[BACKEND] Initialize Go backend structure and dependencies (#23)

server/middleware/errors.go

@@ -0,0 +1,114 @@
+package middleware
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+// ErrorHandlerConfig holds the configuration for the error handler middleware
+type ErrorHandlerConfig struct {
+	TimeFormat     string
+	TimeZone       string
+}
+
+// DefaultErrorHandlerConfig returns the default error handler configuration
+func DefaultErrorHandlerConfig() *ErrorHandlerConfig {
+	return &ErrorHandlerConfig{
+		TimeFormat: "2006/01/02 - 15:04:05",
+		TimeZone:   "UTC",
+	}
+}
+
+// ErrorHandler returns a Gin middleware handler for centralized error handling
+func ErrorHandler() gin.HandlerFunc {
+	return ErrorHandlerWithConfig(DefaultErrorHandlerConfig())
+}
+
+// ErrorHandlerWithConfig returns a Gin middleware handler for centralized error handling with custom configuration
+func ErrorHandlerWithConfig(config *ErrorHandlerConfig) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.Next()
+		
+		// Check if there were any errors
+		if len(c.Errors) > 0 {
+			err := c.Errors.Last()
+			
+			// Determine the status code
+			statusCode := http.StatusInternalServerError
+			if gin.Mode() != gin.ReleaseMode {
+				// In development mode, return detailed error information
+				c.JSON(http.StatusInternalServerError, gin.H{
+					"error":   "internal server error",
+					"message": err.Error(),
+					"details": c.Errors,
+				})
+				return
+			}
+			
+			// In production mode, return a generic error message
+			c.JSON(statusCode, gin.H{
+				"error": "internal server error",
+			})
+		}
+	}
+}
+
+// ErrorResponse represents a standard error response
+type ErrorResponse struct {
+	Error   string            `json:"error"`
+	Code    string            `json:"code,omitempty"`
+	Details map[string]string `json:"details,omitempty"`
+}
+
+// NewErrorResponse creates a new error response
+func NewErrorResponse(error string, code string, details map[string]string) *ErrorResponse {
+	return &ErrorResponse{
+		Error:   error,
+		Code:    code,
+		Details: details,
+	}
+}
+
+// BadRequest creates a 400 Bad Request response
+func BadRequest(c *gin.Context, message string) {
+	c.JSON(http.StatusBadRequest, gin.H{
+		"error": message,
+	})
+}
+
+// Unauthorized creates a 401 Unauthorized response
+func Unauthorized(c *gin.Context, message string) {
+	c.JSON(http.StatusUnauthorized, gin.H{
+		"error": message,
+	})
+}
+
+// Forbidden creates a 403 Forbidden response
+func Forbidden(c *gin.Context, message string) {
+	c.JSON(http.StatusForbidden, gin.H{
+		"error": message,
+	})
+}
+
+// NotFound creates a 404 Not Found response
+func NotFound(c *gin.Context, message string) {
+	c.JSON(http.StatusNotFound, gin.H{
+		"error": message,
+	})
+}
+
+// InternalServerError creates a 500 Internal Server Error response
+func InternalServerError(c *gin.Context, message string) {
+	c.JSON(http.StatusInternalServerError, gin.H{
+		"error": message,
+	})
+}
+
+// ValidationError creates a response for validation errors
+func ValidationError(c *gin.Context, errors map[string]string) {
+	c.JSON(http.StatusBadRequest, gin.H{
+		"error":   "validation failed",
+		"details": errors,
+	})
+}