loop

type Callbacks struct {
	OnToken    func(token string)
	OnThinking func(token string)
	OnToolUse  func(name string, args map[string]any)
	OnTrim     func(dropped []Message) // Called when context trimming drops messages.
	OnDone     func(durationMs int64)
}

type ContextStrategy interface {
	// Trim returns the messages to send to the LLM.
	// The input slice must not be modified.
	Trim(messages []Message) []Message
}

type ContextStrategyFunc func(messages []Message) []Message

type DoneEvent struct {
	Content    string
	Thinking   string
	DurationMs int64
}

type Event struct {
	// Exactly one of these is set per event.
	Token    string        // incremental content token
	Thinking string        // incremental thinking token
	ToolUse  *ToolUseEvent // a tool was invoked
	Trim     *TrimEvent    // context was trimmed
	Done     *DoneEvent    // the loop completed
	Err      error         // the loop failed
}

type LLMClient interface {
	Chat(ctx context.Context, req *Request, fn func(Response) error) error
}

type Message struct {
	Role       Role
	Content    string
	Thinking   string
	ToolCalls  []ToolCall
	ToolCallID string // Correlates a tool result with its originating ToolCall.
}

type Request struct {
	Model         string
	Messages      []Message
	Tools         []tool.ToolDef
	Stream        bool
	Think         *bool
	Options       map[string]any
	MaxIterations int // Maximum tool-call loop iterations. Defaults to 20 if 0.
	MaxTokens     int // Maximum estimated token budget for messages. 0 means no limit.
}

type Response struct {
	Content   string
	Thinking  string
	Done      bool
	ToolCalls []ToolCall
}

type Result struct {
	Content  string
	Thinking string
}

type Role string

type RunConfig struct {
	Client  LLMClient
	Request *Request
	Tools   map[string]tool.ToolDef
	ToolCtx *tool.ToolContext
	Context ContextStrategy // Optional; trims messages before each LLM call.
	Callbacks
}

type ToolCall struct {
	ID        string // Provider-assigned correlation ID (e.g. OpenAI tool_call_id).
	Name      string
	Arguments map[string]any
}

type ToolUseEvent struct {
	Name string
	Args map[string]any
}

type TrimEvent struct {
	Dropped []Message
}