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

class LocationStatistics(models.Model):
    """货位统计模型"""
    warehouse_code = models.CharField(max_length=255, verbose_name="仓库代码")
    warehouse_name = models.CharField(max_length=255, verbose_name="仓库名称")
    layer = models.IntegerField(verbose_name="楼层")
    
    # 按货位类型统计
    t5_total = models.IntegerField(default=0, verbose_name="5货位总数")
    t5_used = models.IntegerField(default=0, verbose_name="5货位已用")
    t5_available = models.IntegerField(default=0, verbose_name="5货位可用")
    
    t4_total = models.IntegerField(default=0, verbose_name="4货位总数")
    t4_used = models.IntegerField(default=0, verbose_name="4货位已用")
    t4_available = models.IntegerField(default=0, verbose_name="4货位可用")
    
    s4_total = models.IntegerField(default=0, verbose_name="4单货位总数")
    s4_used = models.IntegerField(default=0, verbose_name="4单货位已用")
    s4_available = models.IntegerField(default=0, verbose_name="4单货位可用")
    
    t2_total = models.IntegerField(default=0, verbose_name="2货位总数")
    t2_used = models.IntegerField(default=0, verbose_name="2货位已用")
    t2_available = models.IntegerField(default=0, verbose_name="2货位可用")
    
    t1_total = models.IntegerField(default=0, verbose_name="散货位总数")
    t1_used = models.IntegerField(default=0, verbose_name="散货位已用")
    t1_available = models.IntegerField(default=0, verbose_name="散货位可用")
    
    # 汇总统计
    total_locations = models.IntegerField(default=0, verbose_name="总货位数")
    total_used = models.IntegerField(default=0, verbose_name="总已用数")
    total_available = models.IntegerField(default=0, verbose_name="总可用数")
    utilization_rate = models.DecimalField(max_digits=5, decimal_places=2, default=0, verbose_name="使用率(%)")
    
    # 统计时间
    statistic_time = models.DateTimeField(default=timezone.now, verbose_name="统计时间")
    is_latest = models.BooleanField(default=False, verbose_name="是否最新统计")
    
    class Meta:
        db_table = 'location_statistics'
        verbose_name = '货位统计'
        verbose_name_plural = "货位统计"
        ordering = ['-statistic_time', 'warehouse_code', 'layer']
        unique_together = ['warehouse_code', 'layer', 'statistic_time']
    
    def __str__(self):
        return f"{self.warehouse_name}-{self.layer}层-{self.statistic_time.strftime('%Y-%m-%d %H:%M')}"

class LocationGroupStatistics(models.Model):
    """货位组统计模型"""
    warehouse_code = models.CharField(max_length=255, verbose_name="仓库代码")
    warehouse_name = models.CharField(max_length=255, verbose_name="仓库名称")
    layer = models.IntegerField(verbose_name="楼层")
    location_group = models.CharField(max_length=20, verbose_name="库位组")
    
    # 统计信息
    total_locations = models.IntegerField(default=0, verbose_name="组内总货位数")
    used_locations = models.IntegerField(default=0, verbose_name="组内已用货位数")
    available_locations = models.IntegerField(default=0, verbose_name="组内可用货位数")
    utilization_rate = models.DecimalField(max_digits=5, decimal_places=2, default=0, verbose_name="使用率(%)")
    
    # 按货位类型细分
    location_type_breakdown = models.JSONField(default=dict, verbose_name="货位类型细分")
    
    statistic_time = models.DateTimeField(default=timezone.now, verbose_name="统计时间")
    
    class Meta:
        db_table = 'location_group_statistics'
        verbose_name = '货位组统计'
        verbose_name_plural = "货位组统计"
        ordering = ['warehouse_code', 'layer', 'total_locations']
    
    def __str__(self):
        return f"{self.warehouse_name}-{self.layer}层-{self.location_group}"