first commit

internal/config/config.go

@@ -0,0 +1,76 @@
+package config
+
+import (
+	"log"
+	"os"
+	"strconv"
+)
+
+type Config struct {
+	Server   ServerConfig
+	Database DatabaseConfig
+}
+
+type ServerConfig struct {
+	Port int
+	Mode string
+}
+
+type DatabaseConfig struct {
+	Host     string
+	Port     int
+	Username string
+	Password string
+	Database string
+	Schema   string
+}
+
+func LoadConfig() *Config {
+	config := &Config{
+		Server: ServerConfig{
+			Port: getEnvAsInt("PORT", 8080),
+			Mode: getEnv("GIN_MODE", "debug"),
+		},
+		Database: DatabaseConfig{
+			Host:     getEnv("BLUEPRINT_DB_HOST", "localhost"),
+			Port:     getEnvAsInt("BLUEPRINT_DB_PORT", 5432),
+			Username: getEnv("BLUEPRINT_DB_USERNAME", "postgres"),
+			Password: getEnv("BLUEPRINT_DB_PASSWORD", "postgres"),
+			Database: getEnv("BLUEPRINT_DB_DATABASE", "api_service"),
+			Schema:   getEnv("BLUEPRINT_DB_SCHEMA", "public"),
+		},
+	}
+
+	return config
+}
+
+func getEnv(key, defaultValue string) string {
+	if value := os.Getenv(key); value != "" {
+		return value
+	}
+	return defaultValue
+}
+
+func getEnvAsInt(key string, defaultValue int) int {
+	valueStr := getEnv(key, "")
+	if value, err := strconv.Atoi(valueStr); err == nil {
+		return value
+	}
+	return defaultValue
+}
+
+func (c *Config) Validate() error {
+	if c.Database.Host == "" {
+		log.Fatal("Database host is required")
+	}
+	if c.Database.Username == "" {
+		log.Fatal("Database username is required")
+	}
+	if c.Database.Password == "" {
+		log.Fatal("Database password is required")
+	}
+	if c.Database.Database == "" {
+		log.Fatal("Database name is required")
+	}
+	return nil
+}

internal/database/database.go

@@ -0,0 +1,115 @@
+package database
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"time"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+	_ "github.com/joho/godotenv/autoload"
+)
+
+// Service represents a service that interacts with a database.
+type Service interface {
+	// Health returns a map of health status information.
+	// The keys and values in the map are service-specific.
+	Health() map[string]string
+
+	// Close terminates the database connection.
+	// It returns an error if the connection cannot be closed.
+	Close() error
+}
+
+type service struct {
+	db *sql.DB
+}
+
+var (
+	database   = os.Getenv("BLUEPRINT_DB_DATABASE")
+	password   = os.Getenv("BLUEPRINT_DB_PASSWORD")
+	username   = os.Getenv("BLUEPRINT_DB_USERNAME")
+	port       = os.Getenv("BLUEPRINT_DB_PORT")
+	host       = os.Getenv("BLUEPRINT_DB_HOST")
+	schema     = os.Getenv("BLUEPRINT_DB_SCHEMA")
+	dbInstance *service
+)
+
+func New() Service {
+	// Reuse Connection
+	if dbInstance != nil {
+		return dbInstance
+	}
+	connStr := fmt.Sprintf("postgres://%s:%s@%s:%s/%s?sslmode=disable&search_path=%s", username, password, host, port, database, schema)
+	db, err := sql.Open("pgx", connStr)
+	if err != nil {
+		log.Fatal(err)
+	}
+	dbInstance = &service{
+		db: db,
+	}
+	return dbInstance
+}
+
+// Health checks the health of the database connection by pinging the database.
+// It returns a map with keys indicating various health statistics.
+func (s *service) Health() map[string]string {
+	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+	defer cancel()
+
+	stats := make(map[string]string)
+
+	// Ping the database
+	err := s.db.PingContext(ctx)
+	if err != nil {
+		stats["status"] = "down"
+		stats["error"] = fmt.Sprintf("db down: %v", err)
+		log.Fatalf("db down: %v", err) // Log the error and terminate the program
+		return stats
+	}
+
+	// Database is up, add more statistics
+	stats["status"] = "up"
+	stats["message"] = "It's healthy"
+
+	// Get database stats (like open connections, in use, idle, etc.)
+	dbStats := s.db.Stats()
+	stats["open_connections"] = strconv.Itoa(dbStats.OpenConnections)
+	stats["in_use"] = strconv.Itoa(dbStats.InUse)
+	stats["idle"] = strconv.Itoa(dbStats.Idle)
+	stats["wait_count"] = strconv.FormatInt(dbStats.WaitCount, 10)
+	stats["wait_duration"] = dbStats.WaitDuration.String()
+	stats["max_idle_closed"] = strconv.FormatInt(dbStats.MaxIdleClosed, 10)
+	stats["max_lifetime_closed"] = strconv.FormatInt(dbStats.MaxLifetimeClosed, 10)
+
+	// Evaluate stats to provide a health message
+	if dbStats.OpenConnections > 40 { // Assuming 50 is the max for this example
+		stats["message"] = "The database is experiencing heavy load."
+	}
+
+	if dbStats.WaitCount > 1000 {
+		stats["message"] = "The database has a high number of wait events, indicating potential bottlenecks."
+	}
+
+	if dbStats.MaxIdleClosed > int64(dbStats.OpenConnections)/2 {
+		stats["message"] = "Many idle connections are being closed, consider revising the connection pool settings."
+	}
+
+	if dbStats.MaxLifetimeClosed > int64(dbStats.OpenConnections)/2 {
+		stats["message"] = "Many connections are being closed due to max lifetime, consider increasing max lifetime or revising the connection usage pattern."
+	}
+
+	return stats
+}
+
+// Close closes the database connection.
+// It logs a message indicating the disconnection from the specific database.
+// If the connection is successfully closed, it returns nil.
+// If an error occurs while closing the connection, it returns the error.
+func (s *service) Close() error {
+	log.Printf("Disconnected from database: %s", database)
+	return s.db.Close()
+}

internal/database/database_test.go

@@ -0,0 +1,100 @@
+package database
+
+import (
+	"context"
+	"log"
+	"testing"
+	"time"
+
+	"github.com/testcontainers/testcontainers-go"
+	"github.com/testcontainers/testcontainers-go/modules/postgres"
+	"github.com/testcontainers/testcontainers-go/wait"
+)
+
+func mustStartPostgresContainer() (func(context.Context, ...testcontainers.TerminateOption) error, error) {
+	var (
+		dbName = "database"
+		dbPwd  = "password"
+		dbUser = "user"
+	)
+
+	dbContainer, err := postgres.Run(
+		context.Background(),
+		"postgres:latest",
+		postgres.WithDatabase(dbName),
+		postgres.WithUsername(dbUser),
+		postgres.WithPassword(dbPwd),
+		testcontainers.WithWaitStrategy(
+			wait.ForLog("database system is ready to accept connections").
+				WithOccurrence(2).
+				WithStartupTimeout(5*time.Second)),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	database = dbName
+	password = dbPwd
+	username = dbUser
+
+	dbHost, err := dbContainer.Host(context.Background())
+	if err != nil {
+		return dbContainer.Terminate, err
+	}
+
+	dbPort, err := dbContainer.MappedPort(context.Background(), "5432/tcp")
+	if err != nil {
+		return dbContainer.Terminate, err
+	}
+
+	host = dbHost
+	port = dbPort.Port()
+
+	return dbContainer.Terminate, err
+}
+
+func TestMain(m *testing.M) {
+	teardown, err := mustStartPostgresContainer()
+	if err != nil {
+		log.Fatalf("could not start postgres container: %v", err)
+	}
+
+	m.Run()
+
+	if teardown != nil && teardown(context.Background()) != nil {
+		log.Fatalf("could not teardown postgres container: %v", err)
+	}
+}
+
+func TestNew(t *testing.T) {
+	srv := New()
+	if srv == nil {
+		t.Fatal("New() returned nil")
+	}
+}
+
+func TestHealth(t *testing.T) {
+	srv := New()
+
+	stats := srv.Health()
+
+	if stats["status"] != "up" {
+		t.Fatalf("expected status to be up, got %s", stats["status"])
+	}
+
+	if _, ok := stats["error"]; ok {
+		t.Fatalf("expected error not to be present")
+	}
+
+	if stats["message"] != "It's healthy" {
+		t.Fatalf("expected message to be 'It's healthy', got %s", stats["message"])
+	}
+}
+
+func TestClose(t *testing.T) {
+	srv := New()
+
+	if srv.Close() != nil {
+		t.Fatalf("expected Close() to return nil")
+	}
+}

internal/handlers/example.go

@@ -0,0 +1,57 @@
+package handlers
+
+import (
+	"net/http"
+
+	"api-service/internal/models"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+)
+
+// ExampleHandler handles example GET and POST services
+type ExampleHandler struct{}
+
+// NewExampleHandler creates a new ExampleHandler
+func NewExampleHandler() *ExampleHandler {
+	return &ExampleHandler{}
+}
+
+// GetExample godoc
+// @Summary Example GET service
+// @Description Returns a simple message for GET request
+// @Tags example
+// @Accept json
+// @Produce json
+// @Success 200 {object} models.ExampleGetResponse "Example GET response"
+// @Router /api/v1/example [get]
+func (h *ExampleHandler) GetExample(c *gin.Context) {
+	response := models.ExampleGetResponse{
+		Message: "This is a GET example response",
+	}
+	c.JSON(http.StatusOK, response)
+}
+
+// PostExample godoc
+// @Summary Example POST service
+// @Description Accepts a JSON payload and returns a response with an ID
+// @Tags example
+// @Accept json
+// @Produce json
+// @Param request body models.ExamplePostRequest true "Example POST request"
+// @Success 200 {object} models.ExamplePostResponse "Example POST response"
+// @Failure 400 {object} models.ErrorResponse "Bad request"
+// @Router /api/v1/example [post]
+func (h *ExampleHandler) PostExample(c *gin.Context) {
+	var req models.ExamplePostRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	response := models.ExamplePostResponse{
+		ID:      uuid.NewString(),
+		Message: "Received data for " + req.Name,
+	}
+	c.JSON(http.StatusOK, response)
+}

internal/handlers/health.go

@@ -0,0 +1,55 @@
+package handlers
+
+import (
+	"net/http"
+	"time"
+
+	"api-service/internal/models"
+
+	"github.com/gin-gonic/gin"
+)
+
+// HealthHandler handles health check endpoints
+type HealthHandler struct{}
+
+// NewHealthHandler creates a new HealthHandler
+func NewHealthHandler() *HealthHandler {
+	return &HealthHandler{}
+}
+
+// GetHealth godoc
+// @Summary Health check endpoint
+// @Description Returns the health status of the API service
+// @Tags health
+// @Accept json
+// @Produce json
+// @Success 200 {object} models.HealthResponse "Health status"
+// @Failure 500 {object} models.ErrorResponse "Internal server error"
+// @Router /health [get]
+func (h *HealthHandler) GetHealth(c *gin.Context) {
+	health := models.HealthResponse{
+		Status:    "healthy",
+		Timestamp: time.Now().Format(time.RFC3339),
+		Details: map[string]string{
+			"service": "api-service",
+			"version": "1.0.0",
+		},
+	}
+	c.JSON(http.StatusOK, health)
+}
+
+// HelloWorld godoc
+// @Summary Hello World endpoint
+// @Description Returns a hello world message
+// @Tags root
+// @Accept json
+// @Produce json
+// @Success 200 {object} models.HelloWorldResponse "Hello world message"
+// @Router / [get]
+func (h *HealthHandler) HelloWorld(c *gin.Context) {
+	response := models.HelloWorldResponse{
+		Message: "Hello World",
+		Version: "1.0.0",
+	}
+	c.JSON(http.StatusOK, response)
+}

internal/middleware/error_handler.go

@@ -0,0 +1,55 @@
+package middleware
+
+import (
+	"net/http"
+
+	"api-service/internal/models"
+
+	"github.com/gin-gonic/gin"
+)
+
+// ErrorHandler handles errors globally
+func ErrorHandler() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.Next()
+
+		if len(c.Errors) > 0 {
+			err := c.Errors.Last()
+			status := http.StatusInternalServerError
+
+			// Determine status code based on error type
+			switch err.Type {
+			case gin.ErrorTypeBind:
+				status = http.StatusBadRequest
+			case gin.ErrorTypeRender:
+				status = http.StatusUnprocessableEntity
+			case gin.ErrorTypePrivate:
+				status = http.StatusInternalServerError
+			}
+
+			response := models.ErrorResponse{
+				Error:   "internal_error",
+				Message: err.Error(),
+				Code:    status,
+			}
+
+			c.JSON(status, response)
+		}
+	}
+}
+
+// CORS middleware configuration
+func CORSConfig() gin.HandlerFunc {
+	return gin.HandlerFunc(func(c *gin.Context) {
+		c.Header("Access-Control-Allow-Origin", "*")
+		c.Header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, PATCH")
+		c.Header("Access-Control-Allow-Headers", "Origin, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")
+
+		if c.Request.Method == "OPTIONS" {
+			c.AbortWithStatus(204)
+			return
+		}
+
+		c.Next()
+	})
+}

internal/models/example.go

@@ -0,0 +1,18 @@
+package models
+
+// ExampleGetResponse represents the response for the GET example service
+type ExampleGetResponse struct {
+	Message string `json:"message"`
+}
+
+// ExamplePostRequest represents the request body for the POST example service
+type ExamplePostRequest struct {
+	Name string `json:"name" binding:"required"`
+	Age  int    `json:"age" binding:"required"`
+}
+
+// ExamplePostResponse represents the response for the POST example service
+type ExamplePostResponse struct {
+	ID      string `json:"id"`
+	Message string `json:"message"`
+}

internal/models/health.go

@@ -0,0 +1,42 @@
+package models
+
+// HealthResponse represents the health check response
+type HealthResponse struct {
+	Status    string            `json:"status"`
+	Timestamp string            `json:"timestamp"`
+	Details   map[string]string `json:"details"`
+}
+
+// HelloWorldResponse represents the hello world response
+type HelloWorldResponse struct {
+	Message string `json:"message"`
+	Version string `json:"version"`
+}
+
+// ErrorResponse represents an error response
+type ErrorResponse struct {
+	Error   string `json:"error"`
+	Message string `json:"message"`
+	Code    int    `json:"code"`
+}
+
+// SuccessResponse represents a generic success response
+type SuccessResponse struct {
+	Success bool        `json:"success"`
+	Message string      `json:"message"`
+	Data    interface{} `json:"data,omitempty"`
+}
+
+// Pagination represents pagination metadata
+type Pagination struct {
+	Page       int `json:"page"`
+	Limit      int `json:"limit"`
+	Total      int `json:"total"`
+	TotalPages int `json:"total_pages"`
+}
+
+// PaginatedResponse represents a paginated response
+type PaginatedResponse struct {
+	Data       interface{} `json:"data"`
+	Pagination Pagination  `json:"pagination"`
+}

internal/routes/v1/routes.go

@@ -0,0 +1,51 @@
+package v1
+
+import (
+	"net/http"
+
+	"api-service/internal/handlers"
+	"api-service/internal/middleware"
+
+	"github.com/gin-gonic/gin"
+	swaggerFiles "github.com/swaggo/files"
+	ginSwagger "github.com/swaggo/gin-swagger"
+)
+
+// RegisterRoutes registers all API routes for version 1
+func RegisterRoutes() *gin.Engine {
+	router := gin.New()
+
+	// Add middleware
+	router.Use(middleware.CORSConfig())
+	router.Use(middleware.ErrorHandler())
+	router.Use(gin.Logger())
+	router.Use(gin.Recovery())
+
+	// Swagger UI route
+	router.GET("/swagger/*any", ginSwagger.WrapHandler(swaggerFiles.Handler))
+
+	// API v1 group
+	v1 := router.Group("/api/v1")
+	{
+		// Health endpoints
+		healthHandler := handlers.NewHealthHandler()
+		v1.GET("/health", healthHandler.GetHealth)
+		v1.GET("/", healthHandler.HelloWorld)
+
+		// Example endpoints
+		exampleHandler := handlers.NewExampleHandler()
+		v1.GET("/example", exampleHandler.GetExample)
+		v1.POST("/example", exampleHandler.PostExample)
+
+		// WebSocket endpoint
+		v1.GET("/websocket", WebSocketHandler)
+	}
+
+	return router
+}
+
+// WebSocketHandler handles WebSocket connections
+func WebSocketHandler(c *gin.Context) {
+	// This will be implemented with proper WebSocket handling
+	c.JSON(http.StatusOK, gin.H{"message": "WebSocket endpoint"})
+}

internal/server/routes.go

@@ -0,0 +1,71 @@
+package server
+
+import (
+	"net/http"
+
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/gin-contrib/cors"
+	"github.com/gin-gonic/gin"
+
+	"github.com/coder/websocket"
+)
+
+func (s *Server) RegisterRoutes() http.Handler {
+	r := gin.Default()
+
+	r.Use(cors.New(cors.Config{
+		AllowOrigins:     []string{"http://localhost:5173"}, // Add your frontend URL
+		AllowMethods:     []string{"GET", "POST", "PUT", "DELETE", "OPTIONS", "PATCH"},
+		AllowHeaders:     []string{"Accept", "Authorization", "Content-Type"},
+		AllowCredentials: true, // Enable cookies/auth
+	}))
+
+	r.GET("/", s.HelloWorldHandler)
+
+	r.GET("/health", s.healthHandler)
+
+	r.GET("/websocket", s.websocketHandler)
+
+	return r
+}
+
+func (s *Server) HelloWorldHandler(c *gin.Context) {
+	resp := make(map[string]string)
+	resp["message"] = "Hello World"
+
+	c.JSON(http.StatusOK, resp)
+}
+
+func (s *Server) healthHandler(c *gin.Context) {
+	c.JSON(http.StatusOK, s.db.Health())
+}
+
+func (s *Server) websocketHandler(c *gin.Context) {
+	w := c.Writer
+	r := c.Request
+	socket, err := websocket.Accept(w, r, nil)
+
+	if err != nil {
+		log.Printf("could not open websocket: %v", err)
+		_, _ = w.Write([]byte("could not open websocket"))
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	defer socket.Close(websocket.StatusGoingAway, "server closing websocket")
+
+	ctx := r.Context()
+	socketCtx := socket.CloseRead(ctx)
+
+	for {
+		payload := fmt.Sprintf("server timestamp: %d", time.Now().UnixNano())
+		err := socket.Write(socketCtx, websocket.MessageText, []byte(payload))
+		if err != nil {
+			break
+		}
+		time.Sleep(time.Second * 2)
+	}
+}

internal/server/routes_test.go

@@ -0,0 +1,32 @@
+package server
+
+import (
+	"github.com/gin-gonic/gin"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestHelloWorldHandler(t *testing.T) {
+	s := &Server{}
+	r := gin.New()
+	r.GET("/", s.HelloWorldHandler)
+	// Create a test HTTP request
+	req, err := http.NewRequest("GET", "/", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Create a ResponseRecorder to record the response
+	rr := httptest.NewRecorder()
+	// Serve the HTTP request
+	r.ServeHTTP(rr, req)
+	// Check the status code
+	if status := rr.Code; status != http.StatusOK {
+		t.Errorf("Handler returned wrong status code: got %v want %v", status, http.StatusOK)
+	}
+	// Check the response body
+	expected := "{\"message\":\"Hello World\"}"
+	if rr.Body.String() != expected {
+		t.Errorf("Handler returned unexpected body: got %v want %v", rr.Body.String(), expected)
+	}
+}

internal/server/server.go

@@ -0,0 +1,47 @@
+package server
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"strconv"
+	"time"
+
+	_ "github.com/joho/godotenv/autoload"
+
+	"api-service/internal/config"
+	"api-service/internal/database"
+	v1 "api-service/internal/routes/v1"
+)
+
+type Server struct {
+	port int
+	db   database.Service
+}
+
+func NewServer() *http.Server {
+	// Load configuration
+	cfg := config.LoadConfig()
+	cfg.Validate()
+
+	port, _ := strconv.Atoi(os.Getenv("PORT"))
+	if port == 0 {
+		port = cfg.Server.Port
+	}
+
+	NewServer := &Server{
+		port: port,
+		db:   database.New(),
+	}
+
+	// Declare Server config
+	server := &http.Server{
+		Addr:         fmt.Sprintf(":%d", NewServer.port),
+		Handler:      v1.RegisterRoutes(),
+		IdleTimeout:  time.Minute,
+		ReadTimeout:  10 * time.Second,
+		WriteTimeout: 30 * time.Second,
+	}
+
+	return server
+}