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

# Calculate the project root (tipitaka-api folder)
PROJECT_ROOT = Path(__file__).resolve().parent.parent

# Detect Data Directory
# 1. Environment variable DATA_DIR
# 2. Docker standard path /app/data (Only if on Linux/Docker)
# 3. Local project 'data' folder
# Detect Data Directory
if os.getenv("DATA_DIR"):
    DATA_DIR_DEFAULT = os.getenv("DATA_DIR")
elif os.name != 'nt' and os.path.exists("/app/data"):
    DATA_DIR_DEFAULT = "/app/data"
else:
    # Use 'data' folder in project root as default
    DATA_DIR_DEFAULT = str(PROJECT_ROOT / "data")

DATA_DIR = Path(DATA_DIR_DEFAULT)

class Settings(BaseSettings):
    """Application settings — loaded from .env file or environment variables."""

    # ── LLM Provider ──
    LLM_API_KEY: str = ""
    LLM_BASE_URL: str = "https://api.deepseek.com"
    LLM_MODEL_FAST: str = "deepseek-chat"
    LLM_MODEL_REASONER: str = "deepseek-reasoner"

    # ── Paths ──
    DATA_DIR: str = str(DATA_DIR)
    DATABASE_PATH: str = ""
    QDRANT_PATH: str = ""
    SNAPSHOT_DIR: str = ""
    QDRANT_URL: str | None = None
    ST_EMBED_MODEL: str = "jinaai/jina-embeddings-v5-text-small-retrieval"
    QDRANT_COLLECTION: str = "tipitaka_chunks"
    
    def __init__(self, **values):
        super().__init__(**values)
        data_path = Path(self.DATA_DIR)
        rag_root = PROJECT_ROOT.parent.parent # F:\_Ai\Tipitaka-AI-Expert\RAG
        
        # Initialize paths if not explicitly provided
        if not self.DATABASE_PATH:
            # Priority: 1. data/tipitaka_mcu.db, 2. RAG_ROOT/tipitaka_mcu.db
            local_db = data_path / "tipitaka_mcu.db"
            root_db = rag_root / "tipitaka_mcu.db"
            if local_db.exists():
                self.DATABASE_PATH = str(local_db)
            elif root_db.exists():
                self.DATABASE_PATH = str(root_db)
            else:
                self.DATABASE_PATH = str(local_db) # Fallback

        if not self.QDRANT_PATH:
            self.QDRANT_PATH = str(data_path / "qdrant_storage")
            
        if not self.SNAPSHOT_DIR:
            # Priority: 1. DATA_DIR/snapshots, 2. RAG_ROOT/snapshots
            local_snapshots = data_path / "snapshots"
            root_snapshots = rag_root / "snapshots"
            
            if local_snapshots.exists():
                self.SNAPSHOT_DIR = str(local_snapshots)
            elif root_snapshots.exists():
                self.SNAPSHOT_DIR = str(root_snapshots)
            else:
                self.SNAPSHOT_DIR = str(local_snapshots) # Fallback

    # ── CORS ──
    CORS_ORIGINS: str = "*"

    # ── Discord Webhook (health alerts) ──
    DISCORD_WEBHOOK_URL: str = ""
    DEBUG: bool = True
    PORT: int = 8000

    # ── Production static file serving ──
    SERVE_STATIC: bool = False
    STATIC_DIR: str = ""

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


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