Initial commit

internal/feed/reddit.go

@@ -0,0 +1,83 @@
+package feed
+
+import (
+	"fmt"
+	"html"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+type subredditResponseJson struct {
+	Data struct {
+		Children []struct {
+			Data struct {
+				Title         string  `json:"title"`
+				Upvotes       int     `json:"ups"`
+				Url           string  `json:"url"`
+				Time          float64 `json:"created"`
+				CommentsCount int     `json:"num_comments"`
+				Domain        string  `json:"domain"`
+				Permalink     string  `json:"permalink"`
+				Stickied      bool    `json:"stickied"`
+				Pinned        bool    `json:"pinned"`
+				IsSelf        bool    `json:"is_self"`
+				Thumbnail     string  `json:"thumbnail"`
+			} `json:"data"`
+		} `json:"children"`
+	} `json:"data"`
+}
+
+func FetchSubredditPosts(subreddit string) (ForumPosts, error) {
+	requestUrl := fmt.Sprintf("https://www.reddit.com/r/%s/hot.json", url.QueryEscape(subreddit))
+	request, err := http.NewRequest("GET", requestUrl, nil)
+
+	if err != nil {
+		return nil, err
+	}
+
+	// Required to increase rate limit, otherwise Reddit randomly returns 429 even after just 2 requests
+	addBrowserUserAgentHeader(request)
+	responseJson, err := decodeJsonFromRequest[subredditResponseJson](defaultClient, request)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if len(responseJson.Data.Children) == 0 {
+		return nil, fmt.Errorf("no posts found")
+	}
+
+	posts := make(ForumPosts, 0, len(responseJson.Data.Children))
+
+	for i := range responseJson.Data.Children {
+		post := &responseJson.Data.Children[i].Data
+
+		if post.Stickied || post.Pinned {
+			continue
+		}
+
+		forumPost := ForumPost{
+			Title:           html.UnescapeString(post.Title),
+			DiscussionUrl:   "https://www.reddit.com" + post.Permalink,
+			TargetUrlDomain: post.Domain,
+			CommentCount:    post.CommentsCount,
+			Score:           post.Upvotes,
+			TimePosted:      time.Unix(int64(post.Time), 0),
+		}
+
+		if post.Thumbnail != "" && post.Thumbnail != "self" && post.Thumbnail != "default" {
+			forumPost.ThumbnailUrl = post.Thumbnail
+		}
+
+		if !post.IsSelf {
+			forumPost.TargetUrl = post.Url
+		}
+
+		posts = append(posts, forumPost)
+	}
+
+	posts.CalculateEngagement()
+
+	return posts, nil
+}