from rest_framework import serializers
from .models import ESP32Config, Order, Salesperson, Service, VCCourse, ProductFeature, ServiceOrder, WeChatUser, Distributor, Withdrawal, CommissionLog, CourseEnrollment
from .utils import get_current_wechat_user

class CommissionLogSerializer(serializers.ModelSerializer):
    """
    佣金记录序列化器
    """
    order_info = serializers.SerializerMethodField()
    
    class Meta:
        model = CommissionLog
        fields = ['id', 'amount', 'level', 'status', 'created_at', 'order_info']
        read_only_fields = ['id', 'amount', 'level', 'status', 'created_at', 'order_info']

    def get_order_info(self, obj):
        return {
            'order_id': obj.order.id,
            'total_price': obj.order.total_price,
            'customer_name': obj.order.customer_name
        }

class WeChatUserSerializer(serializers.ModelSerializer):
    is_admin = serializers.SerializerMethodField()
    has_web_account = serializers.SerializerMethodField()

    class Meta:
        model = WeChatUser
        fields = ['id', 'openid', 'nickname', 'avatar_url', 'gender', 'country', 'province', 'city', 'phone_number', 'is_star', 'title', 'skills', 'is_admin', 'has_web_account', 'has_web_badge']
        read_only_fields = ['id', 'openid', 'phone_number', 'is_star', 'title', 'skills', 'is_admin', 'has_web_account', 'has_web_badge']

    def get_is_admin(self, obj):
        # 检查是否关联了系统用户且具有管理员权限
        return bool(obj.user and obj.user.is_staff)

    def get_has_web_account(self, obj):
        # 检查是否关联了系统用户（即网页账号）
        return obj.user is not None

class DistributorSerializer(serializers.ModelSerializer):
    user_info = WeChatUserSerializer(source='user', read_only=True)
    
    class Meta:
        model = Distributor
        fields = ['id', 'user_info', 'level', 'commission_rate', 'total_earnings', 'withdrawable_balance', 'status', 'invite_code', 'qr_code_url']
        read_only_fields = ['level', 'commission_rate', 'total_earnings', 'withdrawable_balance', 'status', 'invite_code', 'qr_code_url']

class WithdrawalSerializer(serializers.ModelSerializer):
    class Meta:
        model = Withdrawal
        fields = ['id', 'amount', 'status', 'remark', 'created_at']
        read_only_fields = ['status', 'created_at', 'remark']

class ProductFeatureSerializer(serializers.ModelSerializer):
    """
    产品特性序列化器
    """
    display_icon = serializers.SerializerMethodField()

    class Meta:
        model = ProductFeature
        fields = ['title', 'description', 'icon_name', 'display_icon', 'order']
    
    def get_display_icon(self, obj):
        if obj.icon_url:
            return obj.icon_url
        if obj.icon_image:
            return obj.icon_image.url
        return None

class ServiceSerializer(serializers.ModelSerializer):
    """
    AI服务序列化器
    """
    features_list = serializers.SerializerMethodField()
    display_icon = serializers.SerializerMethodField()
    display_detail_image = serializers.SerializerMethodField()

    class Meta:
        model = Service
        fields = '__all__'

    def get_features_list(self, obj):
        if obj.features:
            return [line.strip() for line in obj.features.split('\n') if line.strip()]
        return []
    
    def get_display_icon(self, obj):
        if obj.icon_url:
            return obj.icon_url
        if obj.icon:
            return obj.icon.url
        return None

    def get_display_detail_image(self, obj):
        if obj.detail_image_url:
            return obj.detail_image_url
        if obj.detail_image:
            return obj.detail_image.url
        return None

class CourseEnrollmentSerializer(serializers.ModelSerializer):
    """
    课程报名序列化器
    """
    course_title = serializers.CharField(source='course.title', read_only=True)
    ref_code = serializers.CharField(write_only=True, required=False, allow_blank=True)

    class Meta:
        model = CourseEnrollment
        fields = ['id', 'course', 'course_title', 'customer_name', 'phone_number', 'email', 'wechat_id', 'message', 'status', 'created_at', 'ref_code']
        read_only_fields = ['status', 'created_at']

    def create(self, validated_data):
        ref_code = validated_data.pop('ref_code', None)
        
        # 尝试关联销售员或分销员
        if ref_code:
            try:
                salesperson = Salesperson.objects.get(code=ref_code)
                validated_data['salesperson'] = salesperson
            except Salesperson.DoesNotExist:
                pass
            
            try:
                distributor = Distributor.objects.get(invite_code=ref_code)
                validated_data['distributor'] = distributor
            except Distributor.DoesNotExist:
                pass
                
        return super().create(validated_data)

class ServiceOrderSerializer(serializers.ModelSerializer):
    """
    AI服务订单序列化器
    """
    service_name = serializers.CharField(source='service.title', read_only=True)
    # 接收前端传来的 ref_code
    ref_code = serializers.CharField(write_only=True, required=False, allow_blank=True)

    class Meta:
        model = ServiceOrder
        fields = ['id', 'service', 'service_name', 'customer_name', 'company_name', 
                  'phone_number', 'email', 'requirements', 'total_price', 'status', 'created_at', 'ref_code']
        read_only_fields = ['total_price', 'status', 'created_at']
    
    def create(self, validated_data):
        ref_code = validated_data.pop('ref_code', None)
        service = validated_data.get('service')
        
        # 默认设置预估总价为服务起步价
        if service:
            validated_data['total_price'] = service.price

        # 尝试关联销售员
        if ref_code:
            try:
                salesperson = Salesperson.objects.get(code=ref_code)
                validated_data['salesperson'] = salesperson
            except Salesperson.DoesNotExist:
                pass
            
            try:
                distributor = Distributor.objects.get(invite_code=ref_code)
                validated_data['distributor'] = distributor
            except Distributor.DoesNotExist:
                pass

        return super().create(validated_data)

class VCCourseSerializer(serializers.ModelSerializer):
    """
    VC课程序列化器
    """
    display_cover_image = serializers.SerializerMethodField()
    display_detail_image = serializers.SerializerMethodField()
    course_type_display = serializers.CharField(source='get_course_type_display', read_only=True)
    video_url = serializers.SerializerMethodField()
    video_embed_code = serializers.SerializerMethodField()
    is_purchased = serializers.SerializerMethodField()

    class Meta:
        model = VCCourse
        fields = '__all__'
    
    def get_display_cover_image(self, obj):
        if obj.cover_image_url:
            return obj.cover_image_url
        if obj.cover_image:
            return obj.cover_image.url
        return None

    def get_display_detail_image(self, obj):
        if obj.detail_image_url:
            return obj.detail_image_url
        if obj.detail_image:
            return obj.detail_image.url
        return None

    def _check_purchased(self, obj):
        request = self.context.get('request')
        if not request:
            return False
            
        # 尝试获取当前用户
        user = get_current_wechat_user(request)
        if not user:
            return False
            
        # 如果是管理员，视为已购买
        if user.user and user.user.is_staff:
            return True

        # 检查是否已购买/报名 (通过已支付的订单)
        has_order = Order.objects.filter(
            wechat_user=user,
            course=obj,
            status__in=['paid', 'shipped', 'completed']
        ).exists()
        
        return has_order

    def get_is_purchased(self, obj):
        return self._check_purchased(obj)

    def get_video_url(self, obj):
        """
        仅当用户已付费/报名时返回视频URL
        """
        if not obj.is_video_course:
            return None
            
        if self._check_purchased(obj):
            return obj.video_url
            
        return None

    def get_video_embed_code(self, obj):
        """
        仅当用户已付费/报名时返回视频嵌入代码
        """
        if not obj.is_video_course:
            return None
            
        if self._check_purchased(obj):
            return obj.video_embed_code
            
        return None

class ESP32ConfigSerializer(serializers.ModelSerializer):
    """
    ESP32配置序列化器
    """
    display_detail_image = serializers.SerializerMethodField()
    features = ProductFeatureSerializer(many=True, read_only=True)

    class Meta:
        model = ESP32Config
        fields = '__all__'
    
    def get_display_detail_image(self, obj):
        if obj.detail_image_url:
            return obj.detail_image_url
        if obj.detail_image:
            return obj.detail_image.url
        return None


class OrderSerializer(serializers.ModelSerializer):
    """
    订单序列化器
    """
    config_name = serializers.CharField(source='config.name', read_only=True)
    course_title = serializers.CharField(source='course.title', read_only=True)
    activity_title = serializers.CharField(source='activity.title', read_only=True)
    config_image = serializers.SerializerMethodField()
    salesperson_name = serializers.CharField(source='salesperson.name', read_only=True)
    salesperson_code = serializers.CharField(source='salesperson.code', read_only=True)
    # 接收前端传来的 ref_code，用于查找 Salesperson
    ref_code = serializers.CharField(write_only=True, required=False, allow_blank=True)
    
    class Meta:
        model = Order
        fields = ['id', 'config', 'config_name', 'config_image', 'course', 'course_title', 'activity', 'activity_title', 'quantity', 'total_price', 'status', 'created_at', 'updated_at', 'wechat_trade_no', 
                  'customer_name', 'phone_number', 'shipping_address', 'ref_code', 'salesperson_name', 'salesperson_code', 'courier_name', 'tracking_number']
        read_only_fields = ['total_price', 'status', 'wechat_trade_no', 'created_at', 'updated_at']
        extra_kwargs = {
            'customer_name': {'required': True},
            'phone_number': {'required': True},
        }

    def validate(self, data):
        # 如果是部分更新 (PATCH)，可能不需要校验所有字段，但这里主要用于创建
        if self.instance:
            return data

        config = data.get('config')
        course = data.get('course')
        activity = data.get('activity')

        if not config and not course and not activity:
             raise serializers.ValidationError("必须选择一种商品（硬件配置、课程或活动）")
        
        # Count how many types are selected
        selected_types = sum([bool(config), bool(course), bool(activity)])
        if selected_types > 1:
             raise serializers.ValidationError("一次只能购买一种类型的商品")

        if config and not data.get('shipping_address'):
             raise serializers.ValidationError({"shipping_address": "购买硬件产品需要填写收货地址"})
        
        return data

    def get_config_image(self, obj):
        if obj.config:
            if obj.config.static_image_url:
                return obj.config.static_image_url
            if obj.config.detail_image_url:
                return obj.config.detail_image_url
            if obj.config.detail_image:
                return obj.config.detail_image.url
        elif obj.course:
            if obj.course.cover_image_url:
                return obj.course.cover_image_url
            if obj.course.cover_image:
                return obj.course.cover_image.url
        elif obj.activity:
            # Use activity.display_banner_url logic
            if obj.activity.banner:
                return obj.activity.banner.url
            if obj.activity.banner_url:
                return obj.activity.banner_url
        return None

    def create(self, validated_data):
        """
        重写创建方法，自动计算总价并关联销售员/分销员
        """
        config = validated_data.get('config')
        course = validated_data.get('course')
        activity = validated_data.get('activity')
        quantity = validated_data.get('quantity', 1)
        ref_code = validated_data.pop('ref_code', None)

        if config:
            validated_data['total_price'] = config.price * quantity
        elif course:
            validated_data['total_price'] = course.price * quantity
        elif activity:
            validated_data['total_price'] = activity.price * quantity
        
        # 尝试关联销售员或分销员
        if ref_code:
            # 1. 尝试查找旧版销售员
            try:
                salesperson = Salesperson.objects.get(code=ref_code)
                validated_data['salesperson'] = salesperson
            except Salesperson.DoesNotExist:
                pass

            # 2. 尝试查找新版分销员
            try:
                distributor = Distributor.objects.get(invite_code=ref_code)
                validated_data['distributor'] = distributor
            except Distributor.DoesNotExist:
                pass

        return super().create(validated_data)