package agents

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"

	"g.fc.run/ai/byre/internal/mcp"
	"g.fc.run/ai/byre/internal/store"
)

const messageLeadGuidance = "\n- To contact the human's lead agent, use message_lead with a self-contained message (for example, a task brief the human asked you to pass along). You don't need to find a session or ask the human to paste it. Your final messages also reach the lead automatically."

func (m *Manager) messageLeadTool(l *live) mcp.Tool {
	return mcp.Tool{
		Name:        "message_lead",
		Description: "Send a message to this task creator's lead agent. Use it to pass along a task brief, request coordination, or share information the lead needs before your turn ends. Include all the context the lead needs; it cannot see your conversation. Your final messages already reach the lead automatically.",
		InputSchema: json.RawMessage(`{"type":"object","properties":{"text":{"type":"string","description":"A self-contained message for the lead."}},"required":["text"]}`),
		Handler: mcp.Typed(func(ctx context.Context, args struct {
			Text string `json:"text"`
		}) (string, error) {
			text := strings.TrimSpace(args.Text)
			if text == "" {
				return "", fmt.Errorf("%w: text must not be empty", ErrInvalid)
			}
			task, err := m.store.GetTask(ctx, l.taskID)
			if err != nil {
				return "", err
			}
			_, found, err := m.activeLead(ctx, task.CreatedBy)
			if err != nil {
				return "", err
			}
			if !found {
				return "", fmt.Errorf("%w: %s has no lead agent to receive the message", ErrConflict, task.CreatedBy)
			}
			signal := fmt.Sprintf("Message from the agent working on %s (project %s):\n\n%s", m.taskLabel(ctx, task.Id), task.ProjectId, text)
			err = m.addLeadInput(ctx, store.LeadInput{Owner: task.CreatedBy, Kind: store.LeadSignal, Actor: "byre", Text: signal})
			if err != nil {
				return "", err
			}
			return "Message sent to the lead.", nil
		}),
	}
}