"""Debug endpoint to see extracted text from PDF."""
from fastapi import APIRouter, Depends, HTTPException, UploadFile, File, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
import logging

from app.core.config import get_settings
from app.core.security import decode_access_token
from app.services.pdf_text import extract_text_from_pdf, PDFExtractionError

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/v1/debug", tags=["Debug"])
security = HTTPBearer()
settings = get_settings()


def get_current_user(credentials: HTTPAuthorizationCredentials = Depends(security)) -> str:
    """Validate JWT token."""
    payload = decode_access_token(credentials.credentials)
    return payload.get("sub")


@router.post("/extract-text")
async def debug_extract_text(
    file: UploadFile = File(...),
    current_user: str = Depends(get_current_user)
):
    """
    Debug endpoint to see raw extracted text from PDF.
    Shows exactly what text was extracted and which method was used.
    """
    # Validate file type
    if file.content_type != "application/pdf":
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Invalid file type: {file.content_type}. Only PDF files are allowed."
        )
    
    # Read file
    pdf_bytes = await file.read()
    
    # Validate size
    file_size_mb = len(pdf_bytes) / (1024 * 1024)
    if file_size_mb > settings.max_file_mb:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"File size ({file_size_mb:.2f} MB) exceeds maximum allowed size of {settings.max_file_mb} MB"
        )
    
    # Extract text
    try:
        text, page_count, extraction_method = extract_text_from_pdf(
            pdf_bytes,
            enable_ocr=settings.ocr_enabled,
            ocr_lang=settings.ocr_language
        )
        
        # Get first and last 500 characters
        text_preview_start = text[:500] if len(text) > 500 else text
        text_preview_end = text[-500:] if len(text) > 500 else ""
        
        return {
            "status": "success",
            "extraction_info": {
                "method": extraction_method,
                "pages": page_count,
                "total_characters": len(text),
                "total_words": len(text.split()),
                "total_lines": len(text.split('\n'))
            },
            "text_preview": {
                "first_500_chars": text_preview_start,
                "last_500_chars": text_preview_end if text_preview_end else None
            },
            "full_text": text,  # Complete extracted text
            "ocr_settings": {
                "ocr_enabled": settings.ocr_enabled,
                "ocr_language": settings.ocr_language,
                "ocr_dpi": settings.ocr_dpi
            }
        }
        
    except PDFExtractionError as e:
        logger.error(f"Extraction failed: {str(e)}")
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Failed to extract text from PDF: {str(e)}"
        )