import uuid

from django.contrib.auth.models import AbstractUser
from django.db import models


class Team(models.Model):
    """团队模型 — 额度管理的核心单位。"""
    name = models.CharField(max_length=100, unique=True, verbose_name='团队名称')
    total_seconds_pool = models.BigIntegerField(default=0, verbose_name='总额度池(秒)')
    total_seconds_used = models.FloatField(default=0, verbose_name='已消耗总秒数')
    monthly_seconds_limit = models.IntegerField(default=6000, verbose_name='每月消费上限(秒)')
    daily_member_limit_default = models.IntegerField(default=600, verbose_name='新成员默认每日限额(秒)')
    is_active = models.BooleanField(default=True, verbose_name='启用状态')
    expected_regions = models.CharField(max_length=500, blank=True, default='', verbose_name='预期登录城市（逗号分隔）')
    disabled_by = models.CharField(max_length=10, blank=True, default='', verbose_name='禁用来源')
    created_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')
    updated_at = models.DateTimeField(auto_now=True, verbose_name='更新时间')

    class Meta:
        verbose_name = '团队'
        verbose_name_plural = '团队'

    def __str__(self):
        return self.name

    @property
    def remaining_seconds(self):
        return self.total_seconds_pool - self.total_seconds_used


class User(AbstractUser):
    """Extended user model — Phase 5: team-based quota."""
    email = models.EmailField(unique=True, verbose_name='邮箱')
    team = models.ForeignKey(
        Team, on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='members',
        verbose_name='所属团队',
    )
    is_team_admin = models.BooleanField(default=False, verbose_name='团队管理员')
    daily_seconds_limit = models.IntegerField(default=600, verbose_name='每日秒数上限')
    monthly_seconds_limit = models.IntegerField(default=6000, verbose_name='每月秒数上限')
    must_change_password = models.BooleanField(default=True, verbose_name='必须修改密码')
    disabled_by = models.CharField(max_length=10, blank=True, default='', verbose_name='禁用来源')
    created_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')
    updated_at = models.DateTimeField(auto_now=True, verbose_name='更新时间')

    class Meta:
        verbose_name = '用户'
        verbose_name_plural = '用户'

    def __str__(self):
        return self.username

    @property
    def role(self):
        if self.is_staff and self.team is None:
            return 'super_admin'
        if self.is_team_admin and self.team is not None:
            return 'team_admin'
        return 'member'


class AdminAuditLog(models.Model):
    """管理员操作审计日志"""
    ACTION_CHOICES = [
        ('team_create', '创建团队'),
        ('team_update', '更新团队'),
        ('team_topup', '团队充值'),
        ('team_set_pool', '设置团队额度池'),
        ('team_create_admin', '创建团队管理员'),
        ('user_create', '创建用户'),
        ('user_quota_update', '更新用户额度'),
        ('user_status_toggle', '切换用户状态'),
        ('settings_update', '更新系统设置'),
        ('member_create', '创建团队成员'),
        ('member_quota_update', '更新成员额度'),
        ('member_status_toggle', '切换成员状态'),
        ('user_password_reset', '重置用户密码'),
    ]

    operator = models.ForeignKey(
        User, on_delete=models.SET_NULL,
        null=True, related_name='audit_logs',
        verbose_name='操作人',
    )
    operator_name = models.CharField(max_length=150, verbose_name='操作人用户名')
    action = models.CharField(max_length=30, choices=ACTION_CHOICES, verbose_name='操作类型')
    target_type = models.CharField(max_length=20, verbose_name='目标类型')
    target_id = models.IntegerField(null=True, blank=True, verbose_name='目标ID')
    target_name = models.CharField(max_length=200, blank=True, default='', verbose_name='目标名称')
    before = models.JSONField(null=True, blank=True, verbose_name='变更前')
    after = models.JSONField(null=True, blank=True, verbose_name='变更后')
    ip_address = models.GenericIPAddressField(null=True, blank=True, verbose_name='IP地址')
    created_at = models.DateTimeField(auto_now_add=True, db_index=True, verbose_name='操作时间')

    class Meta:
        verbose_name = '审计日志'
        verbose_name_plural = '审计日志'
        ordering = ['-created_at']

    def __str__(self):
        return f'{self.operator_name} - {self.get_action_display()} - {self.target_name}'


class ActiveSession(models.Model):
    """活跃会话 — 用于并发登录设备限制。"""
    DEVICE_TYPE_CHOICES = [
        ('desktop', '桌面端'),
        ('mobile', '移动端'),
        ('unknown', '未知'),
    ]

    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='active_sessions', verbose_name='用户')
    session_id = models.UUIDField(default=uuid.uuid4, unique=True, db_index=True, verbose_name='会话ID')
    device_type = models.CharField(max_length=10, choices=DEVICE_TYPE_CHOICES, default='unknown', verbose_name='设备类型')
    user_agent = models.TextField(blank=True, default='', verbose_name='User-Agent')
    created_at = models.DateTimeField(auto_now_add=True, verbose_name='创建时间')

    class Meta:
        verbose_name = '活跃会话'
        verbose_name_plural = '活跃会话'
        ordering = ['created_at']

    def __str__(self):
        return f'{self.user.username} - {self.device_type} - {self.session_id}'


class LoginRecord(models.Model):
    """登录记录 — 含 IP 归属地，供异常检测使用。"""
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='login_records', verbose_name='用户')
    team = models.ForeignKey(Team, on_delete=models.SET_NULL, null=True, blank=True, related_name='login_records', verbose_name='所属团队')
    ip_address = models.GenericIPAddressField(null=True, blank=True, verbose_name='IP地址')
    user_agent = models.TextField(blank=True, default='', verbose_name='User-Agent')
    geo_country = models.CharField(max_length=50, blank=True, default='', verbose_name='国家')
    geo_province = models.CharField(max_length=50, blank=True, default='', verbose_name='省份')
    geo_city = models.CharField(max_length=50, blank=True, default='', verbose_name='城市')
    geo_source = models.CharField(max_length=10, blank=True, default='', verbose_name='归属地来源')
    created_at = models.DateTimeField(auto_now_add=True, db_index=True, verbose_name='登录时间')

    class Meta:
        verbose_name = '登录记录'
        verbose_name_plural = '登录记录'
        ordering = ['-created_at']

    def __str__(self):
        return f'{self.user.username} - {self.ip_address} - {self.geo_city} - {self.created_at}'


class TeamAnomalyConfig(models.Model):
    """团队级异常检测阈值配置 — 未设置的字段使用全局默认值。"""
    team = models.OneToOneField(Team, on_delete=models.CASCADE, related_name='anomaly_config', verbose_name='团队')
    r1_enabled = models.BooleanField(null=True, blank=True, verbose_name='R1 开关')
    r2_enabled = models.BooleanField(null=True, blank=True, verbose_name='R2 开关')
    r2_window_seconds = models.IntegerField(null=True, blank=True, verbose_name='R2 时间窗口(秒)')
    r3_enabled = models.BooleanField(null=True, blank=True, verbose_name='R3 开关')
    r3_window_seconds = models.IntegerField(null=True, blank=True, verbose_name='R3 时间窗口(秒)')
    r3_max_count = models.IntegerField(null=True, blank=True, verbose_name='R3 最大登录次数')
    r4_enabled = models.BooleanField(null=True, blank=True, verbose_name='R4 开关')
    r4_window_seconds = models.IntegerField(null=True, blank=True, verbose_name='R4 时间窗口(秒)')
    r4_city_count = models.IntegerField(null=True, blank=True, verbose_name='R4 预期外城市数阈值')
    r5_enabled = models.BooleanField(null=True, blank=True, verbose_name='R5 开关')
    r5_days = models.IntegerField(null=True, blank=True, verbose_name='R5 统计天数')
    r5_country_count = models.IntegerField(null=True, blank=True, verbose_name='R5 海外国家数阈值')

    class Meta:
        verbose_name = '团队异常检测配置'
        verbose_name_plural = '团队异常检测配置'

    def __str__(self):
        return f'{self.team.name} 异常检测配置'


class LoginAnomaly(models.Model):
    """登录异常记录。"""
    LEVEL_CHOICES = [
        ('warning', '警告'),
        ('critical', '严重'),
    ]
    RULE_CHOICES = [
        ('region_mismatch', '登录地区不对'),
        ('impossible_travel', '不可能的旅行'),
        ('login_frequency', '登录太频繁'),
        ('multi_city', '团队遍地开花'),
        ('overseas_ip_diversity', '海外IP太杂'),
    ]

    team = models.ForeignKey(Team, on_delete=models.CASCADE, related_name='login_anomalies', verbose_name='团队')
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='login_anomalies', verbose_name='用户')
    login_record = models.ForeignKey(LoginRecord, on_delete=models.CASCADE, related_name='anomalies', verbose_name='触发登录记录')
    level = models.CharField(max_length=10, choices=LEVEL_CHOICES, verbose_name='严重程度')
    rule = models.CharField(max_length=30, choices=RULE_CHOICES, verbose_name='触发规则')
    detail = models.JSONField(default=dict, verbose_name='详情')
    alerted = models.BooleanField(default=False, verbose_name='已发告警')
    auto_disabled = models.BooleanField(default=False, verbose_name='已自动封禁')
    disabled_target = models.CharField(max_length=10, blank=True, default='', verbose_name='封禁对象')
    created_at = models.DateTimeField(auto_now_add=True, db_index=True, verbose_name='创建时间')

    class Meta:
        verbose_name = '登录异常'
        verbose_name_plural = '登录异常'
        ordering = ['-created_at']

    def __str__(self):
        return f'{self.team.name} - {self.get_rule_display()} - {self.get_level_display()}'


def get_client_ip(request):
    """从请求中提取客户端 IP 地址。"""
    return request.META.get('HTTP_X_FORWARDED_FOR', '').split(',')[0].strip() or request.META.get('REMOTE_ADDR')


def parse_device_type(user_agent):
    """根据 User-Agent 判断设备类型。"""
    ua_lower = (user_agent or '').lower()
    mobile_keywords = ['iphone', 'ipad', 'android', 'mobile', 'ipod', 'windows phone']
    if any(kw in ua_lower for kw in mobile_keywords):
        return 'mobile'
    if ua_lower:
        return 'desktop'
    return 'unknown'


def log_admin_action(request, action, target_type, target_id=None, target_name='', before=None, after=None):
    """记录管理员操作日志"""
    ip = get_client_ip(request)
    AdminAuditLog.objects.create(
        operator=request.user,
        operator_name=request.user.username,
        action=action,
        target_type=target_type,
        target_id=target_id,
        target_name=target_name,
        before=before,
        after=after,
        ip_address=ip,
    )