/*
 * Copyright 2014-2023 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
 */

package content.functions

import org.jetbrains.dokka.base.testApi.testRunner.BaseAbstractTest
import org.jetbrains.dokka.links.DRI
import org.jetbrains.dokka.links.TypeConstructor
import org.jetbrains.dokka.model.DClass
import org.jetbrains.dokka.model.DPackage
import org.jetbrains.dokka.model.dfs
import org.jetbrains.dokka.pages.*
import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertNotNull
import kotlin.test.assertNull


class ContentForBriefTest : BaseAbstractTest() {
    private val testConfiguration = dokkaConfiguration {
        sourceSets {
            sourceSet {
                sourceRoots = listOf("src/")
                analysisPlatform = "jvm"
            }
        }
    }

    private val codeWithSecondaryAndPrimaryConstructorsDocumented =
        """
            |/src/main/kotlin/test/source.kt
            |package test
            |
            |/**
            | * Dummy text.
            | *
            | * @constructor constructor docs
            | * @param exampleParameter dummy parameter.
            | */
            |class Example(val exampleParameter: Int) {
            | 
            |    /**
            |     * secondary constructor
            |     * @param param1 param1 docs
            |     */
            |    constructor(param1: String) : this(1)
            |}
        """.trimIndent()

    private val codeWithDocumentedParameter =
        """
            |/src/main/kotlin/test/source.kt
            |package test
            |
            |/**
            | * Dummy text.
            | *
            | * @param exampleParameter dummy parameter.
            | */
            |class Example(val exampleParameter: Int) {
            |}
        """.trimIndent()


    @Test
    fun `primary constructor should not inherit docs from its parameter`() {
        testInline(codeWithSecondaryAndPrimaryConstructorsDocumented, testConfiguration) {
            pagesTransformationStage = { module ->
                val classPage = module.findClassPage("Example")

                val constructorsWithBriefs = classPage.findConstructorsWithBriefs()
                val constructorDocs = constructorsWithBriefs.findConstructorDocs {
                    it.callable?.params?.first() == TypeConstructor("kotlin.Int", emptyList())
                }

                assertEquals("constructor docs", constructorDocs.text)
            }
        }
    }

    @Test
    fun `secondary constructor should not inherit docs from its parameter`() {
        testInline(codeWithSecondaryAndPrimaryConstructorsDocumented, testConfiguration) {
            pagesTransformationStage = { module ->
                val classPage = module.findClassPage("Example")

                val constructorsWithBriefs = classPage.findConstructorsWithBriefs()
                val constructorDocs = constructorsWithBriefs.findConstructorDocs {
                    it.callable?.params?.first() == TypeConstructor("kotlin.String", emptyList())
                }

                assertEquals("secondary constructor", constructorDocs.text)
            }
        }
    }

    /**
     * All constructors are merged in one block (like overloaded functions).
     * That leads to the structure where content block (`constructorsWithBriefs`) consist of plain list
     * of constructors and briefs. In that list constructor is above, brief is below.
     */
    private fun ContentPage.findConstructorsWithBriefs(): List<ContentNode> {
        val constructorsTable = this.content.dfs {
            it is ContentTable && it.dci.kind == ContentKind.Constructors
        } as ContentTable

        val constructorsWithBriefs = constructorsTable.dfs {
            it is ContentGroup && it.dci.kind == ContentKind.SourceSetDependentHint
        }?.children
        assertNotNull(constructorsWithBriefs, "Content node with constructors and briefs is not found")

        return constructorsWithBriefs
    }

    private fun List<ContentNode>.findConstructorDocs(constructorMatcher: (DRI) -> Boolean): ContentText {
        val constructorIndex = this.indexOfFirst { constructorMatcher(it.dci.dri.first()) }
        return this[constructorIndex + 1] // expect that the relevant comment is below the constructor
            .dfs { it is ContentText && it.dci.kind == ContentKind.Comment } as ContentText
    }

    @Test
    fun `primary constructor should not inherit docs from its parameter when no specific docs are provided`() {
        testInline(codeWithDocumentedParameter, testConfiguration) {
            pagesTransformationStage = { module ->
                val classPage = module.findClassPage("Example")
                val constructorsTable =
                    classPage.content.dfs { it is ContentTable && it.dci.kind == ContentKind.Constructors } as ContentTable

                assertEquals(1, constructorsTable.children.size)
                val primary = constructorsTable.children.first()
                val primaryConstructorDocs = primary.dfs { it is ContentText && it.dci.kind == ContentKind.Comment }

                assertNull(primaryConstructorDocs, "Expected no primary constructor docs to be present")
            }
        }
    }

    @Test
    fun `brief should work for typealias`() {
        testInline(
            """
            |/src/main/kotlin/test/source.kt
            |package test
            |
            |/**
            |* This is an example <!-- not visible --> of html
            |*
            |* This is definitely not a brief
            |*/
            |typealias A = Int
        """.trimIndent(),
            testConfiguration
        ) {
            pagesTransformationStage = { module ->
                val functionBriefDocs = module.singleTypeAliasesDescription("test")

                assertEquals(
                    "This is an example <!-- not visible --> of html",
                    functionBriefDocs.children.joinToString("") { (it as ContentText).text })
            }
        }
    }

    @Test
    fun `brief for functions should work with html`() {
        testInline(
            """
            |/src/main/kotlin/test/source.kt
            |package test
            |
            |class Example(val exampleParameter: Int) {
            |   /**
            |    * This is an example <!-- not visible --> of html
            |    *
            |    * This is definitely not a brief
            |    */
            |   fun test(): String = "TODO"
            |}
        """.trimIndent(),
            testConfiguration
        ) {
            pagesTransformationStage = { module ->
                val functionBriefDocs = module.singleFunctionDescription("Example")

                assertEquals(
                    "This is an example <!-- not visible --> of html",
                    functionBriefDocs.children.joinToString("") { (it as ContentText).text })
            }
        }
    }

    @Test
    fun `brief for functions should work with ie`() {
        testInline(
            """
            |/src/main/kotlin/test/source.kt
            |package test
            |
            |class Example(val exampleParameter: Int) {
            |   /**
            |    * The user token, i.e. "Bearer xyz". Throw an exception if not available.
            |    *
            |    * This is definitely not a brief
            |    */
            |   fun test(): String = "TODO"
            |}
        """.trimIndent(),
            testConfiguration
        ) {
            pagesTransformationStage = { module ->
                val functionBriefDocs = module.singleFunctionDescription("Example")

                assertEquals(
                    "The user token, i.e. \"Bearer xyz\". Throw an exception if not available.",
                    functionBriefDocs.children.joinToString("") { (it as ContentText).text })
            }
        }
    }

    @Test
    fun `brief for functions should work with eg`() {
        testInline(
            """
            |/src/main/kotlin/test/source.kt
            |package test
            |
            |class Example(val exampleParameter: Int) {
            |   /**
            |    * The user token, e.g. "Bearer xyz". Throw an exception if not available.
            |    *
            |    * This is definitely not a brief
            |    */
            |   fun test(): String = "TODO"
            |}
        """.trimIndent(),
            testConfiguration
        ) {
            pagesTransformationStage = { module ->
                val functionBriefDocs = module.singleFunctionDescription("Example")

                assertEquals(
                    "The user token, e.g. \"Bearer xyz\". Throw an exception if not available.",
                    functionBriefDocs.children.joinToString("") { (it as ContentText).text })
            }
        }
    }

    @Test
    fun `brief for functions should be first sentence for Java`() {
        testInline(
            """
            |/src/main/java/test/Example.java
            |package test;
            |
            |public class Example {
            |   /**
            |    * The user token, or not. This is definitely not a brief in java
            |    */
            |   public static String test() {
            |       return "TODO";
            |   }
            |}
        """.trimIndent(),
            testConfiguration
        ) {
            pagesTransformationStage = { module ->
                val functionBriefDocs = module.singleFunctionDescription("Example")

                assertEquals(
                    "The user token, or not.",
                    functionBriefDocs.children.joinToString("") { (it as ContentText).text })
            }
        }
    }

    @Test
    fun `brief for functions should work with ie for Java`() {
        testInline(
            """
            |/src/main/java/test/Example.java
            |package test;
            |
            |public class Example {
            |   /**
            |    * The user token, e.g.&nbsp;"Bearer xyz". This is definitely not a brief in java
            |    */
            |   public static String test() {
            |       return "TODO";
            |   }
            |}
        """.trimIndent(),
            testConfiguration
        ) {
            pagesTransformationStage = { module ->
                val functionBriefDocs = module.singleFunctionDescription("Example")

                assertEquals(
                    "The user token, e.g. \"Bearer xyz\".",
                    functionBriefDocs.children.joinToString("") { (it as ContentText).text })
            }
        }
    }

    //Source: https://www.oracle.com/technical-resources/articles/java/javadoc-tool.html#exampleresult
    @Test
    fun `brief for functions should work with html comment for Java`() {
        testInline(
            """
            |/src/main/java/test/Example.java
            |package test;
            |
            |public class Example {
            |   /**
            |    * This is a simulation of Prof.<!-- --> Knuth's MIX computer. This is definitely not a brief in java
            |    */
            |   public static String test() {
            |       return "TODO";
            |   }
            |}
        """.trimIndent(),
            testConfiguration
        ) {
            pagesTransformationStage = { module ->
                val functionBriefDocs = module.singleFunctionDescription("Example")

                assertEquals(
                    "This is a simulation of Prof.<!-- --> Knuth's MIX computer.",
                    functionBriefDocs.children.joinToString("") { (it as ContentText).text })
            }
        }
    }

    @Test
    fun `brief for functions should work with html comment at the end for Java`() {
        testInline(
            """
            |/src/main/java/test/Example.java
            |package test;
            |
            |public class Example {
            |   /**
            |    * This is a simulation of Prof.<!-- --> Knuth's MIX computer. This is definitely not a brief in java <!-- -->
            |    */
            |   public static String test() {
            |       return "TODO";
            |   }
            |}
        """.trimIndent(),
            testConfiguration
        ) {
            pagesTransformationStage = { module ->
                val functionBriefDocs = module.singleFunctionDescription("Example")

                assertEquals(
                    "This is a simulation of Prof.<!-- --> Knuth's MIX computer.",
                    functionBriefDocs.children.joinToString("") { (it as ContentText).text })
            }
        }
    }

    private fun RootPageNode.findClassPage(className: String): ContentPage {
        return this.dfs {
            it.name == className && (it as WithDocumentables).documentables.firstOrNull() is DClass
        } as ContentPage
    }

    private fun RootPageNode.singleFunctionDescription(className: String): ContentGroup {
        val classPage =
            dfs { it.name == className && (it as WithDocumentables).documentables.firstOrNull() is DClass } as ContentPage
        val functionsTable =
            classPage.content.dfs { it is ContentTable && it.dci.kind == ContentKind.Functions } as ContentTable

        assertEquals(1, functionsTable.children.size)
        val function = functionsTable.children.first()
        return function.dfs { it is ContentGroup && it.dci.kind == ContentKind.Comment && it.children.all { it is ContentText } } as ContentGroup
    }
    private fun RootPageNode.singleTypeAliasesDescription(packageName: String): ContentGroup {
        val packagePage =
            dfs { it.name == packageName && (it as WithDocumentables).documentables.firstOrNull() is DPackage } as ContentPage
        val contentTable =
            packagePage.content.dfs { it is ContentTable && it.dci.kind == ContentKind.Classlikes } as ContentTable

        assertEquals(1, contentTable.children.size)
        val row = contentTable.children.first()
        return row.dfs { it is ContentGroup && it.dci.kind == ContentKind.Comment && it.children.all { it is ContentText } } as ContentGroup
    }
}