from django.core.exceptions import ValidationError
from django.apps import apps


class ExcelDataSaver:
    def __init__(self, model_name, data):
        app_name, model_name = model_name.split('.')
        self.model = apps.get_model(app_name, model_name)
        self.data = data
        self.field_mapping, self.reverse_field_mapping = self._generate_field_mapping()
        self.errors = []

    def _generate_field_mapping(self):
        field_mapping = {}
        reverse_field_mapping = {}
        for field in self.model._meta.get_fields():
            if hasattr(field, 'verbose_name'):
                field_mapping[field.verbose_name] = field.name
                reverse_field_mapping[field.name] = field.verbose_name
        return field_mapping, reverse_field_mapping

    def validate_data(self):
        for row_num, row in enumerate(self.data):
            instance = self.model()
            for field, value in row.items():
                actual_field = self.field_mapping.get(field)
                if not actual_field:
                    self.errors.append(f"第【{row_num + 1}】行找不到对应的模型字段: 【{self.reverse_field_mapping[field] + ':' + field}】")
                    continue
                setattr(instance, actual_field, value)

            # 在设置所有字段值之后再调用 full_clean
            try:
                instance.full_clean()
            except ValidationError as e:
                for field, errors in e.message_dict.items():
                    for error in errors:
                        try:
                            self.errors.append(f"第【{row_num + 1}】行【{self.reverse_field_mapping[field]}】字段输入错误: {error}")
                        except KeyError:
                            self.errors.append(f"第【{row_num + 1}】行，错误原因: {error}")
                        except Exception as e:
                            self.errors.append(f"其他错误: {e}")
        return len(self.errors) == 0

    def save_data(self):
        if self.validate_data():
            for row in self.data:
                row_data = {self.field_mapping[field]: value for field, value in row.items() if field in self.field_mapping}
                instance = self.model(**row_data)
                instance.save()
            return True
        return False

    def get_errors(self):
        return self.errors

    def add_custom_validation(self, custom_validation_func):
        self.custom_validation_func = custom_validation_func
        self.validate_data = self._validate_data_with_custom

    def _validate_data_with_custom(self):
        basic_valid = self.validate_data()
        custom_valid = self.custom_validation_func(self.data)
        return basic_valid and custom_valid