# license_manager.py  (PyQt5 版本)
import os
import json
import base64
import hashlib
import uuid
import platform
import subprocess
import sys
from datetime import datetime, timedelta

try:
    from cryptography.hazmat.primitives.ciphers.aead import AESGCM
except ImportError:
    raise ImportError("请先安装依赖: pip install cryptography")

ENCRYPTION_KEY = b"0123456789abcdef0123456789abcdef"


def get_app_dir():
    if getattr(sys, 'frozen', False):
        return os.path.dirname(sys.executable)
    return os.path.dirname(os.path.abspath(__file__))


LICENSE_FILE = os.path.join(get_app_dir(), "license.lic")


def get_machine_guid():
    system = platform.system()
    if system == "Windows":
        try:
            import winreg
            with winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, r"SOFTWARE\Microsoft\Cryptography") as key:
                return winreg.QueryValueEx(key, "MachineGuid")[0]
        except Exception:
            pass
    elif system == "Linux":
        for path in ["/etc/machine-id", "/var/lib/dbus/machine-id"]:
            if os.path.exists(path):
                with open(path, "r", encoding="utf-8") as f:
                    return f.read().strip()
    elif system == "Darwin":
        try:
            result = subprocess.run(
                ["ioreg", "-rd1", "-c", "IOPlatformExpertDevice"],
                capture_output=True, text=True
            )
            for line in result.stdout.split("\n"):
                if "IOPlatformUUID" in line:
                    return line.split('"')[-2]
        except Exception:
            pass
    return str(uuid.getnode())


def get_machine_code():
    guid = get_machine_guid()
    h = hashlib.sha256()
    h.update(b"LicenseSystem")
    h.update(guid.encode("utf-8"))
    return h.hexdigest()


def decrypt_key(encrypted_key: str):
    try:
        data = base64.b64decode(encrypted_key)
    except Exception:
        raise ValueError("Base64 解码失败")
    if len(data) < 12:
        raise ValueError("密文太短")
    aesgcm = AESGCM(ENCRYPTION_KEY)
    nonce = data[:12]
    ciphertext = data[12:]
    try:
        plaintext = aesgcm.decrypt(nonce, ciphertext, None)
    except Exception:
        raise ValueError("解密失败，密钥无效或已被篡改")
    try:
        return json.loads(plaintext.decode("utf-8"))
    except Exception:
        raise ValueError("许可证数据解析失败")


def validate_key(key: str):
    machine_code = get_machine_code()
    license_info = decrypt_key(key)
    if license_info.get("machine_code") != machine_code:
        raise ValueError("机器码不匹配，该密钥无法在本机使用")
    expire_str = license_info.get("expire_time")
    if not expire_str:
        raise ValueError("许可证信息不完整")
    expire_time = datetime.fromisoformat(expire_str)
    if datetime.now() > expire_time:
        raise ValueError("许可证已过期")
    return license_info


def save_license(license_info: dict):
    with open(LICENSE_FILE, "w", encoding="utf-8") as f:
        json.dump(license_info, f, indent=2, ensure_ascii=False)


def load_license():
    if not os.path.exists(LICENSE_FILE):
        return None
    try:
        with open(LICENSE_FILE, "r", encoding="utf-8") as f:
            return json.load(f)
    except Exception:
        return None


def verify_license():
    """
    PyQt5 弹窗验证许可证。
    返回 True：验证通过。
    返回 False：用户关闭窗口，程序应退出。
    """
    from PyQt5.QtWidgets import (QApplication, QDialog, QVBoxLayout, QLabel,
                                  QLineEdit, QPushButton, QHBoxLayout, QMessageBox)
    from PyQt5.QtCore import Qt
    from PyQt5.QtGui import QFont

    # 1. 先尝试本地缓存
    cached = load_license()
    if cached:
        try:
            if cached.get("machine_code") != get_machine_code():
                raise ValueError("机器码不匹配")
            if datetime.now() > datetime.fromisoformat(cached.get("expire_time")):
                raise ValueError("许可证已过期")
            return True
        except Exception:
            if os.path.exists(LICENSE_FILE):
                os.remove(LICENSE_FILE)

    machine_code = get_machine_code()

    # 确保有 QApplication 实例
    app = QApplication.instance()
    if not app:
        app = QApplication(sys.argv)

    dialog = QDialog()
    dialog.setWindowTitle("软件激活")
    dialog.setFixedSize(450, 300)
    dialog.setWindowFlags(dialog.windowFlags() & ~Qt.WindowContextHelpButtonHint)

    # 窗口居中
    screen = app.primaryScreen().geometry()
    dialog.move(
        (screen.width() - dialog.width()) // 2,
        (screen.height() - dialog.height()) // 2
    )

    layout = QVBoxLayout()

    # 机器码（可复制）
    layout.addWidget(QLabel("您的机器码（可复制）："))
    mc_edit = QLineEdit(machine_code)
    mc_edit.setReadOnly(True)
    mc_edit.setFont(QFont("Consolas", 10))
    mc_edit.setAlignment(Qt.AlignCenter)
    layout.addWidget(mc_edit)

    tip = QLabel("请将机器码发给管理员获取密钥")
    tip.setAlignment(Qt.AlignCenter)
    tip.setStyleSheet("color: gray;")
    layout.addWidget(tip)

    # 密钥输入
    layout.addWidget(QLabel("许可证密钥："))
    key_edit = QLineEdit()
    key_edit.setEchoMode(QLineEdit.Password)
    key_edit.setFont(QFont("Consolas", 10))
    key_edit.setAlignment(Qt.AlignCenter)
    key_edit.setPlaceholderText("在此粘贴密钥")
    layout.addWidget(key_edit)

    # 错误提示
    error_label = QLabel("")
    error_label.setStyleSheet("color: red;")
    error_label.setAlignment(Qt.AlignCenter)
    layout.addWidget(error_label)

    # 按钮
    btn_layout = QHBoxLayout()
    ok_btn = QPushButton("确认激活")
    close_btn = QPushButton("关闭")
    btn_layout.addWidget(ok_btn)
    btn_layout.addWidget(close_btn)
    layout.addLayout(btn_layout)

    dialog.setLayout(layout)

    # 结果标志
    result = [False]

    def on_verify():
        key = key_edit.text().strip()
        if not key:
            error_label.setText("密钥不能为空")
            return
        try:
            info = validate_key(key)
            save_license(info)
            expire = datetime.fromisoformat(info["expire_time"])
            days_left = (expire - datetime.now()).days
            QMessageBox.information(
                dialog, "激活成功",
                f"✓ 验证通过！\n有效期至：{expire.strftime('%Y-%m-%d %H:%M:%S')}\n剩余天数：{days_left} 天"
            )
            result[0] = True
            dialog.accept()
        except Exception as e:
            error_label.setText(str(e))
            key_edit.clear()
            key_edit.setFocus()

    def on_close():
        dialog.reject()

    ok_btn.clicked.connect(on_verify)
    close_btn.clicked.connect(on_close)
    key_edit.returnPressed.connect(on_verify)

    ret = dialog.exec_()
    return result[0] and ret == QDialog.Accepted