"""Application configuration using pydantic-settings."""

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


class Settings(BaseSettings):
    """Application settings loaded from environment variables."""

    # App info
    app_name: str = "Data Entry API"
    app_version: str = "1.0.0"
    debug: bool = False

    # API
    api_host: str = "0.0.0.0"
    api_port: int = 8003

    # SQLite Database
    sqlite_database_path: str = "data/receipts/receipts.db"

    # File uploads
    upload_path: str = "data/uploads"
    max_upload_size_mb: int = 10
    allowed_mime_types: List[str] = [
        "image/jpeg",
        "image/png",
        "image/gif",
        "image/webp",
        "application/pdf",
    ]

    # Oracle Database (for nomenclatures)
    oracle_user: str = ""
    oracle_password: str = ""
    oracle_host: str = "localhost"
    oracle_port: int = 1526
    oracle_sid: str = "ROA"

    # JWT Authentication
    jwt_secret_key: str = "change-me-in-production"
    jwt_algorithm: str = "HS256"
    jwt_expire_minutes: int = 480

    # CORS
    cors_origins: str = "http://localhost:3010,http://localhost:3000"

    # OCR Engines (comma-separated list of active engines shown in UI)
    # Available: tesseract, paddleocr, doctr, doctr_plus
    # doctr_plus is recommended (2-tier sequential with early exit)
    ocr_active_engines: str = "doctr,doctr_plus"

    class Config:
        env_file = ".env"
        env_file_encoding = "utf-8"
        extra = "ignore"

    @property
    def database_url(self) -> str:
        """Get SQLite database URL for async."""
        return f"sqlite+aiosqlite:///{self.sqlite_database_path}"

    @property
    def sync_database_url(self) -> str:
        """Get SQLite database URL for sync operations (Alembic)."""
        return f"sqlite:///{self.sqlite_database_path}"

    @property
    def upload_path_resolved(self) -> Path:
        """Get resolved upload path."""
        path = Path(self.upload_path)
        path.mkdir(parents=True, exist_ok=True)
        return path

    @property
    def max_upload_size_bytes(self) -> int:
        """Get max upload size in bytes."""
        return self.max_upload_size_mb * 1024 * 1024

    @property
    def cors_origins_list(self) -> List[str]:
        """Get CORS origins as list."""
        return [origin.strip() for origin in self.cors_origins.split(",")]

    @property
    def ocr_active_engines_list(self) -> List[str]:
        """Get OCR active engines as list."""
        return [engine.strip() for engine in self.ocr_active_engines.split(",")]

    @property
    def oracle_dsn(self) -> str:
        """Get Oracle DSN string."""
        return f"{self.oracle_host}:{self.oracle_port}/{self.oracle_sid}"


@lru_cache()
def get_settings() -> Settings:
    """Get cached settings instance."""
    return Settings()


# Convenience instance
settings = get_settings()