From 830684231063aa6163afea2c7ec4f2f0d4f797fd Mon Sep 17 00:00:00 2001
From: Ke Chen <JingYiJun3104@outlook.com>
Date: Thu, 28 Sep 2023 13:28:30 +0800
Subject: [PATCH] feat: maintain course_group.credits

---
 internal/repository/course.go | 49 +++++++++++++++++++++++++++++++----
 internal/service/course.go    | 29 ++++++++++++++++++---
 2 files changed, 69 insertions(+), 9 deletions(-)

diff --git a/internal/repository/course.go b/internal/repository/course.go
index 530c12d..fa5765f 100644
--- a/internal/repository/course.go
+++ b/internal/repository/course.go
@@ -2,6 +2,9 @@ package repository
 
 import (
 	"context"
+	"slices"
+	"strconv"
+	"strings"
 
 	"gorm.io/gorm"
 
@@ -11,9 +14,22 @@ import (
 type CourseRepository interface {
 	Repository
 
-	FindCourseByID(ctx context.Context, id int, conditions ...func(db *gorm.DB) *gorm.DB) (course *model.Course, err error)
-	FindCoursesByGroupID(ctx context.Context, groupID int) (courses []*model.Course, err error)
-	CreateCourse(ctx context.Context, course *model.Course) (err error)
+	FindCourseByID(
+		ctx context.Context,
+		id int,
+		conditions ...func(db *gorm.DB) *gorm.DB,
+	) (course *model.Course, err error)
+
+	FindCoursesByGroupID(
+		ctx context.Context,
+		groupID int,
+	) (courses []*model.Course, err error)
+
+	CreateCourse(
+		ctx context.Context,
+		course *model.CourseGroup,
+		courseGroup *model.Course,
+	) (err error)
 }
 
 type courseRepository struct {
@@ -42,14 +58,37 @@ func (r *courseRepository) FindCoursesByGroupID(ctx context.Context, groupID int
 	return
 }
 
-func (r *courseRepository) CreateCourse(ctx context.Context, course *model.Course) (err error) {
+func (r *courseRepository) CreateCourse(
+	ctx context.Context,
+	courseGroup *model.CourseGroup,
+	course *model.Course,
+) (err error) {
 	err = r.Transaction(ctx, func(ctx context.Context) error {
 		err = r.GetDB(ctx).Create(course).Error
 		if err != nil {
 			return err
 		}
 
-		return r.GetDB(ctx).Model(&model.CourseGroup{ID: course.CourseGroupID}).Update("course_count", gorm.Expr("course_count + 1")).Error
+		updateColumes := map[string]any{
+			"course_count": gorm.Expr("course_count + 1"),
+		}
+
+		if !slices.Contains(courseGroup.Credits, course.Credit) {
+			courseGroup.Credits = append(courseGroup.Credits, course.Credit)
+			var creditsString strings.Builder
+			creditsString.WriteByte('[')
+			for i, credit := range courseGroup.Credits {
+				if i != 0 {
+					creditsString.WriteByte(',')
+				}
+				creditsString.WriteString(strconv.FormatFloat(credit, 'f', -1, 64))
+			}
+			creditsString.WriteByte(']')
+			updateColumes["credits"] = creditsString.String()
+		}
+
+		return r.GetDB(ctx).Model(&model.CourseGroup{ID: course.CourseGroupID}).
+			Updates(updateColumes).Error
 	})
 	if err != nil {
 		return err
diff --git a/internal/service/course.go b/internal/service/course.go
index 3ac0d06..a9a83c2 100644
--- a/internal/service/course.go
+++ b/internal/service/course.go
@@ -15,8 +15,23 @@ type CourseService interface {
 	Service
 
 	ListCoursesV1(ctx context.Context) (response []*schema.CourseGroupV1Response, err error)
-	GetCourseV1(ctx context.Context, user *model.User, id int) (response *schema.CourseV1Response, err error)
-	AddCourseV1(ctx context.Context, request *schema.CreateCourseV1Request) (response *schema.CourseV1Response, err error)
+
+	GetCourseV1(
+		ctx context.Context,
+		user *model.User,
+		id int,
+	) (
+		response *schema.CourseV1Response,
+		err error,
+	)
+
+	AddCourseV1(
+		ctx context.Context,
+		request *schema.CreateCourseV1Request,
+	) (
+		response *schema.CourseV1Response,
+		err error,
+	)
 }
 
 type courseService struct {
@@ -85,7 +100,13 @@ func (s *courseService) GetCourseV1(ctx context.Context, user *model.User, id in
 	return new(schema.CourseV1Response).FromModel(user, course, votesMap), nil
 }
 
-func (s *courseService) AddCourseV1(ctx context.Context, request *schema.CreateCourseV1Request) (response *schema.CourseV1Response, err error) {
+func (s *courseService) AddCourseV1(
+	ctx context.Context,
+	request *schema.CreateCourseV1Request,
+) (
+	response *schema.CourseV1Response,
+	err error,
+) {
 	group, err := s.courseGroupRepository.FindGroupByCode(ctx, request.Code, func(db *gorm.DB) *gorm.DB {
 		return db.Preload("Courses")
 	})
@@ -103,7 +124,7 @@ func (s *courseService) AddCourseV1(ctx context.Context, request *schema.CreateC
 	}
 
 	course := request.ToModel(group.ID)
-	err = s.courseRepository.CreateCourse(ctx, course)
+	err = s.courseRepository.CreateCourse(ctx, group, course)
 	if err != nil {
 		return nil, err
 	}