src/youtube/playlist.sgl — sigil-youtube

1;;; (youtube playlist) - YouTube playlist management.

2;;;

3;;; CRUD operations for playlists and playlist items.

4;;; Write operations cost 50 quota units each; reads cost 1 unit.

5;;;

6;;; Tip: The uploads playlist for a channel is always

7;;; "UU" + channel_id (without the "UC" prefix).

8;;; Using playlistItems.list on this is much cheaper than search.list.

10(define-library (youtube playlist)

11 (import (sigil core)

12 (sigil dict)

13 (sigil string)

14 (sigil struct)

15 (sigil json)

16 (only (sigil http) build-query-string)

17 (sigil http client)

18 (youtube))

20 (export ;; Records

21 youtube-playlist

22 youtube-playlist?

23 youtube-playlist-id

24 youtube-playlist-title

25 youtube-playlist-description

26 youtube-playlist-item-count

27 youtube-playlist-privacy-status

29 youtube-playlist-item

30 youtube-playlist-item?

31 youtube-playlist-item-id

32 youtube-playlist-item-video-id

33 youtube-playlist-item-title

34 youtube-playlist-item-position

36 ;; Parsing

37 parse-playlist

38 parse-playlist-item

40 ;; Playlist operations

41 youtube-playlists

42 youtube-playlists-by-channel

43 youtube-create-playlist

44 youtube-update-playlist

45 youtube-delete-playlist

47 ;; Playlist item operations

48 youtube-playlist-items

49 youtube-add-to-playlist

50 youtube-remove-from-playlist

51 youtube-reorder-playlist-item)

53 (begin

55 ;; ---------------------------------------------------------------

56 ;; Records

57 ;; ---------------------------------------------------------------

59 (define-struct youtube-playlist

60 (id)

61 (title default: "")

62 (description default: "")

63 (item-count default: 0)

64 (privacy-status default: "public"))

66 (define-struct youtube-playlist-item

67 (id)

68 (video-id default: "")

69 (title default: "")

70 (position default: 0))

72 ;; ---------------------------------------------------------------

73 ;; Parsing

74 ;; ---------------------------------------------------------------

76 ;;; Parse a playlist resource into a youtube-playlist record.

77 (define (parse-playlist data)

78 (let ((snippet (dict-ref data snippet: #{}))

79 (content (dict-ref data contentDetails: #{}))

80 (status (dict-ref data status: #{})))

81 (youtube-playlist

82 id: (dict-ref data id:)

83 title: (dict-ref snippet title: "")

84 description: (dict-ref snippet description: "")

85 item-count: (dict-ref content itemCount: 0)

86 privacy-status: (dict-ref status privacyStatus: "public"))))

88 ;;; Parse a playlistItem resource into a youtube-playlist-item record.

89 (define (parse-playlist-item data)

90 (let ((snippet (dict-ref data snippet: #{})))

91 (let ((resource-id (dict-ref snippet resourceId: #{})))

92 (youtube-playlist-item

93 id: (dict-ref data id:)

94 video-id: (dict-ref resource-id videoId: "")

95 title: (dict-ref snippet title: "")

96 position: (dict-ref snippet position: 0)))))

98 ;; ---------------------------------------------------------------

99 ;; Playlist operations

100 ;; ---------------------------------------------------------------

101

102 ;; Shared list-playlists implementation.

103 (define (list-playlists-internal client filter-params . rest)

104 (let ((opts (if (null? rest) #{} (car rest))))

105 (let* ((params (maybe-add-api-key client

106 (append

107 (list (cons "part" "snippet,contentDetails,status"))

108 filter-params

109 (list (cons "maxResults"

110 (number->string

111 (dict-ref opts max-results: 25)))

112 (cons "pageToken"

113 (dict-ref opts page-token: #f))))))

114 (url (string-append

115 (youtube-api-url client "playlists")

116 (build-query-string params)))

117 (data (youtube-get/json client url))

118 (items (dict-ref data items: #[])))

119 (array->list (array-map parse-playlist items)))))

120

121 ;;; List playlists for the authenticated user.

122 ;;; Optional opts dict: max-results (default 25), page-token.

123 ;;; Quota cost: 1 unit.

124 (define (youtube-playlists client . rest)

125 (apply list-playlists-internal client

126 (list (cons "mine" "true")) rest))

127

128 ;;; List playlists for a specific channel.

129 ;;; Quota cost: 1 unit.

130 (define (youtube-playlists-by-channel client channel-id . rest)

131 (apply list-playlists-internal client

132 (list (cons "channelId" channel-id)) rest))

133

134 ;;; Create a new playlist.

135 ;;; Quota cost: 50 units.

136 (define (youtube-create-playlist client title . rest)

137 (let ((opts (if (null? rest) #{} (car rest))))

138 (let* ((description (dict-ref opts description: ""))

139 (privacy (dict-ref opts privacy-status: "public"))

140 (body #{ snippet:

141 #{ title: title

142 description: description }

143 status:

144 #{ privacyStatus: privacy } })

145 (url (string-append

146 (youtube-api-url client "playlists")

147 (build-query-string

148 (list (cons "part" "snippet,status")))))

149 (result (youtube-post/json client url body)))

150 (parse-playlist result))))

151

152 ;;; Update a playlist's metadata.

153 ;;; All fields (title:, description:, privacy-status:) are required since

154 ;;; YouTube's PUT replaces the entire resource. Fetch first if you only

155 ;;; want to change one field.

156 ;;; Quota cost: 50 units.

157 (define (youtube-update-playlist client playlist-id title description

158 privacy-status)

159 (let* ((body #{ id: playlist-id

160 snippet:

161 #{ title: title

162 description: description }

163 status:

164 #{ privacyStatus: privacy-status } })

165 (url (string-append

166 (youtube-api-url client "playlists")

167 (build-query-string

168 (list (cons "part" "snippet,status")))))

169 (result (youtube-put/json client url body)))

170 (parse-playlist result)))

171

172 ;;; Delete a playlist.

173 ;;; Quota cost: 50 units.

174 (define (youtube-delete-playlist client playlist-id)

175 (let ((url (string-append

176 (youtube-api-url client "playlists")

177 (build-query-string

178 (list (cons "id" playlist-id))))))

179 (youtube-delete/json client url)))

180

181 ;; ---------------------------------------------------------------

182 ;; Playlist item operations

183 ;; ---------------------------------------------------------------

184

185 ;;; List items in a playlist.

186 ;;; Returns a list of youtube-playlist-item records.

187 ;;; Optional opts dict:

188 ;;; max-results: number (default: 50, max: 50)

189 ;;; page-token: pagination token

190 ;;;

191 ;;; Quota cost: 1 unit per page.

192 (define (youtube-playlist-items client playlist-id . rest)

193 (let ((opts (if (null? rest) #{} (car rest))))

194 (let* ((params (maybe-add-api-key client

195 (list (cons "part" "snippet,contentDetails")

196 (cons "playlistId" playlist-id)

197 (cons "maxResults"

198 (number->string

199 (dict-ref opts max-results: 50)))

200 (cons "pageToken"

201 (dict-ref opts page-token: #f)))))

202 (url (string-append

203 (youtube-api-url client "playlistItems")

204 (build-query-string params)))

205 (data (youtube-get/json client url))

206 (items (dict-ref data items: #[])))

207 (array->list (array-map parse-playlist-item items)))))

208

209 ;;; Add a video to a playlist.

210 ;;; Optional position parameter specifies the 0-based index.

211 ;;; Quota cost: 50 units.

212 (define (youtube-add-to-playlist client playlist-id video-id . rest)

213 (let ((position (if (null? rest) #f (car rest))))

214 (let* ((snippet #{ playlistId: playlist-id

215 resourceId:

216 #{ kind: "youtube#video"

217 videoId: video-id } })

218 (snippet (if position

219 (dict-set snippet position: position)

220 snippet))

221 (body #{ snippet: snippet })

222 (url (string-append

223 (youtube-api-url client "playlistItems")

224 (build-query-string

225 (list (cons "part" "snippet")))))

226 (result (youtube-post/json client url body)))

227 (parse-playlist-item result))))

228

229 ;;; Remove an item from a playlist by playlist item ID.

230 ;;; Note: this requires the playlist *item* ID, not the video ID.

231 ;;; Get item IDs from youtube-playlist-items.

232 ;;; Quota cost: 50 units.

233 (define (youtube-remove-from-playlist client item-id)

234 (let ((url (string-append

235 (youtube-api-url client "playlistItems")

236 (build-query-string

237 (list (cons "id" item-id))))))

238 (youtube-delete/json client url)))

239

240 ;;; Reorder a playlist item by updating its position.

241 ;;; item-id: the playlist item ID

242 ;;; playlist-id: the playlist this item belongs to

243 ;;; video-id: the video ID of this item

244 ;;; new-position: the new 0-based position

245 ;;; Quota cost: 50 units.

246 (define (youtube-reorder-playlist-item client item-id playlist-id

247 video-id new-position)

248 (let* ((body #{ id: item-id

249 snippet:

250 #{ playlistId: playlist-id

251 resourceId:

252 #{ kind: "youtube#video"

253 videoId: video-id }

254 position: new-position } })

255 (url (string-append

256 (youtube-api-url client "playlistItems")

257 (build-query-string

258 (list (cons "part" "snippet")))))

259 (result (youtube-put/json client url body)))

260 (parse-playlist-item result)))

261

262 ))