from decimal import Decimal

from django.db import models
from flower.common import ModelBase
from django.contrib.auth.models import User


# ==================== 常量定义 ====================
METER_TO_YARD_RATE = 0.9144
YARD_TO_METER_RATE = 1.09361


# ==================== 枚举类定义 ====================

class WareHouseModeEnum(models.IntegerChoices):
    """仓库出入库模式枚举"""
    RESTRICT_IN = 1, '严进宽出'
    RESTRICT_IN_OUT = 2, '严进严出'
    UNRESTRICTED = 3, '宽进宽出'


class WarehouseTypeEnum(models.IntegerChoices):
    """仓库类别枚举"""
    WHOLE = 1, '整仓'
    SCATTERED = 2, '散仓'


class MerchantTypeEnum(models.IntegerChoices):
    """商户类型枚举"""
    STORE = 1, '布行'
    FACTORY = 2, '印花厂'


class ProductUnitEnum(models.IntegerChoices):
    """产品单位枚举"""
    METER = 1, '米'
    YARD = 2, '码'
    KG = 3, '公斤'


class EmployeeTypeEnum(models.TextChoices):
    """员工职位类型枚举"""
    PRINTER = '打纸', '打纸'
    ROLLING = '滚筒', '滚筒'
    WARE = '仓库', '仓库'
    DELIVERY = '送货', '送货'


class EmployeeStatusEnum(models.TextChoices):
    """员工状态枚举"""
    ACTIVE = '在职', '在职'
    INACTIVE = '离职', '离职'


class DeviceStatusEnum(models.TextChoices):
    """设备状态枚举"""
    ACTIVE = '使用中', '使用中'
    INACTIVE = '停用', '停用'
    MAINTENANCE = '维修中', '维修中'


class DeviceTypeEnum(models.TextChoices):
    """设备类型枚举"""
    ROLLING = '滚筒', '滚筒'
    PRINTER = '打印', '打印'


# ==================== 模型定义 ====================


class EmployeeType(ModelBase):
    """员工职位类型"""
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='employee_types', verbose_name='所属商户')
    title = models.CharField(max_length=50, verbose_name='职位名称')
    description = models.TextField(blank=True, null=True, verbose_name='职位描述')
    reverse = models.CharField(max_length=100, blank=True, null=True, verbose_name='预留字段')

    def __str__(self):
        return self.title

    class Meta:
        verbose_name = '员工职位类型'
        verbose_name_plural = '员工职位类型'
        unique_together = ('merchant', 'title')


class QuickInput(ModelBase):
    id = models.BigAutoField(primary_key=True)
    name = models.CharField(max_length=100, verbose_name='名')
    value = models.CharField(max_length=200, verbose_name='值')
    group = models.CharField(verbose_name='组')

    def __str__(self):
        return f'{self.group}-{self.name}'

    class Meta:
        verbose_name = '快捷输入'
        verbose_name_plural = '快捷输入'
        unique_together = ('name', 'group')


class Merchant(ModelBase):
    id = models.BigAutoField(primary_key=True)
    name = models.CharField(max_length=100, verbose_name='商户名称')
    type = models.IntegerField(choices=MerchantTypeEnum.choices, verbose_name='商户类型')
    area = models.CharField(max_length=100, blank=True, null=True, verbose_name='地区')
    email = models.EmailField(blank=True, null=True, verbose_name='电子邮箱')
    mobile = models.CharField(max_length=20, blank=True, null=True, verbose_name='手机')
    contact = models.TextField(blank=True, null=True, verbose_name='联系人')
    auto_complete_stock_change = models.BooleanField(
        default=False, 
        verbose_name='自动确认库存变动',
    )
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = '商户资料'
        verbose_name_plural = '商户资料'


class VehicleType(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='vehicle_types', verbose_name='所属商户')
    name = models.CharField(max_length=50, verbose_name='车辆类型名称')
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = '车辆类型'
        verbose_name_plural = '车辆类型'


class WareHouse(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='warehouses', verbose_name='所属商户')
    name = models.CharField(max_length=100, verbose_name='仓库名称')
    location = models.CharField(max_length=200, blank=True, null=True, verbose_name='仓库地址')
    type = models.IntegerField(
        choices=WarehouseTypeEnum.choices,
        default=WarehouseTypeEnum.WHOLE,
        verbose_name='仓库类别',
    )
    mode = models.IntegerField(
        choices=WareHouseModeEnum.choices,
        default=WareHouseModeEnum.RESTRICT_IN,
        verbose_name='出入库模式',
    )
    contact = models.CharField(max_length=100, blank=True, null=True, verbose_name='联系人')
    mobile = models.CharField(max_length=20, blank=True, null=True, verbose_name='手机')
    area = models.CharField(max_length=100, blank=True, null=True, verbose_name='地区')
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = '仓库资料'
        verbose_name_plural = '仓库资料'


class Supplier(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='suppliers', verbose_name='所属商户')
    name = models.CharField(max_length=100, verbose_name='供应商名称')
    area = models.CharField(max_length=100, blank=True, null=True, verbose_name='地区')
    email = models.EmailField(blank=True, null=True, verbose_name='电子邮箱')
    mobile = models.CharField(max_length=20, blank=True, null=True, verbose_name='手机')
    contact = models.TextField(blank=True, null=True, verbose_name='联系人')
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = '供应商'
        verbose_name_plural = '供应商'


class BankAccount(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='bank_accounts', verbose_name='所属商户')
    name = models.CharField(max_length=100, verbose_name='名称')
    auto_number = models.CharField(max_length=50, verbose_name='自动编号')
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')
    attachment = models.FileField(upload_to='bank_accounts/', blank=True, null=True, verbose_name='附件')

    def __str__(self):
        return f'{self.name} - {self.auto_number}'

    class Meta:
        verbose_name = '银行账户'
        verbose_name_plural = '银行账户'


class ProductCategory(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='product_categories', verbose_name='所属商户')
    name = models.CharField(max_length=100, verbose_name='类别名称')
    description = models.TextField(blank=True, null=True, verbose_name='类别描述')
    product_prefix = models.CharField(max_length=5, verbose_name='产品编号前缀')

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = '产品类别'
        verbose_name_plural = '产品类别'


class Product(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, verbose_name='所属商户')
    category = models.ForeignKey(
        ProductCategory,
        on_delete=models.PROTECT,
        related_name='products',
        verbose_name='产品类别',
    )
    name = models.CharField(max_length=100, verbose_name='产品名')
    human_id = models.CharField(max_length=100, verbose_name='产品编号', blank=True)
    color = models.CharField(max_length=50, blank=True, null=True, verbose_name='颜色')
    width_size = models.DecimalField(max_digits=10, decimal_places=2, blank=True, null=True, verbose_name='宽幅')
    single_price_in = models.DecimalField(
        max_digits=10,
        decimal_places=2,
        verbose_name='参考进价',
        blank=True,
        null=True,
    )
    single_price_out = models.DecimalField(
        max_digits=10,
        decimal_places=2,
        verbose_name='参考售价',
        blank=True,
        null=True,
    )
    unit = models.IntegerField(
        choices=ProductUnitEnum.choices,
        default=ProductUnitEnum.METER,
        verbose_name='单位',
    )
    spec = models.CharField(max_length=100, blank=True, null=True, verbose_name='规格')
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')
    image = models.ImageField(
        upload_to='product_images/', 
        blank=True, 
        null=True, 
        verbose_name='产品图片',
    )
    minimum_quantity = models.IntegerField(null=True, blank=True, verbose_name='最低库存量')
    transform_rate = models.DecimalField(
        max_digits=10,
        decimal_places=4,
        blank=True,
        null=True,
        verbose_name='公斤转换率',
    )

    def __str__(self):
        return self.name

    def save(
            self,
            *args,
            force_insert=False,
            force_update=False,
            using=None,
            update_fields=None,
    ):
        super().save(
            *args,
            force_insert=force_insert,
            force_update=force_update,
            using=using,
            update_fields=update_fields,
        )
        # Generate human_id if not set after saving to get the ID
        if not self.human_id and self.category:
            self.human_id = f'{self.category.product_prefix}{self.id:05d}'
            super().save(
                *args,
                force_insert=False,
                force_update=False,
                using=using,
                update_fields=['human_id'],
            )

    class Meta:
        verbose_name = '产品资料'
        verbose_name_plural = '产品资料'


class Customer(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='customers', verbose_name='所属商户')
    name = models.CharField(max_length=100, verbose_name='客户名称')
    visible_employees = models.ManyToManyField(
        'Employee', 
        blank=True, 
        related_name='visible_customers',
        verbose_name='可见该客户的员工',
    )
    created_by = models.ForeignKey(
        'Employee', 
        on_delete=models.PROTECT, 
        related_name='created_customers',
        null=True,
        verbose_name='创建者',
    )
    mobile = models.CharField(max_length=20, verbose_name='手机')
    area = models.CharField(max_length=100, blank=True, null=True, verbose_name='地区')
    email = models.EmailField(blank=True, null=True, verbose_name='电子邮箱')
    contact = models.CharField(blank=True, null=True, verbose_name='联系人')
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = '客户资料'
        verbose_name_plural = '客户资料'


class Employee(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='employees', verbose_name='所属商户')
    sys_user = models.OneToOneField(
        User,
        on_delete=models.PROTECT,
        related_name='employee',
        null=True,
        blank=True,
        verbose_name='系统用户',
    )
    name = models.CharField(max_length=100, verbose_name='员工姓名')
    position = models.ForeignKey(
        'EmployeeType',
        on_delete=models.PROTECT,
        related_name='employees',
        null=True,
        blank=True,
        verbose_name='职位',
    )
    mobile = models.CharField(max_length=20, blank=True, null=True, verbose_name='手机')
    area = models.CharField(max_length=100, blank=True, null=True, verbose_name='地区')
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')
    status = models.CharField(
        max_length=20,
        choices=EmployeeStatusEnum.choices,
        default=EmployeeStatusEnum.ACTIVE,
        verbose_name='员工状态',
    )

    @property
    def job_type(self) -> str:
        """
        返回职位名称（向后兼容）
        
        如果有关联的职位类型，返回其 title，否则返回空字符串
        """
        if self.position:
            return self.position.title
        return ''

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = '员工资料'
        verbose_name_plural = '员工资料'


class DeviceInfo(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='devices', verbose_name='所属商户')
    name = models.CharField(max_length=100, verbose_name='设备名称')
    type = models.CharField(
        max_length=20,
        choices=DeviceTypeEnum.choices,
        default=DeviceTypeEnum.ROLLING,
        verbose_name='设备类型',
    )
    status = models.CharField(
        max_length=20,
        choices=DeviceStatusEnum.choices,
        default=DeviceStatusEnum.ACTIVE,
        verbose_name='设备状态',
    )
    start_working_at = models.DateField(blank=True, null=True, verbose_name='开始服役日期')
    stop_working_at = models.DateField(blank=True, null=True, verbose_name='停止服役日期')
    is_occupied = models.BooleanField(default=False, verbose_name='是否被占用')
    description = models.TextField(blank=True, null=True, verbose_name='备注描述')

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = '设备资料'
        verbose_name_plural = '设备资料'


class VehicleTransportRecord(ModelBase):
    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey('Merchant', on_delete=models.PROTECT, related_name='vehicle_transport_records', verbose_name='所属商户')
    vehicle_type = models.ForeignKey(
        VehicleType,
        on_delete=models.PROTECT,
        related_name='vehicles',
        verbose_name='车次',
    )
    driver_name = models.CharField(max_length=100, verbose_name='司机姓名')
    contact_number = models.CharField(max_length=20, blank=True, null=True, verbose_name='联系电话')
    license_plate = models.CharField(max_length=20, verbose_name='车牌号码', null=True, blank=True)
    delivery_date = models.DateField(verbose_name='送货日期')

    def __str__(self):
        return f'{self.vehicle_type}-{self.driver_name}-{self.delivery_date}'

    class Meta:
        verbose_name = '司机车次'
        verbose_name_plural = '司机车次'