"""
Configuration settings for the application.
Uses Pydantic settings management with environment variable support.
"""

import os
from typing import List, Optional
from pydantic_settings import BaseSettings
from pydantic import AnyHttpUrl, validator


class Settings(BaseSettings):
    """Application settings."""

    # API Settings
    API_V1_STR: str = "/api/v1"
    PROJECT_NAME: str = "Daily Journal Prompt Generator API"
    VERSION: str = "1.0.0"
    DEBUG: bool = False
    ENVIRONMENT: str = "development"

    # Server Settings
    HOST: str = "0.0.0.0"
    PORT: int = 8000

    # CORS Settings
    BACKEND_CORS_ORIGINS: List[AnyHttpUrl] = [
        "http://localhost:3000",  # Frontend dev server
        "http://localhost:80",    # Frontend production
    ]

    # API Keys
    DEEPSEEK_API_KEY: Optional[str] = None
    OPENAI_API_KEY: Optional[str] = None
    API_BASE_URL: str = "https://api.deepseek.com"
    MODEL: str = "deepseek-chat"

    # Application Settings
    MIN_PROMPT_LENGTH: int = 500
    MAX_PROMPT_LENGTH: int = 1000
    NUM_PROMPTS_PER_SESSION: int = 3
    CACHED_POOL_VOLUME: int = 20
    HISTORY_BUFFER_SIZE: int = 60
    FEEDBACK_HISTORY_SIZE: int = 30

    # File Paths (relative to project root)
    DATA_DIR: str = "data"
    PROMPT_TEMPLATE_PATH: str = "data/ds_prompt.txt"
    FEEDBACK_TEMPLATE_PATH: str = "data/ds_feedback.txt"
    SETTINGS_CONFIG_PATH: str = "data/settings.cfg"

    # Data File Names (relative to DATA_DIR)
    PROMPTS_HISTORIC_FILE: str = "prompts_historic.json"
    PROMPTS_POOL_FILE: str = "prompts_pool.json"
    FEEDBACK_HISTORIC_FILE: str = "feedback_historic.json"
    # Note: feedback_words.json is deprecated and merged into feedback_historic.json

    @validator("BACKEND_CORS_ORIGINS", pre=True)
    def assemble_cors_origins(cls, v: str | List[str]) -> List[str] | str:
        """Parse CORS origins from string or list."""
        if isinstance(v, str) and not v.startswith("["):
            return [i.strip() for i in v.split(",")]
        elif isinstance(v, (list, str)):
            return v
        raise ValueError(v)

    class Config:
        """Pydantic configuration."""
        env_file = ".env"
        case_sensitive = True
        extra = "ignore"


# Create global settings instance
settings = Settings()