add ai feature

internal/ai/flow/rename_flow.go

@@ -0,0 +1,197 @@
+package flow
+
+import (
+	"context"
+	_ "embed"
+	"errors"
+	"fmt"
+	"path"
+	"sort"
+	"strings"
+	"text/template"
+	"unicode"
+
+	"github.com/firebase/genkit/go/core"
+	"github.com/firebase/genkit/go/genkit"
+)
+
+//go:embed prompt.tmpl
+var promptTemplateSource string
+
+var (
+	promptTemplate = template.Must(template.New("renameFlowPrompt").Parse(promptTemplateSource))
+)
+
+// RenameFlowInput mirrors the JSON payload passed into the Genkit flow.
+type RenameFlowInput struct {
+ FileNames  []string `json:"fileNames"`
+ UserPrompt string   `json:"userPrompt"`
+ SequenceSeparator string `json:"sequenceSeparator,omitempty"`
+}
+
+// Validate ensures the flow input is well formed.
+func (in *RenameFlowInput) Validate() error {
+	if in == nil {
+		return errors.New("rename flow input cannot be nil")
+	}
+	if len(in.FileNames) == 0 {
+		return errors.New("no file names provided to rename flow")
+	}
+	if len(in.FileNames) > 200 {
+		return fmt.Errorf("rename flow supports up to 200 files per invocation (received %d)", len(in.FileNames))
+	}
+	normalized := make([]string, len(in.FileNames))
+	for i, name := range in.FileNames {
+		trimmed := strings.TrimSpace(name)
+		if trimmed == "" {
+			return fmt.Errorf("file name at index %d is empty", i)
+		}
+		normalized[i] = toSlash(trimmed)
+	}
+	// Ensure no duplicates to simplify downstream validation.
+ if dup := firstDuplicate(normalized); dup != "" {
+  return fmt.Errorf("duplicate file name %q detected in flow input", dup)
+ }
+ in.FileNames = normalized
+
+ sep := strings.TrimSpace(in.SequenceSeparator)
+ if sep == "" {
+  sep = "."
+ }
+ if strings.ContainsAny(sep, "/\\") {
+  return fmt.Errorf("sequence separator %q cannot contain path separators", sep)
+ }
+ if strings.ContainsAny(sep, "\n\r") {
+  return errors.New("sequence separator cannot contain newline characters")
+ }
+ in.SequenceSeparator = sep
+ return nil
+}
+
+// RenderPrompt materialises the prompt template for the provided input.
+func RenderPrompt(input RenameFlowInput) (string, error) {
+	if err := input.Validate(); err != nil {
+		return "", err
+	}
+
+	var builder strings.Builder
+	if err := promptTemplate.Execute(&builder, input); err != nil {
+		return "", fmt.Errorf("render rename prompt: %w", err)
+	}
+	return builder.String(), nil
+}
+
+// Define registers the rename flow on the supplied Genkit instance.
+func Define(g *genkit.Genkit) *core.Flow[*RenameFlowInput, *Output, struct{}] {
+	if g == nil {
+		panic("genkit instance cannot be nil")
+	}
+	return genkit.DefineFlow(g, "renameFlow", flowFn)
+}
+
+func flowFn(ctx context.Context, input *RenameFlowInput) (*Output, error) {
+ if err := input.Validate(); err != nil {
+  return nil, err
+ }
+
+ prefix := slugify(input.UserPrompt)
+ suggestions := make([]Suggestion, 0, len(input.FileNames))
+ dirCounters := make(map[string]int)
+
+ for _, name := range input.FileNames {
+  suggestion := deterministicSuggestion(name, prefix, dirCounters, input.SequenceSeparator)
+  suggestions = append(suggestions, Suggestion{
+   Original:  name,
+   Suggested: suggestion,
+  })
+ }
+
+	sort.SliceStable(suggestions, func(i, j int) bool {
+		return suggestions[i].Original < suggestions[j].Original
+	})
+
+	return &Output{Suggestions: suggestions}, nil
+}
+
+func deterministicSuggestion(rel string, promptPrefix string, dirCounters map[string]int, separator string) string {
+ rel = toSlash(rel)
+ dir := path.Dir(rel)
+ if dir == "." {
+  dir = ""
+ }
+
+	base := path.Base(rel)
+	ext := path.Ext(base)
+	name := strings.TrimSuffix(base, ext)
+
+	sanitizedName := slugify(name)
+
+ candidate := sanitizedName
+ if promptPrefix != "" {
+  switch {
+  case candidate == "":
+   candidate = promptPrefix
+  default:
+			candidate = fmt.Sprintf("%s-%s", promptPrefix, candidate)
+		}
+	}
+
+	if candidate == "" {
+		candidate = "renamed"
+	}
+
+	counterKey := dir
+ dirCounters[counterKey]++
+ seq := dirCounters[counterKey]
+
+ sep := separator
+ if sep == "" {
+  sep = "."
+ }
+ numbered := fmt.Sprintf("%02d%s%s", seq, sep, candidate)
+ proposed := numbered + ext
+ if dir != "" {
+  return path.Join(dir, proposed)
+ }
+	return proposed
+}
+
+func slugify(value string) string {
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return ""
+	}
+	var b strings.Builder
+	b.Grow(len(value))
+	lastHyphen := false
+	for _, r := range value {
+		switch {
+		case unicode.IsLetter(r) || unicode.IsDigit(r):
+			b.WriteRune(unicode.ToLower(r))
+			lastHyphen = false
+		case r == ' ' || r == '-' || r == '_' || r == '.':
+			if !lastHyphen && b.Len() > 0 {
+				b.WriteRune('-')
+				lastHyphen = true
+			}
+		}
+	}
+	result := strings.Trim(b.String(), "-")
+	return result
+}
+
+func toSlash(pathStr string) string {
+	return strings.ReplaceAll(pathStr, "\\", "/")
+}
+
+func firstDuplicate(values []string) string {
+	seen := make(map[string]struct{}, len(values))
+	for _, v := range values {
+		lower := strings.ToLower(v)
+		if _, exists := seen[lower]; exists {
+			return v
+		}
+		seen[lower] = struct{}{}
+	}
+	return ""
+}