Search/node-request-forums.go

//go:build experimental
// +build experimental

package main

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"time"
)

var forumResultsChan = make(chan []ForumSearchResult)

func sendForumSearchRequestToNode(target, query, safe, lang string, page int, visitedNodes []string) ([]ForumSearchResult, error) {
	payload, err := encodeSearchTextParams(query, safe, lang, page) // reuse text param encoding
	if err != nil {
		return nil, fmt.Errorf("encode error: %v", err)
	}

	msg := Message{
		ID:      generateMessageID(),
		Type:    MsgTypeSearchForumRequest,
		Content: payload,
		Target:  target,
	}

	if err := sendMessage(msg); err != nil {
		return nil, fmt.Errorf("send error: %v", err)
	}

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

func handleForumResultsMessage(msg Message) {
	results, err := decodeForumResults([]byte(msg.Content))
	if err != nil {
		printWarn("Error decoding forum results: %v", err)
		return
	}
	printDebug("Received forum results: %+v", results)

	go func() {
		forumResultsChan <- results
	}()
}

func encodeForumResults(results []ForumSearchResult) ([]byte, error) {
	buf := new(bytes.Buffer)

	if err := binary.Write(buf, binary.BigEndian, uint16(len(results))); err != nil {
		return nil, err
	}

	for _, r := range results {
		if err := writeString(buf, r.URL); err != nil {
			return nil, err
		}
		if err := writeString(buf, r.Header); err != nil {
			return nil, err
		}
		if err := writeString(buf, r.Description); err != nil {
			return nil, err
		}
		if err := binary.Write(buf, binary.BigEndian, r.PublishedDate.Unix()); err != nil {
			return nil, err
		}
		if err := writeString(buf, r.ImgSrc); err != nil {
			return nil, err
		}
		if err := writeString(buf, r.ThumbnailSrc); err != nil {
			return nil, err
		}
	}

	return buf.Bytes(), nil
}

func decodeForumResults(data []byte) ([]ForumSearchResult, error) {
	buf := bytes.NewReader(data)

	var count uint16
	if err := binary.Read(buf, binary.BigEndian, &count); err != nil {
		return nil, err
	}

	results := make([]ForumSearchResult, 0, count)
	for i := 0; i < int(count); i++ {
		url, err := readString(buf)
		if err != nil {
			return nil, err
		}
		header, err := readString(buf)
		if err != nil {
			return nil, err
		}
		desc, err := readString(buf)
		if err != nil {
			return nil, err
		}
		var unixTime int64
		if err := binary.Read(buf, binary.BigEndian, &unixTime); err != nil {
			return nil, err
		}
		imgSrc, err := readString(buf)
		if err != nil {
			return nil, err
		}
		thumbSrc, err := readString(buf)
		if err != nil {
			return nil, err
		}

		results = append(results, ForumSearchResult{
			URL:           url,
			Header:        header,
			Description:   desc,
			PublishedDate: time.Unix(unixTime, 0),
			ImgSrc:        imgSrc,
			ThumbnailSrc:  thumbSrc,
		})
	}
	return results, nil
}