feat: add contact repository and base repository for shared db logic

internal/repository/base_repository.go

@@ -0,0 +1,76 @@
+package repository
+
+import (
+	"database/sql"
+	"fmt"
+)
+
+type baseRepository[T any] struct {
+	db        *sql.DB
+	tableName string
+}
+
+func NewBaseRepository[T any](db *sql.DB, tableName string) Repository[T] {
+	return &baseRepository[T]{
+		db:        db,
+		tableName: tableName,
+	}
+}
+
+func (r *baseRepository[T]) BuildQuery(baseQuery string) string {
+	return fmt.Sprintf(baseQuery, r.tableName)
+}
+
+func (r *baseRepository[T]) GetDB() *sql.DB {
+	return r.db
+}
+
+func (r *baseRepository[T]) GetByID(id int) (*T, error) {
+	var entity T
+
+	query := r.BuildQuery("SELECT * FROM %s WHERE id = ?")
+	err := r.db.QueryRow(
+		query,
+		id,
+	).Scan(entity)
+
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, nil
+		}
+		return nil, err
+	}
+
+	return &entity, nil
+}
+
+func (r *baseRepository[T]) GetAll() ([]T, error) {
+	query := r.BuildQuery("SELECT * FROM %s ORDER BY id DESC")
+
+	rows, err := r.db.Query(query)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	entities := make([]T, 0)
+	for rows.Next() {
+		var entity T
+		if err := rows.Scan(entity); err != nil {
+			return nil, err
+		}
+		entities = append(entities, entity)
+	}
+
+	if err = rows.Err(); err != nil {
+		return nil, err
+	}
+
+	return entities, nil
+}
+
+func (r *baseRepository[T]) Delete(id int) error {
+	query := r.BuildQuery("DELETE %s WHERE id = ? LIMIT 1")
+	_, err := r.db.Exec(query, id)
+	return err
+}

internal/repository/contact_repository.go

@@ -0,0 +1,57 @@
+package repository
+
+import (
+	"database/sql"
+
+	"gitea.gabilandia.com/gabdlr/agenda-web-go/internal/models"
+)
+
+type ContactRepository struct {
+	baseRepository[models.Contact]
+}
+
+func NewContactRepository(db *sql.DB) *ContactRepository {
+	return &ContactRepository{
+		baseRepository[models.Contact]{
+			db:        db,
+			tableName: "contacts",
+		}}
+}
+
+func (r *ContactRepository) Create(contact *models.Contact) (int64, error) {
+	query := r.BuildQuery("INSERT INTO %s (name, company, phone) VALUES (?, ?, ?)")
+
+	result, err := r.db.Exec(
+		query,
+		contact.Name, contact.Company, contact.Phone,
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	id, err := result.LastInsertId()
+	if err != nil {
+		return 0, err
+	}
+
+	contact.ID = int(id)
+	return id, nil
+}
+
+func (r *ContactRepository) Update(contact *models.Contact) (int64, error) {
+	query := r.BuildQuery("UPDATE %s SET name = ?, company = ?, phone = ? WHERE id = ?")
+	result, err := r.db.Exec(query,
+		contact.Name, contact.Company, contact.Phone, contact.ID,
+	)
+
+	if err != nil {
+		return 0, err
+	}
+
+	rowsAffected, err := result.RowsAffected()
+	if err != nil {
+		return 0, err
+	}
+
+	return rowsAffected, nil
+}

internal/repository/interfaces.go

@@ -0,0 +1,8 @@
+package repository
+
+type Repository[T any] interface {
+	BuildQuery(s string) string
+	GetByID(id int) (*T, error)
+	GetAll() ([]T, error)
+	Delete(id int) error
+}