// Package basic 钱包基础业务逻辑
package basic

import (
	"context"

	"bsm/full/module/finance/wallet/internal/excode"
	"bsm/full/module/finance/wallet/internal/impl"
	"bsm/full/module/finance/wallet/internal/models"
	"git.apinb.com/bsm-sdk/core/errcode"
	"git.apinb.com/bsm-sdk/core/utils"
	"golang.org/x/crypto/bcrypt"
	"gorm.io/gorm"
)

// WalletPay 钱包支付结构体
type WalletPay struct {
	ctx  context.Context
	Body *models.WalletBasic
}

// NewWallet 创建钱包支付实例
// 验证用户身份、钱包状态、支付密码和余额
func NewWallet(passportIdentity, pwd string, amount int64) (*WalletPay, error) {
	// 检查钱包是否存在
	wallet := models.WalletExists(passportIdentity)
	if wallet == nil {
		return nil, errcode.ErrNotFound(404, "wallet")
	}

	// 检查钱包状态
	if wallet.Status == -1 {
		return nil, errcode.ErrPermissionDenied
	}

	// 校验支付密码
	if !VerifyPayPassword(wallet.PayPassword, pwd) {
		return nil, errcode.ErrPassword
	}

	// 检查金额合法性
	if amount <= 0 {
		return nil, excode.ErrAmount
	}

	// 检查余额是否足够
	if amount > wallet.Balance {
		return nil, excode.ErrBalanceNotEnough
	}

	return &WalletPay{
		Body: wallet,
	}, nil
}

// TradeConsum 执行交易消费
// 使用单条条件更新原子扣减余额与可提现余额，避免"读后写"造成的并发双花；
// 余额变更与消费流水写入放在同一事务内，保证账实一致。
func (srv *WalletPay) TradeConsum(amount int64) error {
	if amount <= 0 {
		return excode.ErrAmount
	}

	return impl.DBService.Transaction(func(tx *gorm.DB) error {
		// 条件更新：余额与可提现余额均充足且钱包未禁用时才扣减
		res := tx.Model(&models.WalletBasic{}).
			Where("identity = ? AND status <> -1 AND balance >= ? AND withdrawal_balance >= ?", srv.Body.Identity, amount, amount).
			UpdateColumns(map[string]interface{}{
				"balance":            gorm.Expr("balance - ?", amount),
				"withdrawal_balance": gorm.Expr("withdrawal_balance - ?", amount),
			})
		if res.Error != nil {
			return res.Error
		}
		if res.RowsAffected == 0 {
			return excode.ErrBalanceNotEnough
		}

		// 同一事务内写入消费流水
		record := &models.WalletRecord{
			WalletIdentity: srv.Body.Identity,
			TransType:      -1, // 支出
			InTradeNo:      utils.UUID(),
			Money:          amount,
			TradeType:      3,         // 消费
			PayChannel:     3,         // 钱包余额
			PayType:        "BALANCE", // 余额支付
		}
		record.Identity = utils.UUID()
		record.PassportID = srv.Body.PassportID
		record.PassportIdentity = srv.Body.PassportIdentity
		models.FillRecordYmd(record)
		return tx.Create(record).Error
	})
}

// EncodePassword 使用 bcrypt 生成支付密码哈希
func EncodePassword(pwd string) (string, error) {
	hashed, err := bcrypt.GenerateFromPassword([]byte(pwd), bcrypt.DefaultCost)
	if err != nil {
		return "", err
	}
	return string(hashed), nil
}

// VerifyPayPassword 校验支付密码
// 仅接受 bcrypt 哈希；历史 SHA256 摘要无法校验，需通过重置流程重新设置。
func VerifyPayPassword(hashed, pwd string) bool {
	if hashed == "" || pwd == "" {
		return false
	}
	return bcrypt.CompareHashAndPassword([]byte(hashed), []byte(pwd)) == nil
}