Fix missing emojis in about screen + revamp implementation (#176)

* Refactor replaceMarkdownEmojis to extension function

* Replace markdown emojis in oss items

* Replace markdown emojis in changelog items

* Use idiomatic buildString()

* Print longest alias

* Update markdown parser with more sequence implementation

Should be more efficient and also friendlier to potentially infinite streams

app/src/main/kotlin/io/sweers/catchup/ui/about/ChangelogFragment.kt

@@ -37,6 +37,8 @@ import io.sweers.catchup.R
 import io.sweers.catchup.R.layout
 import io.sweers.catchup.data.LinkManager
 import io.sweers.catchup.data.github.RepoReleasesQuery
+import io.sweers.catchup.gemoji.EmojiMarkdownConverter
+import io.sweers.catchup.gemoji.replaceMarkdownEmojisIn
 import io.sweers.catchup.service.api.UrlMeta
 import io.sweers.catchup.ui.Scrollable
 import io.sweers.catchup.ui.base.CatchUpItemViewHolder
@@ -57,6 +59,8 @@ class ChangelogFragment : InjectableBaseFragment(), Scrollable {
   lateinit var apolloClient: ApolloClient
   @Inject
   internal lateinit var linkManager: LinkManager
+  @Inject
+  internal lateinit var markdownConverter: EmojiMarkdownConverter
 
   private val progressBar by bindView<ProgressBar>(R.id.progress)
   private val recyclerView by bindView<RecyclerView>(R.id.list)
@@ -129,6 +133,12 @@ class ChangelogFragment : InjectableBaseFragment(), Scrollable {
             )
           }
         }
+        .map {
+          it.copy(
+              name = markdownConverter.replaceMarkdownEmojisIn(it.name),
+              description = markdownConverter.replaceMarkdownEmojisIn(it.description)
+          )
+        }
         .toList()
   }
 

app/src/main/kotlin/io/sweers/catchup/ui/about/LicensesFragment.kt

@@ -58,6 +58,8 @@ import io.sweers.catchup.data.github.ProjectOwnersByIdsQuery.AsUser
 import io.sweers.catchup.data.github.RepositoriesByIdsQuery
 import io.sweers.catchup.data.github.RepositoryByNameAndOwnerQuery
 import io.sweers.catchup.flowbinding.safeOffer
+import io.sweers.catchup.gemoji.EmojiMarkdownConverter
+import io.sweers.catchup.gemoji.replaceMarkdownEmojisIn
 import io.sweers.catchup.service.api.TemporaryScopeHolder
 import io.sweers.catchup.service.api.UrlMeta
 import io.sweers.catchup.service.api.temporaryScope
@@ -116,6 +118,9 @@ class LicensesFragment : InjectableBaseFragment(), Scrollable {
   @Inject
   internal lateinit var linkManager: LinkManager
 
+  @Inject
+  internal lateinit var markdownConverter: EmojiMarkdownConverter
+
   private val dimenSize by lazy {
     resources.getDimensionPixelSize(R.dimen.avatar)
   }
@@ -249,6 +254,17 @@ class LicensesFragment : InjectableBaseFragment(), Scrollable {
         .groupBy { it.author }
         .sortBy { it.first }
         .flatMapConcat { it.second.asFlow().sortBy { it.name } }
+        .map {
+          // TODO use CopyDynamic when 0.3.0 is out
+          it.copy(
+              author = markdownConverter.replaceMarkdownEmojisIn(it.author),
+              name = markdownConverter.replaceMarkdownEmojisIn(it.name),
+              description = it.description?.let {
+                markdownConverter.replaceMarkdownEmojisIn(it)
+              } ?: it.description
+          )
+        }
+        .flowOn(Dispatchers.IO)
         .toList()
         .let {
           val collector = mutableListOf<OssBaseItem>()

libraries/gemoji/src/main/kotlin/io/sweers/catchup/gemoji/EmojiMarkdownConverter.kt

@@ -26,50 +26,92 @@ internal class GemojiEmojiMarkdownConverter(
   private val gemojiDao: GemojiDao
 ) : EmojiMarkdownConverter {
   override fun convert(alias: String): String? {
-    return if (alias.startsWith(':') && alias.endsWith(":")) {
-      gemojiDao.getEmoji(alias.substring(1, alias.lastIndex))
-    } else {
-      null
-    }
+    return gemojiDao.getEmoji(alias)
+  }
+}
+
+fun Sequence<Char>.asString(): String {
+  return buildString {
+    this@asString.forEach { append(it) }
+  }
+}
+
+fun Sequence<Char>.asString(capacity: Int): String {
+  return buildString(capacity) {
+    this@asString.forEach { append(it) }
   }
 }
 
 /**
  * Returns a [String] that replaces occurrences of markdown emojis with android render-able emojis.
  */
-fun replaceMarkdownEmojis(markdown: String, converter: EmojiMarkdownConverter): String {
-  val sb = StringBuilder(markdown.length)
-  var potentialAliasStart = -1
+fun EmojiMarkdownConverter.replaceMarkdownEmojisIn(markdown: String): String {
+  return replaceMarkdownEmojisIn(markdown.asSequence()).asString(markdown.length)
+}
+
+/**
+ * This is the longest possible alias length, so we can use its length for our aliasBuilder var
+ * below to reuse it and never have to resize it.
+ */
+private const val MAX_ALIAS_LENGTH = "south_georgia_south_sandwich_islands".length
 
-  markdown.forEachIndexed { index, char ->
-    if (char == ':') {
-      potentialAliasStart = if (potentialAliasStart == -1) {
-        // If we have no potential start, any : is a potential start
-        index
+/**
+ * Returns a [Sequence<Char>][Sequence] that replaces occurrences of markdown emojis with android
+ * render-able emojis.
+ */
+fun EmojiMarkdownConverter.replaceMarkdownEmojisIn(markdown: Sequence<Char>): Sequence<Char> {
+  val aliasBuilder = StringBuilder(MAX_ALIAS_LENGTH)
+  var startAlias = false
+  return sequence {
+    markdown.forEach { char ->
+      if (startAlias || aliasBuilder.isNotEmpty()) {
+        if (startAlias && char == ':') {
+          // Double ::, so emit a colon and keep startAlias set
+          yield(':')
+          return@forEach
+        }
+        startAlias = false
+        when (char) {
+          ' ' -> {
+            // Aliases can't have spaces, so bomb out and restart
+            yield(':')
+            yieldAll(aliasBuilder.asSequence())
+            yield(' ')
+            aliasBuilder.setLength(0)
+          }
+          ':' -> {
+            val potentialAlias = aliasBuilder.toString()
+            val potentialEmoji = convert(potentialAlias)
+            // If we find an emoji append it and reset alias start, if we don't find an emoji
+            // append between the potential start and this index *and* consider this index the new
+            // potential start.
+            if (potentialEmoji != null) {
+              yieldAll(potentialEmoji.asSequence())
+            } else {
+              yield(':')
+              yieldAll(potentialAlias.asSequence())
+              // Start a new alias from this colon as we didn't have a match with the existing close
+              startAlias = true
+            }
+            aliasBuilder.setLength(0)
+          }
+          else -> aliasBuilder.append(char)
+        }
       } else {
-        val potentialAlias = markdown.substring(potentialAliasStart, index + 1)
-        val potentialEmoji = converter.convert(potentialAlias)
-        // If we find an emoji append it and reset alias start, if we don't find an emoji
-        // append between the potential start and this index *and* consider this index the new
-        // potential start.
-        if (potentialEmoji != null) {
-          sb.append(potentialEmoji)
-          -1
+        if (char == ':') {
+          startAlias = true
         } else {
-          sb.append(markdown, potentialAliasStart, index)
-          index
+          yield(char)
         }
       }
-      // While not looking for an alias end append all non possible alias chars to the string
-    } else if (potentialAliasStart == -1) {
-      sb.append(char)
     }
-  }
 
-  // Finished iterating markdown while looking for an end, append anything remaining
-  if (potentialAliasStart != -1) {
-    sb.append(markdown, potentialAliasStart, markdown.length)
+    // If we started an alias but ran out of characters, flush it
+    if (startAlias) {
+      yield(':')
+    } else if (aliasBuilder.isNotEmpty()) {
+      yield(':')
+      yieldAll(aliasBuilder.asSequence())
+    }
   }
-
-  return sb.toString()
 }

libraries/gemoji/src/test/java/io/sweers/catchup/gemoji/EmojiMarkdownConverterTest.kt

@@ -20,15 +20,18 @@ import org.junit.Test
 
 class EmojiMarkdownConverterTest {
 
-  val replaced = "replaced"
-  val emoji = ":emoji:"
-  val converter = object : EmojiMarkdownConverter {
-    override fun convert(alias: String) = if (alias == ":emoji:") replaced else null
+  companion object {
+    const val replaced = "replaced"
+    const val emoji = ":emoji:"
+  }
+
+  private val converter = object : EmojiMarkdownConverter {
+    override fun convert(alias: String) = if (alias == "emoji") replaced else null
   }
 
   @Test
   fun testEmpty() {
-    val converted = replaceMarkdownEmojis("", converter)
+    val converted = converter.replaceMarkdownEmojisIn("")
     assertThat(converted).isEmpty()
   }
 
@@ -92,5 +95,5 @@ class EmojiMarkdownConverterTest {
     assertThat(converted).isEqualTo("$replaced:notEmoji:$replaced:")
   }
 
-  private fun convert(markdown: String) = replaceMarkdownEmojis(markdown, converter)
+  private fun convert(markdown: String) = converter.replaceMarkdownEmojisIn(markdown)
 }

scripts/gemoji/gemoji.py

@@ -43,3 +43,7 @@
 
 connection.commit()
 connection.close()
+
+print("Longest alias")
+longestAlias = max([alias for alias in [max(gemoji['aliases'], key=len) for gemoji in gemojis]], key=len)
+print(longestAlias)

services/github/src/main/kotlin/io/sweers/catchup/service/github/GitHubService.kt

@@ -30,7 +30,7 @@ import dagger.multibindings.IntoMap
 import io.reactivex.Observable
 import io.reactivex.Single
 import io.sweers.catchup.gemoji.EmojiMarkdownConverter
-import io.sweers.catchup.gemoji.replaceMarkdownEmojis
+import io.sweers.catchup.gemoji.replaceMarkdownEmojisIn
 import io.sweers.catchup.libraries.retrofitconverters.DecodingConverter
 import io.sweers.catchup.libraries.retrofitconverters.delegatingCallFactory
 import io.sweers.catchup.service.api.CatchUpItem
@@ -140,7 +140,7 @@ internal class GitHubService @Inject constructor(
               .map {
                 with(it) {
                   val description = description
-                      ?.let { " — ${replaceMarkdownEmojis(it, emojiMarkdownConverter.get())}" }
+                      ?.let { " — ${emojiMarkdownConverter.get().replaceMarkdownEmojisIn(it)}" }
                       .orEmpty()
 
                   CatchUpItem(