Added bio to User and reworked file structure for user interaction

db/user_functions.go

@@ -0,0 +1,108 @@
+package db
+
+import (
+	"database/sql"
+	"fmt"
+
+	"github.com/pkg/errors"
+)
+
+// Creates a new user in the database and returns a pointer
+func CreateNewUser(conn *sql.DB, username string, password string) (*User, error) {
+	query := `INSERT INTO users (username) VALUES (?)`
+	_, err := conn.Exec(query, username)
+	if err != nil {
+		return nil, errors.Wrap(err, "conn.Exec")
+	}
+	user, err := GetUserFromUsername(conn, username)
+	if err != nil {
+		return nil, errors.Wrap(err, "GetUserFromUsername")
+	}
+	err = user.SetPassword(conn, password)
+	if err != nil {
+		return nil, errors.Wrap(err, "user.SetPassword")
+	}
+	return user, nil
+}
+
+// Fetches data from the users table using "WHERE column = 'value'"
+func fetchUserData(conn *sql.DB, column string, value interface{}) (*sql.Rows, error) {
+	query := fmt.Sprintf(
+		`SELECT 
+            id,
+            username, 
+            password_hash, 
+            created_at,
+            bio
+        FROM users 
+	    WHERE %s = ? COLLATE NOCASE LIMIT 1`,
+		column,
+	)
+	rows, err := conn.Query(query, value)
+	if err != nil {
+		return nil, errors.Wrap(err, "conn.Query")
+	}
+	return rows, nil
+}
+
+// Scan the next row into the provided user pointer. Calls rows.Next() and
+// assumes only row in the result. Providing a rows object with more than 1
+// row may result in undefined behaviour.
+func scanUserRow(user *User, rows *sql.Rows) error {
+	for rows.Next() {
+		err := rows.Scan(
+			&user.ID,
+			&user.Username,
+			&user.Password_hash,
+			&user.Created_at,
+			&user.Bio,
+		)
+		if err != nil {
+			return errors.Wrap(err, "rows.Scan")
+		}
+	}
+	return nil
+}
+
+// Queries the database for a user matching the given username.
+// Query is case insensitive
+func GetUserFromUsername(conn *sql.DB, username string) (*User, error) {
+	rows, err := fetchUserData(conn, "username", username)
+	if err != nil {
+		return nil, errors.Wrap(err, "fetchUserData")
+	}
+	defer rows.Close()
+	var user User
+	err = scanUserRow(&user, rows)
+	if err != nil {
+		return nil, errors.Wrap(err, "scanUserRow")
+	}
+	return &user, nil
+}
+
+// Queries the database for a user matching the given ID.
+func GetUserFromID(conn *sql.DB, id int) (*User, error) {
+	rows, err := fetchUserData(conn, "id", id)
+	if err != nil {
+		return nil, errors.Wrap(err, "fetchUserData")
+	}
+	defer rows.Close()
+	var user User
+	err = scanUserRow(&user, rows)
+	if err != nil {
+		return nil, errors.Wrap(err, "scanUserRow")
+	}
+	return &user, nil
+}
+
+// Checks if the given username is unique. Returns true if not taken
+func CheckUsernameUnique(conn *sql.DB, username string) (bool, error) {
+	query := `SELECT 1 FROM users WHERE username = ? COLLATE NOCASE LIMIT 1`
+	rows, err := conn.Query(query, username)
+	if err != nil {
+		return false, errors.Wrap(err, "conn.Query")
+	}
+	defer rows.Close()
+	taken := rows.Next()
+	return !taken, nil
+}