from pathlib import Path
from typing import Union, List, Iterator

from phi.document import Document
from phi.document.reader.pdf import PDFReader, PDFUrlReader, PDFImageReader, PDFUrlImageReader
from phi.knowledge.agent import AgentKnowledge
from phi.utils.log import logger


class PDFKnowledgeBase(AgentKnowledge):
    path: Union[str, Path]
    reader: Union[PDFReader, PDFImageReader] = PDFReader()

    @property
    def document_lists(self) -> Iterator[List[Document]]:
        """Iterate over PDFs and yield lists of documents.
        Each object yielded by the iterator is a list of documents.

        Returns:
            Iterator[List[Document]]: Iterator yielding list of documents
        """

        _pdf_path: Path = Path(self.path) if isinstance(self.path, str) else self.path

        if _pdf_path.exists() and _pdf_path.is_dir():
            for _pdf in _pdf_path.glob("**/*.pdf"):
                yield self.reader.read(pdf=_pdf)
        elif _pdf_path.exists() and _pdf_path.is_file() and _pdf_path.suffix == ".pdf":
            yield self.reader.read(pdf=_pdf_path)


class PDFUrlKnowledgeBase(AgentKnowledge):
    urls: List[str] = []
    reader: Union[PDFUrlReader, PDFUrlImageReader] = PDFUrlReader()

    @property
    def document_lists(self) -> Iterator[List[Document]]:
        """Iterate over PDF urls and yield lists of documents.
        Each object yielded by the iterator is a list of documents.

        Returns:
            Iterator[List[Document]]: Iterator yielding list of documents
        """

        for url in self.urls:
            if url.endswith(".pdf"):
                yield self.reader.read(url=url)
            else:
                logger.error(f"Unsupported URL: {url}")