Change structure of code to a frontend and backend one

2024-07-13 13:58:36 +02:00
parent 21fd3403b2
commit ce152a13b8
18 changed files with 197 additions and 126 deletions
--- a/cmd/backend/users.go
+++ b/cmd/backend/users.go
@ -0,0 +1,380 @@
+package backend
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"log"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+const (
+	Admin = iota
+	Publisher
+	Editor
+	Author
+	NonExistent
+)
+
+type User struct {
+	UserName  string
+	FirstName string
+	LastName  string
+	ID        int64
+	Role      int
+}
+
+func (db *DB) AddUser(u *User, pass string) (int64, error) {
+	hashedPass, err := bcrypt.GenerateFromPassword([]byte(pass), bcrypt.DefaultCost)
+	if err != nil {
+		return 0, fmt.Errorf("error creating password hash: %v", err)
+	}
+
+	query := `
+    INSERT INTO users (username, password, first_name, last_name, role)
+    VALUES (?, ?, ?, ?, ?)
+    `
+	result, err := db.Exec(query, u.UserName, string(hashedPass), u.FirstName, u.LastName, u.Role)
+	if err != nil {
+		return 0, fmt.Errorf("error inserting new user %v into DB: %v", u.UserName, err)
+	}
+	id, err := result.LastInsertId()
+	if err != nil {
+		return 0, fmt.Errorf("error inserting user into DB: %v", err)
+	}
+
+	return id, nil
+}
+
+func (db *DB) GetID(userName string) (int64, bool) {
+	var id int64
+
+	query := `
+    SELECT id
+    FROM users
+    WHERE username = ?
+    `
+	row := db.QueryRow(query, userName)
+	if err := row.Scan(&id); err != nil {
+		return 0, false
+	}
+
+	return id, true
+}
+
+func (db *DB) CheckPassword(id int64, pass string) error {
+	var queriedPass string
+
+	query := `
+    SELECT password
+    FROM users
+    WHERE id = ?
+    `
+	row := db.QueryRow(query, id)
+	if err := row.Scan(&queriedPass); err != nil {
+		return fmt.Errorf("error reading password from DB: %v", err)
+	}
+
+	if err := bcrypt.CompareHashAndPassword([]byte(queriedPass), []byte(pass)); err != nil {
+		return fmt.Errorf("incorrect password: %v", err)
+	}
+
+	return nil
+}
+
+func (tx *Tx) ChangePassword(id int64, oldPass, newPass string) error {
+	var queriedPass string
+	getQuery := `
+    SELECT password
+    FROM users
+    WHERE id = ?
+    `
+	row := tx.QueryRow(getQuery, id)
+	if err := row.Scan(&queriedPass); err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
+		return fmt.Errorf("error reading password from DB: %v", err)
+	}
+
+	if err := bcrypt.CompareHashAndPassword([]byte(queriedPass), []byte(oldPass)); err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
+		return fmt.Errorf("incorrect password: %v", err)
+	}
+
+	newHashedPass, err := bcrypt.GenerateFromPassword([]byte(newPass), bcrypt.DefaultCost)
+	if err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
+		return fmt.Errorf("error creating password hash: %v", err)
+	}
+
+	setQuery := `
+    UPDATE users
+    SET password = ?
+    WHERE id = ?
+    `
+	if _, err = tx.Exec(setQuery, string(newHashedPass), id); err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
+		return fmt.Errorf("error updating password in DB: %v", err)
+	}
+
+	return nil
+}
+
+// TODO: No need for ID field in general
+func (db *DB) GetUser(id int64) (*User, error) {
+	user := new(User)
+	query := `
+    SELECT id, username, first_name, last_name, role
+    FROM users
+    WHERE id = ?
+    `
+
+	row := db.QueryRow(query, id)
+	if err := row.Scan(&user.ID, &user.UserName, &user.FirstName,
+		&user.LastName, &user.Role); err != nil {
+		return nil, fmt.Errorf("error reading user information: %v", err)
+	}
+
+	return user, nil
+}
+
+func (db *DB) UpdateOwnAttributes(id int64, user, first, last, oldPass, newPass, newPass2 string) error {
+	passwordEmpty := true
+	if len(newPass) > 0 || len(newPass2) > 0 {
+		if newPass != newPass2 {
+			return fmt.Errorf("error: passwords do not match")
+		}
+		passwordEmpty = false
+	}
+
+	tx := new(Tx)
+	var err error
+
+	for i := 0; i < TxMaxRetries; i++ {
+		err := func() error {
+			tx.Tx, err = db.Begin()
+			if err != nil {
+				return fmt.Errorf("error starting transaction: %v", err)
+			}
+
+			if !passwordEmpty {
+				if err = tx.ChangePassword(id, oldPass, newPass); err != nil {
+					if rollbackErr := tx.Rollback(); rollbackErr != nil {
+						log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+					}
+					return fmt.Errorf("error changing password: %v", err)
+				}
+			}
+
+			if err = tx.UpdateAttributes(
+				&Attribute{Table: "users", ID: id, AttName: "username", Value: user},
+				&Attribute{Table: "users", ID: id, AttName: "first_name", Value: first},
+				&Attribute{Table: "users", ID: id, AttName: "last_name", Value: last},
+			); err != nil {
+				if rollbackErr := tx.Rollback(); rollbackErr != nil {
+					log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+				}
+				return fmt.Errorf("error updating attributes in DB: %v", err)
+			}
+
+			if err = tx.Commit(); err != nil {
+				return fmt.Errorf("error committing transaction: %v", err)
+			}
+
+			return nil
+		}()
+		if err == nil {
+			return nil
+		}
+
+		log.Println(err)
+		wait(i)
+	}
+
+	return fmt.Errorf("error: %v unsuccessful retries for DB operation, aborting", TxMaxRetries)
+}
+
+func (db *DB) AddFirstUser(u *User, pass string) (int64, error) {
+	var numUsers int64
+	txOptions := &sql.TxOptions{Isolation: sql.LevelSerializable}
+	selectQuery := "SELECT COUNT(*) FROM users"
+	insertQuery := `
+    INSERT INTO users (username, password, first_name, last_name, role)
+    VALUES (?, ?, ?, ?, ?)
+    `
+
+	for i := 0; i < TxMaxRetries; i++ {
+		id, err := func() (int64, error) {
+			tx, err := db.BeginTx(context.Background(), txOptions)
+			if err != nil {
+				return 0, fmt.Errorf("error starting transaction: %v", err)
+			}
+
+			if err := tx.QueryRow(selectQuery).Scan(&numUsers); err != nil {
+				if rollbackErr := tx.Rollback(); rollbackErr != nil {
+					log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+				}
+				return 0, fmt.Errorf("error getting ID of %v: %v", u.UserName, err)
+			}
+			if numUsers != 0 {
+				if err = tx.Commit(); err != nil {
+					return 0, fmt.Errorf("error committing transaction: %v", err)
+				}
+				return 2, nil
+			}
+
+			hashedPass, err := bcrypt.GenerateFromPassword([]byte(pass), bcrypt.DefaultCost)
+			if err != nil {
+				if rollbackErr := tx.Rollback(); rollbackErr != nil {
+					log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+				}
+				return 0, fmt.Errorf("error creating password hash: %v", err)
+			}
+
+			result, err := tx.Exec(insertQuery, u.UserName, string(hashedPass), u.FirstName, u.LastName, u.Role)
+			if err != nil {
+				if rollbackErr := tx.Rollback(); rollbackErr != nil {
+					log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+				}
+				return 0, fmt.Errorf("error inserting new user %v into DB: %v", u.UserName, err)
+			}
+
+			id, err := result.LastInsertId()
+			if err != nil {
+				if rollbackErr := tx.Rollback(); rollbackErr != nil {
+					log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+				}
+				return 0, fmt.Errorf("error inserting user into DB: %v", err)
+			}
+
+			if err = tx.Commit(); err != nil {
+				return 0, fmt.Errorf("error committing transaction: %v", err)
+			}
+			return id, nil
+		}()
+		if err == nil {
+			return id, nil
+		}
+
+		log.Println(err)
+		wait(i)
+	}
+	return 0, fmt.Errorf("error: %v unsuccessful retries for DB operation, aborting", TxMaxRetries)
+}
+
+func (db *DB) GetAllUsers() (map[int64]*User, error) {
+	query := "SELECT id, username, first_name, last_name, role FROM users"
+
+	rows, err := db.Query(query)
+	if err != nil {
+		return nil, fmt.Errorf("error getting all users from DB: %v", err)
+	}
+
+	users := make(map[int64]*User, 0)
+	for rows.Next() {
+		user := new(User)
+		if err = rows.Scan(&user.ID, &user.UserName, &user.FirstName,
+			&user.LastName, &user.Role); err != nil {
+			return nil, fmt.Errorf("error getting user info: %v", err)
+		}
+		users[user.ID] = user
+	}
+
+	return users, nil
+}
+
+func (tx *Tx) SetPassword(id int64, newPass string) error {
+	hashedPass, err := bcrypt.GenerateFromPassword([]byte(newPass), bcrypt.DefaultCost)
+	if err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
+		return fmt.Errorf("error creating password hash: %v", err)
+	}
+
+	setQuery := "UPDATE users SET password = ? WHERE id = ?"
+	if _, err = tx.Exec(setQuery, string(hashedPass), id); err != nil {
+		if rollbackErr := tx.Rollback(); rollbackErr != nil {
+			log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+		}
+		return fmt.Errorf("error updating password in DB: %v", err)
+	}
+
+	return nil
+}
+
+func (db *DB) UpdateUserAttributes(id int64, user, first, last, newPass, newPass2 string, role int) error {
+	passwordEmpty := true
+	if len(newPass) > 0 || len(newPass2) > 0 {
+		if newPass != newPass2 {
+			return fmt.Errorf("error: passwords do not match")
+		}
+		passwordEmpty = false
+	}
+
+	tx := new(Tx)
+	var err error
+
+	for i := 0; i < TxMaxRetries; i++ {
+		err := func() error {
+			tx.Tx, err = db.Begin()
+			if err != nil {
+				return fmt.Errorf("error starting transaction: %v", err)
+			}
+
+			if !passwordEmpty {
+				if err = tx.SetPassword(id, newPass); err != nil {
+					if rollbackErr := tx.Rollback(); rollbackErr != nil {
+						log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+					}
+					return fmt.Errorf("error changing password: %v", err)
+				}
+			}
+
+			if err = tx.UpdateAttributes(
+				&Attribute{Table: "users", ID: id, AttName: "username", Value: user},
+				&Attribute{Table: "users", ID: id, AttName: "first_name", Value: first},
+				&Attribute{Table: "users", ID: id, AttName: "last_name", Value: last},
+				&Attribute{Table: "users", ID: id, AttName: "role", Value: role},
+			); err != nil {
+				if rollbackErr := tx.Rollback(); rollbackErr != nil {
+					log.Fatalf("transaction error: %v, rollback error: %v", err, rollbackErr)
+				}
+				return fmt.Errorf("error updating attributes in DB: %v", err)
+			}
+
+			if err = tx.Commit(); err != nil {
+				return fmt.Errorf("error committing transaction: %v", err)
+			}
+
+			return nil
+		}()
+		if err == nil {
+			return nil
+		}
+
+		log.Println(err)
+		wait(i)
+	}
+
+	return fmt.Errorf("error: %v unsuccessful retries for DB operation, aborting", TxMaxRetries)
+}
+
+func (db *DB) DeleteUser(id int64) error {
+	query := "DELETE FROM users WHERE id = ?"
+
+	_, err := db.Exec(query, id)
+	if err != nil {
+		return fmt.Errorf("error deleting user %v from DB: %v", id, err)
+	}
+
+	return nil
+}