add ai feature

internal/ai/validation.go

@@ -0,0 +1,169 @@
+package ai
+
+import (
+	"fmt"
+	"path"
+	"strings"
+
+	"github.com/rogeecn/renamer/internal/ai/flow"
+)
+
+var invalidCharacters = []rune{'/', '\\', ':', '*', '?', '"', '<', '>', '|'}
+
+// Conflict captures a validation failure for a proposed rename.
+type Conflict struct {
+	Original  string
+	Suggested string
+	Reason    string
+}
+
+// ValidationResult aggregates conflicts and warnings.
+type ValidationResult struct {
+	Conflicts []Conflict
+	Warnings  []string
+}
+
+// ValidateSuggestions enforces rename safety rules before applying suggestions.
+func ValidateSuggestions(expected []string, suggestions []flow.Suggestion) ValidationResult {
+	result := ValidationResult{}
+
+	expectedSet := make(map[string]struct{}, len(expected))
+	for _, name := range expected {
+		expectedSet[strings.ToLower(flowToKey(name))] = struct{}{}
+	}
+
+	seenTargets := make(map[string]string)
+
+	for _, suggestion := range suggestions {
+		key := strings.ToLower(flowToKey(suggestion.Original))
+		if _, ok := expectedSet[key]; !ok {
+			result.Conflicts = append(result.Conflicts, Conflict{
+				Original:  suggestion.Original,
+				Suggested: suggestion.Suggested,
+				Reason:    "original file not present in scope",
+			})
+			continue
+		}
+
+		cleaned := strings.TrimSpace(suggestion.Suggested)
+		if cleaned == "" {
+			result.Conflicts = append(result.Conflicts, Conflict{
+				Original:  suggestion.Original,
+				Suggested: suggestion.Suggested,
+				Reason:    "suggested name is empty",
+			})
+			continue
+		}
+
+		normalizedOriginal := flowToKey(suggestion.Original)
+		normalizedSuggested := flowToKey(cleaned)
+
+		if strings.HasPrefix(normalizedSuggested, "/") {
+			result.Conflicts = append(result.Conflicts, Conflict{
+				Original:  suggestion.Original,
+				Suggested: suggestion.Suggested,
+				Reason:    "suggested name must be relative",
+			})
+			continue
+		}
+
+		if containsParentSegment(normalizedSuggested) {
+			result.Conflicts = append(result.Conflicts, Conflict{
+				Original:  suggestion.Original,
+				Suggested: suggestion.Suggested,
+				Reason:    "suggested name cannot traverse directories",
+			})
+			continue
+		}
+
+		base := path.Base(cleaned)
+		if containsInvalidCharacter(base) {
+			result.Conflicts = append(result.Conflicts, Conflict{
+				Original:  suggestion.Original,
+				Suggested: suggestion.Suggested,
+				Reason:    "suggested name contains invalid characters",
+			})
+			continue
+		}
+
+		if !extensionsMatch(suggestion.Original, cleaned) {
+			result.Conflicts = append(result.Conflicts, Conflict{
+				Original:  suggestion.Original,
+				Suggested: suggestion.Suggested,
+				Reason:    "file extension changed",
+			})
+			continue
+		}
+
+		if path.Dir(normalizedOriginal) != path.Dir(normalizedSuggested) {
+			result.Warnings = append(result.Warnings, fmt.Sprintf("suggestion for %q moves file to a different directory", suggestion.Original))
+		}
+
+		targetKey := strings.ToLower(normalizedSuggested)
+		if existing, ok := seenTargets[targetKey]; ok && existing != suggestion.Original {
+			result.Conflicts = append(result.Conflicts, Conflict{
+				Original:  suggestion.Original,
+				Suggested: suggestion.Suggested,
+				Reason:    "duplicate target generated",
+			})
+			continue
+		}
+		seenTargets[targetKey] = suggestion.Original
+
+		if normalizedOriginal == normalizedSuggested {
+			result.Warnings = append(result.Warnings, fmt.Sprintf("suggestion for %q does not change the filename", suggestion.Original))
+		}
+	}
+
+	if len(suggestions) != len(expected) {
+		result.Warnings = append(result.Warnings, fmt.Sprintf("expected %d suggestions but received %d", len(expected), len(suggestions)))
+	}
+
+	return result
+}
+
+func flowToKey(value string) string {
+	return strings.ReplaceAll(strings.TrimSpace(value), "\\", "/")
+}
+
+func containsInvalidCharacter(value string) bool {
+	for _, ch := range invalidCharacters {
+		if strings.ContainsRune(value, ch) {
+			return true
+		}
+	}
+	return false
+}
+
+func extensionsMatch(original, proposed string) bool {
+	origExt := strings.ToLower(path.Ext(original))
+	propExt := strings.ToLower(path.Ext(proposed))
+	return origExt == propExt
+}
+
+// SummarizeConflicts renders a human-readable summary of conflicts.
+func SummarizeConflicts(conflicts []Conflict) string {
+	if len(conflicts) == 0 {
+		return ""
+	}
+	builder := strings.Builder{}
+	for _, c := range conflicts {
+		builder.WriteString(fmt.Sprintf("%s -> %s (%s); ", c.Original, c.Suggested, c.Reason))
+	}
+	return strings.TrimSpace(builder.String())
+}
+
+// SummarizeWarnings renders warnings as a delimited string.
+func SummarizeWarnings(warnings []string) string {
+	return strings.Join(warnings, "; ")
+}
+
+func containsParentSegment(value string) bool {
+	parts := strings.Split(value, "/")
+	for _, part := range parts {
+		if part == ".." {
+			return true
+		}
+	}
+	return false
+}