main.py

"""
FastAPI application for PDF redaction using NER
"""
from fastapi import FastAPI, File, UploadFile, HTTPException, BackgroundTasks
from fastapi.responses import FileResponse
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel
from typing import List, Optional, Dict
import uvicorn
import os
import uuid
import shutil
from pathlib import Path
import logging

from app.redaction import PDFRedactor
from client_supabase import supabase  # Supabase client in separate file

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

# Initialize FastAPI app
app = FastAPI(
    title="PDF Redaction API",
    description="Redact sensitive information from PDFs using Named Entity Recognition",
    version="1.0.0"
)

# CORS middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Create directories
UPLOAD_DIR = Path("uploads")
OUTPUT_DIR = Path("outputs")
UPLOAD_DIR.mkdir(exist_ok=True)
OUTPUT_DIR.mkdir(exist_ok=True)

# Initialize redactor
redactor = PDFRedactor()

# ---------------- In-Memory Redaction Status Tracker ----------------
# request_id -> status (pending | processing | completed | failed)
redaction_status: Dict[str, str] = {}

# ---------------- Response Models ----------------
class RedactionEntity(BaseModel):
    entity_type: str
    entity_text: str
    page: int
    word_count: int

class RedactionResponse(BaseModel):
    job_id: str
    status: str
    message: str
    entities: Optional[List[RedactionEntity]] = None
    redacted_file_url: Optional[str] = None

class RedactionStatusResponse(BaseModel):
    request_id: str
    status: str
    files: List[str]
    message: str


class HealthResponse(BaseModel):
    status: str
    version: str
    model_loaded: bool

# ---------------- Helper Functions ----------------
def get_public_url(bucket: str, storage_path: str) -> str:
    return f"{os.getenv('SUPABASE_URL')}/storage/v1/object/public/{bucket}/{storage_path}"
def cleanup_files(job_id: str):
    """Clean up temporary files after a delay"""
    try:
        upload_path = UPLOAD_DIR / f"{job_id}.pdf"
        if upload_path.exists():
            upload_path.unlink()
        logger.info(f"Cleaned up files for job {job_id}")
    except Exception as e:
        logger.error(f"Error cleaning up files for job {job_id}: {str(e)}")

def cleanup_temp_files(paths: List[Path]):
    for path in paths:
        if path.exists():
            path.unlink()

def download_file_from_supabase(bucket: str, storage_path: str, local_path: Path):
    logger.info(f"Downloading {storage_path} to {local_path}")
    data = supabase.storage.from_(bucket).download(storage_path)
    if not data:
        raise Exception(f"Failed to download {storage_path}")
    with local_path.open("wb") as f:
        f.write(data)

def upload_file_to_supabase(bucket: str, storage_path: str, local_path: Path):
    logger.info(f"Uploading {local_path} to {storage_path}")

    with local_path.open("rb") as f:
        content = f.read()

    supabase.storage.from_(bucket).upload(
        path=storage_path,
        file=content,
        file_options={
            "upsert": "true",
            "content-type": "application/pdf"
        }
    )

def redact_request(request_id: str, bucket: str = "doc_storage"):
    """Background task: redact all files for a given request_id"""
    try:
        redaction_status[request_id] = "processing"

        # Fetch all files for this request_id
        response = (
            supabase
            .from_("request_files")
            .select("id, storage_path")
            .eq("request_id", request_id)
            .execute()
        )

        files = response.data

        if not files:
            raise Exception(f"No files found for request {request_id}")
        if not files:
            raise Exception(f"No files found for request {request_id}")

        for file in files:
            storage_path = file["storage_path"]
            local_upload = UPLOAD_DIR / f"{uuid.uuid4()}.pdf"
            local_output = OUTPUT_DIR / f"{uuid.uuid4()}_redacted.pdf"

            # Download from Supabase
            download_file_from_supabase(bucket, storage_path, local_upload)

            # Redact
            redactor.redact_document(pdf_path=str(local_upload), output_path=str(local_output))

            # Upload redacted back to same path
            upload_file_to_supabase(bucket, storage_path, local_output)

            # Cleanup local files
            cleanup_temp_files([local_upload, local_output])

        redaction_status[request_id] = "completed"

    except Exception as e:
        logger.error(f"Redaction failed for {request_id}: {str(e)}")
        redaction_status[request_id] = "failed"

# ----------------- Existing Endpoints -----------------
@app.get("/", response_model=HealthResponse)
async def root():
    return HealthResponse(
        status="healthy",
        version="1.0.0",
        model_loaded=redactor.is_model_loaded()
    )

@app.get("/health", response_model=HealthResponse)
async def health_check():
    return HealthResponse(
        status="healthy",
        version="1.0.0",
        model_loaded=redactor.is_model_loaded()
    )

@app.post("/redact", response_model=RedactionResponse)
async def redact_pdf(
    background_tasks: BackgroundTasks,
    file: UploadFile = File(...),
    dpi: int = 300,
    entity_types: Optional[str] = None
):
    if not file.filename.endswith('.pdf'):
        raise HTTPException(status_code=400, detail="Only PDF files are supported")
    job_id = str(uuid.uuid4())
    upload_path = UPLOAD_DIR / f"{job_id}.pdf"
    output_path = OUTPUT_DIR / f"{job_id}_redacted.pdf"
    try:
        with upload_path.open("wb") as buffer:
            shutil.copyfileobj(file.file, buffer)

        entity_filter = None
        if entity_types:
            entity_filter = [et.strip() for et in entity_types.split(',')]

        result = redactor.redact_document(
            pdf_path=str(upload_path),
            output_path=str(output_path),
            dpi=dpi,
            entity_filter=entity_filter
        )

        response_entities = [
            RedactionEntity(
                entity_type=e['entity_type'],
                entity_text=e['entity_text'],
                page=e['words'][0]['page'] if e['words'] else 0,
                word_count=len(e['words'])
            ) for e in result['entities']
        ]

        background_tasks.add_task(cleanup_files, job_id)

        return RedactionResponse(
            job_id=job_id,
            status="completed",
            message=f"Successfully redacted {len(result['entities'])} entities",
            entities=response_entities,
            redacted_file_url=f"/download/{job_id}"
        )

    except Exception as e:
        logger.error(f"Error processing job {job_id}: {str(e)}")
        if upload_path.exists():
            upload_path.unlink()
        if output_path.exists():
            output_path.unlink()
        raise HTTPException(status_code=500, detail=f"Error processing PDF: {str(e)}")

@app.get("/download/{job_id}")
async def download_redacted_pdf(job_id: str):
    output_path = OUTPUT_DIR / f"{job_id}_redacted.pdf"
    if not output_path.exists():
        raise HTTPException(status_code=404, detail="Redacted file not found")
    return FileResponse(
        path=output_path,
        media_type="application/pdf",
        filename=f"redacted_{job_id}.pdf"
    )

@app.delete("/cleanup/{job_id}")
async def cleanup_job(job_id: str):
    try:
        cleanup_files(job_id)
        output_path = OUTPUT_DIR / f"{job_id}_redacted.pdf"
        if output_path.exists():
            output_path.unlink()
        return {"message": f"Successfully cleaned up files for job {job_id}"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Error cleaning up: {str(e)}")

@app.get("/stats")
async def get_stats():
    upload_count = len(list(UPLOAD_DIR.glob("*.pdf")))
    output_count = len(list(OUTPUT_DIR.glob("*.pdf")))
    return {
        "pending_uploads": upload_count,
        "processed_files": output_count,
        "model_loaded": redactor.is_model_loaded()
    }

# ----------------- NEW Endpoints -----------------
@app.post("/redact_by_request/{request_id}", response_model=RedactionStatusResponse)
async def redact_by_request(request_id: str, background_tasks: BackgroundTasks):
    if redaction_status.get(request_id) == "processing":
        return RedactionStatusResponse(
            request_id=request_id,
            status="processing",
            files=[],
            message="Redaction already in progress"
        )
    redaction_status[request_id] = "pending"
    background_tasks.add_task(redact_request, request_id)
    return RedactionStatusResponse(
        request_id=request_id,
        status="pending",
        files=[],
        message="Redaction started in background"
    )

@app.get("/redaction_status/{request_id}", response_model=RedactionStatusResponse)
async def get_redaction_status(request_id: str):
    status = redaction_status.get(request_id, "not_found")

    # Default empty response
    files: List[str] = []

    if status == "completed":
        # Fetch file paths from DB
        response = (
            supabase
            .from_("request_files")
            .select("storage_path")
            .eq("request_id", request_id)
            .execute()
        )
        
        if response.data:
            files = [
                get_public_url("doc_storage", row["storage_path"])
                for row in response.data
            ]

    message = (
        "Redaction completed"
        if status == "completed"
        else "Redaction pending"
        if status == "pending"
        else "Redaction failed"
        if status == "failed"
        else "Request not found"
    )

    return RedactionStatusResponse(
        request_id=request_id,
        status=status,
        files=files,
        message=message
    )

# ----------------- Run Server -----------------
# if __name__ == "__main__":
#     uvicorn.run(
#         "main:app",
#         host="localhost",
#         port=2700,
#         reload=False
#     )