1 files changed, 119 insertions, 0 deletions
diff --git a/internal/askcli/task_selector.go b/internal/askcli/task_selector.go
new file mode 100644
index 0000000..7702153
--- /dev/null
+++ b/internal/askcli/task_selector.go
@@ -0,0 +1,119 @@
+package askcli
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"strings"
+)
+
+type resolvedTaskSelector struct {
+	Input     string
+	UUID      string
+	Alias     string
+	UsedAlias bool
+}
+
+func (d Dispatcher) resolveTaskSelector(ctx context.Context, selector string, stderr io.Writer) (resolvedTaskSelector, []TaskExport, int, error) {
+	normalized, requiresLookup, err := normalizeTaskSelectorInput(selector)
+	if err != nil {
+		return resolvedTaskSelector{}, nil, 1, err
+	}
+
+	resolved, err := resolveTaskSelectorFromCache(normalized, requiresLookup)
+	if err != nil {
+		return resolvedTaskSelector{}, nil, 1, err
+	}
+
+	tasks, code, err := d.exportTasks(ctx, []string{"uuid:" + resolved.UUID, "export"}, stderr)
+	if err != nil {
+		if resolved.UsedAlias && strings.Contains(err.Error(), "task not found") {
+			return resolvedTaskSelector{}, nil, 1, fmt.Errorf("alias %q is stale: task %s was not found", selector, resolved.UUID)
+		}
+		return resolvedTaskSelector{}, nil, code, err
+	}
+
+	aliases, err := ensureTaskAliases(tasks)
+	if err != nil {
+		return resolvedTaskSelector{}, nil, 1, err
+	}
+	if alias, ok := aliases[resolved.UUID]; ok {
+		resolved.Alias = alias
+	}
+	return resolved, tasks, 0, nil
+}
+
+func normalizeTaskSelectorInput(selector string) (string, bool, error) {
+	normalized := NormalizeUUID(selector)
+	if selector != normalized && IsNumericID(normalized) {
+		return "", false, fmt.Errorf(strings.TrimSpace(RejectNumericID()))
+	}
+	return normalized, selector == normalized, nil
+}
+
+func resolveTaskSelectorFromCache(selector string, allowAlias bool) (resolvedTaskSelector, error) {
+	resolved := resolvedTaskSelector{Input: selector, UUID: selector}
+	if !allowAlias || !looksLikeTaskAlias(selector) {
+		return resolved, nil
+	}
+
+	cache, path, err := loadTaskAliasCache()
+	if err != nil {
+		return resolvedTaskSelector{}, err
+	}
+
+	now := nowTaskAliasCache().UTC()
+	changed := cache.prune(now)
+	uuidFromAlias, aliasFound, aliasChanged := cache.lookupUUIDByAlias(selector, now)
+	changed = changed || aliasChanged
+	aliasForUUID, uuidFound, uuidChanged := cache.lookupAliasByUUID(selector, now)
+	changed = changed || uuidChanged
+
+	switch {
+	case aliasFound && uuidFound && uuidFromAlias != selector:
+		if changed {
+			if err := cache.save(path); err != nil {
+				return resolvedTaskSelector{}, err
+			}
+		}
+		return resolvedTaskSelector{}, fmt.Errorf("task selector %q is ambiguous: it matches alias for %s and UUID %s; use uuid:%s to force UUID", selector, uuidFromAlias, selector, selector)
+	case aliasFound:
+		if changed {
+			if err := cache.save(path); err != nil {
+				return resolvedTaskSelector{}, err
+			}
+		}
+		return resolvedTaskSelector{
+			Input:     selector,
+			UUID:      uuidFromAlias,
+			Alias:     selector,
+			UsedAlias: true,
+		}, nil
+	case uuidFound:
+		if changed {
+			if err := cache.save(path); err != nil {
+				return resolvedTaskSelector{}, err
+			}
+		}
+		return resolvedTaskSelector{
+			Input: selector,
+			UUID:  selector,
+			Alias: aliasForUUID,
+		}, nil
+	default:
+		if IsNumericID(selector) {
+			return resolvedTaskSelector{}, fmt.Errorf(strings.TrimSpace(RejectNumericID()))
+		}
+		if changed {
+			if err := cache.save(path); err != nil {
+				return resolvedTaskSelector{}, err
+			}
+		}
+		return resolvedTaskSelector{}, fmt.Errorf("task selector %q did not match a known alias; use uuid:%s to force UUID", selector, selector)
+	}
+}
+
+func looksLikeTaskAlias(selector string) bool {
+	_, ok := decodeTaskAliasID(selector)
+	return ok && !strings.Contains(selector, "-")
+}