from django.db import models
from shop.models import WeChatUser, ESP32Config, Order, Service, VCCourse, ServiceOrder

class Activity(models.Model):
    """
    社区活动模型
    """
    title = models.CharField(max_length=100, verbose_name="活动标题")
    description = models.TextField(verbose_name="活动详情")
    banner = models.ImageField(upload_to='activities/banners/', verbose_name="活动Banner图", null=True, blank=True)
    banner_url = models.URLField(verbose_name="活动Banner链接", null=True, blank=True, help_text="可直接填写图片链接，若同时上传图片，将优先显示上传的图片")
    start_time = models.DateTimeField(verbose_name="开始时间")
    end_time = models.DateTimeField(verbose_name="结束时间")
    location = models.CharField(max_length=100, verbose_name="活动地点")
    max_participants = models.IntegerField(default=50, verbose_name="最大报名人数")
    is_active = models.BooleanField(default=True, verbose_name="是否启用")
    created_at = models.DateTimeField(auto_now_add=True, verbose_name="创建时间")

    def clean(self):
        from django.core.exceptions import ValidationError
        if not self.banner and not self.banner_url:
            raise ValidationError("Banner图片和Banner链接必须至少填写一项")

    def save(self, *args, **kwargs):
        self.clean()
        super().save(*args, **kwargs)

    @property
    def display_banner_url(self):
        """
        获取Banner显示的URL，优先使用上传的图片
        """
        if self.banner:
            return self.banner.url
        return self.banner_url

    def __str__(self):
        return self.title

    class Meta:
        verbose_name = "社区活动"
        verbose_name_plural = "社区活动管理"


class ActivitySignup(models.Model):
    """
    活动报名记录
    """
    STATUS_CHOICES = (
        ('pending', '审核中'),
        ('confirmed', '报名成功'),
        ('cancelled', '已取消'),
    )

    activity = models.ForeignKey(Activity, on_delete=models.CASCADE, related_name='signups', verbose_name="活动")
    user = models.ForeignKey(WeChatUser, on_delete=models.CASCADE, related_name='activity_signups', verbose_name="报名用户")
    signup_time = models.DateTimeField(auto_now_add=True, verbose_name="报名时间")
    status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='confirmed', verbose_name="状态")

    def __str__(self):
        return f"{self.user.nickname} - {self.activity.title}"

    class Meta:
        verbose_name = "活动报名"
        verbose_name_plural = "活动报名管理"
        unique_together = ('activity', 'user')


class Topic(models.Model):
    """
    论坛帖子/主题
    """
    title = models.CharField(max_length=200, verbose_name="标题")
    
    CATEGORY_CHOICES = (
        ('discussion', '技术讨论'),
        ('help', '求助问答'),
        ('share', '经验分享'),
        ('notice', '官方公告'),
    )
    category = models.CharField(max_length=20, choices=CATEGORY_CHOICES, default='discussion', verbose_name="分类")
    
    content = models.TextField(verbose_name="内容", help_text="支持Markdown格式，支持插入图片")
    author = models.ForeignKey(WeChatUser, on_delete=models.CASCADE, related_name='topics', verbose_name="作者")
    
    # 关联对象：硬件、服务、课程
    related_product = models.ForeignKey(ESP32Config, on_delete=models.SET_NULL, null=True, blank=True, verbose_name="关联硬件")
    related_service = models.ForeignKey(Service, on_delete=models.SET_NULL, null=True, blank=True, verbose_name="关联服务")
    related_course = models.ForeignKey(VCCourse, on_delete=models.SET_NULL, null=True, blank=True, verbose_name="关联课程")
    
    view_count = models.IntegerField(default=0, verbose_name="浏览量")
    is_pinned = models.BooleanField(default=False, verbose_name="置顶")
    created_at = models.DateTimeField(auto_now_add=True, verbose_name="发布时间")
    updated_at = models.DateTimeField(auto_now=True, verbose_name="更新时间")

    def __str__(self):
        return self.title

    @property
    def is_verified_owner(self):
        """
        判断作者是否为关联项目（硬件/服务/课程）的已购用户（Verified Owner）
        """
        # 1. 验证硬件
        if self.related_product:
            if Order.objects.filter(
                wechat_user=self.author,
                config=self.related_product,
                status__in=['paid', 'shipped']
            ).exists():
                return True
        
        # 2. 验证课程
        if self.related_course:
            if Order.objects.filter(
                wechat_user=self.author,
                course=self.related_course,
                status__in=['paid', 'shipped']
            ).exists():
                return True
        
        # 3. 验证服务
        if self.related_service:
            # ServiceOrder 模型中没有 direct link to WeChatUser (only phone/name), 
            # 但我们假设通过手机号或未来关联来验证，目前先检查 ServiceOrder 是否有对应记录。
            # 由于 ServiceOrder 目前设计没有直接关联 WeChatUser 字段，我们暂时尝试通过名字或后续改进。
            # 经检查 shop/models.py, ServiceOrder 确实只有 customer_name/phone_number. 
            # 这里为了严谨，我们暂时仅对有关联的进行检查，或者需要改进 ServiceOrder。
            # 鉴于当前任务范围，如果 ServiceOrder 没有 user 字段，我们可能无法精确验证，
            # 除非我们假设用户填写的手机号与微信用户关联。
            # *修正*: 为了快速实现，我们先跳过 ServiceOrder 的精确验证，或者仅仅返回 False，
            # 等待后续 ServiceOrder 添加 wechat_user 字段。
            pass
            
        return False

    class Meta:
        verbose_name = "论坛帖子"
        verbose_name_plural = "论坛帖子管理"
        ordering = ['-is_pinned', '-created_at']


class Reply(models.Model):
    """
    帖子回复
    """
    topic = models.ForeignKey(Topic, on_delete=models.CASCADE, related_name='replies', verbose_name="所属帖子")
    content = models.TextField(verbose_name="回复内容", help_text="支持Markdown格式")
    author = models.ForeignKey(WeChatUser, on_delete=models.CASCADE, related_name='replies', verbose_name="回复者")
    reply_to = models.ForeignKey('self', on_delete=models.SET_NULL, null=True, blank=True, related_name='children', verbose_name="回复楼层")
    created_at = models.DateTimeField(auto_now_add=True, verbose_name="回复时间")

    def __str__(self):
        return f"回复: {self.topic.title}"

    class Meta:
        verbose_name = "帖子回复"
        verbose_name_plural = "帖子回复管理"
        ordering = ['created_at']


class TopicMedia(models.Model):
    """
    论坛多媒体资源（图片/视频/文件）
    """
    MEDIA_TYPE_CHOICES = (
        ('image', '图片'),
        ('video', '视频'),
        ('file', '文件'),
    )

    topic = models.ForeignKey(Topic, on_delete=models.CASCADE, related_name='media', verbose_name="所属帖子", null=True, blank=True)
    reply = models.ForeignKey(Reply, on_delete=models.CASCADE, related_name='media', verbose_name="所属回复", null=True, blank=True)
    file = models.FileField(upload_to='community/media/', verbose_name="文件")
    media_type = models.CharField(max_length=10, choices=MEDIA_TYPE_CHOICES, default='image', verbose_name="媒体类型")
    created_at = models.DateTimeField(auto_now_add=True, verbose_name="上传时间")

    def __str__(self):
        return f"{self.media_type} - {self.file.name}"

    class Meta:
        verbose_name = "论坛媒体资源"
        verbose_name_plural = "论坛媒体资源管理"