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

internal/workflow/file.go

@@ -0,0 +1,107 @@
+package workflow
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"slices"
+	"strings"
+
+	"go.yaml.in/yaml/v3"
+
+	"g.fc.run/misc/byre/internal/api"
+)
+
+var keyOrder = []string{"description", "stages", "name", "vendor", "model", "prompt"}
+
+func Parse(data []byte) (api.WorkflowDefinition, error) {
+	raw := any(nil)
+	err := yaml.Unmarshal(data, &raw)
+	if err != nil {
+		return api.WorkflowDefinition{}, fmt.Errorf("%w: %v", ErrInvalid, err)
+	}
+	j, err := json.Marshal(raw)
+	if err != nil {
+		return api.WorkflowDefinition{}, fmt.Errorf("%w: %v", ErrInvalid, err)
+	}
+
+	def := api.WorkflowDefinition{}
+	dec := json.NewDecoder(bytes.NewReader(j))
+	dec.DisallowUnknownFields()
+	err = dec.Decode(&def)
+	if err != nil {
+		return api.WorkflowDefinition{}, fmt.Errorf("%w: %v", ErrInvalid, err)
+	}
+	return def, Validate(def)
+}
+
+func Format(def api.WorkflowDefinition) ([]byte, error) {
+	j, err := json.Marshal(def)
+	if err != nil {
+		return nil, err
+	}
+	doc := yaml.Node{}
+	err = yaml.Unmarshal(j, &doc)
+	if err != nil {
+		return nil, err
+	}
+	restyle(&doc)
+
+	out := &bytes.Buffer{}
+	enc := yaml.NewEncoder(out)
+	enc.SetIndent(2)
+	err = enc.Encode(&doc)
+	if err != nil {
+		return nil, err
+	}
+	err = enc.Close()
+	if err != nil {
+		return nil, err
+	}
+	return out.Bytes(), nil
+}
+
+func Filename(name string) string {
+	return strings.Map(func(r rune) rune {
+		if strings.ContainsRune(`/\:*?"<>|`, r) {
+			return '_'
+		}
+		return r
+	}, name) + ".yaml"
+}
+
+func restyle(n *yaml.Node) {
+	switch n.Kind {
+	case yaml.ScalarNode:
+		n.Style = 0
+		if n.Tag == "!!str" && strings.Contains(n.Value, "\n") {
+			n.Style = yaml.LiteralStyle
+		}
+	case yaml.MappingNode:
+		n.Style = 0
+		pairs := [][2]*yaml.Node{}
+		for i := 0; i+1 < len(n.Content); i += 2 {
+			pairs = append(pairs, [2]*yaml.Node{n.Content[i], n.Content[i+1]})
+		}
+		slices.SortStableFunc(pairs, func(a, b [2]*yaml.Node) int {
+			return keyRank(a[0].Value) - keyRank(b[0].Value)
+		})
+		n.Content = n.Content[:0]
+		for _, p := range pairs {
+			n.Content = append(n.Content, p[0], p[1])
+		}
+	case yaml.SequenceNode:
+		n.Style = 0
+	}
+	for _, c := range n.Content {
+		restyle(c)
+	}
+}
+
+func keyRank(key string) int {
+	i := slices.Index(keyOrder, key)
+	if i < 0 {
+		return len(keyOrder)
+	}
+	return i
+}

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
+}