"""RAG pipeline for Graphics Guide / Design Assistant"""

from typing import Iterator, Optional, List, Tuple
from .vectorstore import GraphicsVectorStore, create_vectorstore
from .llm_client import InferenceProviderClient, create_llm_client
from .prompts import (
    SYSTEM_PROMPT,
    DESIGN_PROMPT,
    get_design_prompt
)


class GraphicsDesignPipeline:
    """RAG pipeline for generating graphics and design recommendations"""

    def __init__(
        self,
        vectorstore: Optional[GraphicsVectorStore] = None,
        llm_client: Optional[InferenceProviderClient] = None,
        retrieval_k: int = 5
    ):
        """
        Initialize the RAG pipeline

        Args:
            vectorstore: Vector store instance (creates default if None)
            llm_client: LLM client instance (creates default if None)
            retrieval_k: Number of document chunks to retrieve for context
        """
        self.vectorstore = vectorstore or create_vectorstore()
        self.llm_client = llm_client or create_llm_client()
        self.retrieval_k = retrieval_k

    def retrieve_documents(self, query: str, k: Optional[int] = None) -> List:
        """
        Retrieve relevant document chunks for a query

        Args:
            query: User's design query
            k: Number of documents to retrieve (uses default if None)

        Returns:
            List of relevant document chunks
        """
        k = k or self.retrieval_k
        return self.vectorstore.similarity_search(query, k=k)

    def generate_recommendations(
        self,
        query: str,
        stream: bool = False
    ) -> str | Iterator[str]:
        """
        Generate design recommendations for a query

        Args:
            query: User's design query
            stream: Whether to stream the response

        Returns:
            Generated recommendations (string or iterator)
        """
        # Retrieve relevant documents
        relevant_docs = self.retrieve_documents(query)

        # Format documents for context
        context = self.vectorstore.format_documents_for_context(relevant_docs)

        # Generate prompt
        prompt_template = get_design_prompt()
        full_prompt = prompt_template.format(query=query, context=context)

        # Generate response
        if stream:
            return self.llm_client.generate_stream(
                prompt=full_prompt,
                system_prompt=SYSTEM_PROMPT
            )
        else:
            return self.llm_client.generate(
                prompt=full_prompt,
                system_prompt=SYSTEM_PROMPT
            )

    def chat(
        self,
        message: str,
        history: Optional[List[Tuple[str, str]]] = None,
        stream: bool = False
    ) -> str | Iterator[str]:
        """
        Handle a chat message with conversation history

        Args:
            message: User's message
            history: Conversation history as list of (user_msg, assistant_msg) tuples
            stream: Whether to stream the response

        Returns:
            Generated response (string or iterator)
        """
        # For now, treat each message as a new design query
        # In the future, could implement follow-up handling
        return self.generate_recommendations(message, stream=stream)

    def get_relevant_examples(
        self,
        query: str,
        k: int = 5
    ) -> List[dict]:
        """
        Get relevant examples and knowledge with metadata

        Args:
            query: Design query
            k: Number of examples to recommend

        Returns:
            List of document dictionaries with metadata
        """
        docs = self.retrieve_documents(query, k=k)

        examples = []
        for doc in docs:
            example = {
                "source": doc.metadata.get("source_id", "Unknown"),
                "source_type": doc.metadata.get("source_type", "N/A"),
                "page": doc.metadata.get("page_number"),
                "content": doc.page_content,
                "similarity": doc.metadata.get("similarity")
            }
            examples.append(example)

        return examples


def create_pipeline(
    retrieval_k: int = 5,
    model: str = "meta-llama/Llama-3.1-8B-Instruct",
    temperature: float = 0.2
) -> GraphicsDesignPipeline:
    """
    Factory function to create a configured RAG pipeline

    Args:
        retrieval_k: Number of documents to retrieve
        model: LLM model identifier
        temperature: LLM temperature

    Returns:
        Configured GraphicsDesignPipeline
    """
    vectorstore = create_vectorstore()
    llm_client = create_llm_client(model=model, temperature=temperature)

    return GraphicsDesignPipeline(
        vectorstore=vectorstore,
        llm_client=llm_client,
        retrieval_k=retrieval_k
    )