from typing import List

from crewai.knowledge.embedder.base_embedder import BaseEmbedder
from crewai.knowledge.source.base_knowledge_source import BaseKnowledgeSource


class StringKnowledgeSource(BaseKnowledgeSource):
    """A knowledge source that stores and queries plain text content using embeddings."""

    def __init__(
        self,
        content: str,
        chunk_size: int = 1000,
        chunk_overlap: int = 200,
    ):
        super().__init__(
            chunk_size,
            chunk_overlap,
        )
        self.content = content
        self.load_content()

    def load_content(self):
        """Load and preprocess string content."""
        if not isinstance(self.content, str):
            raise ValueError("StringKnowledgeSource only accepts string content")

    def add(self, embedder: BaseEmbedder) -> None:
        """
        Add string content to the knowledge source, chunk it, compute embeddings,
        and save the embeddings.
        """
        new_chunks = self._chunk_text(self.content)
        self.chunks.extend(new_chunks)
        # Compute embeddings for the new chunks
        new_embeddings = embedder.embed_chunks(new_chunks)
        # Save the embeddings
        self.chunk_embeddings.extend(new_embeddings)

    def _chunk_text(self, text: str) -> List[str]:
        """Utility method to split text into chunks."""
        return [
            text[i : i + self.chunk_size]
            for i in range(0, len(text), self.chunk_size - self.chunk_overlap)
        ]