from pydantic_settings import BaseSettings
from functools import lru_cache
from pathlib import Path
import os


def _find_env_file():
    candidates = [Path.cwd() / ".env", Path(__file__).resolve().parent.parent.parent.parent / ".env"]
    for p in candidates:
        if p.exists():
            return str(p)
    return ".env"


class Settings(BaseSettings):
    app_name: str = "PharmacopoeiaAI"
    app_env: str = "development"
    app_debug: bool = True
    secret_key: str = "change-me"
    api_prefix: str = "/api/v1"

    postgres_host: str = "localhost"
    postgres_port: int = 5432
    postgres_db: str = "pharmacopoeia"
    postgres_user: str = "postgres"
    postgres_password: str = "postgres"

    redis_host: str = "localhost"
    redis_port: int = 6379
    redis_password: str = ""
    redis_db: int = 0

    milvus_host: str = "localhost"
    milvus_port: int = 19530
    milvus_collection: str = "drug_entries"

    llm_provider: str = "qwen"
    qwen_api_key: str = ""
    qwen_base_url: str = "https://dashscope.aliyuncs.com/compatible-mode/v1"
    qwen_model: str = "qwen-max"
    qwen_max_tokens: int = 4096
    qwen_temperature: float = 0.1

    qwen_local_base_url: str = "http://localhost:8000/v1"
    qwen_local_model: str = "Qwen3-35B-A3B"

    embedding_model: str = "BAAI/bge-m3"
    embedding_dim: int = 1024
    embedding_device: str = "cpu"

    reranker_model: str = "BAAI/bge-reranker-v2-m3"

    wechat_appid: str = ""
    wechat_secret: str = ""

    rate_limit_per_minute: int = 60
    rate_limit_per_hour: int = 1000

    log_level: str = "INFO"
    log_file: str = "logs/app.log"

    @property
    def database_url(self) -> str:
        return (
            f"postgresql+asyncpg://{self.postgres_user}:{self.postgres_password}"
            f"@{self.postgres_host}:{self.postgres_port}/{self.postgres_db}"
        )

    @property
    def database_url_sync(self) -> str:
        return (
            f"postgresql://{self.postgres_user}:{self.postgres_password}"
            f"@{self.postgres_host}:{self.postgres_port}/{self.postgres_db}"
        )

    model_config = {"env_file": _find_env_file(), "case_sensitive": False, "extra": "ignore"}


@lru_cache
def get_settings() -> Settings:
    return Settings()