from langchain_community.document_loaders import (
    PyPDFLoader,
    UnstructuredWordDocumentLoader,
    YoutubeLoader
)
from langchain_community.document_loaders.generic import GenericLoader
from langchain_community.document_loaders.parsers.audio import OpenAIWhisperParser
from langchain.text_splitter import RecursiveCharacterTextSplitter
from youtube_transcript_api import YouTubeTranscriptApi
import re

class ContentProcessor:
    def __init__(self):
        self.text_splitter = RecursiveCharacterTextSplitter(
            chunk_size=1000,
            chunk_overlap=200
        )
    
    def process_pdf(self, file_path):
        loader = PyPDFLoader(file_path)
        pages = loader.load_and_split(self.text_splitter)
        return pages
    
    def process_docx(self, file_path):
        loader = UnstructuredWordDocumentLoader(file_path)
        pages = loader.load_and_split(self.text_splitter)
        return pages
    
    def process_youtube(self, video_url):
        video_id = self._extract_video_id(video_url)
        if not video_id:
            raise ValueError("This appears to be an invalid YouTube URL. Please check the URL and try again.")
        
        try:
            transcript_list = YouTubeTranscriptApi.get_transcript(video_id)
            full_transcript = " ".join([entry['text'] for entry in transcript_list])
            
            # Create a document-like structure
            from langchain.schema import Document
            doc = Document(
                page_content=full_transcript,
                metadata={"source": video_url}
            )
            
            return self.text_splitter.split_documents([doc])
            
        except TranscriptsDisabled:
            raise Exception("This video does not have subtitles/captions enabled. Please try a different video that has captions available.")
        except Exception as e:
            raise Exception(f"Unable to get transcript: {str(e)}. Please ensure the video has captions enabled.")
    
    def _extract_video_id(self, url):
        # Handle different YouTube URL formats
        patterns = [
            r'(?:youtube\.com\/watch\?v=|youtu.be\/|youtube.com\/embed\/)([^&\n?]*)',
            r'(?:youtube\.com\/shorts\/)([^&\n?]*)'
        ]
        
        for pattern in patterns:
            match = re.search(pattern, url)
            if match:
                return match.group(1)
        return None
    
    def process_audio(self, audio_file):
        loader = GenericLoader(
            audio_file,
            parser=OpenAIWhisperParser()
        )
        transcript = loader.load()
        return self.text_splitter.split_documents(transcript)