finance/backend: feat: set up logging and error handling

1 files changed, 83 insertions, 0 deletions

diff --git a/backend/middleware/middleware.go b/backend/middleware/middleware.go
new file mode 100644
index 0000000..d319c47
--- /dev/null
+++ b/backend/middleware/middleware.go
@@ -0,0 +1,83 @@
+package middleware
+
+import (
+	"finance/backend/internal/logger"
+	"net/http"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+// Logger is middleware for logging HTTP requests
+func Logger(log *logger.Logger) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		// Start timer
+		start := time.Now()
+
+		// Process request
+		c.Next()
+
+		// Calculate latency
+		latency := time.Since(start)
+
+		// Log request
+		log.LogRequest(
+			c.Request.Method,
+			c.Request.URL.Path,
+			c.ClientIP(),
+			c.Request.UserAgent(),
+			c.Writer.Status(),
+			latency,
+		)
+	}
+}
+
+// ErrorHandler is middleware for handling errors
+func ErrorHandler(log *logger.Logger) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.Next()
+
+		// Handle errors after request is processed
+		if len(c.Errors) > 0 {
+			for _, e := range c.Errors {
+				log.Error(e.Err)
+			}
+
+			// Return last error to client if response wasn't already sent
+			if !c.Writer.Written() {
+				c.JSON(http.StatusInternalServerError, gin.H{
+					"error": c.Errors.Last().Error(),
+				})
+			}
+		}
+	}
+}
+
+// NotFoundHandler handles 404 errors
+func NotFoundHandler(c *gin.Context) {
+	c.JSON(http.StatusNotFound, gin.H{
+		"error": "Resource not found",
+	})
+}
+
+// MethodNotAllowedHandler handles 405 errors
+func MethodNotAllowedHandler(c *gin.Context) {
+	c.JSON(http.StatusMethodNotAllowed, gin.H{
+		"error": "Method not allowed",
+	})
+}
+
+// RecoveryWithLogger recovers from any panics and logs errors
+func RecoveryWithLogger(log *logger.Logger) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		defer func() {
+			if err := recover(); err != nil {
+				log.Errorf("Panic recovered: %v", err)
+				c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{
+					"error": "Internal server error",
+				})
+			}
+		}()
+		c.Next()
+	}
+}