feat: add user posts

app/models/posts.go

@@ -2,6 +2,7 @@ package models
 
 import (
 	"context"
+	"errors"
 
 	"quyun/app/requests"
 	"quyun/database/fields"
@@ -9,6 +10,7 @@ import (
 	"quyun/database/schemas/public/table"
 
 	. "github.com/go-jet/jet/v2/postgres"
+	"github.com/go-jet/jet/v2/qrm"
 	"github.com/sirupsen/logrus"
 )
 
@@ -147,3 +149,58 @@ func (m *postsModel) List(ctx context.Context, pagination *requests.Pagination,
 		Pagination: *pagination,
 	}, nil
 }
+
+func (m *postsModel) IsUserBought(ctx context.Context, userId int64, postId int64) (bool, error) {
+	tbl := table.UserPosts
+	stmt := tbl.
+		SELECT(tbl.ID).
+		WHERE(
+			tbl.UserID.EQ(Int64(userId)).AND(
+				tbl.PostID.EQ(Int64(postId)),
+			),
+		)
+	m.log.Infof("sql: %s", stmt.DebugSql())
+
+	var userPost model.UserPosts
+	err := stmt.QueryContext(ctx, db, &userPost)
+	if err != nil {
+		if errors.Is(err, qrm.ErrNoRows) {
+			return false, nil
+		}
+
+		m.log.Errorf("error querying user post item: %v", err)
+		return false, err
+	}
+
+	return userPost.ID > 0, nil
+}
+
+func (m *postsModel) Buy(ctx context.Context, userId int64, postId int64) error {
+	tbl := table.UserPosts
+
+	post, err := m.GetByID(ctx, postId)
+	if err != nil {
+		m.log.Errorf("error getting post by ID: %v", err)
+		return err
+	}
+
+	user, err := Users.GetByID(ctx, userId)
+	if err != nil {
+		m.log.Errorf("error getting user by ID: %v", err)
+		return err
+	}
+
+	record := model.UserPosts{
+		UserID: user.ID,
+		PostID: post.ID,
+		Price:  post.Price * int64(post.Discount) / 100,
+	}
+	stmt := tbl.INSERT(tbl.MutableColumns).MODEL(record)
+	m.log.Infof("sql: %s", stmt.DebugSql())
+
+	if _, err := stmt.ExecContext(ctx, db); err != nil {
+		m.log.Errorf("error buying post: %v", err)
+		return err
+	}
+	return nil
+}