package service

import (
	"log/slog"

	"codespace/internal/acp"
	"codespace/internal/model"
	"codespace/internal/process"
	"codespace/internal/workspace"
)

// AcpService wraps the low-level acp.Service with logging and model mapping.
type AcpService struct {
	svc acp.Service
	lg  *slog.Logger
}

// NewAcpService creates an AcpService.
// If lg is nil, slog.Default() is used.
func NewAcpService(processes process.Manager, workspaces workspace.Manager, lg *slog.Logger) *AcpService {
	if lg == nil {
		lg = slog.Default()
	}
	return &AcpService{svc: acp.NewService(processes, workspaces, lg), lg: lg}
}

// Status returns the ACP status for the workspace.
func (s *AcpService) Status(workspaceID string) (model.AcpStatusResponse, error) {
	status, err := s.svc.Status(workspaceID)
	if err != nil {
		s.lg.Error("acp status failed", "workspace_id", workspaceID, "error", err)
		return model.AcpStatusResponse{}, err
	}
	return model.AcpStatusResponse{
		WorkspaceID: status.WorkspaceID,
		Ready:       status.Ready,
		SessionID:   status.SessionID,
		Running:     status.Running,
		PID:         status.PID,
		Error:       status.Error,
	}, nil
}

// History returns the ACP conversation history for the workspace.
func (s *AcpService) History(workspaceID string) (model.AcpHistoryResponse, error) {
	hist, err := s.svc.History(workspaceID)
	if err != nil {
		s.lg.Error("acp history failed", "workspace_id", workspaceID, "error", err)
		return model.AcpHistoryResponse{}, err
	}
	messages := make([]model.AcpMessage, len(hist.Messages))
	for i, m := range hist.Messages {
		messages[i] = model.AcpMessage{Role: m.Role, Text: m.Text, Time: m.Time, MessageID: m.MessageID}
	}
	return model.AcpHistoryResponse{SessionID: hist.SessionID, Messages: messages}, nil
}

// Prompt sends a prompt to the agent and returns its response.
func (s *AcpService) Prompt(workspaceID string, content string) (model.AcpPromptResponse, error) {
	res, err := s.svc.Prompt(workspaceID, content)
	if err != nil {
		s.lg.Error("acp prompt failed", "workspace_id", workspaceID, "error", err)
		return model.AcpPromptResponse{}, err
	}
	return model.AcpPromptResponse{
		SessionID:  res.SessionID,
		StopReason: res.StopReason,
		Text:       res.Text,
	}, nil
}

// Cancel interrupts an in-flight prompt.
func (s *AcpService) Cancel(workspaceID string) error {
	if err := s.svc.Cancel(workspaceID); err != nil {
		s.lg.Error("acp cancel failed", "workspace_id", workspaceID, "error", err)
		return err
	}
	return nil
}

// Stream sends a prompt to the agent and forwards streamed events to out.
func (s *AcpService) Stream(workspaceID string, content string, out chan<- model.AcpStreamEvent) error {
	acpOut := make(chan acp.StreamEvent, 32)

	var streamErr error
	done := make(chan struct{})
	go func() {
		defer close(done)
		streamErr = s.svc.Stream(workspaceID, content, acpOut)
		close(acpOut)
	}()

	for ev := range acpOut {
		out <- model.AcpStreamEvent{
			Type:       ev.Type,
			MessageID:  ev.MessageID,
			Text:       ev.Text,
			StopReason: ev.StopReason,
			Error:      ev.Error,
		}
	}
	<-done

	if streamErr != nil {
		s.lg.Error("acp stream failed", "workspace_id", workspaceID, "error", streamErr)
	}
	return streamErr
}

// EnsureReady ensures the ACP process is started and initialized.
func (s *AcpService) EnsureReady(workspaceID string) error {
	if err := s.svc.EnsureReady(workspaceID); err != nil {
		s.lg.Error("acp ensure ready failed", "workspace_id", workspaceID, "error", err)
		return err
	}
	return nil
}