feat: provide recently used and VCS-extracted commit tokens

src/main/kotlin/com/github/lppedd/cc/CCExtensions.kt

@@ -317,6 +317,25 @@ internal inline operator fun <T, C : MutableList<T>> T.plus(list: C): C {
   return list
 }
 
+// endregion
+// region Sequence
+
+@InlineOnly
+internal inline fun Sequence<String>.mapToLowerCase(): Sequence<String> =
+  map(String::toLowerCase)
+
+@InlineOnly
+internal inline fun Sequence<String>.filterNotEmpty(): Sequence<String> =
+  filterNot(String::isEmpty)
+
+@InlineOnly
+internal inline fun Sequence<String>.filterNotBlank(): Sequence<String> =
+  filterNot(String::isBlank)
+
+@InlineOnly
+internal inline fun Sequence<String>.trim(): Sequence<String> =
+  map(String::trim)
+
 // endregion
 // region Utilities
 

src/main/kotlin/com/github/lppedd/cc/CCIcons.kt

@@ -16,6 +16,8 @@ object CCIcons {
   object Provider {
     @JvmField val Unknown: Icon = getIcon("provider/unknown.svg")
     @JvmField val Disabled: Icon = getIcon("provider/disabled.svg")
+    @JvmField val Recent: Icon = getIcon("provider/recent.svg")
+    @JvmField val Vcs: Icon = getIcon("provider/vcs.svg")
   }
 
   object Tokens {

src/main/kotlin/com/github/lppedd/cc/api/RecentCommitTokenProvider.kt

@@ -0,0 +1,149 @@
+package com.github.lppedd.cc.api
+
+import com.github.lppedd.cc.*
+import com.github.lppedd.cc.api.CommitTokenElement.CommitTokenRendering
+import com.github.lppedd.cc.parser.CCParser
+import com.github.lppedd.cc.parser.CommitTokens
+import com.github.lppedd.cc.parser.FooterTokens
+import com.github.lppedd.cc.parser.ValidToken
+import com.github.lppedd.cc.vcs.CCVcsHandler
+import com.intellij.openapi.components.service
+import com.intellij.openapi.project.Project
+import com.intellij.openapi.vcs.VcsConfiguration
+import org.jetbrains.annotations.ApiStatus.*
+import kotlin.text.RegexOption.MULTILINE
+
+/**
+ * Provides the most recently used commit tokens.
+ *
+ * @author Edoardo Luppi
+ */
+@Internal
+internal class RecentCommitTokenProvider(project: Project)
+  : CommitTypeProvider,
+    CommitScopeProvider,
+    CommitSubjectProvider,
+    CommitFooterValueProvider {
+  companion object {
+    const val ID: String = "f3be5600-71b8-401c-bf50-e2465d8efca8"
+
+    private val regexBeginEndWs = Regex("""^\s+|\s+$""")
+    private val regexBlankLines = Regex("""^\s*$""", MULTILINE)
+    private val recentCommitRendering = CommitTokenRendering(type = "Recently used")
+  }
+
+  private val vcsHandler = project.service<CCVcsHandler>()
+  private val vcsConfiguration = VcsConfiguration.getInstance(project)
+
+  override fun getId(): String = ID
+
+  override fun getPresentation(): ProviderPresentation =
+    ProviderPresentation("Recently used", CCIcons.Provider.Recent)
+
+  override fun getCommitTypes(prefix: String?): Collection<CommitType> =
+    (getOrderedSavedCommitMessages(10) + getOrderedVcsCommitMessages(20))
+      .map { it.lines().first(String::isNotBlank) }
+      .mapToLowerCase()
+      .distinct()
+      .map(CCParser::parseHeader)
+      .map(CommitTokens::type)
+      .filterIsInstance<ValidToken>()
+      .map(ValidToken::value)
+      .trim()
+      .filterNotEmpty()
+      .distinct()
+      .take(3)
+      .map(::RecentCommitType)
+      .toList()
+
+  override fun getCommitScopes(commitType: String?): Collection<CommitScope> =
+    (getOrderedSavedCommitMessages(10) + getOrderedVcsCommitMessages(20))
+      .map { it.lines().first(String::isNotBlank) }
+      .mapToLowerCase()
+      .distinct()
+      .map(CCParser::parseHeader)
+      .map(CommitTokens::scope)
+      .filterIsInstance<ValidToken>()
+      .map(ValidToken::value)
+      .trim()
+      .filterNotEmpty()
+      .distinct()
+      .take(3)
+      .map(::RecentCommitScope)
+      .toList()
+
+  override fun getCommitSubjects(commitType: String?, commitScope: String?): Collection<CommitSubject> =
+    (getOrderedSavedCommitMessages(10) + getOrderedVcsCommitMessages(20))
+      .map { it.lines().first(String::isNotBlank) }
+      .distinctBy(String::toLowerCase)
+      .map(CCParser::parseHeader)
+      .map(CommitTokens::subject)
+      .filterIsInstance<ValidToken>()
+      .map(ValidToken::value)
+      .trim()
+      .filterNotEmpty()
+      .distinctBy(String::toLowerCase)
+      .take(3)
+      .map(::RecentCommitSubject)
+      .toList()
+
+  override fun getCommitFooterValues(
+      footerType: String,
+      commitType: String?,
+      commitScope: String?,
+      commitSubject: String?,
+  ): Collection<CommitFooterValue> {
+    val n = if ("co-authored-by".equals(footerType, true)) 5 else 15
+    return (getOrderedSavedCommitMessages(10) + getOrderedVcsCommitMessages(20))
+      .flatMap { message -> getFooterValues(footerType, message) }
+      .distinctBy(String::toLowerCase)
+      .take(n)
+      .map(::RecentCommitFooterValue)
+      .toList()
+  }
+
+  private fun getFooterValues(footerType: String, message: String): Sequence<String> =
+    message.replace(regexBeginEndWs, "")
+      .split(regexBlankLines)
+      .drop(1)
+      .asReversed()
+      .asSequence()
+      .map { it.replace(regexBeginEndWs, "") }
+      .filterNotBlank()
+      .map(CCParser::parseFooter)
+      .filter { footerType == (it.type as? ValidToken)?.value }
+      .map(FooterTokens::footer)
+      .filterIsInstance<ValidToken>()
+      .map(ValidToken::value)
+      .trim()
+      .filterNotEmpty()
+
+  @Suppress("SameParameterValue")
+  private fun getOrderedVcsCommitMessages(limit: Int): Sequence<String> =
+    vcsHandler.getOrderedCommits(limit)
+      .asSequence()
+      .map { it.fullMessage }
+
+  @Suppress("SameParameterValue")
+  private fun getOrderedSavedCommitMessages(limit: Int): Sequence<String> =
+    vcsConfiguration.recentMessages
+      .asReversed()
+      .asSequence()
+      .take(limit)
+
+  private class RecentCommitType(text: String) : CommitType(text) {
+    override fun getRendering() = recentCommitRendering
+  }
+
+  private class RecentCommitScope(text: String) : CommitScope(text) {
+    override fun getRendering() = recentCommitRendering
+  }
+
+  private class RecentCommitSubject(text: String) : CommitSubject(text) {
+    override fun getRendering() = recentCommitRendering
+  }
+
+  private class RecentCommitFooterValue(text: String) : CommitFooterValue(text) {
+    override fun getRendering() = recentCommitRendering
+  }
+}