Add server-side workflows with YAML files, task freeze and lead tools

internal/workflow/workflow.go

@@ -0,0 +1,83 @@
+package workflow
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"g.fc.run/misc/byre/internal/api"
+)
+
+var ErrInvalid = errors.New("invalid workflow")
+
+const maxNameRunes = 100
+
+func VendorOf(model string) api.AgentSessionVendor {
+	if strings.HasPrefix(model, "gpt-") {
+		return api.Codex
+	}
+	return api.Claude
+}
+
+func CleanName(name string) (string, error) {
+	name = strings.TrimSpace(name)
+	problem := nameProblem(name)
+	if problem != "" {
+		return "", fmt.Errorf("%w: workflow name %s", ErrInvalid, problem)
+	}
+	return name, nil
+}
+
+func nameProblem(name string) string {
+	switch {
+	case strings.TrimSpace(name) == "":
+		return "is empty"
+	case strings.TrimSpace(name) != name:
+		return fmt.Sprintf("%q has leading or trailing spaces", name)
+	case utf8.RuneCountInString(name) > maxNameRunes:
+		return fmt.Sprintf("%q is longer than %d characters", name, maxNameRunes)
+	case strings.ContainsFunc(name, unicode.IsControl):
+		return fmt.Sprintf("%q isn't a single line", name)
+	}
+	return ""
+}
+
+func Validate(def api.WorkflowDefinition) error {
+	problems := []string{}
+	if len(def.Stages) == 0 {
+		problems = append(problems, "it has no stages")
+	}
+
+	seen := map[string]bool{}
+	for i, s := range def.Stages {
+		where := fmt.Sprintf("stage %d (%q)", i+1, s.Name)
+		p := nameProblem(s.Name)
+		if p != "" {
+			problems = append(problems, fmt.Sprintf("%s: name %s", where, p))
+		}
+		if seen[s.Name] {
+			problems = append(problems, fmt.Sprintf("%s: another stage has the same name", where))
+		}
+		seen[s.Name] = true
+
+		switch {
+		case !s.Vendor.Valid():
+			problems = append(problems, fmt.Sprintf("%s: vendor must be claude or codex, not %q", where, s.Vendor))
+		case strings.TrimSpace(s.Model) == "":
+			problems = append(problems, fmt.Sprintf("%s: model is required", where))
+		case string(VendorOf(s.Model)) != string(s.Vendor):
+			problems = append(problems, fmt.Sprintf("%s: %s is a %s model, not %s", where, s.Model, VendorOf(s.Model), s.Vendor))
+		}
+
+		if strings.TrimSpace(s.Prompt) == "" {
+			problems = append(problems, fmt.Sprintf("%s: prompt is empty", where))
+		}
+	}
+
+	if len(problems) > 0 {
+		return fmt.Errorf("%w: %s", ErrInvalid, strings.Join(problems, "; "))
+	}
+	return nil
+}