"""
Fase 1: Analiza remitentes sin borrar nada.
Genera report.txt con todos los senders agrupados por categoria.
"""
import os
import sys
import re
import pickle
from collections import defaultdict
from google.auth.transport.requests import Request
from google_auth_oauthlib.flow import InstalledAppFlow
from googleapiclient.discovery import build

sys.stdout.reconfigure(encoding='utf-8')

SCOPES = ['https://www.googleapis.com/auth/gmail.readonly']
CREDENTIALS_FILE = os.path.join(os.path.dirname(__file__), 'credentials.json')


def authenticate(account_name):
    token_file = os.path.join(os.path.dirname(__file__), f'token_{account_name}.pickle')
    creds = None
    if os.path.exists(token_file):
        with open(token_file, 'rb') as f:
            creds = pickle.load(f)
    if not creds or not creds.valid:
        if creds and creds.expired and creds.refresh_token:
            creds.refresh(Request())
        else:
            flow = InstalledAppFlow.from_client_secrets_file(CREDENTIALS_FILE, SCOPES)
            creds = flow.run_local_server(port=0)
        with open(token_file, 'wb') as f:
            pickle.dump(creds, f)
    return build('gmail', 'v1', credentials=creds)


def get_header(headers, name):
    for h in headers:
        if h['name'].lower() == name.lower():
            return h['value']
    return ''


def extract_domain(sender):
    match = re.search(r'@([\w.\-]+)', sender)
    return match.group(1).lower() if match else sender.lower()


def analyze_account(account_name, email):
    print(f"\nConectando {email}...")
    service = authenticate(account_name)
    print(f"Autenticado. Leyendo correos...")

    senders = defaultdict(int)  # domain -> count
    sender_names = {}           # domain -> full sender example

    queries = [
        ('Promotions', 'category:promotions'),
        ('Updates',    'category:updates'),
        ('Inbox',      'in:inbox'),
    ]

    for category, query in queries:
        print(f"  Escaneando: {category}...")
        page_token = None
        count = 0
        while True:
            kwargs = {'userId': 'me', 'q': query, 'maxResults': 500}
            if page_token:
                kwargs['pageToken'] = page_token
            result = service.users().messages().list(**kwargs).execute()
            messages = result.get('messages', [])
            if not messages:
                break
            for msg_ref in messages:
                try:
                    msg = service.users().messages().get(
                        userId='me', id=msg_ref['id'],
                        format='metadata',
                        metadataHeaders=['From']
                    ).execute()
                    headers = msg.get('payload', {}).get('headers', [])
                    sender = get_header(headers, 'From')
                    domain = extract_domain(sender)
                    senders[domain] += 1
                    if domain not in sender_names:
                        sender_names[domain] = sender
                    count += 1
                except Exception:
                    pass
            page_token = result.get('nextPageToken')
            if not page_token:
                break
        print(f"    {count} mensajes procesados")

    return senders, sender_names


def main():
    accounts = [
        ('alro65',    'alro65@gmail.com'),
        ('alro65usa', 'alro65usa@gmail.com'),
    ]

    report_lines = []

    for account_name, email in accounts:
        senders, sender_names = analyze_account(account_name, email)

        report_lines.append(f"\n{'='*60}")
        report_lines.append(f"CUENTA: {email}")
        report_lines.append(f"{'='*60}")
        report_lines.append(f"Total remitentes unicos: {len(senders)}")
        report_lines.append(f"\nRemitentes ordenados por cantidad de correos:\n")

        for domain, count in sorted(senders.items(), key=lambda x: -x[1]):
            full_sender = sender_names.get(domain, domain)
            report_lines.append(f"  {count:5d}  {domain:<40}  {full_sender[:60]}")

    report_path = os.path.join(os.path.dirname(__file__), 'report.txt')
    with open(report_path, 'w', encoding='utf-8') as f:
        f.write('\n'.join(report_lines))

    print(f"\nReporte guardado en: {report_path}")
    print("Revisalo y dime que hacer con cada remitente.")

    # Also print top 30
    print("\n--- TOP senders (preview) ---")
    for line in report_lines[-50:]:
        print(line)


if __name__ == '__main__':
    main()