Add experimental support for unified_card

Closes #345

src/experimental/parser/unifiedcard.nim

@@ -0,0 +1,91 @@
+import std/[options, tables, strutils, strformat, sugar]
+import jsony
+import ../types/unifiedcard
+from ../../types import Card, CardKind, Video
+from ../../utils import twimg, https
+
+proc getImageUrl(entity: MediaEntity): string =
+  entity.mediaUrlHttps.dup(removePrefix(twimg), removePrefix(https))
+
+proc parseDestination(id: string; card: UnifiedCard; result: var Card) =
+  let destination = card.destinationObjects[id].data
+  result.dest = destination.urlData.vanity
+  result.url = destination.urlData.url
+
+proc parseDetails(data: ComponentData; card: UnifiedCard; result: var Card) =
+  data.destination.parseDestination(card, result)
+
+  result.text = data.title
+  if result.text.len == 0:
+    result.text = data.name
+
+proc parseMediaDetails(data: ComponentData; card: UnifiedCard; result: var Card) =
+  data.destination.parseDestination(card, result)
+
+  result.kind = summary
+  result.image = card.mediaEntities[data.mediaId].getImageUrl
+  result.text = data.topicDetail.title
+  result.dest = "Topic"
+
+proc parseAppDetails(data: ComponentData; card: UnifiedCard; result: var Card) =
+  let app = card.appStoreData[data.appId][0]
+
+  case app.kind
+  of androidApp:
+    result.url = "http://play.google.com/store/apps/details?id=" & app.id
+  of iPhoneApp, iPadApp:
+    result.url = "https://itunes.apple.com/app/id" & app.id
+
+  result.text = app.title
+  result.dest = app.category
+
+proc parseListDetails(data: ComponentData; result: var Card) =
+  result.dest = &"List · {data.memberCount} Members"
+
+proc parseCommunityDetails(data: ComponentData; result: var Card) =
+  result.dest = &"Community · {data.memberCount} Members"
+
+proc parseMedia(component: Component; card: UnifiedCard; result: var Card) =
+  let mediaId =
+    if component.kind == swipeableMedia:
+      component.data.mediaList[0].id
+    else:
+      component.data.id
+
+  let rMedia = card.mediaEntities[mediaId]
+  case rMedia.kind:
+  of photo:
+    result.kind = summaryLarge
+    result.image = rMedia.getImageUrl
+  of video:
+    let videoInfo = rMedia.videoInfo.get
+    result.kind = promoVideo
+    result.video = some Video(
+      available: true,
+      thumb: rMedia.getImageUrl,
+      durationMs: videoInfo.durationMillis,
+      variants: videoInfo.variants
+    )
+
+proc parseUnifiedCard*(json: string): Card =
+  let card = json.fromJson(UnifiedCard)
+
+  for component in card.componentObjects.values:
+    case component.kind
+    of details, communityDetails, twitterListDetails:
+      component.data.parseDetails(card, result)
+    of appStoreDetails:
+      component.data.parseAppDetails(card, result)
+    of mediaWithDetailsHorizontal:
+      component.data.parseMediaDetails(card, result)
+    of media, swipeableMedia:
+      component.parseMedia(card, result)
+    of buttonGroup:
+      discard
+
+    case component.kind
+    of twitterListDetails:
+      component.data.parseListDetails(result)
+    of communityDetails:
+      component.data.parseCommunityDetails(result)
+    else: discard