Move everything to new reddit/ folder

Signed-off-by: Vartan Benohanian <vartanbeno@gmail.com>

reddit/listings.go

@@ -0,0 +1,57 @@
+package reddit
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strings"
+)
+
+// ListingsService handles communication with the listing
+// related methods of the Reddit API.
+//
+// Reddit API docs: https://www.reddit.com/dev/api/#section_listings
+type ListingsService struct {
+	client *Client
+}
+
+// Get returns posts, comments, and subreddits from their full IDs.
+func (s *ListingsService) Get(ctx context.Context, ids ...string) ([]*Post, []*Comment, []*Subreddit, *Response, error) {
+	path := fmt.Sprintf("api/info?id=%s", strings.Join(ids, ","))
+
+	req, err := s.client.NewRequest(http.MethodGet, path, nil)
+	if err != nil {
+		return nil, nil, nil, nil, err
+	}
+
+	root := new(rootListing)
+	resp, err := s.client.Do(ctx, req, root)
+	if err != nil {
+		return nil, nil, nil, resp, err
+	}
+
+	posts := root.getPosts().Posts
+	comments := root.getComments().Comments
+	subreddits := root.getSubreddits().Subreddits
+
+	return posts, comments, subreddits, resp, nil
+}
+
+// GetPosts returns posts from their full IDs.
+func (s *ListingsService) GetPosts(ctx context.Context, ids ...string) ([]*Post, *Response, error) {
+	path := fmt.Sprintf("by_id/%s", strings.Join(ids, ","))
+
+	req, err := s.client.NewRequest(http.MethodGet, path, nil)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	root := new(rootListing)
+	resp, err := s.client.Do(ctx, req, root)
+	if err != nil {
+		return nil, resp, err
+	}
+
+	posts := root.getPosts().Posts
+	return posts, resp, nil
+}