from google.oauth2 import service_account
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
from typing import Dict

class GoogleDocsReader:
    def __init__(self, credentials_dict: dict):
        """
        Initialize with credentials dictionary (decoded from base64)
        """
        self.credentials = service_account.Credentials.from_service_account_info(
            credentials_dict,
            scopes=['https://www.googleapis.com/auth/documents.readonly']
        )
        self.service = build('docs', 'v1', credentials=self.credentials)
    
    def read_document(self, document_id: str) -> str:
        """
        Read the content of a Google Doc and return as plain text
        """
        try:
            # Get the document
            document = self.service.documents().get(documentId=document_id).execute()
            
            # Extract text content
            content = document.get('body', {}).get('content', [])
            text_parts = []
            
            for element in content:
                if 'paragraph' in element:
                    paragraph = element['paragraph']
                    for text_element in paragraph.get('elements', []):
                        if 'textRun' in text_element:
                            text_parts.append(text_element['textRun'].get('content', ''))
                elif 'table' in element:
                    # Handle tables
                    table = element['table']
                    for row in table.get('tableRows', []):
                        for cell in row.get('tableCells', []):
                            for cell_element in cell.get('content', []):
                                if 'paragraph' in cell_element:
                                    paragraph = cell_element['paragraph']
                                    for text_element in paragraph.get('elements', []):
                                        if 'textRun' in text_element:
                                            text_parts.append(text_element['textRun'].get('content', ''))
            
            return ''.join(text_parts)
        
        except HttpError as e:
            if e.resp.status == 404:
                raise Exception(f"Document not found: {document_id}")
            elif e.resp.status == 403:
                raise Exception(
                    f"Permission denied. Please ensure:\n"
                    f"1. The document is shared with your service account\n"
                    f"2. Service account has at least 'Viewer' access"
                )
            else:
                raise Exception(f"Error reading document: {str(e)}")
        except Exception as e:
            raise Exception(f"Error reading document: {str(e)}")
    
    def get_document_title(self, document_id: str) -> str:
        """
        Get the title of a Google Doc
        """
        try:
            document = self.service.documents().get(documentId=document_id).execute()
            return document.get('title', 'Untitled')
        except Exception as e:
            raise Exception(f"Error getting document title: {str(e)}")