",
) -> None:
    profile_xml = _build_open_profile_xml(profile_name, ssid, connection_mode=connection_mode)
    temp_path: Path | None = None
    try:
        with tempfile.NamedTemporaryFile(
            mode="w",
            suffix=".xml",
            delete=False,
            encoding="utf-8",
        ) as handle:
            handle.write(profile_xml)
            temp_path = Path(handle.name)

        command = ["netsh", "wlan", "add", "profile", f"filename={temp_path}", "user=current"]
        if interface_name:
            command.append(f"interface={interface_name}")
        run_command(command)
    except WifiCommandError as exc:
        raise WifiCommandError(
            f'Failed to create an open Wi-Fi profile for SSID "{ssid}": {exc}',
        ) from exc
    finally:
        if temp_path is not None:
            temp_path.unlink(missing_ok=True)


def wait_for_ssid(
    target_ssid: str,
    timeout_seconds: int,
    preferred_interface_name: str | None = None,
) -> WifiStatus:
    deadline = time.monotonic() + timeout_seconds
    while time.monotonic() < deadline:
        status = get_wifi_status(preferred_interface_name)
        if status.is_connected and status.ssid == target_ssid:
            return status
        time.sleep(1)
    return get_wifi_status(preferred_interface_name)


def ensure_hardware_mac(adapter_locator: str | None = None) -> bool:
    adapter_name = adapter_locator or _require_adapter_name()
    reg_path = find_adapter_registry_key(adapter_name)
    if not reg_path:
        raise WifiCommandError(f"Could not find registry entry for adapter '{adapter_name}'")

    try:
        key = winreg.OpenKey(
            winreg.HKEY_LOCAL_MACHINE,
            reg_path,
            0,
            winreg.KEY_SET_VALUE,
        )
        try:
            winreg.DeleteValue(key, "NetworkAddress")
        except FileNotFoundError:
            return False
        finally:
            winreg.CloseKey(key)
    except PermissionError as exc:
        raise WifiCommandError("Administrator privileges are required to restore hardware MAC") from exc
    return True


def randomize_mac(adapter_locator: str | None = None) -> str:
    adapter_name = adapter_locator or _require_adapter_name()
    reg_path = find_adapter_registry_key(adapter_name)
    if not reg_path:
        raise WifiCommandError(f"Could not find registry entry for adapter '{adapter_name}'")

    mac_bytes = [random.randint(0x00, 0xFF) for _ in range(6)]
    mac_bytes[0] = (mac_bytes[0] & 0xFC) | 0x02
    mac_compact = "".join(f"{part:02X}" for part in mac_bytes)

    try:
        key = winreg.OpenKey(
            winreg.HKEY_LOCAL_MACHINE,
            reg_path,
            0,
            winreg.KEY_SET_VALUE,
        )
        winreg.SetValueEx(key, "NetworkAddress", 0, winreg.REG_SZ, mac_compact)
        winreg.CloseKey(key)
    except PermissionError as exc:
        raise WifiCommandError("Administrator privileges are required to randomize the MAC address") from exc

    return ":".join(f"{part:02X}" for part in mac_bytes)


def find_adapter_registry_key(adapter_name: str) -> str | None:
    base_path = r"SYSTEM\CurrentControlSet\Control\Class\{4d36e972-e325-11ce-bfc1-08002be10318}"
    try:
        base_key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, base_path)
    except OSError:
        return None

    try:
        index = 0
        adapter_name_folded = adapter_name.casefold()
        while True:
            try:
                subkey_name = winreg.EnumKey(base_key, index)
            except OSError:
                return None
            index += 1

            full_path = f"{base_path}\\{subkey_name}"
            try:
                subkey = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, full_path)
            except OSError:
                continue

            try:
                for field_name in ("DriverDesc", "NetCfgInstanceId", "ComponentId"):
                    try:
                        value, _ = winreg.QueryValueEx(subkey, field_name)
                    except OSError:
                        continue
                    if adapter_name_folded in str(value).casefold():
                        return full_path

                try:
                    connection_key = winreg.OpenKey(subkey, "Connection")
                except OSError:
                    connection_key = None
                if connection_key is not None:
                    try:
                        connection_name, _ = winreg.QueryValueEx(connection_key, "Name")
                        if adapter_name_folded in str(connection_name).casefold():
                            return full_path
                    except OSError:
                        pass
                    finally:
                        winreg.CloseKey(connection_key)
            finally:
                winreg.CloseKey(subkey)
    finally:
        winreg.CloseKey(base_key)


def run_command(command: list[str]) -> str:
    result = subprocess.run(command, capture_output=True, text=False, check=False)
    stdout = _decode_output(result.stdout)
    stderr = _decode_output(result.stderr)
    if result.returncode != 0:
        message = stderr or stdout or f"Command failed: {' '.join(command)}"
        raise WifiCommandError(message.strip())
    return stdout


def _is_missing_profile_error(message: str, profile_name: str) -> bool:
    folded = message.casefold()
    profile_folded = profile_name.casefold()
    return (
        "there is no profile" in folded
        or "is not found on the system" in folded
        or f'profile "{profile_folded}"' in folded and "not found" in folded
    )


def _build_open_profile_xml(profile_name: str, ssid: str, *, connection_mode: str) -> str:
    escaped_name = _xml_escape(profile_name)
    escaped_ssid = _xml_escape(ssid)
    return f"""<?xml version="1.0"?>
<WLANProfile xmlns="http://www.microsoft.com/networking/WLAN/profile/v1">
    <name>{escaped_name}</name>
    <SSIDConfig>
        <SSID>
            <name>{escaped_ssid}</name>
        </SSID>
        <nonBroadcast>false</nonBroadcast>
    </SSIDConfig>
    <connectionType>ESS</connectionType>
    <connectionMode>{connection_mode}</connectionMode>
    <MSM>
        <security>
            <authEncryption>
                <authentication>open</authentication>
                <encryption>none</encryption>
                <useOneX>false</useOneX>
            </authEncryption>
        </security>
    </MSM>
</WLANProfile>
"""


def _xml_escape(value: str) -> str:
    return (
        value.replace("&", "&amp;")
        .replace("<", "&lt;")
        .replace(">", "&gt;")
        .replace('"', "&quot;")
        .replace("'", "&apos;")
    )


def _normalize_url(url: str) -> str:
    return url.strip().rstrip("/").casefold()


def _require_adapter_name() -> str:
    status = get_wifi_status()
    if not status.interface_name:
        raise WifiCommandError("Could not find a Wi-Fi adapter from 'netsh wlan show interfaces'")
    return status.interface_name


def _decode_output(raw: bytes) -> str:
    for encoding in _candidate_encodings():
        try:
            return raw.decode(encoding)
        except UnicodeDecodeError:
            continue
    return raw.decode("utf-8", errors="replace")


def _candidate_encodings() -> list[str]:
    preferred = locale.getpreferredencoding(False)
    return [preferred, "utf-8", "gbk", "cp936", "big5"]


def _parse_key_value_block(block: str) -> dict[str, str]:
    mapping: dict[str, str] = {}
    for raw_line in block.splitlines():
        line = raw_line.strip()
        if not line or ":" not in line:
            continue
        key, value = line.split(":", 1)
        normalized = _normalize_key(key.strip())
        if normalized:
            mapping[normalized] = value.strip()
    return mapping


def _normalize_key(key: str) -> str | None:
    lookup = {
        "name": "name",
        "名称": "name",
        "description": "description",
        "描述": "description",
        "state": "state",
        "状态": "state",
        "ssid": "ssid",
    }
    normalized = key.strip().casefold()
    if normalized == "bssid":
        return None
    return lookup.get(key.strip(), lookup.get(normalized))