from __future__ import annotations

from functools import lru_cache
from pathlib import Path
from urllib.parse import quote_plus

from pydantic_settings import BaseSettings, SettingsConfigDict

PROJECT_ROOT = Path(__file__).resolve().parents[2]


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=PROJECT_ROOT / ".env",
        env_file_encoding="utf-8",
        case_sensitive=False,
        extra="ignore",
    )

    app_name: str = "矿山通防智能管控平台"
    app_env: str = "development"
    debug: bool = True
    api_v1_prefix: str = "/api/v1"
    secret_key: str = "change-me-in-production"

    host: str = "0.0.0.0"
    port: int = 8090
    log_level: str = "INFO"

    database_dialect: str = "sqlite"
    sqlite_path: str = "data/vent_platform.sqlite"
    mysql_host: str = "127.0.0.1"
    mysql_port: int = 3306
    mysql_user: str = "root"
    mysql_password: str = ""
    mysql_database: str = "vent_platform"
    database_echo: bool = False

    openai_api_key: str = ""
    openai_base_url: str = "https://api.deepseek.com"
    deepagent_model: str = "deepseek-flash"
    deepagent_thinking: str = "off"
    openai_timeout: int = 180
    mineru_api_base: str = "https://mineru.net"
    mineru_token: str = ""
    mineru_timeout: int = 900
    mineru_poll_interval: float = 2.0
    document_extraction_max_chars: int = 80000

    knowledge_service_base: str = ""
    knowledge_service_api_key: str = ""
    knowledge_service_timeout: float = 30.0
    knowledge_catalog_cache_ttl: int = 300
    knowledge_search_mode: str = "keyword"
    knowledge_search_top_k: int = 5
    knowledge_search_min_score: float = 0.0
    knowledge_search_min_match_ratio: float = 0.0
    knowledge_rag_context_max_chars: int = 12000
    knowledge_rag_source_max_chars: int = 2800

    cors_origins: str = (
        "http://127.0.0.1:5173,http://localhost:5173,"
        "http://127.0.0.1:8080,http://localhost:8080"
    )
    default_mine_code: str = "shangwan"
    upload_dir: str = "data/uploads"
    storage_capacity_gb: float = 1024.0
    seed_demo_data: bool = False

    request_trace_header: str = "X-Trace-Id"

    @property
    def cors_origin_list(self) -> list[str]:
        return [item.strip() for item in self.cors_origins.split(",") if item.strip()]

    @property
    def sqlite_file(self) -> Path:
        path = Path(self.sqlite_path)
        return path if path.is_absolute() else PROJECT_ROOT / path

    @property
    def database_url(self) -> str:
        dialect = self.database_dialect.strip().lower()
        if dialect == "sqlite":
            return f"sqlite:///{self.sqlite_file.as_posix()}"
        if dialect in {"mysql", "mysql+pymysql"}:
            user = quote_plus(self.mysql_user)
            password = quote_plus(self.mysql_password)
            return (
                f"mysql+pymysql://{user}:{password}@"
                f"{self.mysql_host}:{self.mysql_port}/{self.mysql_database}"
                "?charset=utf8mb4"
            )
        raise ValueError("DATABASE_DIALECT 仅支持 sqlite 或 mysql")

    @property
    def upload_path(self) -> Path:
        path = Path(self.upload_dir)
        return path if path.is_absolute() else PROJECT_ROOT / path

    @property
    def model_configured(self) -> bool:
        return bool(self.openai_api_key)

    @property
    def knowledge_service_configured(self) -> bool:
        return bool(self.knowledge_service_base.strip())


@lru_cache(maxsize=1)
def get_settings() -> Settings:
    return Settings()


settings = get_settings()