from pathlib import Path
from typing import Annotated, Literal

from pydantic import AfterValidator, Field
from pydantic_settings import BaseSettings, SettingsConfigDict


PROJECT_ROOT = Path(__file__).resolve().parents[1]


def resolve_model_dir(value: Path) -> Path:
    """将模型目录解析为项目根目录下的绝对路径。"""
    path = value.expanduser()
    if not path.is_absolute():
        path = PROJECT_ROOT / path
    path = path.resolve()
    if not path.is_dir():
        raise ValueError(f"OCR模型目录不存在: {path}")
    return path


ModelDir = Annotated[Path, AfterValidator(resolve_model_dir)]


class Settings(BaseSettings):
    """应用配置"""

    model_config = SettingsConfigDict(
        env_file=PROJECT_ROOT / ".env",
        case_sensitive=False,
        extra="ignore",
    )

    host: str = "0.0.0.0"
    port: int = 15651
    debug: bool = False

    # OCR阶段
    ocr_use_det: bool = True
    ocr_use_cls: bool = False
    ocr_use_rec: bool = True

    # 模型与常用调优参数
    ocr_model_dir: ModelDir = Path("model")
    ocr_text_score: float = Field(default=0.5, ge=0.0, le=1.0)
    ocr_max_side_len: int = Field(default=2000, ge=32, le=16384)
    ocr_det_limit_side_len: int = Field(default=736, ge=32, le=8192)
    ocr_det_box_thresh: float = Field(default=0.5, ge=0.0, le=1.0)
    ocr_det_thresh: float = Field(default=0.3, ge=0.0, le=1.0)
    ocr_rec_batch_num: int = Field(default=6, ge=1, le=256)

    # 推理设备
    ocr_device: Literal["cpu", "cuda", "dml", "tensorrt"] = "cpu"
    ocr_device_id: int = Field(default=0, ge=0)
    ocr_intra_threads: int = Field(default=4, ge=1)
    ocr_inter_threads: int = Field(default=2, ge=1)

    # 竖排文字补充通道（边缘带旋转90°检测，需 model/PP-OCRv4 目录下的 server 模型）
    ocr_enable_vertical: bool = False


settings = Settings()