package agent

import (
	"context"
	"fmt"

	rvboxv1 "github.com/rvbox/rvbox/gen/go/rvbox/v1"
	"github.com/rvbox/rvbox/internal/agentproto"
	"google.golang.org/protobuf/proto"
)

// SendCommandEvent writes a previously durable, sequence-assigned event. It
// derives the immutable digest at the final wire boundary so retrying the same
// event produces byte-equivalent protocol evidence.
func SendCommandEvent(ctx context.Context, transport Transport, session Session, event *rvboxv1.CommandEvent, limits agentproto.Limits) error {
	if transport == nil || event == nil || session.ID == "" || session.Generation == 0 {
		return ErrProtocolHandshake
	}
	copyEvent := proto.Clone(event).(*rvboxv1.CommandEvent)
	digest, err := agentproto.CommandEventDigest(copyEvent)
	if err != nil {
		return err
	}
	copyEvent.ImmutableEventSha256 = digest[:]
	envelope := &rvboxv1.AgentEnvelope{SessionId: session.ID, SessionGeneration: session.Generation, Payload: &rvboxv1.AgentEnvelope_CommandEvent{CommandEvent: copyEvent}}
	if err := agentproto.ValidateEnvelope(envelope, limits, rvboxv1.Platform_PLATFORM_WINDOWS); err != nil {
		return fmt.Errorf("validate command event: %w", err)
	}
	encoded, err := proto.Marshal(envelope)
	if err != nil {
		return err
	}
	return transport.Write(ctx, encoded)
}