import imaplib
import email
import os
import time
import requests

MAIL_SERVER = 'imap.gmail.com'
EMAIL_USER = 'shrutj2104@gmail.com'
EMAIL_PASS = 'aymw wxrh fmea bxfz'
MAIL_BOX = 'INBOX'
DOWNLOAD_FOLDER = "./downloaded_pdfs"
BACKEND_UPLOAD_URL = "http://127.0.0.1:8000/documents/upload"

os.makedirs(DOWNLOAD_FOLDER, exist_ok=True)

def upload_file_to_backend(file_path):
    """
    Uploads a PDF to the backend. The server will handle setting the defaults.
    """
    print(f"--- Uploading {os.path.basename(file_path)} to the server... ---")
    try:
        with open(file_path, "rb") as f:
            # We ONLY need to send the file now. No more payload.
            files = {"file": (os.path.basename(file_path), f, "application/pdf")}
            response = requests.post(BACKEND_UPLOAD_URL, files=files) # The 'data' parameter is removed
            response.raise_for_status()

            print(f"✅ Successfully uploaded and processed {os.path.basename(file_path)}.")
            return True

    except requests.exceptions.RequestException as e:
        print(f"❌ ERROR: Failed to upload {os.path.basename(file_path)}.")
        print(f"Reason: {e}")
        if e.response:
            print(f"--- Server's Detailed Error Response ---")
            try: print(e.response.json())
            except ValueError: print(e.response.text)
            print(f"------------------------------------")
        return False


def download_and_process_attachments(mail):
    """
    Searches for UNSEEN emails, downloads PDF attachments, and uploads them.
    """
    mail.select(MAIL_BOX)
    # IMPORTANT: Changed to 'UNSEEN' to only process new emails
    status, mails = mail.search(None, 'UNSEEN')
    if status != 'OK':
        print("Error searching for emails.")
        return

    email_ids = mails[0].split()

    if not email_ids:
        print("No new emails found.")
        return

    print(f"Found {len(email_ids)} new emails to process.")
    for eid in email_ids:
        _, msg_data = mail.fetch(eid, "(RFC822)")
        msg = email.message_from_bytes(msg_data[0][1])

        for part in msg.walk():
            # Skip container parts and parts without a filename
            if part.get_content_maintype() == 'multipart' or part.get('Content-Disposition') is None:
                continue

            filename = part.get_filename()
            # Check if there is a filename and it ends with .pdf
            if filename and filename.lower().endswith(".pdf"):

                # 1. DOWNLOAD the file to a temporary location
                filepath = os.path.join(DOWNLOAD_FOLDER, filename)
                with open(filepath, 'wb') as f:
                    f.write(part.get_payload(decode=True))
                print(f"Downloaded temporary file: {filepath}")

                # 2. UPLOAD the file to the backend
                upload_success = upload_file_to_backend(filepath)

                # 3. CLEAN UP the temporary file after processing
                try:
                    os.remove(filepath)
                    print(f"Cleaned up temporary file: {filepath}")
                except OSError as e:
                    print(f"Error during file cleanup: {e}")


if __name__ == "__main__":
    while True:
        try:
            mail = imaplib.IMAP4_SSL(MAIL_SERVER)
            mail.login(EMAIL_USER, EMAIL_PASS)
            print("✅ Logged in successfully. Starting to monitor for new emails...")

            while True:
                download_and_process_attachments(mail)
                print("--- Waiting for 60 seconds before next check... ---")
                time.sleep(60)

        except Exception as e:
            print(f"An unexpected error occurred: {e}")
            print("--- Attempting to reconnect in 60 seconds... ---")
            time.sleep(60)