import os
import socket
import smtplib
import ssl
import traceback
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.header import Header

import gradio as gr


# 建议在 Hugging Face Space Settings -> Variables / Secrets 中配置
DEFAULT_SMTP_SERVER = os.getenv("SMTP_SERVER", "smtpauth.intel.com")
DEFAULT_SMTP_PORT = int(os.getenv("SMTP_PORT", "587"))

DEFAULT_MAIL_SENDER = os.getenv("MAIL_SENDER", "wenjiao.yue@intel.com")
DEFAULT_MAIL_TO = os.getenv("MAIL_TO", "wenjiao.yue@intel.com")

MAIL_PASSWORD = os.getenv("MAIL_PASSWORD")


def test_dns(smtp_server: str, smtp_port: int):
    """
    测试 DNS 解析。
    如果这里失败，说明还没到端口连接阶段。
    """
    try:
        results = socket.getaddrinfo(smtp_server, smtp_port)
        formatted = []

        for item in results:
            family, socktype, proto, canonname, sockaddr = item
            formatted.append(
                f"family={family}, socktype={socktype}, proto={proto}, "
                f"canonname={canonname}, sockaddr={sockaddr}"
            )

        return True, "DNS 解析成功：\n" + "\n".join(formatted)

    except Exception as e:
        return False, (
            f"DNS 解析失败：{repr(e)}\n\n"
            f"SMTP_SERVER={smtp_server}\n"
            f"SMTP_PORT={smtp_port}\n\n"
            "说明 Hugging Face Space 当前无法把这个域名解析成 IP。\n"
            "这通常不是端口问题，而是域名在公网 DNS 中不可解析，"
            "或者它依赖公司内网 DNS。"
        )


def test_tcp_connection(smtp_server: str, smtp_port: int):
    """
    测试 TCP 连接。
    DNS 成功后，才会测试到这一步。
    """
    try:
        with socket.create_connection((smtp_server, smtp_port), timeout=15) as sock:
            peer = sock.getpeername()

        return True, f"TCP 连接成功：{smtp_server}:{smtp_port}, peer={peer}"

    except Exception as e:
        return False, (
            f"TCP 连接失败：{repr(e)}\n\n"
            "如果 DNS 成功但这里失败，才可能是端口、防火墙、网络策略问题。"
        )


def test_smtp_handshake(smtp_server: str, smtp_port: int):
    """
    测试 SMTP EHLO 和 STARTTLS。
    """
    logs = []

    try:
        with smtplib.SMTP(smtp_server, smtp_port, timeout=30) as smtp:
            smtp.set_debuglevel(0)

            code, msg = smtp.ehlo()
            logs.append(f"EHLO 返回：code={code}, msg={msg!r}")

            if code != 250:
                return False, "\n".join(logs) + "\n\nEHLO 失败。"

            context = ssl._create_unverified_context()
            code, msg = smtp.starttls(context=context)
            logs.append(f"STARTTLS 返回：code={code}, msg={msg!r}")

            code, msg = smtp.ehlo()
            logs.append(f"TLS 后 EHLO 返回：code={code}, msg={msg!r}")

        return True, "SMTP 握手成功：\n" + "\n".join(logs)

    except Exception as e:
        logs.append(f"SMTP 握手失败：{repr(e)}")
        logs.append(traceback.format_exc())
        return False, "\n".join(logs)


def test_smtp_login(smtp_server: str, smtp_port: int, mail_sender: str):
    """
    测试 SMTP 登录。
    需要 MAIL_PASSWORD 在 HF Space Secrets 中配置。
    """
    if not MAIL_PASSWORD:
        return False, (
            "MAIL_PASSWORD 未设置。\n\n"
            "请在 Hugging Face Space 里配置：\n"
            "Settings -> Variables and secrets -> New secret\n\n"
            "MAIL_PASSWORD=你的邮箱密码或授权码"
        )

    logs = []

    try:
        context = ssl._create_unverified_context()

        with smtplib.SMTP(smtp_server, smtp_port, timeout=30) as smtp:
            code, msg = smtp.ehlo()
            logs.append(f"EHLO 返回：code={code}, msg={msg!r}")

            code, msg = smtp.starttls(context=context)
            logs.append(f"STARTTLS 返回：code={code}, msg={msg!r}")

            code, msg = smtp.ehlo()
            logs.append(f"TLS 后 EHLO 返回：code={code}, msg={msg!r}")

            smtp.login(mail_sender, MAIL_PASSWORD)
            logs.append("SMTP 登录成功。")

        return True, "\n".join(logs)

    except Exception as e:
        logs.append(f"SMTP 登录失败：{repr(e)}")
        logs.append(traceback.format_exc())
        return False, "\n".join(logs)


def send_test_email(
    smtp_server: str,
    smtp_port: int,
    mail_sender: str,
    mail_to: str,
):
    """
    真实发送测试邮件。
    """
    if not MAIL_PASSWORD:
        return False, (
            "MAIL_PASSWORD 未设置，无法发送邮件。\n\n"
            "请在 Hugging Face Space Secrets 中设置 MAIL_PASSWORD。"
        )

    subject = "Hugging Face Space SMTP Test"
    html_body = f"""
    <h3>Hugging Face Space SMTP Test</h3>
    <p>这是一封来自 Hugging Face Space 的 SMTP 测试邮件。</p>
    <p><b>SMTP Server:</b> {smtp_server}</p>
    <p><b>SMTP Port:</b> {smtp_port}</p>
    <p><b>Sender:</b> {mail_sender}</p>
    <p><b>Recipient:</b> {mail_to}</p>
    """

    msg = MIMEMultipart("alternative")
    msg["From"] = Header(mail_sender)
    msg["To"] = Header(mail_to)
    msg["Subject"] = Header(subject, "utf-8")
    msg.attach(MIMEText(html_body, "html", "utf-8"))

    logs = []

    try:
        context = ssl._create_unverified_context()

        with smtplib.SMTP(smtp_server, smtp_port, timeout=60) as smtp:
            code, message = smtp.ehlo()
            logs.append(f"EHLO 返回：code={code}, msg={message!r}")

            code, message = smtp.starttls(context=context)
            logs.append(f"STARTTLS 返回：code={code}, msg={message!r}")

            code, message = smtp.ehlo()
            logs.append(f"TLS 后 EHLO 返回：code={code}, msg={message!r}")

            smtp.login(mail_sender, MAIL_PASSWORD)
            logs.append("SMTP 登录成功。")

            smtp.sendmail(mail_sender, [mail_to], msg.as_string())
            logs.append(f"测试邮件发送成功：{mail_sender} -> {mail_to}")

        return True, "\n".join(logs)

    except Exception as e:
        logs.append(f"测试邮件发送失败：{repr(e)}")
        logs.append(traceback.format_exc())
        return False, "\n".join(logs)


def run_all_tests(
    smtp_server: str,
    smtp_port: int,
    mail_sender: str,
    mail_to: str,
    actually_send_email: bool,
):
    """
    按顺序执行所有测试。
    """
    smtp_server = smtp_server.strip()
    smtp_port = int(smtp_port)
    mail_sender = mail_sender.strip()
    mail_to = mail_to.strip()

    final_logs = []

    final_logs.append("========== 配置 ==========")
    final_logs.append(f"SMTP_SERVER={smtp_server}")
    final_logs.append(f"SMTP_PORT={smtp_port}")
    final_logs.append(f"MAIL_SENDER={mail_sender}")
    final_logs.append(f"MAIL_TO={mail_to}")
    final_logs.append(f"MAIL_PASSWORD_SET={bool(MAIL_PASSWORD)}")
    final_logs.append("")

    final_logs.append("========== 1. DNS 测试 ==========")
    ok, log = test_dns(smtp_server, smtp_port)
    final_logs.append(log)
    final_logs.append("")

    if not ok:
        final_logs.append("结论：DNS 解析失败。")
        final_logs.append("这不是端口问题，因为程序还没有进入连接端口阶段。")
        return "\n".join(final_logs)

    final_logs.append("========== 2. TCP 连接测试 ==========")
    ok, log = test_tcp_connection(smtp_server, smtp_port)
    final_logs.append(log)
    final_logs.append("")

    if not ok:
        final_logs.append("结论：DNS 成功，但 TCP 连接失败。")
        final_logs.append("这可能是端口、防火墙、网络策略或 SMTP 服务不允许外部访问。")
        return "\n".join(final_logs)

    final_logs.append("========== 3. SMTP EHLO / STARTTLS 测试 ==========")
    ok, log = test_smtp_handshake(smtp_server, smtp_port)
    final_logs.append(log)
    final_logs.append("")

    if not ok:
        final_logs.append("结论：TCP 连接成功，但 SMTP 握手或 STARTTLS 失败。")
        return "\n".join(final_logs)

    final_logs.append("========== 4. SMTP 登录测试 ==========")
    ok, log = test_smtp_login(smtp_server, smtp_port, mail_sender)
    final_logs.append(log)
    final_logs.append("")

    if not ok:
        final_logs.append("结论：SMTP 服务可访问，但登录失败。")
        final_logs.append("请检查 MAIL_SENDER 和 MAIL_PASSWORD。")
        return "\n".join(final_logs)

    if actually_send_email:
        final_logs.append("========== 5. 发送测试邮件 ==========")
        ok, log = send_test_email(
            smtp_server=smtp_server,
            smtp_port=smtp_port,
            mail_sender=mail_sender,
            mail_to=mail_to,
        )
        final_logs.append(log)
        final_logs.append("")

        if ok:
            final_logs.append("最终结论：SMTP 全流程成功，邮件已发送。")
        else:
            final_logs.append("最终结论：登录成功，但发送邮件失败。")
    else:
        final_logs.append("========== 5. 发送测试邮件 ==========")
        final_logs.append("已跳过真实发信。勾选 `Actually send test email` 后才会发送。")
        final_logs.append("")
        final_logs.append("最终结论：DNS、TCP、STARTTLS、登录测试均通过。")

    return "\n".join(final_logs)


with gr.Blocks() as demo:
    gr.Markdown("# Hugging Face Space SMTP 诊断工具")

    gr.Markdown(
        """
        这个页面用于测试 Hugging Face Space 是否能访问你的 SMTP 服务器。

        重点判断：
        - 如果 DNS 失败：不是端口问题。
        - 如果 DNS 成功但 TCP 失败：可能是端口、防火墙或网络策略问题。
        - 如果 TCP 成功但登录失败：可能是用户名、密码或权限问题。
        """
    )

    with gr.Row():
        smtp_server_input = gr.Textbox(
            label="SMTP_SERVER",
            value=DEFAULT_SMTP_SERVER,
        )
        smtp_port_input = gr.Number(
            label="SMTP_PORT",
            value=DEFAULT_SMTP_PORT,
            precision=0,
        )

    with gr.Row():
        mail_sender_input = gr.Textbox(
            label="MAIL_SENDER",
            value=DEFAULT_MAIL_SENDER,
        )
        mail_to_input = gr.Textbox(
            label="MAIL_TO",
            value=DEFAULT_MAIL_TO,
        )

    actually_send_email = gr.Checkbox(
        label="Actually send test email",
        value=False,
    )

    run_button = gr.Button("Run SMTP Tests")

    output = gr.Textbox(
        label="测试结果",
        lines=30,
    )

    run_button.click(
        fn=run_all_tests,
        inputs=[
            smtp_server_input,
            smtp_port_input,
            mail_sender_input,
            mail_to_input,
            actually_send_email,
        ],
        outputs=output,
    )


demo.queue()
demo.launch()