package pubsub

import (
	"context"
	"fmt"
)

// GossipPublisher is a thin wrapper around the CHORUS PubSub system that
// satisfies the hmmm.PubSubAdapter interface. It ensures that HMMM messages
// are published as raw JSON payloads to dynamic, per-issue topics.
type GossipPublisher struct {
	ps *PubSub
}

// NewGossipPublisher creates a new HMMM adapter for the CHORUS pubsub system.
func NewGossipPublisher(ps *PubSub) *GossipPublisher {
	return &GossipPublisher{ps: ps}
}

// Publish ensures the agent is subscribed to the per-issue topic and then
// publishes the raw payload. This method is the primary bridge between HMMM's
// routing logic and CHORUS's underlying gossipsub network.
//
// It performs two key actions:
// 1. Joins the dynamic topic (e.g., "CHORUS/meta/issue/42") to ensure message delivery.
// 2. Publishes the byte payload directly, bypassing the standard CHORUS message envelope.
func (g *GossipPublisher) Publish(ctx context.Context, topic string, payload []byte) error {
	// 1. Ensure the node is subscribed to the dynamic topic.
	//    This is idempotent and safe to call multiple times.
	if err := g.ps.JoinDynamicTopic(topic); err != nil {
		return fmt.Errorf("hmmm adapter failed to join dynamic topic %s: %w", topic, err)
	}

	// 2. Publish the raw message payload to the topic.
	if err := g.ps.PublishRaw(topic, payload); err != nil {
		return fmt.Errorf("hmmm adapter failed to publish raw message to topic %s: %w", topic, err)
	}

	return nil
}