#!/usr/bin/env python3
import os

from fastapi import FastAPI, HTTPException, UploadFile, File, status
from starlette.middleware.sessions import SessionMiddleware
from starlette.config import Config
from starlette.middleware.trustedhost import TrustedHostMiddleware
from uvicorn.middleware.proxy_headers import ProxyHeadersMiddleware
from app.database import init_db
from app.config import settings
from app.tasks.upload_to_s3 import upload_to_s3
from app.tasks.upload_to_dropbox import upload_to_dropbox
from app.tasks.upload_to_paperless import upload_to_paperless
from app.tasks.upload_to_nextcloud import upload_to_nextcloud
from app.tasks.send_to_all import send_to_all_destinations
from pathlib import Path

from app.api import router as api_router
from app.frontend import router as frontend_router
from app.auth import router as auth_router

BASE_DIR = Path(__file__).resolve().parent  # this is /app in many Docker setups
FRONTEND_DIR = BASE_DIR / "frontend"



# Load configuration from .env for the session key
config = Config(".env")
SESSION_SECRET = config(
    "SESSION_SECRET",
    default="YOUR_DEFAULT_SESSION_SECRET_MUST_BE_32_CHARS_OR_MORE"
)

app = FastAPI(title="Document Processing API")


# 1) Session Middleware (for request.session to work)
app.add_middleware(SessionMiddleware, secret_key=SESSION_SECRET)

# 2) Respect the X-Forwarded-* headers from Traefik
#    so your request.url_for(...) uses https://docparse.hosterra.net
app.add_middleware(ProxyHeadersMiddleware, trusted_hosts="*")

# 3) (Optional but recommended) Restrict valid hosts:
app.add_middleware(TrustedHostMiddleware, allowed_hosts=[
    "docparse.hosterra.net",
    "localhost",
    "127.0.0.1"
])

@app.on_event("startup")
def on_startup():
    init_db()  # Create tables if they don't exist

@app.get("/")
def root():
    return {"message": "Document Processing API"}

@app.post("/process/")
def process(file_path: str):
    """
    API Endpoint to start document processing.
    This enqueues the first task (upload_to_s3), which handles the full pipeline.
    """
    if not os.path.isabs(file_path):
        file_path = os.path.join(settings.workdir, file_path)

    if not os.path.exists(file_path):
        raise HTTPException(
            status_code=400, detail=f"File {file_path} not found."
        )

    task = upload_to_s3.delay(file_path)
    return {"task_id": task.id, "status": "queued"}

@app.post("/send_to_dropbox/")
def send_to_dropbox(file_path: str):
    if not os.path.isabs(file_path):
        file_path = os.path.join(settings.workdir, 'processed', file_path)
    if not os.path.exists(file_path):
        raise HTTPException(
            status_code=400, detail=f"File {file_path} not found."
        )
    task = upload_to_dropbox.delay(file_path)
    return {"task_id": task.id, "status": "queued"}

@app.post("/send_to_paperless/")
def send_to_paperless(file_path: str):
    if not os.path.isabs(file_path):
        file_path = os.path.join(settings.workdir, 'processed', file_path)
    if not os.path.exists(file_path):
        raise HTTPException(
            status_code=400, detail=f"File {file_path} not found."
        )
    task = upload_to_paperless.delay(file_path)
    return {"task_id": task.id, "status": "queued"}

@app.post("/send_to_nextcloud/")
def send_to_nextcloud(file_path: str):
    if not os.path.isabs(file_path):
        file_path = os.path.join(settings.workdir, 'processed', file_path)
    if not os.path.exists(file_path):
        raise HTTPException(
            status_code=400, detail=f"File {file_path} not found."
        )
    task = upload_to_nextcloud.delay(file_path)
    return {"task_id": task.id, "status": "queued"}

@app.post("/send_to_all_destinations/")
def send_to_all_destinations_endpoint(file_path: str):
    """
    Call the aggregator task that sends this file to dropbox, nextcloud, and paperless.
    """
    if not os.path.isabs(file_path):
        file_path = os.path.join(settings.workdir, 'processed', file_path)

    if not os.path.exists(file_path):
        raise HTTPException(
            status_code=400, detail=f"File {file_path} not found."
        )

    task = send_to_all_destinations.delay(file_path)
    return {"task_id": task.id, "status": "queued", "file_path": file_path}

@app.post("/processall")
def process_all_pdfs_in_workdir():
    """
    Finds all .pdf files in <workdir> and enqueues them for upload_to_s3.
    """
    target_dir = settings.workdir
    if not os.path.exists(target_dir):
        raise HTTPException(
            status_code=400, detail=f"Directory {target_dir} does not exist."
        )

    pdf_files = []
    for filename in os.listdir(target_dir):
        if filename.lower().endswith(".pdf"):
            pdf_files.append(filename)

    if not pdf_files:
        return {"message": "No PDF files found in that directory."}

    task_ids = []
    for pdf in pdf_files:
        file_path = os.path.join(target_dir, pdf)
        task = upload_to_s3.delay(file_path)
        task_ids.append(task.id)

    return {
        "message": f"Enqueued {len(pdf_files)} PDFs to upload_to_s3",
        "pdf_files": pdf_files,
        "task_ids": task_ids
    }

@app.post("/ui-upload")
async def ui_upload(file: UploadFile = File(...)):
    """Endpoint to accept a user-uploaded file and enqueue it to S3."""
    workdir = "/workdir"
    target_path = os.path.join(workdir, file.filename)
    try:
        with open(target_path, "wb") as f:
            content = await file.read()
            f.write(content)
    except Exception as e:
        raise HTTPException(
            status_code=500,
            detail=f"Failed to save file: {e}"
        )

    task = upload_to_s3.delay(target_path)
    return {"task_id": task.id, "status": "queued"}

@app.exception_handler(404)
async def custom_404_handler(request: Request, exc: HTTPException):
    return FileResponse(
        FRONTEND_DIR / "404.html",
        status_code=status.HTTP_404_NOT_FOUND
    )

# Include the frontend and auth routers
app.include_router(frontend_router)
app.include_router(auth_router)
app.include_router(api_router, prefix="/api")