Search/node-request-forums.go

package main

import (
	"encoding/json"
	"fmt"
	"log"
	"time"
)

var forumResultsChan = make(chan []ForumSearchResult)

func tryOtherNodesForForumSearch(query, safe, lang string, page int) []ForumSearchResult {
	for _, nodeAddr := range peers {
		results, err := sendForumSearchRequestToNode(nodeAddr, query, safe, lang, page, []string{})
		if err != nil {
			log.Printf("Error contacting node %s: %v", nodeAddr, err)
			continue
		}
		if len(results) > 0 {
			return results
		}
	}
	return nil
}

func sendForumSearchRequestToNode(nodeAddr, query, safe, lang string, page int, visitedNodes []string) ([]ForumSearchResult, error) {
	// Check if the current node has already been visited
	for _, node := range visitedNodes {
		if node == hostID {
			return nil, fmt.Errorf("loop detected: this node (%s) has already been visited", hostID)
		}
	}

	// Add current node to the list of visited nodes
	visitedNodes = append(visitedNodes, hostID)

	searchParams := struct {
		Query        string   `json:"query"`
		Safe         string   `json:"safe"`
		Lang         string   `json:"lang"`
		Page         int      `json:"page"`
		ResponseAddr string   `json:"responseAddr"`
		VisitedNodes []string `json:"visitedNodes"`
	}{
		Query:        query,
		Safe:         safe,
		Lang:         lang,
		Page:         page,
		ResponseAddr: fmt.Sprintf("http://localhost:%d/node", config.Port),
		VisitedNodes: visitedNodes,
	}

	msgBytes, err := json.Marshal(searchParams)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal search parameters: %v", err)
	}

	msg := Message{
		ID:      hostID,
		Type:    "search-forum",
		Content: string(msgBytes),
	}

	err = sendMessage(nodeAddr, msg)
	if err != nil {
		return nil, fmt.Errorf("failed to send search request to node %s: %v", nodeAddr, err)
	}

	// Wait for results
	select {
	case res := <-forumResultsChan:
		return res, nil
	case <-time.After(20 * time.Second):
		return nil, fmt.Errorf("timeout waiting for results from node %s", nodeAddr)
	}
}

func handleForumResultsMessage(msg Message) {
	var results []ForumSearchResult
	err := json.Unmarshal([]byte(msg.Content), &results)
	if err != nil {
		log.Printf("Error unmarshalling forum results: %v", err)
		return
	}

	log.Printf("Received forum results: %+v", results)
	// Send results to forumResultsChan
	go func() {
		forumResultsChan <- results
	}()
}

// Used only to answer requests
func fetchForumResults(query, safe, lang string, page int) []ForumSearchResult {
	results, err := PerformRedditSearch(query, safe, page)
	if err != nil {
		log.Printf("Error fetching forum results: %v", err)
		return nil
	}
	return results
}