Add large examples and questions

.idea/gradle.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>

.idea/kotlinc.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="KotlinJpsPluginSettings">
+    <option name="version" value="1.9.10" />
+  </component>
+</project>

build.gradle.kts

@@ -1,5 +1,6 @@
 plugins {
     kotlin("jvm") version "1.9.10"
+    kotlin("plugin.serialization") version "1.9.10"
 }
 
 group = "center.sciprog"
@@ -11,6 +12,8 @@ repositories {
 
 dependencies {
     implementation("org.jetbrains.kotlinx:kotlinx-datetime:0.4.1")
+    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.0")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.7.3")
     testImplementation(kotlin("test"))
 }
 

questions.md

@@ -0,0 +1,10 @@
+* Создание объектов
+  * Стоит ли использовать вторичные конструкторы или лучше фабричные методы в компаньоне
+  * Что лучше - публичный конструктор или приватный с фабричным методом в компаньоне
+  * Проверка параметров в публичном конструкторе или в фабричном методе с передачей в приватный конструктор
+  * init блок или специальный метод init() в классах и object
+* Enum VS sealed
+* Когда использовать `T.() -> R`, а когда `(T) -> R`, а если два параметра, то `T.(T2) -> R`, `T2.(T) -> R`, или `(T, T2) -> R`
+* Обновление кэша
+* Выбор обработчика по объекту событию/полю объекта
+* `a.b!! -> a.b ?: error("b should be not a null")`

src/main/kotlin/WikiGame.kt

@@ -0,0 +1,92 @@
+import kotlinx.coroutines.*
+import kotlinx.coroutines.channels.Channel
+import java.util.concurrent.ConcurrentHashMap
+
+
+/**
+ * Смотреть доклад тут: https://jokerconf.com/talks/726fdf3540524be28c8f5901c1800583
+ */
+
+interface WikiGame {
+    fun play(startPageTitle: String, endPageTitle: String, maxDepth: Int): List<String?>
+}
+
+data class Page(val title: String, val parentPage: Page?) : Comparable<Page> {
+    override fun compareTo(other: Page): Int {
+        return title.compareTo(other.title)
+    }
+}
+
+
+interface WikiRemoteDataSource {
+    suspend fun getLinksByTitle(title: String): List<String>
+
+    suspend fun getBacklinksByTitle(title: String): List<String>
+}
+
+class WikiGameCoroImpl : WikiGame {
+    private val wikiRemoteDataSource: WikiRemoteDataSource = TODO()
+
+    override fun play(startPageTitle: String, endPageTitle: String, maxDepth: Int): List<String> = runBlocking {
+        val visitedPages: MutableMap<String, Boolean> = ConcurrentHashMap()
+
+        val startPage = Page(startPageTitle, null)
+
+        val resultPage = processPage(startPage, endPageTitle, 0, maxDepth, visitedPages)
+
+        val path = mutableListOf<String>()
+
+        var curPg: Page? = resultPage
+        do {
+            path.add(curPg!!.title)
+            curPg = curPg.parentPage
+        } while (curPg != null)
+
+        return@runBlocking path.reversed()
+    }
+
+    private suspend fun processPage(
+        page: Page,
+        endPageTitle: String,
+        curDepth: Int,
+        maxDepth: Int,
+        visitedPages: MutableMap<String, Boolean>,
+    ): Page {
+        if (visitedPages.putIfAbsent(page.title, true) != null) {
+            throw RuntimeException("Already visited")
+        }
+
+        if (page.title == endPageTitle) {
+            return page
+        }
+
+        if (curDepth == maxDepth) {
+            throw RuntimeException("Depth reached")
+        }
+
+        val links = wikiRemoteDataSource.getLinksByTitle(page.title)
+
+        val pageChannel = Channel<Page>()
+
+        val scope = CoroutineScope(SupervisorJob() + CoroutineExceptionHandler { _, _ -> })
+        links.forEach { link ->
+            scope.launch {
+                val pageResult = processPage(
+                    Page(link, page),
+                    endPageTitle,
+                    curDepth + 1,
+                    maxDepth,
+                    visitedPages,
+                )
+
+                pageChannel.send(pageResult)
+            }
+        }
+
+        val resultPage = pageChannel.receive()
+
+        scope.cancel()
+
+        return resultPage
+    }
+}

src/main/kotlin/conference/ConferenceUtils.kt

@@ -1,4 +1,4 @@
-package com.jokerconf.kotlin.idiomatik
+package com.jokerconf.kotlin.idiomatik.conference
 
 import kotlinx.datetime.Instant
 import kotlin.time.Duration.Companion.minutes

src/main/kotlin/conference/Schedule.kt

@@ -1,4 +1,4 @@
-package com.jokerconf.kotlin.idiomatik
+package com.jokerconf.kotlin.idiomatik.conference
 
 import kotlinx.datetime.Instant
 import kotlin.time.Duration

src/main/kotlin/conference/ScheduleBuilder.kt

@@ -1,4 +1,4 @@
-package com.jokerconf.kotlin.idiomatik
+package com.jokerconf.kotlin.idiomatik.conference
 
 import kotlinx.datetime.Instant
 import kotlin.time.Duration

src/main/kotlin/conference/Speaker.kt

@@ -1,4 +1,4 @@
-package com.jokerconf.kotlin.idiomatik
+package com.jokerconf.kotlin.idiomatik.conference
 
 class Speaker {
     var name: String? = null

src/main/kotlin/versionPuller.kt

@@ -0,0 +1,53 @@
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.Json
+import java.net.URI
+
+const val token = "********"
+const val BASE_API_URL = "http://gitlab.com/api/v4"
+const val SECURITY_QUERY_PARAM = "private_token=${token}"
+const val GET_PROJECT_BY_NAME_PATH_TEMPLATE = "$BASE_API_URL/projects?search=%s&$SECURITY_QUERY_PARAM"
+const val GET_ALL_TAGS_BY_PROJECT_ID_PATH_TEMPLATE = "$BASE_API_URL/projects/%d/repository/tags?$SECURITY_QUERY_PARAM"
+
+fun main() {
+    val json = Json { ignoreUnknownKeys = true }
+    listOf(
+        "ProjectA",
+        "ProjectB",
+        "ProjectC",
+    ).forEach { projectName ->
+        val projectsJson = httpGet(GET_PROJECT_BY_NAME_PATH_TEMPLATE.format(projectName))
+        val projects = json.decodeFromString<List<Project>>(projectsJson)
+
+        projects
+            .filter { it.name == projectName }
+            .forEach {
+                val tagsJson = httpGet(GET_ALL_TAGS_BY_PROJECT_ID_PATH_TEMPLATE.format(it.id))
+                val tags = json.decodeFromString<List<Tag>>(tagsJson)
+                val lastTag = tags.map(Tag::name).maxWith(::semVerComparator)
+
+                println("Project ${it.name}: last tag = $lastTag")
+            }
+    }
+}
+
+fun httpGet(url: String): String = URI.create(url).toURL().readText()
+
+fun semVerComparator(a: String, b: String): Int {
+    val aParts = a.split('.').map(String::toInt)
+    val bParts = b.split('.').map(String::toInt)
+    for (i in 0..2) {
+        if (aParts[i] > bParts[i]) {
+            return 1
+        }
+        if (aParts[i] < bParts[i]) {
+            return -1
+        }
+    }
+    return 0
+}
+
+@Serializable
+data class Project(val id: Int, val name: String)
+
+@Serializable
+data class Tag(val name: String, val message: String)