package model

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"github.com/zeromicro/go-zero/core/stores/cache"
	"github.com/zeromicro/go-zero/core/stores/sqlx"
	"strings"
)

var _ WalletsModel = (*customWalletsModel)(nil)

type (
	// WalletsModel is an interface to be customized, add more methods here,
	// and implement the added methods in customWalletsModel.
	WalletsModel interface {
		walletsModel
		InsertWalletsTrans(ctx context.Context, wallets *Wallets, session sqlx.Session) (sql.Result, error)
		UpdateBalance(session sqlx.Session, ctx context.Context, userId int64, amount float64) error
		TransCtx(ctx context.Context, fn func(ctx context.Context, session sqlx.Session) error) error
		FindWalletsByUserIds(ctx context.Context, userIds []int64) (map[int64]*Wallets, error)
	}

	customWalletsModel struct {
		*defaultWalletsModel
	}
)

var ErrBalanceNotEnough = errors.New("余额不足")
var ErrVersionMismatch = errors.New("版本号不匹配，请重试")

// NewWalletsModel returns a model for the database table.
func NewWalletsModel(conn sqlx.SqlConn, c cache.CacheConf, opts ...cache.Option) WalletsModel {
	return &customWalletsModel{
		defaultWalletsModel: newWalletsModel(conn, c, opts...),
	}
}
func (m *customWalletsModel) TransCtx(ctx context.Context, fn func(ctx context.Context, session sqlx.Session) error) error {
	// 使用带 ctx 的事务处理
	err := m.TransactCtx(ctx, func(ctx context.Context, session sqlx.Session) error {
		return fn(ctx, session)
	})
	return err
}

// 更新余额的方法
func (m *customWalletsModel) UpdateBalance(session sqlx.Session, ctx context.Context, userId int64, amount float64) error {

	wallet, err := m.FindOneByUserId(ctx, userId)
	if err != nil {
		return err
	}

	// 检查当前版本是否达到了上限
	newVersion := wallet.Version + 1
	if newVersion > 100000000 { // 你可以根据实际需要设定上限，比如 UNSIGNED INT 的最大值
		newVersion = 1 // 或者设置为其他重置值，比如 0
	}

	// 使用乐观锁更新余额和版本
	result, err := session.Exec("UPDATE wallets SET balance = balance + ?, version = ? WHERE user_id = ? AND version = ?", amount, newVersion, userId, wallet.Version)
	if err != nil {
		return err
	}

	// 检查影响的行数，确保更新成功
	rowsAffected, err := result.RowsAffected()
	if err != nil {
		return err
	}
	if rowsAffected == 0 {
		return ErrVersionMismatch
	}

	walletsUserIdKey := fmt.Sprintf("%s%v", cacheWalletsUserIdPrefix, userId)
	cacheErrors := m.DelCacheCtx(ctx, walletsUserIdKey)
	if cacheErrors != nil {
		return cacheErrors
	}
	return nil
}
func (m *customWalletsModel) InsertWalletsTrans(ctx context.Context, wallets *Wallets, session sqlx.Session) (sql.Result, error) {
	query := fmt.Sprintf("INSERT INTO %s (%s) VALUES (?, ?, ?)", m.table, walletsRowsExpectAutoSet)
	ret, err := session.ExecCtx(ctx, query, wallets.UserId, wallets.Balance, wallets.Version)
	if err != nil {
		return nil, err
	}

	return ret, err
}
func (m *customWalletsModel) FindWalletsByUserIds(ctx context.Context, userIds []int64) (map[int64]*Wallets, error) {
	if len(userIds) == 0 {
		return make(map[int64]*Wallets), nil
	}

	queryBuilder := strings.Builder{}
	queryBuilder.WriteString(fmt.Sprintf("SELECT user_id, balance FROM %s WHERE user_id IN (", m.table))

	placeholders := make([]string, len(userIds))
	args := make([]interface{}, len(userIds))
	for i, userId := range userIds {
		placeholders[i] = "?"
		args[i] = userId
	}

	queryBuilder.WriteString(strings.Join(placeholders, ","))
	queryBuilder.WriteString(")")

	query := queryBuilder.String()

	var wallets []*Wallets
	err := m.QueryRowNoCacheCtx(ctx, &wallets, query, args...)
	if err != nil {
		return nil, err
	}

	walletMap := make(map[int64]*Wallets)
	for _, wallet := range wallets {
		walletMap[wallet.UserId] = wallet
	}

	return walletMap, nil
}