from django.db import models
from django.contrib.auth import get_user_model
import uuid

User = get_user_model()


class Meeting(models.Model):
    """会议室模型"""
    STATUS_CHOICES = [
        ('pending', '待开始'),
        ('active', '进行中'),
        ('ended', '已结束'),
    ]
    
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    topic = models.CharField(max_length=200, verbose_name='会议主题')
    host = models.ForeignKey(User, on_delete=models.CASCADE, related_name='hosted_meetings')
    status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='pending')
    invite_code = models.CharField(max_length=20, unique=True, verbose_name='邀请码')
    created_at = models.DateTimeField(auto_now_add=True)
    started_at = models.DateTimeField(null=True, blank=True)
    ended_at = models.DateTimeField(null=True, blank=True)
    expires_at = models.DateTimeField(null=True, blank=True, verbose_name="过期时间")
    
    # 主持龙虾（负责生成会议纪要）
    host_agent_id = models.CharField(max_length=100, null=True, blank=True, verbose_name='主持 Agent ID')
    host_instance_id = models.CharField(max_length=100, null=True, blank=True, verbose_name='主持实例 ID')
    minutes_generated = models.BooleanField(default=False, verbose_name='纪要已生成')
    minutes_uploaded_at = models.DateTimeField(null=True, blank=True, verbose_name='纪要上传时间')
    
    class Meta:
        db_table = 'meetings'
        verbose_name = '会议室'
        verbose_name_plural = '会议室'
        ordering = ['-created_at']
    
    def __str__(self):
        return f"{self.topic} ({self.host.username})"
    
    def save(self, *args, **kwargs):
        if not self.invite_code:
            self.invite_code = uuid.uuid4().hex[:8].upper()
        super().save(*args, **kwargs)


class Participant(models.Model):
    """参会者模型"""
    AGENT_TYPE_CHOICES = [
        ('human', '人类'),
        ('openclaw', 'OpenClaw Agent'),
        ('other', '其他 AI'),
    ]
    
    meeting = models.ForeignKey(Meeting, on_delete=models.CASCADE, related_name='participants')
    user = models.ForeignKey(User, null=True, blank=True, on_delete=models.CASCADE)
    
    # Agent 信息
    agent_type = models.CharField(max_length=20, choices=AGENT_TYPE_CHOICES)
    agent_id = models.CharField(max_length=100, null=True, blank=True)
    agent_name = models.CharField(max_length=100, verbose_name='Agent 名称')
    agent_emoji = models.CharField(max_length=10, default='🤖', verbose_name='Agent 表情')
    
    # 显示信息
    nickname = models.CharField(max_length=100, verbose_name='昵称')
    is_host = models.BooleanField(default=False)
    joined_at = models.DateTimeField(auto_now_add=True)
    left_at = models.DateTimeField(null=True, blank=True)
    
    # API 认证（Agent 用）
    api_key = models.CharField(max_length=255, null=True, blank=True)
    
    class Meta:
        db_table = 'participants'
        verbose_name = '参会者'
        verbose_name_plural = '参会者'
        indexes = [
            models.Index(fields=['meeting', 'agent_id']),
            models.Index(fields=['agent_type', 'meeting']),
        ]
    
    def __str__(self):
        return f"{self.agent_emoji} {self.nickname}"
    
    def save(self, *args, **kwargs):
        if not self.api_key and self.agent_type != 'human':
            self.api_key = uuid.uuid4().hex
        super().save(*args, **kwargs)


class Message(models.Model):
    """消息模型"""
    meeting = models.ForeignKey(Meeting, on_delete=models.CASCADE, related_name='messages')
    sender = models.ForeignKey(Participant, on_delete=models.CASCADE, related_name='sent_messages')
    content = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)
    
    # 信箱机制
    is_broadcast = models.BooleanField(default=True, verbose_name='群发消息')
    requires_response = models.BooleanField(default=False, verbose_name='需要回复')
    in_reply_to = models.ForeignKey('self', null=True, blank=True, on_delete=models.SET_NULL, related_name='replies')
    
    # 读取状态
    read_by = models.ManyToManyField(Participant, related_name='read_messages', blank=True)
    
    class Meta:
        db_table = 'messages'
        verbose_name = '消息'
        verbose_name_plural = '消息'
        ordering = ['created_at']
        indexes = [
            models.Index(fields=['meeting', 'created_at']),
            models.Index(fields=['is_broadcast', 'created_at']),
        ]
    
    def __str__(self):
        return f"{self.sender.nickname}: {self.content[:50]}"


class MeetingMinutes(models.Model):
    """会议纪要模型"""
    meeting = models.OneToOneField(Meeting, on_delete=models.CASCADE, related_name='minutes')
    content = models.TextField()
    generated_at = models.DateTimeField(auto_now_add=True)
    exported_at = models.DateTimeField(null=True, blank=True)
    
    class Meta:
        db_table = 'meeting_minutes'
        verbose_name = '会议纪要'
        verbose_name_plural = '会议纪要'
    
    def __str__(self):
        return f"会议纪要 - {self.meeting.topic}"