X-Git-Url: https://git.giacomolli.uk/onechat/blobdiff_plain/4a605fa39078354654ae648e489c117c7a445197..b1be0ee8530df5db8973bfe355f2f6d3149383a0:/agent.go?ds=inline

diff --git a/agent.go b/agent.go
index 1b4873a..b86880e 100644
--- a/agent.go
+++ b/agent.go
@@ -10,38 +10,21 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
+
+	"golang.org/x/sys/unix"
 )
 
 const (
-	// instructionsFileName is the file of the user's instructions in the
-	// directory of an agent.
-	instructionsFileName = "instructions.md"
+	// agentInstructionsFileName is the file of the user's instructions in
+	// the directory of an agent.
+	agentInstructionsFileName = "instructions.md"
 
 	// agentIDBytes is the number of random bytes of an agent ID.
 	agentIDBytes = 16
 )
 
-// AgentConfig holds the settings of the config.json of an agent. ID is random,
-// made once when the file is made, and never changes. The cache key comes from
-// the ID, so a rename keeps the prompt cache and two agents with one name do
-// not share a key. Workdir is the directory where the commands of the agent
-// run.
-type AgentConfig struct {
-	Name    string `json:"name"`
-	ID      string `json:"id"`
-	Model   string `json:"model"`
-	Effort  string `json:"effort"`
-	Workdir string `json:"workdir"`
-}
-
-// Agent is one agent and its directory. The directory holds config.json, the
-// user's instructions in instructions.md, the chat, and the usage file.
-type Agent struct {
-	dir    string
-	config AgentConfig
-}
-
 // openAgent reads the config.json of the agent in dir. When the file does not
 // exist, it makes the directory and writes the file with the defaults and a new
 // ID. A missing field of an existing file takes the default, but the ID must be
@@ -70,6 +53,7 @@ func openAgent(dir string) (*Agent, error) {
 
 	decoder := json.NewDecoder(bytes.NewReader(data))
 	decoder.DisallowUnknownFields()
+
 	err = decoder.Decode(&config)
 	if err == nil && !errors.Is(decoder.Decode(&struct{}{}), io.EOF) {
 		err = errors.New("data after the JSON object")
@@ -89,51 +73,231 @@ func openAgent(dir string) (*Agent, error) {
 	}, nil
 }
 
-// createAgent writes the config.json of a new agent in dir with the defaults
-// and a new ID.
-func createAgent(dir string) (*Agent, error) {
-	config, err := defaultAgentConfig()
+// Agent is one agent and its directory. The directory holds config.json, the
+// user's instructions in instructions.md, the chat, and the usage file.
+type Agent struct {
+	dir    string
+	config AgentConfig
+}
+
+// Images returns the shared data-directory image store, also for a child.
+func (a *Agent) Images() *ImageStore {
+	root := a.dir
+	if a.config.Parent != "" {
+		root = filepath.Dir(filepath.Dir(root))
+	}
+
+	return &ImageStore{dir: filepath.Join(filepath.Dir(root), imageDirName)}
+}
+
+// CacheKey returns the prompt cache key of every model call of the agent.
+func (a *Agent) CacheKey() string {
+	return "onechat-" + a.config.ID
+}
+
+// Prompt returns the system prompt of the agent with the user's instructions
+// from instructions.md. It reads the file on each call, so a change applies at
+// the next call. A missing file means no instructions.
+func (a *Agent) Prompt() (string, error) {
+	instructions, err := a.instructions()
 	if err != nil {
-		return nil, err
+		return "", fmt.Errorf("read prompt instructions: %w", err)
 	}
 
-	id := make([]byte, agentIDBytes)
-	_, err = rand.Read(id)
+	path, err := filepath.Abs(filepath.Join(a.dir, agentInstructionsFileName))
 	if err != nil {
-		return nil, fmt.Errorf("make agent ID: %w", err)
+		return "", fmt.Errorf("find instructions path: %w", err)
+	}
+
+	if a.config.Parent != "" {
+		return promptChild(a.config.Name, a.config.Parent, a.config.Responsibility, path, instructions), nil
+	}
+
+	return prompt(a.config.Name, path, instructions), nil
+}
+
+// Tools returns the tools shared by the turns and compactions of this agent. A
+// child has no image output, WhatsApp, child creation, or route tools.
+func (a *Agent) Tools() []ModelTool {
+	tools := promptTools()
+	if a.config.Parent != "" {
+		tools = slices.DeleteFunc(tools, func(tool ModelTool) bool {
+			return strings.HasPrefix(tool.Name, "whatsapp_") || tool.Name == "image_show" || tool.Name == "agent_create" || tool.Name == "route" || tool.Name == "unroute" || tool.Name == "routes"
+		})
+	}
+
+	return tools
+}
+
+// Children reads the direct children in directory order. Each child needs an
+// existing config with its directory name and this agent as parent. Children
+// cannot have children. A missing children directory means no children.
+func (a *Agent) Children() ([]*Agent, error) {
+	dir := filepath.Join(a.dir, "children")
+	entries, err := os.ReadDir(dir)
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, nil
 	}
 
-	config.ID = hex.EncodeToString(id)
-	data, err := json.MarshalIndent(config, "", "  ")
 	if err != nil {
-		return nil, fmt.Errorf("encode agent config: %w", err)
+		return nil, fmt.Errorf("read children: %w", err)
 	}
 
-	err = writeFileAtomic(filepath.Join(dir, "config.json"), append(data, '\n'))
+	if a.config.Parent != "" && len(entries) != 0 {
+		return nil, errors.New("children cannot have children")
+	}
+
+	var children []*Agent
+
+	keys := map[string]bool{a.CacheKey(): true}
+
+	for _, entry := range entries {
+		name := entry.Name()
+		if !entry.IsDir() {
+			return nil, fmt.Errorf("child %q must be a directory", name)
+		}
+
+		path := filepath.Join(dir, name)
+		_, err = os.Stat(filepath.Join(path, "config.json"))
+		if err != nil {
+			return nil, fmt.Errorf("child %q config: %w", name, err)
+		}
+
+		child, err := openAgent(path)
+		if err != nil {
+			return nil, fmt.Errorf("open child %q: %w", name, err)
+		}
+
+		if child.config.Name != name || child.config.Parent != a.config.Name {
+			return nil, fmt.Errorf("child %q needs name %q and parent %q", name, name, a.config.Name)
+		}
+
+		if child.config.Name == a.config.Name || keys[child.CacheKey()] {
+			return nil, fmt.Errorf("child %q must have its own name and ID", name)
+		}
+
+		keys[child.CacheKey()] = true
+		_, err = child.Children()
+		if err != nil {
+			return nil, fmt.Errorf("read child %q: %w", name, err)
+		}
+
+		children = append(children, child)
+	}
+
+	return children, nil
+}
+
+// CreateChild writes a new direct child with its own ID and the model, effort,
+// and working directory of the root. Child and subagent names share a
+// namespace. The config is complete before an atomic rename publishes the
+// child. Preparation stays outside children, so an interrupted write cannot
+// stop startup.
+func (a *Agent) CreateChild(name, responsibility string, subagents *Subagents) (_ *Agent, err error) {
+	if a.config.Parent != "" {
+		return nil, errors.New("only the root can create children")
+	}
+
+	if !agentChildNameValid(name) {
+		return nil, errors.New("name must have 2 to 32 ASCII letters and start with a capital letter")
+	}
+
+	if name == a.config.Name {
+		return nil, errors.New("the name is already used by the root")
+	}
+
+	responsibility = strings.TrimSpace(responsibility)
+	if responsibility == "" {
+		return nil, errors.New("responsibility must not be empty")
+	}
+
+	err = subagents.Reserve(name)
 	if err != nil {
-		return nil, fmt.Errorf("write agent config: %w", err)
+		return nil, fmt.Errorf("reserve child name: %w", err)
 	}
 
-	return &Agent{
-		dir:    dir,
-		config: config,
-	}, nil
+	published := false
+	defer func() {
+		if !published {
+			subagents.Release(name)
+		}
+	}()
+
+	staged, err := os.MkdirTemp(a.dir, ".child-*")
+	if err != nil {
+		return nil, fmt.Errorf("prepare child directory: %w", err)
+	}
+
+	defer func() {
+		cleanupErr := os.RemoveAll(staged)
+		if cleanupErr != nil {
+			err = errors.Join(err, fmt.Errorf("remove prepared child: %w", cleanupErr))
+		}
+	}()
+
+	config := a.config
+	config.Name = name
+	config.ID = ""
+	config.Parent = a.config.Name
+	config.Responsibility = responsibility
+	child, err := writeAgent(staged, config)
+	if err != nil {
+		return nil, fmt.Errorf("write child: %w", err)
+	}
+
+	dir := filepath.Join(a.dir, "children")
+	err = os.MkdirAll(dir, 0o700)
+	if err != nil {
+		return nil, fmt.Errorf("create children directory: %w", err)
+	}
+
+	dir = filepath.Join(dir, name)
+	err = unix.Renameat2(unix.AT_FDCWD, staged, unix.AT_FDCWD, dir, unix.RENAME_NOREPLACE)
+	if err != nil {
+		return nil, fmt.Errorf("publish child directory: %w", err)
+	}
+
+	published = true
+	child.dir = dir
+
+	return child, nil
 }
 
-// defaultAgentConfig returns the settings of a new agent, without an ID. The
-// commands run in the home directory of the user.
-func defaultAgentConfig() (AgentConfig, error) {
-	home, err := os.UserHomeDir()
+// SubagentPrompt returns the system prompt of a subagent of the agent, with the
+// user's instructions as Prompt reads them.
+func (a *Agent) SubagentPrompt() (string, error) {
+	instructions, err := a.instructions()
 	if err != nil {
-		return AgentConfig{}, fmt.Errorf("find working directory: %w", err)
+		return "", err
 	}
 
-	return AgentConfig{
-		Name:    "OneChat",
-		Model:   "gpt-6.1-sol",
-		Effort:  "medium",
-		Workdir: home,
-	}, nil
+	return promptSubagent(a.config.Name, instructions), nil
+}
+
+// instructions reads the user's instructions from instructions.md. A missing
+// file means no instructions.
+func (a *Agent) instructions() (string, error) {
+	data, err := os.ReadFile(filepath.Join(a.dir, agentInstructionsFileName))
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return "", fmt.Errorf("read instructions: %w", err)
+	}
+
+	return string(data), nil
+}
+
+// AgentConfig holds the settings of the config.json of an agent. ID is random,
+// made once when the file is made, and never changes. The cache key comes from
+// the ID, so a rename keeps the prompt cache and two agents with one name do
+// not share a key. Workdir is the directory where the commands of the agent
+// run. Responsibility and Parent are set together for a child agent.
+type AgentConfig struct {
+	Name           string `json:"name"`
+	ID             string `json:"id"`
+	Model          string `json:"model"`
+	Effort         string `json:"effort"`
+	Workdir        string `json:"workdir"`
+	Responsibility string `json:"responsibility,omitempty"`
+	Parent         string `json:"parent,omitempty"`
 }
 
 // validate makes sure that each setting has a valid value.
@@ -151,6 +315,14 @@ func (c AgentConfig) validate() error {
 		return errors.New("agent needs a model and an effort")
 	}
 
+	if (strings.TrimSpace(c.Responsibility) == "") != (c.Parent == "") {
+		return errors.New("a child needs both responsibility and parent")
+	}
+
+	if strings.ContainsAny(c.Parent, "\r\n") {
+		return errors.New("parent must be one line of text")
+	}
+
 	if !filepath.IsAbs(c.Workdir) {
 		return fmt.Errorf("workdir %q is not an absolute path", c.Workdir)
 	}
@@ -158,19 +330,71 @@ func (c AgentConfig) validate() error {
 	return nil
 }
 
-// CacheKey returns the prompt cache key of every model call of the agent.
-func (a *Agent) CacheKey() string {
-	return "onechat-" + a.config.ID
+// agentChildNameValid accepts one word of 2 to 32 ASCII letters with an initial
+// capital letter. Child names describe their area.
+func agentChildNameValid(name string) bool {
+	if len(name) < 2 || len(name) > 32 || name[0] < 'A' || name[0] > 'Z' {
+		return false
+	}
+
+	for i := 1; i < len(name); i++ {
+		letter := name[i]
+		if (letter < 'A' || letter > 'Z') && (letter < 'a' || letter > 'z') {
+			return false
+		}
+	}
+
+	return true
 }
 
-// Prompt returns the system prompt of the agent with the user's instructions
-// from instructions.md. It reads the file on each call, so a change applies at
-// the next call. A missing file means no instructions.
-func (a *Agent) Prompt() (string, error) {
-	data, err := os.ReadFile(filepath.Join(a.dir, instructionsFileName))
-	if err != nil && !errors.Is(err, os.ErrNotExist) {
-		return "", fmt.Errorf("read instructions: %w", err)
+// createAgent writes the config.json of a new agent in dir with the defaults
+// and a new ID.
+func createAgent(dir string) (*Agent, error) {
+	config, err := defaultAgentConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	return writeAgent(dir, config)
+}
+
+// writeAgent gives config a new ID and writes it in dir.
+func writeAgent(dir string, config AgentConfig) (*Agent, error) {
+	id := make([]byte, agentIDBytes)
+	_, err := rand.Read(id)
+	if err != nil {
+		return nil, fmt.Errorf("make agent ID: %w", err)
+	}
+
+	config.ID = hex.EncodeToString(id)
+	data, err := json.MarshalIndent(config, "", "  ")
+	if err != nil {
+		return nil, fmt.Errorf("encode agent config: %w", err)
+	}
+
+	err = writeFileAtomic(filepath.Join(dir, "config.json"), append(data, '\n'))
+	if err != nil {
+		return nil, fmt.Errorf("write agent config: %w", err)
 	}
 
-	return prompt(a.config.Name, string(data)), nil
+	return &Agent{
+		dir:    dir,
+		config: config,
+	}, nil
+}
+
+// defaultAgentConfig returns the settings of a new agent, without an ID. The
+// commands run in the home directory of the user.
+func defaultAgentConfig() (AgentConfig, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return AgentConfig{}, fmt.Errorf("find working directory: %w", err)
+	}
+
+	return AgentConfig{
+		Name:    "OneChat",
+		Model:   "gpt-6.1-sol",
+		Effort:  "medium",
+		Workdir: home,
+	}, nil
 }