import smtplib
import time
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage
from email.utils import formataddr
from pathlib import Path
from flask import current_app, render_template

from app.services.ticket_service import generate_ticket_image
from app.utils.paths import event_qr_folder


OUTLOOK_CONTENT_ID_PROP = "http://schemas.microsoft.com/mapi/proptag/0x3712001F"


def _build_mime_message(to_address, subject, html_body, sender_name, attachments):
    """Собирает MIME-сообщение с inline-вложениями."""
    config = current_app.config
    sender = config.get("MAIL_DEFAULT_SENDER") or config.get("MAIL_USERNAME", "")

    msg = MIMEMultipart("related")
    msg["Subject"] = subject
    msg["From"] = formataddr((sender_name, sender))
    msg["To"] = to_address
    msg["Date"] = email.utils.formatdate(localtime=True)
    msg.attach(MIMEText(html_body, "html", "utf-8"))

    for att in attachments:
        path = att["path"]
        cid = att.get("cid")
        filename = att.get("filename", path.name)
        with open(path, "rb") as img_file:
            img = MIMEImage(img_file.read())
            if cid:
                img.add_header("Content-ID", f"<{cid}>")
            img.add_header("Content-Disposition", "inline", filename=filename)
            msg.attach(img)

    return msg


def _send_smtp_email(to_address, subject, html_body, sender_name, attachments):
    """Отправляет письмо через SMTP с inline-вложениями."""
    config = current_app.config

    server = config.get("MAIL_SERVER", "")
    port = config.get("MAIL_PORT", 465)
    username = config.get("MAIL_USERNAME", "")
    password = config.get("MAIL_PASSWORD", "")
    use_ssl = config.get("MAIL_USE_SSL", True)

    if not username or not password:
        raise ValueError("MAIL_USERNAME и MAIL_PASSWORD должны быть указаны в конфигурации")
    if not server or not port:
        raise ValueError("MAIL_SERVER и MAIL_PORT должны быть указаны в конфигурации")

    msg = _build_mime_message(to_address, subject, html_body, sender_name, attachments)

    if use_ssl:
        with smtplib.SMTP_SSL(server, port) as smtp:
            smtp.login(username, password)
            smtp.send_message(msg)
    else:
        with smtplib.SMTP(server, port) as smtp:
            smtp.starttls()
            smtp.login(username, password)
            smtp.send_message(msg)

    return msg


def _send_outlook_email(to_address, subject, html_body, sender_name, attachments):
    """Отправляет письмо через локальный Outlook (MAPI/COM)."""
    try:
        import win32com.client
    except ImportError as e:
        raise RuntimeError("Для отправки через Outlook необходима библиотека pywin32") from e

    try:
        outlook = win32com.client.Dispatch("Outlook.Application")
    except Exception as e:
        raise RuntimeError("Не удалось подключиться к Outlook. Убедитесь, что Outlook установлен и запущен.") from e

    mail = outlook.CreateItem(0)  # olMailItem
    mail.To = to_address
    mail.Subject = subject
    mail.HTMLBody = html_body

    for att in attachments:
        path = att["path"]
        cid = att.get("cid")
        filename = att.get("filename", path.name)
        # 1 = olByValue, 0 = позиция (inline)
        attachment = mail.Attachments.Add(str(path), 1, 0, filename)
        if cid:
            attachment.PropertyAccessor.SetProperty(OUTLOOK_CONTENT_ID_PROP, cid)

    mail.Send()


def _send_ews_email(to_address, subject, html_body, sender_name, attachments):
    """Отправляет письмо через Exchange Web Services (EWS)."""
    try:
        from exchangelib import Credentials, Configuration, Account, Message, Mailbox, HTMLBody, FileAttachment
    except ImportError as e:
        raise RuntimeError("Для отправки через EWS необходима библиотека exchangelib") from e

    config = current_app.config
    ews_url = config.get("EWS_URL", "")
    username = config.get("MAIL_USERNAME", "")
    password = config.get("MAIL_PASSWORD", "")

    if not ews_url or not username or not password:
        raise ValueError("Для EWS должны быть указаны EWS URL, логин и пароль")

    try:
        credentials = Credentials(username=username, password=password)
        ews_config = Configuration(service_endpoint=ews_url, credentials=credentials)
        account = Account(
            primary_smtp_address=username,
            config=ews_config,
            autodiscover=False,
            access_type="delegate",
        )

        msg = Message(
            account=account,
            subject=subject,
            body=HTMLBody(html_body),
            to_recipients=[Mailbox(email_address=to_address)],
        )

        for att in attachments:
            path = att["path"]
            filename = att.get("filename", path.name)
            cid = att.get("cid")
            with open(path, "rb") as f:
                content = f.read()
            file_att = FileAttachment(name=filename, content=content, content_id=cid)
            msg.attach(file_att)

        msg.send()
    except Exception as e:
        raise RuntimeError(f"Ошибка отправки через EWS: {e}") from e


def _save_imap_copy(to_address, subject, html_body, sender_name, attachments):
    """Сохраняет копию отправленного письма в IMAP-папку (обычно Sent)."""
    import imaplib

    config = current_app.config
    if not config.get("IMAP_SAVE_COPY"):
        return

    server = config.get("IMAP_SERVER", "")
    port = config.get("IMAP_PORT", 993)
    username = config.get("IMAP_USERNAME", "")
    password = config.get("IMAP_PASSWORD", "")
    folder = config.get("IMAP_FOLDER", "Sent")
    use_ssl = config.get("IMAP_USE_SSL", True)

    if not server or not username or not password:
        raise ValueError("Для сохранения копии в IMAP должны быть указаны сервер, логин и пароль")

    msg = _build_mime_message(to_address, subject, html_body, sender_name, attachments)
    msg_bytes = msg.as_bytes()
    date_str = imaplib.Time2Internaldate(time.time())

    try:
        if use_ssl:
            mail = imaplib.IMAP4_SSL(server, port)
        else:
            mail = imaplib.IMAP4(server, port)
            try:
                mail.starttls()
            except Exception:
                pass

        mail.login(username, password)
        mail.select(folder)
        result, data = mail.append(folder, "", date_str, msg_bytes)
        if result != "OK":
            raise RuntimeError(f"IMAP append failed: {data}")
        mail.close()
        mail.logout()
    except Exception as e:
        raise RuntimeError(f"Ошибка сохранения копии в IMAP: {e}") from e


def _send_email(to_address, subject, html_body, sender_name="InviteMe", attachments=None):
    """Маршрутизирует отправку через SMTP, EWS или локальный Outlook."""
    attachments = attachments or []
    if current_app.config.get("MAIL_USE_LOCAL_OUTLOOK"):
        _send_outlook_email(to_address, subject, html_body, sender_name, attachments)
    elif current_app.config.get("MAIL_USE_EWS"):
        _send_ews_email(to_address, subject, html_body, sender_name, attachments)
    else:
        _send_smtp_email(to_address, subject, html_body, sender_name, attachments)

    # Сохраняем копию в IMAP, если включено
    if current_app.config.get("IMAP_SAVE_COPY"):
        _save_imap_copy(to_address, subject, html_body, sender_name, attachments)


def send_invitation(guest, event_name=None, additional_text=""):
    """Отправляет приглашение гостю на email с QR-кодом и билетом во вложении."""
    config = current_app.config

    if event_name is None:
        event_name = guest.event.name if guest.event else "Мероприятие"

    # Генерируем билет
    try:
        ticket_path = generate_ticket_image(guest, guest.event)
    except Exception as e:
        ticket_path = None
        current_app.logger.warning(f"Не удалось сгенерировать билет для {guest.email}: {e}")

    html_body = render_template(
        "email/invitation.html",
        guest=guest,
        event_name=event_name,
        additional_text=additional_text,
        qr_cid="qr_code_image",
        ticket_cid="ticket_image" if ticket_path else None,
    )

    attachments = []

    # QR-код
    qr_path = event_qr_folder(guest.event_id) / guest.qr_filename
    if not qr_path.exists():
        qr_path = Path(config["QR_FOLDER"]) / guest.qr_filename
    if qr_path.exists():
        attachments.append({"path": qr_path, "cid": "qr_code_image", "filename": guest.qr_filename})

    # Билет
    if ticket_path and ticket_path.exists():
        attachments.append({
            "path": ticket_path,
            "cid": "ticket_image",
            "filename": f"ticket_{guest.token}.png",
        })

    _send_email(
        to_address=guest.email,
        subject=f"Приглашение на мероприятие: {event_name}",
        html_body=html_body,
        attachments=attachments,
    )

    guest.invitation_sent = True
    return True


def send_test_email(to_address):
    """Отправляет тестовое письмо для проверки настроек."""
    html_body = render_template("email/test_email.html")
    _send_email(
        to_address=to_address,
        subject="Тестовое письмо InviteMe",
        html_body=html_body,
    )
    return True