"""
Configuration management for the Technical Mindmap Generator
Handles all application settings and API key management
"""
import os
from dotenv import load_dotenv
from pydantic import BaseModel, Field
from typing import Optional

# Load environment variables from .env file
load_dotenv()


class Settings(BaseModel):
    """
    Application settings with validation

    Attributes:
        gemini_api_key: Google Gemini API key for AI synthesis
        tavily_api_key: Tavily API key for web search
        google_cloud_project_id: Google Cloud project ID for Knowledge Graph
        max_concurrent_requests: Maximum number of parallel API calls
        cache_enabled: Enable/disable result caching
        debug_mode: Enable debug logging
        max_nodes: Maximum nodes in generated mindmap
        max_depth: Maximum depth of node hierarchy
    """

    # API Keys
    gemini_api_key: str = Field(
        default_factory=lambda: os.getenv("GEMINI_API_KEY", ""),
        description="Gemini API key for AI-powered synthesis"
    )

    tavily_api_key: str = Field(
        default_factory=lambda: os.getenv("TAVILY_API_KEY", ""),
        description="Tavily API key for web search"
    )

    google_cloud_api_key: str = Field(
    default_factory=lambda: os.getenv("GOOGLE_CLOUD_API_KEY", ""),
    description="API key for Google Knowledge Graph REST API"
)


    # Application Settings
    max_concurrent_requests: int = Field(
        default_factory=lambda: int(os.getenv("MAX_CONCURRENT_REQUESTS", "3")),
        ge=1,
        le=10,
        description="Maximum concurrent API requests"
    )

    cache_enabled: bool = Field(
        default_factory=lambda: os.getenv("CACHE_ENABLED", "true").lower() == "true",
        description="Enable result caching"
    )

    debug_mode: bool = Field(
        default_factory=lambda: os.getenv("DEBUG_MODE", "false").lower() == "true",
        description="Enable debug mode"
    )

    # Mindmap Settings
    max_nodes: int = Field(
        default_factory=lambda: int(os.getenv("MAX_NODES", "20")),
        ge=5,
        le=50,
        description="Maximum nodes in mindmap"
    )

    max_depth: int = Field(
        default_factory=lambda: int(os.getenv("MAX_DEPTH", "2")),
        ge=1,
        le=5,
        description="Maximum depth of node hierarchy"
    )

    class Config:
        """Pydantic configuration"""
        env_file = ".env"
        case_sensitive = False

    def validate_api_keys(self) -> tuple[bool, list[str]]:
        """
        Validate that all required API keys are present

        Returns:
            Tuple of (is_valid, missing_keys)
        """
        missing_keys = []

        if not self.gemini_api_key:
            missing_keys.append("GEMINI_API_KEY")

        if not self.tavily_api_key:
            missing_keys.append("TAVILY_API_KEY")

        if not self.google_cloud_api_key:
            missing_keys.append("GOOGLE_CLOUD_API_KEY")

        return (len(missing_keys) == 0, missing_keys)


# Create global settings instance
settings = Settings()


def get_settings() -> Settings:
    """
    Get the global settings instance

    Returns:
        Settings object
    """
    return settings


def display_settings_info():
    """Print current settings (for debugging)"""
    print("=" * 50)
    print("TECHNICAL MINDMAP GENERATOR - SETTINGS")
    print("=" * 50)
    print(f"Max Concurrent Requests: {settings.max_concurrent_requests}")
    print(f"Cache Enabled: {settings.cache_enabled}")
    print(f"Debug Mode: {settings.debug_mode}")
    print(f"Max Nodes: {settings.max_nodes}")
    print(f"Max Depth: {settings.max_depth}")

    is_valid, missing = settings.validate_api_keys()
    if is_valid:
        print("✅ All API keys configured")
    else:
        print(f"❌ Missing API keys: {', '.join(missing)}")
    print("=" * 50)