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

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    stream=sys.stdout,
    force=True,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
)
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()

# ---------------- 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

# ---------------- DB Status Helpers ----------------
def set_request_status(request_id: str, status: str):
    """Update the status column in document_requests for the given request_id."""
    supabase.from_("document_requests").update({"status": status}).eq("id", request_id).execute()
    logger.info(f"Request {request_id} status -> {status}")

def get_request_status(request_id: str) -> str:
    """Fetch current status from document_requests."""
    response = (
        supabase
        .from_("document_requests")
        .select("status")
        .eq("id", request_id)
        .maybe_single()
        .execute()
    )
    if response.data:
        return response.data["status"]
    return "not_found"

# ---------------- 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.
    DB writes: 2 total — one at start (redacting), one at end (redacted | failed).
    The 'pending' write is done by the endpoint before this task is dispatched.
    """
    try:
        print("Request arrived at redact_request function")
        # Write 1: mark as redacting
        set_request_status(request_id, "redacting")

        response = (
            supabase
            .from_("request_files")
            .select("id, storage_path")
            .eq("request_id", request_id)
            .execute()
        )

        files = response.data
        if not files:
            set_request_status(request_id, "approved")
            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_file_from_supabase(bucket, storage_path, local_upload)
            redactor.redact_document(pdf_path=str(local_upload), output_path=str(local_output))
            upload_file_to_supabase(bucket, storage_path, local_output)
            cleanup_temp_files([local_upload, local_output])

        # Write 2: mark as redacted
        set_request_status(request_id, "redacted")

    except Exception as e:
        print(f"Redaction failed for {request_id}: {str(e)}")
        logger.error(f"Redaction failed for {request_id}: {str(e)}")
        # Write 2 (error path): mark as failed
        set_request_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):
    # Check current DB status to avoid re-triggering an in-progress job
    current_status = get_request_status(request_id)

    if current_status == "redacting":
        return RedactionStatusResponse(
            request_id=request_id,
            status="redacting",
            files=[],
            message="Redaction already in progress"
        )

    # Write 1: set pending before dispatching background task
    set_request_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 = get_request_status(request_id)

    files: List[str] = []

    if status == "redacted":
        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 = {
        "redacted": "Redaction completed",
        "pending": "Redaction pending",
        "redacting": "Redaction in progress",
        "failed": "Redaction failed",
        "not_found": "Request not found",
    }.get(status, status)

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