import contextlib
import requests
import re
import pandas as pd
from bs4 import BeautifulSoup
from urllib.parse import urljoin
from dataclasses import dataclass
from google.auth.transport.requests import Request
from google_auth_oauthlib.flow import InstalledAppFlow
import pickle
import os
from gspread import auth


@dataclass
class Constants:
    EMAIL_REGEX = r"[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}"
    PHONE_REGEX = r"(\+?\d[\d\s().-]{7,}\d)"
    HEADERS = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:135.0) Gecko/20100101 Firefox/135.0"
    }

    SCOPES: tuple = (
        "https://www.googleapis.com/auth/spreadsheets",
        "https://www.googleapis.com/auth/drive",
    )
    TOKEN_PATH: str = "token.pickle"
    CREDENTIALS_PATH: str = "creds.json"
    SPREADSHEET_NAME: str = "Test"
    SHEET_HEADERS = (
        "Company Name",
        "Website",
        "Contact Email",
        "Phone Number",
        "Contact Page URL",
        "Contact Type",
        "Notes",
        "Source",
    )


def authenticate_google_sheets():
    """Authenticate with Google Sheets API using OAuth 2.0 and return a gspread client."""
    creds = None

    if os.path.exists(Constants.TOKEN_PATH):
        with open(Constants.TOKEN_PATH, "rb") as token:
            creds = pickle.load(token)

    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(
                Constants.CREDENTIALS_PATH, Constants.SCOPES
            )
            creds = flow.run_local_server(port=0)

        with open(Constants.TOKEN_PATH, "wb") as token:
            pickle.dump(creds, token)

    return auth.authorize(creds)


def get_page(url):
    with contextlib.suppress(requests.RequestException):
        r = requests.get(url, headers=Constants.HEADERS, timeout=10)
        if r.status_code == 200:
            return r.text
    return ""


def extract_emails(text):
    return list(set(re.findall(Constants.EMAIL_REGEX, text)))


def extract_phones(text):
    return list(set(re.findall(Constants.PHONE_REGEX, text)))


def find_contact_page(soup, base_url):
    for link in soup.find_all("a", href=True):
        href = link["href"].lower()
        if "contact" in href or "about" in href:
            return urljoin(base_url, link["href"])
    return ""


def scrape_company(name, website):
    print(f"Scraping {name}")
    html = get_page(website)

    if not html:
        return {
            "Company Name": name,
            "Website": website,
            "Contact Email": "",
            "Phone Number": "",
            "Contact Page URL": "",
            "Contact Type": "None",
            "Notes": "Website unreachable",
            "Source": "Website",
        }

    soup = BeautifulSoup(html, "html.parser")

    emails = extract_emails(html)
    phones = extract_phones(html)
    contact_page = find_contact_page(soup, website)

    # Try contact page if no email found
    if not emails and contact_page:
        contact_html = get_page(contact_page)
        emails = extract_emails(contact_html)
        phones += extract_phones(contact_html)

    contact_type = "Email" if emails else ("Form" if contact_page else "None")

    return {
        "Company Name": name,
        "Website": website,
        "Contact Email": emails[0] if emails else "",
        "Phone Number": phones[0] if phones else "",
        "Contact Page URL": contact_page,
        "Contact Type": contact_type,
        "Notes": "",
        "Source": "Website",
    }


def main():
    companies = pd.read_csv("companies.csv")
    client = authenticate_google_sheets()
    worksheet = client.open(Constants.SPREADSHEET_NAME).sheet1
    existing_rows = worksheet.get_all_values()
    if not existing_rows or existing_rows[0] != Constants.SHEET_HEADERS:
        worksheet.clear()
        worksheet.append_row(Constants.SHEET_HEADERS)
        existing_rows = []

    existing_websites = {
        row[1].strip().lower().rstrip("/") for row in existing_rows[1:] if len(row) > 1
    }

    for _, row in companies.iterrows():
        website = row["Website"].strip().lower().rstrip("/")

        if website in existing_websites:
            continue

        data = scrape_company(row["Company Name"], row["Website"])

        worksheet.append_row(
            [
                data["Company Name"],
                data["Website"],
                data["Contact Email"],
                data["Phone Number"],
                data["Contact Page URL"],
                data["Contact Type"],
                data["Notes"],
                data["Source"],
            ]
        )

        existing_websites.add(website)

    print("Done. Data pushed to Google Sheets.")


if __name__ == "__main__":
    main()