feat: implement SQLite storage for state messages and add message retrieval endpoint

internal/handler/handlers.go

@@ -3,9 +3,11 @@ package handler
 import (
 	"database/sql"
 	"net/http"
+	"strconv"
 	"strings"
 	"time"
 
+	"git.piskot.si/SeminarM2/lambdaiot-core/internal/storage"
 	"github.com/gin-gonic/gin"
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/google/uuid"
@@ -243,3 +245,26 @@ func (h *Handler) Protected(c *gin.Context) {
 	}
 	c.JSON(http.StatusUnauthorized, gin.H{"error": "no claims"})
 }
+
+// GetMessages returns the last 100 state messages with optional pagination
+// query parameter: ?page=N (0-based)
+func GetMessages(c *gin.Context) {
+	page := 0
+	if p := c.Query("page"); p != "" {
+		if n, err := strconv.Atoi(p); err == nil && n >= 0 {
+			page = n
+		}
+	}
+	limit := 100
+	offset := page * limit
+	if storage.Default == nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "storage not initialized"})
+		return
+	}
+	msgs, err := storage.Default.QueryMessages(limit, offset)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"messages": msgs})
+}