from typing import Any, Dict, Optional, Union, Type

from pydantic import BaseModel, Field, model_validator


class OpenSearchConfig(BaseModel):
    collection_name: str = Field("mem0", description="Name of the index")
    host: str = Field("localhost", description="OpenSearch host")
    port: int = Field(9200, description="OpenSearch port")
    user: Optional[str] = Field(
        None, description="Username for authentication"
    )
    password: Optional[str] = Field(
        None, description="Password for authentication"
    )
    api_key: Optional[str] = Field(
        None, description="API key for authentication (if applicable)"
    )
    embedding_model_dims: int = Field(
        1536, description="Dimension of the embedding vector"
    )
    verify_certs: bool = Field(
        False, description="Verify SSL certificates (default False for OpenSearch)"
    )
    use_ssl: bool = Field(
        False, description="Use SSL for connection (default False for OpenSearch)"
    )
    http_auth: Optional[object] = Field(
        None, description="HTTP authentication method / AWS SigV4"
    )
    connection_class: Optional[Union[str, Type]] = Field(
        "RequestsHttpConnection", description="Connection class for OpenSearch"
    )
    pool_maxsize: int = Field(
        20, description="Maximum number of connections in the pool"
    )

    @model_validator(mode="before")
    @classmethod
    def validate_auth(cls, values: Dict[str, Any]) -> Dict[str, Any]:
        # Check if host is provided
        if not values.get("host"):
            raise ValueError("Host must be provided for OpenSearch")
        
        return values

    @model_validator(mode="before")
    @classmethod
    def validate_extra_fields(cls, values: Dict[str, Any]) -> Dict[str, Any]:
        allowed_fields = set(cls.model_fields.keys())
        input_fields = set(values.keys())
        extra_fields = input_fields - allowed_fields
        if extra_fields:
            raise ValueError(
                f"Extra fields not allowed: {', '.join(extra_fields)}. "
                f"Allowed fields: {', '.join(allowed_fields)}"
            )
        return values