from django.db import models
from django.contrib.auth import get_user_model
from django.core.validators import MinLengthValidator

User = get_user_model()


class DailyReport(models.Model):
    """日报模型"""
    user = models.ForeignKey(
        User, 
        on_delete=models.CASCADE, 
        verbose_name="提交人",
        related_name='daily_reports'
    )
    work_summary = models.TextField(
        "工作总结", 
        validators=[MinLengthValidator(10, message="工作总结至少需要10个字符")]
    )
    next_day_plan = models.TextField(
        "明日计划",
        validators=[MinLengthValidator(10, message="明日计划至少需要10个字符")]
    )
    difficulties = models.TextField(
        "遇到的困难", 
        blank=True, 
        null=True,
        help_text="可选：描述工作中遇到的问题或困难"
    )
    suggestions = models.TextField(
        "建议或意见", 
        blank=True, 
        null=True,
        help_text="可选：对工作或团队的建议"
    )
    report_date = models.DateField("日报日期", help_text="填写日报对应的日期")
    created_at = models.DateTimeField("提交时间", auto_now_add=True)
    updated_at = models.DateTimeField("更新时间", auto_now=True)
    is_draft = models.BooleanField("草稿状态", default=False, help_text="是否为草稿")
    
    class Meta:
        verbose_name = "日报"
        verbose_name_plural = verbose_name
        ordering = ['-report_date', '-created_at']
        unique_together = [['user', 'report_date']]  # 每个用户每天只能有一份日报
        indexes = [
            models.Index(fields=['user', 'report_date']),
            models.Index(fields=['report_date']),
            models.Index(fields=['-created_at']),
        ]
    
    def __str__(self):
        return f'{self.user.username} - {self.report_date}'
    
    @property
    def work_summary_preview(self):
        """工作总结预览（前100个字符）"""
        return self.work_summary[:100] + '...' if len(self.work_summary) > 100 else self.work_summary
    
    @property
    def next_day_plan_preview(self):
        """明日计划预览（前100个字符）"""
        return self.next_day_plan[:100] + '...' if len(self.next_day_plan) > 100 else self.next_day_plan


class ReportComment(models.Model):
    """日报评论模型"""
    report = models.ForeignKey(
        DailyReport,
        on_delete=models.CASCADE,
        related_name='comments',
        verbose_name="关联日报"
    )
    user = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        verbose_name="评论人"
    )
    content = models.TextField("评论内容")
    created_at = models.DateTimeField("评论时间", auto_now_add=True)
    updated_at = models.DateTimeField("更新时间", auto_now=True)
    
    class Meta:
        verbose_name = "日报评论"
        verbose_name_plural = verbose_name
        ordering = ['-created_at']
    
    def __str__(self):
        return f'{self.user.username} 评论了 {self.report}'