from django.db import models
from django.utils import timezone


class Lobster(models.Model):
    """龙虾模型"""
    name = models.CharField(max_length=50, verbose_name='名称')
    emoji = models.CharField(max_length=10, verbose_name='Emoji')
    port = models.IntegerField(verbose_name='端口')
    specialty = models.CharField(max_length=100, verbose_name='专长')
    container = models.CharField(max_length=100, verbose_name='容器')
    app_name = models.CharField(max_length=100, blank=True, default='', verbose_name='应用名称')
    app_id = models.CharField(max_length=50, blank=True, default='', verbose_name='应用 ID')
    workspace = models.CharField(max_length=100, blank=True, default='', verbose_name='工作区')
    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 = '龙虾'
        verbose_name_plural = '龙虾'
        ordering = ['id']
    
    def __str__(self):
        return f'{self.emoji} {self.name}'


class LobsterDiary(models.Model):
    """龙虾日记模型（支持 RAG）"""
    
    # 分类选择
    CATEGORY_CHOICES = [
        ('chengcai', '成才之路'),
        ('memory', '工作记忆'),
        ('tech', '技术笔记'),
        ('other', '其他'),
    ]
    
    # 关联龙虾
    lobster = models.ForeignKey(
        Lobster, 
        on_delete=models.CASCADE, 
        related_name='diaries',
        verbose_name='龙虾'
    )
    
    # 基本信息
    date = models.DateField(verbose_name='日期')
    title = models.CharField(max_length=200, verbose_name='标题')
    content = models.TextField(verbose_name='内容')
    
    # 分类和标签（RAG 检索的关键元数据）
    category = models.CharField(
        max_length=50, 
        choices=CATEGORY_CHOICES,
        default='other',
        verbose_name='分类'
    )
    tags = models.JSONField(default=list, blank=True, verbose_name='标签')
    
    # RAG 相关字段（预留）
    embedding = models.TextField(
        blank=True, 
        null=True,
        verbose_name='文本向量 (JSON 格式)'
    )
    embedding_model = models.CharField(
        max_length=50, 
        blank=True,
        default='',
        verbose_name='Embedding 模型版本'
    )
    
    # 时间戳
    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 = '龙虾日记'
        verbose_name_plural = '龙虾日记'
        ordering = ['-date', '-created_at']
        indexes = [
            models.Index(fields=['lobster', 'date']),
            models.Index(fields=['category', 'date']),
            models.Index(fields=['date']),
        ]
    
    def __str__(self):
        return f'{self.lobster.emoji} {self.lobster.name} - {self.date} - {self.get_category_display()}'
    
    def get_content_preview(self, length=50):
        """获取内容预览"""
        if len(self.content) <= length:
            return self.content
        return self.content[:length] + '...'