v0.2.0 transitioned to api-only, extended and improved features, docs and tests added

internal/http/handler.go

@@ -0,0 +1,412 @@
+// FILE: internal/http/handler.go
+package http
+
+import (
+	"chess/internal/core"
+	"chess/internal/processor"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/middleware/cors"
+	"github.com/gofiber/fiber/v2/middleware/limiter"
+	"github.com/gofiber/fiber/v2/middleware/logger"
+	"github.com/gofiber/fiber/v2/middleware/recover"
+)
+
+const rateLimitRate = 10 // req/sec
+
+type HTTPHandler struct {
+	proc *processor.Processor
+}
+
+func NewHTTPHandler(proc *processor.Processor) *HTTPHandler {
+	return &HTTPHandler{proc: proc}
+}
+
+func NewFiberApp(proc *processor.Processor, devMode bool) *fiber.App {
+	// Create handler
+	h := NewHTTPHandler(proc)
+
+	// Initialize Fiber app
+	app := fiber.New(fiber.Config{
+		ErrorHandler: customErrorHandler,
+		ReadTimeout:  10 * time.Second,
+		WriteTimeout: 10 * time.Second,
+		IdleTimeout:  30 * time.Second,
+	})
+
+	// Global middleware (order matters)
+	app.Use(recover.New())
+	app.Use(logger.New(logger.Config{
+		Format: "${time} ${status} ${method} ${path} ${latency}\n",
+	}))
+	app.Use(cors.New(cors.Config{
+		AllowOrigins: "*",
+		AllowMethods: "GET,POST,PUT,DELETE,OPTIONS",
+		AllowHeaders: "Origin,Content-Type,Accept",
+	}))
+
+	// Health check (no rate limit)
+	app.Get("/health", h.Health)
+
+	// API v1 routes with rate limiting
+	api := app.Group("/api/v1")
+
+	// Rate limiter: 10/20 req/sec per IP with expiry
+	maxReq := rateLimitRate
+	if devMode {
+		maxReq = rateLimitRate * 2 // Loosen rate limiter for testing
+	}
+	api.Use(limiter.New(limiter.Config{
+		Max:        maxReq,          // Allow requests per second
+		Expiration: 1 * time.Second, // Per second
+		KeyGenerator: func(c *fiber.Ctx) string {
+			// Check X-Forwarded-For first, then X-Real-IP, then RemoteIP
+			if xff := c.Get("X-Forwarded-For"); xff != "" {
+				// Take the first IP from X-Forwarded-For chain
+				if idx := strings.Index(xff, ","); idx != -1 {
+					return strings.TrimSpace(xff[:idx])
+				}
+				return xff
+			}
+			return c.IP()
+		},
+		LimitReached: func(c *fiber.Ctx) error {
+			return c.Status(fiber.StatusTooManyRequests).JSON(core.ErrorResponse{
+				Error:   "rate limit exceeded",
+				Code:    core.ErrRateLimitExceeded,
+				Details: fmt.Sprintf("%d requests per second allowed", maxReq),
+			})
+		},
+		Storage:                nil, // Use in-memory storage (default)
+		SkipFailedRequests:     false,
+		SkipSuccessfulRequests: false,
+	}))
+
+	// Content-Type validation for POST and PUT requests
+	api.Use(contentTypeValidator)
+
+	// Middleware validation for sanitization
+	api.Use(validationMiddleware)
+
+	// Register game routes
+	api.Post("/games", h.CreateGame)
+	api.Put("/games/:gameId/players", h.ConfigurePlayers)
+	api.Get("/games/:gameId", h.GetGame)
+	api.Delete("/games/:gameId", h.DeleteGame)
+	api.Post("/games/:gameId/moves", h.MakeMove)
+	api.Post("/games/:gameId/undo", h.UndoMove)
+	api.Get("/games/:gameId/board", h.GetBoard)
+
+	return app
+}
+
+// contentTypeValidator ensures POST and PUT requests have application/json
+func contentTypeValidator(c *fiber.Ctx) error {
+	method := c.Method()
+	if method == fiber.MethodPost || method == fiber.MethodPut {
+		contentType := c.Get("Content-Type")
+		if contentType != "application/json" && contentType != "" {
+			return c.Status(fiber.StatusUnsupportedMediaType).JSON(core.ErrorResponse{
+				Error:   "unsupported media type",
+				Code:    core.ErrInvalidContent,
+				Details: "Content-Type must be application/json",
+			})
+		}
+	}
+	return c.Next()
+}
+
+// customErrorHandler provides consistent error responses
+func customErrorHandler(c *fiber.Ctx, err error) error {
+	code := fiber.StatusInternalServerError
+	response := core.ErrorResponse{
+		Error: "internal server error",
+		Code:  core.ErrInternalError,
+	}
+
+	// Check if it's a Fiber error
+	if e, ok := err.(*fiber.Error); ok {
+		code = e.Code
+		response.Error = e.Message
+
+		// Map HTTP status to error codes
+		switch code {
+		case fiber.StatusNotFound:
+			response.Code = core.ErrGameNotFound
+		case fiber.StatusBadRequest:
+			response.Code = core.ErrInvalidRequest
+		case fiber.StatusTooManyRequests:
+			response.Code = core.ErrRateLimitExceeded
+		}
+	}
+
+	return c.Status(code).JSON(response)
+}
+
+// Health check endpoint
+func (h *HTTPHandler) Health(c *fiber.Ctx) error {
+	return c.JSON(fiber.Map{
+		"status": "healthy",
+		"time":   time.Now().Unix(),
+	})
+}
+
+// CreateGame creates a new game with specified player types
+func (h *HTTPHandler) CreateGame(c *fiber.Ctx) error {
+	// Ensure middleware validation ran
+	validated, ok := c.Locals("validated").(bool)
+	if !ok || !validated {
+		return c.Status(fiber.StatusInternalServerError).JSON(core.ErrorResponse{
+			Error: "validation bypass detected",
+			Code:  core.ErrInternalError,
+		})
+	}
+
+	// Retrieve validated parsed body
+	validatedBody := c.Locals("validatedBody")
+	if validatedBody == nil {
+		return c.Status(fiber.StatusInternalServerError).JSON(core.ErrorResponse{
+			Error: "validation data missing",
+			Code:  core.ErrInternalError,
+		})
+	}
+	var req core.CreateGameRequest
+	req = *(validatedBody.(*core.CreateGameRequest))
+
+	// Let processor generate game ID via service
+	cmd := processor.NewCreateGameCommand(req)
+
+	resp := h.proc.Execute(cmd)
+
+	// Return appropriate HTTP response
+	if !resp.Success {
+		return c.Status(fiber.StatusBadRequest).JSON(resp.Error)
+	}
+
+	return c.Status(fiber.StatusCreated).JSON(resp.Data)
+}
+
+// ConfigurePlayers updates player configuration mid-game
+func (h *HTTPHandler) ConfigurePlayers(c *fiber.Ctx) error {
+	gameID := c.Params("gameId")
+
+	// Validate UUID format
+	if !isValidUUID(gameID) {
+		return c.Status(fiber.StatusBadRequest).JSON(core.ErrorResponse{
+			Error:   "invalid game ID format",
+			Code:    core.ErrInvalidRequest,
+			Details: "game ID must be a valid UUID",
+		})
+	}
+
+	// Ensure middleware validation ran
+	validated, ok := c.Locals("validated").(bool)
+	if !ok || !validated {
+		return c.Status(fiber.StatusInternalServerError).JSON(core.ErrorResponse{
+			Error: "validation bypass detected",
+			Code:  core.ErrInternalError,
+		})
+	}
+
+	// Retrieve validated parsed body
+	validatedBody := c.Locals("validatedBody")
+	if validatedBody == nil {
+		return c.Status(fiber.StatusInternalServerError).JSON(core.ErrorResponse{
+			Error: "validation data missing",
+			Code:  core.ErrInternalError,
+		})
+	}
+	var req core.ConfigurePlayersRequest
+	req = *(validatedBody.(*core.ConfigurePlayersRequest))
+
+	// Create command and execute
+	cmd := processor.NewConfigurePlayersCommand(gameID, req)
+	resp := h.proc.Execute(cmd)
+
+	// Return appropriate HTTP response
+	if !resp.Success {
+		statusCode := fiber.StatusBadRequest
+		if resp.Error.Code == core.ErrGameNotFound {
+			statusCode = fiber.StatusNotFound
+		}
+		return c.Status(statusCode).JSON(resp.Error)
+	}
+
+	return c.JSON(resp.Data)
+}
+
+// GetGame retrieves current game state
+func (h *HTTPHandler) GetGame(c *fiber.Ctx) error {
+	gameID := c.Params("gameId")
+
+	// Validate UUID format
+	if !isValidUUID(gameID) {
+		return c.Status(fiber.StatusBadRequest).JSON(core.ErrorResponse{
+			Error:   "invalid game ID format",
+			Code:    core.ErrInvalidRequest,
+			Details: "game ID must be a valid UUID",
+		})
+	}
+
+	// Create command and execute
+	cmd := processor.NewGetGameCommand(gameID)
+	resp := h.proc.Execute(cmd)
+
+	// Return appropriate HTTP response
+	if !resp.Success {
+		return c.Status(fiber.StatusNotFound).JSON(resp.Error)
+	}
+
+	return c.JSON(resp.Data)
+}
+
+// MakeMove submits a move
+func (h *HTTPHandler) MakeMove(c *fiber.Ctx) error {
+	gameID := c.Params("gameId")
+
+	// Validate UUID format
+	if !isValidUUID(gameID) {
+		return c.Status(fiber.StatusBadRequest).JSON(core.ErrorResponse{
+			Error:   "invalid game ID format",
+			Code:    core.ErrInvalidRequest,
+			Details: "game ID must be a valid UUID",
+		})
+	}
+
+	// Ensure middleware validation ran
+	validated, ok := c.Locals("validated").(bool)
+	if !ok || !validated {
+		return c.Status(fiber.StatusInternalServerError).JSON(core.ErrorResponse{
+			Error: "validation bypass detected",
+			Code:  core.ErrInternalError,
+		})
+	}
+
+	// Retrieve validated parsed body
+	validatedBody := c.Locals("validatedBody")
+	if validatedBody == nil {
+		return c.Status(fiber.StatusInternalServerError).JSON(core.ErrorResponse{
+			Error: "validation data missing",
+			Code:  core.ErrInternalError,
+		})
+	}
+	var req core.MoveRequest
+	req = *(validatedBody.(*core.MoveRequest))
+
+	// Create command and execute
+	cmd := processor.NewMakeMoveCommand(gameID, req)
+	resp := h.proc.Execute(cmd)
+
+	// Return appropriate HTTP response with correct status code
+	if !resp.Success {
+		statusCode := fiber.StatusBadRequest
+		if resp.Error.Code == core.ErrGameNotFound {
+			statusCode = fiber.StatusNotFound
+		}
+		return c.Status(statusCode).JSON(resp.Error)
+	}
+
+	return c.JSON(resp.Data)
+}
+
+// UndoMove undoes one or more moves
+func (h *HTTPHandler) UndoMove(c *fiber.Ctx) error {
+	gameID := c.Params("gameId")
+
+	// Validate UUID format
+	if !isValidUUID(gameID) {
+		return c.Status(fiber.StatusBadRequest).JSON(core.ErrorResponse{
+			Error:   "invalid game ID format",
+			Code:    core.ErrInvalidRequest,
+			Details: "game ID must be a valid UUID",
+		})
+	}
+
+	// Ensure middleware validation ran
+	validated, ok := c.Locals("validated").(bool)
+	if !ok || !validated {
+		return c.Status(fiber.StatusInternalServerError).JSON(core.ErrorResponse{
+			Error: "validation bypass detected",
+			Code:  core.ErrInternalError,
+		})
+	}
+
+	// Retrieve validated parsed body
+	validatedBody := c.Locals("validatedBody")
+	if validatedBody == nil {
+		return c.Status(fiber.StatusInternalServerError).JSON(core.ErrorResponse{
+			Error: "validation data missing",
+			Code:  core.ErrInternalError,
+		})
+	}
+	var req core.UndoRequest
+	req = *(validatedBody.(*core.UndoRequest))
+
+	// Create command and execute
+	cmd := processor.NewUndoMoveCommand(gameID, req)
+	resp := h.proc.Execute(cmd)
+
+	// Return appropriate HTTP response
+	if !resp.Success {
+		statusCode := fiber.StatusBadRequest
+		if resp.Error.Code == core.ErrGameNotFound {
+			statusCode = fiber.StatusNotFound
+		}
+		return c.Status(statusCode).JSON(resp.Error)
+	}
+
+	return c.JSON(resp.Data)
+}
+
+// DeleteGame ends and cleans up a game
+func (h *HTTPHandler) DeleteGame(c *fiber.Ctx) error {
+	gameID := c.Params("gameId")
+
+	// Validate UUID format
+	if !isValidUUID(gameID) {
+		return c.Status(fiber.StatusBadRequest).JSON(core.ErrorResponse{
+			Error:   "invalid game ID format",
+			Code:    core.ErrInvalidRequest,
+			Details: "game ID must be a valid UUID",
+		})
+	}
+
+	// Create command and execute
+	cmd := processor.NewDeleteGameCommand(gameID)
+	resp := h.proc.Execute(cmd)
+
+	// Return appropriate HTTP response
+	if !resp.Success {
+		return c.Status(fiber.StatusNotFound).JSON(resp.Error)
+	}
+
+	return c.SendStatus(fiber.StatusNoContent)
+}
+
+// GetBoard returns ASCII representation of the board
+func (h *HTTPHandler) GetBoard(c *fiber.Ctx) error {
+	gameID := c.Params("gameId")
+
+	// Validate UUID format
+	if !isValidUUID(gameID) {
+		return c.Status(fiber.StatusBadRequest).JSON(core.ErrorResponse{
+			Error:   "invalid game ID format",
+			Code:    core.ErrInvalidRequest,
+			Details: "game ID must be a valid UUID",
+		})
+	}
+
+	// Create command and execute
+	cmd := processor.NewGetBoardCommand(gameID)
+	resp := h.proc.Execute(cmd)
+
+	// Return appropriate HTTP response
+	if !resp.Success {
+		return c.Status(fiber.StatusNotFound).JSON(resp.Error)
+	}
+
+	return c.JSON(resp.Data)
+}

internal/http/validator.go

@@ -0,0 +1,103 @@
+// FILE: internal/http/handler.go
+package http
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+
+	"chess/internal/core"
+
+	"github.com/go-playground/validator/v10"
+	"github.com/gofiber/fiber/v2"
+	"github.com/google/uuid"
+)
+
+// Add validator instance near top of file
+var validate = validator.New()
+
+// Add custom validation middleware function
+func validationMiddleware(c *fiber.Ctx) error {
+	// Skip validation for GET, DELETE, OPTIONS
+	method := c.Method()
+	if method == fiber.MethodGet || method == fiber.MethodDelete || method == fiber.MethodOptions {
+		return c.Next()
+	}
+
+	// Determine request type based on path
+	path := c.Path()
+	var requestType interface{}
+
+	switch {
+	case strings.HasSuffix(path, "/games") && method == fiber.MethodPost:
+		requestType = &core.CreateGameRequest{}
+	case strings.HasSuffix(path, "/players") && method == fiber.MethodPut:
+		requestType = &core.ConfigurePlayersRequest{}
+	case strings.HasSuffix(path, "/moves") && method == fiber.MethodPost:
+		requestType = &core.MoveRequest{}
+	case strings.HasSuffix(path, "/undo") && method == fiber.MethodPost:
+		requestType = &core.UndoRequest{}
+	default:
+		return c.Next() // No validation for unknown endpoints
+	}
+
+	// Parse body
+	if err := c.BodyParser(requestType); err != nil {
+		return c.Status(fiber.StatusBadRequest).JSON(core.ErrorResponse{
+			Error:   "invalid request body",
+			Code:    core.ErrInvalidRequest,
+			Details: err.Error(),
+		})
+	}
+
+	// Validate
+	if errs := validate.Struct(requestType); errs != nil {
+		var details strings.Builder
+		for _, err := range errs.(validator.ValidationErrors) {
+			if details.Len() > 0 {
+				details.WriteString("; ")
+			}
+			switch err.Tag() {
+			case "required":
+				details.WriteString(fmt.Sprintf("%s is required", err.Field()))
+			case "oneof":
+				details.WriteString(fmt.Sprintf("%s must be one of [%s]", err.Field(), err.Param()))
+			case "min":
+				if err.Type().Kind() == reflect.String {
+					details.WriteString(fmt.Sprintf("%s must be at least %s characters", err.Field(), err.Param()))
+				} else {
+					details.WriteString(fmt.Sprintf("%s must be at least %s", err.Field(), err.Param()))
+				}
+			case "max":
+				if err.Type().Kind() == reflect.String {
+					details.WriteString(fmt.Sprintf("%s must be at most %s characters", err.Field(), err.Param()))
+				} else {
+					details.WriteString(fmt.Sprintf("%s must be at most %s", err.Field(), err.Param()))
+				}
+			case "omitempty": // Skip, a control tag that doesn't error
+				continue
+			case "dive": // Skip, panics on wrong type, no error handling since current code does not call validator on slice or map
+				continue
+			default:
+				details.WriteString(fmt.Sprintf("%s failed %s validation", err.Field(), err.Tag()))
+			}
+		}
+
+		return c.Status(fiber.StatusBadRequest).JSON(core.ErrorResponse{
+			Error:   "validation failed",
+			Code:    core.ErrInvalidRequest,
+			Details: details.String(),
+		})
+	}
+
+	// Store validated body for handler use
+	c.Locals("validatedBody", requestType)
+	c.Locals("validated", true)
+
+	return c.Next()
+}
+
+func isValidUUID(s string) bool {
+	_, err := uuid.Parse(s)
+	return err == nil
+}