package model

import (
	"context"
	"git.noahlan.cn/northlan/ntools-go/gorm-zero/gormc"
	"github.com/pkg/errors"
	"gorm.io/gorm"
	"gorm.io/plugin/optimisticlock"
	"live-service/common/nerr"
)

var _ UserIntegralModel = (*customUserIntegralModel)(nil)

type (
	// UserIntegralModel is an interface to be customized, add more methods here,
	// and implement the added methods in customUserIntegralModel.
	UserIntegralModel interface {
		userIntegralModel
		Transact(ctx context.Context, tx *gorm.DB, fn func(tx *gorm.DB) error) error
		InsertTx(ctx context.Context, tx *gorm.DB, data *UserIntegral) error
		FindOneTx(ctx context.Context, tx *gorm.DB, userId int64) (*UserIntegral, error)
		UpdateTx(ctx context.Context, tx *gorm.DB, integral *UserIntegral) error
		// ChangeIntegral 用户积分变动
		ChangeIntegral(ctx context.Context, tx *gorm.DB, userId int64, change int64) (int64, error)
	}

	customUserIntegralModel struct {
		*defaultUserIntegralModel
	}
)

// NewUserIntegralModel returns a model for the database table.
func NewUserIntegralModel(conn *gorm.DB) UserIntegralModel {
	return &customUserIntegralModel{
		defaultUserIntegralModel: newUserIntegralModel(conn),
	}
}

func (m *customUserIntegralModel) Transact(ctx context.Context, tx *gorm.DB, fn func(tx *gorm.DB) error) error {
	return withTx(ctx, m.conn, tx).Transaction(fn)
}

func (m *customUserIntegralModel) InsertTx(ctx context.Context, tx *gorm.DB, data *UserIntegral) error {
	err := withTx(ctx, m.conn, tx).Create(&data).Error
	return err
}

func (m *customUserIntegralModel) UpdateTx(ctx context.Context, tx *gorm.DB, integral *UserIntegral) error {
	if integral.Integral < 0 {
		return errors.New("无法将积分更新至负数")
	}
	db := withTx(ctx, m.conn, tx)

	result := db.Model(&integral).Updates(&UserIntegral{Integral: integral.Integral, Version: optimisticlock.Version{Int64: 1}})
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return ErrRowsAffectedZero
	}
	return nil
}

func (m *customUserIntegralModel) FindOneTx(ctx context.Context, tx *gorm.DB, userId int64) (*UserIntegral, error) {
	var resp UserIntegral
	err := withTx(ctx, m.conn, tx).Model(&UserIntegral{}).
		Where("`user_id` = ?", userId).Take(&resp).Error
	switch err {
	case nil:
		return &resp, nil
	case gormc.ErrNotFound:
		return nil, ErrNotFound
	default:
		return nil, err
	}
}

func (m *customUserIntegralModel) ChangeIntegral(ctx context.Context, tx *gorm.DB, userId int64, change int64) (int64, error) {
	resp := change
	var err error
	for i := VersionRetryCount; i > 0; i-- {
		err = withTx(ctx, m.conn, tx).Transaction(func(tx *gorm.DB) error {
			data, err := m.FindOneTx(ctx, tx, userId)
			if err != nil {
				if errors.Is(err, ErrNotFound) {
					if change < 0 {
						return nerr.NewWithCode(nerr.UserIntegralNotEnoughError)
					}
					// 用户积分记录不存在,进行插入
					if err = m.InsertTx(ctx, tx, &UserIntegral{
						UserId:   userId,
						Integral: change,
					}); err != nil {
						return errors.Wrap(err, "插入用户积分失败")
					}
					return nil
				} else {
					return errors.Wrap(err, "获取当前用户积分失败")
				}
			}
			if data.Integral+change < 0 {
				return errors.New("用户积分不足")
			}
			data.Integral += change
			if err = m.UpdateTx(ctx, tx, data); err != nil {
				if errors.Is(err, ErrRowsAffectedZero) {
					return err
				}
				return errors.Wrap(err, "更新用户积分失败")
			}
			resp = data.Integral
			return nil
		})
		if err != nil && errors.Is(err, ErrRowsAffectedZero) {
			// 未能正确更新,直接重试
			continue
		} else {
			// 其它错误退出循环
			break
		}
	}

	return resp, err
}