import json
import copy
from pathlib import Path
from typing import Callable

DEFAULT_CONFIG = {
    "active_profile": "pc1_dp",
    "profiles": [
        {
            "id": "pc1_dp",
            "name": "PC1 \u2014 DP",
            "hotkey": "ctrl+alt+1",
            "monitor_inputs": [
                {"monitor_index": 0, "vcp_value": 15},
                {"monitor_index": 1, "vcp_value": 15}
            ]
        },
        {
            "id": "pc2_hdmi",
            "name": "PC2 \u2014 HDMI",
            "hotkey": "ctrl+alt+2",
            "monitor_inputs": [
                {"monitor_index": 0, "vcp_value": 17},
                {"monitor_index": 1, "vcp_value": 17}
            ]
        }
    ],
    "device_triggers": [
        {
            "name": "HP 975 keyboard",
            "bt_device_id": "VID&0203F0_PID&6343",
            "on_connect": "pc1_dp",
            "on_disconnect": "pc2_hdmi",
            "enabled": True
        },
        {
            "name": "MX Anywhere 2S",
            "bt_device_id": "VID&02046D_PID&B01A",
            "on_connect": "pc1_dp",
            "on_disconnect": "pc2_hdmi",
            "enabled": True
        }
    ],
    "general": {
        "autostart": True,
        "minimize_to_tray": True,
        "debounce_ms": 500
    }
}


class ConfigManager:
    def __init__(self, config_path=None):
        if config_path is None:
            config_path = Path(__file__).parent / "config.json"
        self.config_path = Path(config_path)
        self._config: dict = {}
        self._callbacks: list[Callable] = []
        self.load()

    def load(self) -> None:
        if self.config_path.exists():
            try:
                with open(self.config_path, "r", encoding="utf-8") as f:
                    self._config = json.load(f)
            except (json.JSONDecodeError, OSError):
                self._config = copy.deepcopy(DEFAULT_CONFIG)
        else:
            self._config = copy.deepcopy(DEFAULT_CONFIG)
            self.save()

    def save(self) -> None:
        self.config_path.parent.mkdir(parents=True, exist_ok=True)
        with open(self.config_path, "w", encoding="utf-8") as f:
            json.dump(self._config, f, indent=2, ensure_ascii=False)

    def get(self) -> dict:
        return self._config

    def update(self, new_config: dict) -> None:
        self._config = new_config
        self.save()
        for cb in self._callbacks:
            cb(self._config)

    def on_change(self, callback: Callable) -> None:
        self._callbacks.append(callback)

    def get_profile(self, profile_id: str) -> dict | None:
        for p in self._config.get("profiles", []):
            if p["id"] == profile_id:
                return p
        return None

    def get_active_profile_id(self) -> str:
        return self._config.get("active_profile", "pc1_dp")

    def set_active_profile(self, profile_id: str) -> None:
        self._config["active_profile"] = profile_id
        self.save()