package product

import (
	"context"
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"time"

	"perms-system-server/internal/consts"
	authHelper "perms-system-server/internal/logic/auth"
	productModel "perms-system-server/internal/model/product"
	"perms-system-server/internal/model/productmember"
	userModel "perms-system-server/internal/model/user"
	"perms-system-server/internal/response"
	"perms-system-server/internal/svc"
	"perms-system-server/internal/types"

	"github.com/zeromicro/go-zero/core/logx"
	"github.com/zeromicro/go-zero/core/stores/sqlx"
	"golang.org/x/crypto/bcrypt"
)

type CreateProductLogic struct {
	logx.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

func NewCreateProductLogic(ctx context.Context, svcCtx *svc.ServiceContext) *CreateProductLogic {
	return &CreateProductLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

func (l *CreateProductLogic) CreateProduct(req *types.CreateProductReq) (resp *types.CreateProductResp, err error) {
	if err := authHelper.RequireSuperAdmin(l.ctx); err != nil {
		return nil, err
	}

	if len(req.Code) > 64 {
		return nil, response.ErrBadRequest("产品编码长度不能超过64个字符")
	}
	if len(req.Name) > 64 {
		return nil, response.ErrBadRequest("产品名称长度不能超过64个字符")
	}
	if len(req.Remark) > 255 {
		return nil, response.ErrBadRequest("备注长度不能超过255个字符")
	}

	_, findErr := l.svcCtx.SysProductModel.FindOneByCode(l.ctx, req.Code)
	if findErr == nil {
		return nil, response.ErrConflict("产品编码已存在")
	}

	appKey, err := generateRandomHex(32)
	if err != nil {
		return nil, err
	}
	rawAppSecret, err := generateRandomHex(64)
	if err != nil {
		return nil, err
	}
	appSecretHash, err := bcrypt.GenerateFromPassword([]byte(rawAppSecret), bcrypt.DefaultCost)
	if err != nil {
		return nil, err
	}
	now := time.Now().Unix()

	adminUsername := fmt.Sprintf("admin_%s", req.Code)
	if _, err := l.svcCtx.SysUserModel.FindOneByUsername(l.ctx, adminUsername); err == nil {
		return nil, response.ErrConflict(fmt.Sprintf("用户名 %s 已存在，无法自动创建管理员账号", adminUsername))
	}
	adminPassword, err := generateRandomHex(8)
	if err != nil {
		return nil, err
	}
	hashedPwd, err := bcrypt.GenerateFromPassword([]byte(adminPassword), bcrypt.DefaultCost)
	if err != nil {
		return nil, err
	}

	var productId int64

	err = l.svcCtx.SysProductModel.TransactCtx(l.ctx, func(ctx context.Context, session sqlx.Session) error {
		result, err := l.svcCtx.SysProductModel.InsertWithTx(ctx, session, &productModel.SysProduct{
			Code:       req.Code,
			Name:       req.Name,
			AppKey:     appKey,
			AppSecret:  string(appSecretHash),
			Remark:     req.Remark,
			Status:     consts.StatusEnabled,
			CreateTime: now,
			UpdateTime: now,
		})
		if err != nil {
			return err
		}
		productId, _ = result.LastInsertId()

		userResult, err := l.svcCtx.SysUserModel.InsertWithTx(ctx, session, &userModel.SysUser{
			Username:           adminUsername,
			Password:           string(hashedPwd),
			Nickname:           fmt.Sprintf("%s管理员", req.Name),
			IsSuperAdmin:       consts.IsSuperAdminNo,
			MustChangePassword: consts.MustChangePasswordYes,
			Status:             consts.StatusEnabled,
			CreateTime:         now,
			UpdateTime:         now,
		})
		if err != nil {
			return err
		}
		userId, _ := userResult.LastInsertId()

		_, err = l.svcCtx.SysProductMemberModel.InsertWithTx(ctx, session, &productmember.SysProductMember{
			ProductCode: req.Code,
			UserId:      userId,
			MemberType:  consts.MemberTypeAdmin,
			Status:      consts.StatusEnabled,
			CreateTime:  now,
			UpdateTime:  now,
		})
		return err
	})

	if err != nil {
		return nil, err
	}

	return &types.CreateProductResp{
		Id:            productId,
		Code:          req.Code,
		AppKey:        appKey,
		AppSecret:     rawAppSecret,
		AdminUser:     adminUsername,
		AdminPassword: adminPassword,
	}, nil
}

func generateRandomHex(length int) (string, error) {
	b := make([]byte, length)
	if _, err := rand.Read(b); err != nil {
		return "", fmt.Errorf("generate random bytes failed: %w", err)
	}
	return hex.EncodeToString(b)[:length], nil
}