from __future__ import annotations

from pathlib import Path
from typing import Literal

import yaml
from pydantic import BaseModel, ConfigDict, Field, field_validator


class CaptureConfig(BaseModel):
    model_config = ConfigDict(extra="forbid")

    backend: Literal["fixture", "mss", "dxcam"] = "fixture"
    monitor: int = 1
    fps_limit: int = Field(default=10, ge=1, le=240)
    window_title: str | None = None


class VisionConfig(BaseModel):
    model_config = ConfigDict(extra="forbid")

    template_threshold: float = Field(default=0.85, ge=0.0, le=1.0)
    debug_output_dir: Path = Path("botty_next/debug/output")


class InputConfig(BaseModel):
    model_config = ConfigDict(extra="forbid")

    enabled: bool = False
    dry_run: bool = True
    emergency_stop_key: str = "f12"

    @field_validator("dry_run")
    @classmethod
    def dry_run_required_when_disabled(cls, value: bool) -> bool:
        return value


class BottyNextConfig(BaseModel):
    model_config = ConfigDict(extra="forbid")

    profile_name: str = "local"
    capture: CaptureConfig = Field(default_factory=CaptureConfig)
    vision: VisionConfig = Field(default_factory=VisionConfig)
    input: InputConfig = Field(default_factory=InputConfig)

    @field_validator("input")
    @classmethod
    def input_must_be_explicit_and_dry_run_by_default(cls, value: InputConfig) -> InputConfig:
        if value.enabled and value.dry_run is False:
            raise ValueError("live input cannot be enabled without a future explicit safety gate")
        return value


def load_config(path: str | Path) -> BottyNextConfig:
    config_path = Path(path)
    with config_path.open("r", encoding="utf-8") as handle:
        raw = yaml.safe_load(handle) or {}
    return BottyNextConfig.model_validate(raw)