Added cache, funcspec and implemented total cache

pkg/funcspec/hooks_example.go

@@ -0,0 +1,137 @@
+package funcspec
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/bitechdev/ResolveSpec/pkg/logger"
+)
+
+// Example hook functions demonstrating various use cases
+
+// ExampleLoggingHook logs all SQL queries before execution
+func ExampleLoggingHook(ctx *HookContext) error {
+	logger.Info("Executing SQL query for user %s: %s", ctx.UserContext.UserName, ctx.SQLQuery)
+	return nil
+}
+
+// ExampleSecurityHook validates user permissions before executing queries
+func ExampleSecurityHook(ctx *HookContext) error {
+	// Example: Block queries that try to access sensitive tables
+	if strings.Contains(strings.ToLower(ctx.SQLQuery), "sensitive_table") {
+		if ctx.UserContext.UserID != 1 { // Only admin can access
+			ctx.Abort = true
+			ctx.AbortCode = 403
+			ctx.AbortMessage = "Access denied: insufficient permissions"
+			return fmt.Errorf("access denied to sensitive_table")
+		}
+	}
+	return nil
+}
+
+// ExampleQueryModificationHook modifies SQL queries to add user-specific filtering
+func ExampleQueryModificationHook(ctx *HookContext) error {
+	// Example: Automatically add user_id filter for non-admin users
+	if ctx.UserContext.UserID != 1 { // Not admin
+		// Add WHERE clause to filter by user_id
+		if !strings.Contains(strings.ToLower(ctx.SQLQuery), "where") {
+			ctx.SQLQuery = fmt.Sprintf("%s WHERE user_id = %d", ctx.SQLQuery, ctx.UserContext.UserID)
+		} else {
+			ctx.SQLQuery = strings.Replace(
+				ctx.SQLQuery,
+				"WHERE",
+				fmt.Sprintf("WHERE user_id = %d AND", ctx.UserContext.UserID),
+				1,
+			)
+		}
+		logger.Debug("Modified query for user %d: %s", ctx.UserContext.UserID, ctx.SQLQuery)
+	}
+	return nil
+}
+
+// ExampleResultFilterHook filters results after query execution
+func ExampleResultFilterHook(ctx *HookContext) error {
+	// Example: Remove sensitive fields from results for non-admin users
+	if ctx.UserContext.UserID != 1 { // Not admin
+		switch result := ctx.Result.(type) {
+		case []map[string]interface{}:
+			// Filter list results
+			for i := range result {
+				delete(result[i], "password")
+				delete(result[i], "ssn")
+				delete(result[i], "credit_card")
+			}
+		case map[string]interface{}:
+			// Filter single record
+			delete(result, "password")
+			delete(result, "ssn")
+			delete(result, "credit_card")
+		}
+	}
+	return nil
+}
+
+// ExampleAuditHook logs all queries and results for audit purposes
+func ExampleAuditHook(ctx *HookContext) error {
+	// Log to audit table or external system
+	logger.Info("AUDIT: User %s (%d) executed query from %s",
+		ctx.UserContext.UserName,
+		ctx.UserContext.UserID,
+		ctx.Request.RemoteAddr,
+	)
+
+	// In a real implementation, you might:
+	// - Insert into an audit log table
+	// - Send to a logging service
+	// - Write to a file
+
+	return nil
+}
+
+// ExampleCacheHook implements simple response caching
+func ExampleCacheHook(ctx *HookContext) error {
+	// This is a simplified example - real caching would use a proper cache store
+	// Check if we have a cached result for this query
+	// cacheKey := fmt.Sprintf("%s:%s", ctx.UserContext.UserName, ctx.SQLQuery)
+	// if cachedResult := checkCache(cacheKey); cachedResult != nil {
+	//     ctx.Result = cachedResult
+	//     ctx.Abort = true // Skip query execution
+	//     ctx.AbortMessage = "Serving from cache"
+	// }
+	return nil
+}
+
+// ExampleErrorHandlingHook provides custom error handling
+func ExampleErrorHandlingHook(ctx *HookContext) error {
+	if ctx.Error != nil {
+		// Log error with context
+		logger.Error("Query failed for user %s: %v\nQuery: %s",
+			ctx.UserContext.UserName,
+			ctx.Error,
+			ctx.SQLQuery,
+		)
+
+		// You could send notifications, update metrics, etc.
+	}
+	return nil
+}
+
+// Example of registering hooks:
+//
+// func SetupHooks(handler *Handler) {
+//     hooks := handler.Hooks()
+//
+//     // Register security hook before query execution
+//     hooks.Register(BeforeQuery, ExampleSecurityHook)
+//     hooks.Register(BeforeQueryList, ExampleSecurityHook)
+//
+//     // Register logging hook before SQL execution
+//     hooks.Register(BeforeSQLExec, ExampleLoggingHook)
+//
+//     // Register result filtering after query
+//     hooks.Register(AfterQuery, ExampleResultFilterHook)
+//     hooks.Register(AfterQueryList, ExampleResultFilterHook)
+//
+//     // Register audit hook after execution
+//     hooks.RegisterMultiple([]HookType{AfterQuery, AfterQueryList}, ExampleAuditHook)
+// }