app/main.py

# main.py
from fastapi import FastAPI, File, UploadFile, HTTPException
from fastapi.responses import JSONResponse
from typing import Dict, Any
import io
import base64
import logging
from .annotations import analyze_pdf

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI(
    title="PDF Language Issue Analyzer",
    description="An API to analyze PDFs for language issues and provide an annotated PDF.",
    version="1.0.0"
)

@app.get("/", summary="Root Endpoint")
def read_root():
    """
    Root endpoint to verify that the API is running.
    """
    logger.info("Root endpoint accessed.")
    return {"message": "PDF Language Issue Analyzer API is running."}

@app.post("/analyze", summary="Analyze PDF for Language Issues")
async def analyze_pdf_endpoint(file: UploadFile = File(...)):
    """
    Analyze an uploaded PDF file for language issues.

    - **file**: PDF file to be analyzed.
    """
    if file.content_type != "application/pdf":
        logger.error("Invalid file type uploaded: %s", file.content_type)
        raise HTTPException(status_code=400, detail="Invalid file type. Only PDFs are supported.")

    try:
        contents = await file.read()
        file_stream = io.BytesIO(contents)
        language_issues, annotated_pdf = analyze_pdf(file_stream)

        response = {
            "language_issues": language_issues
        }

        if annotated_pdf:
            # Properly encode the annotated PDF in Base64
            encoded_pdf = base64.b64encode(annotated_pdf).decode('utf-8')
            response["annotated_pdf"] = f"data:application/pdf;base64,{encoded_pdf}"
            logger.info("Annotated PDF generated and encoded.")

        logger.info("PDF analysis completed successfully.")
        return JSONResponse(content=response)
    except Exception as e:
        logger.exception("Error occurred during PDF analysis.")
        raise HTTPException(status_code=500, detail=str(e))