package dev.hgh.jai.settings

import com.intellij.openapi.vfs.LocalFileSystem
import com.intellij.psi.PsiFile
import com.intellij.psi.PsiManager
import com.intellij.psi.PsiReferenceService
import com.intellij.psi.search.searches.ReferencesSearch
import com.intellij.psi.util.PsiTreeUtil
import com.intellij.testFramework.fixtures.BasePlatformTestCase
import dev.hgh.jai.psi.JaiDeclName
import dev.hgh.jai.psi.JaiLiteralExpr
import dev.hgh.jai.psi.JaiRefExpr
import java.nio.file.Files
import java.nio.file.Path

class JaiConfiguredRootTest : BasePlatformTestCase() {
    private var temporaryRoot: Path? = null

    fun testConfiguredRootResolvesImportedModuleAndSymbol() {
        val module = configureRoot("Custom/module.jai" to "Helper :: () {}")
        val source =
            myFixture.addFileToProject(
                "consumer.jai",
                """
                #import "Custom";
                main :: () { Helper(); }
                """.trimIndent(),
            )

        val moduleLiteral = literalWithText(source, "\"Custom\"")
        assertEquals(
            module.path,
            onlyReference(moduleLiteral)
                .resolve()
                ?.containingFile
                ?.virtualFile
                ?.path,
        )

        val symbolReference =
            PsiTreeUtil
                .findChildrenOfType(source, JaiRefExpr::class.java)
                .single { it.text == "Helper" }
        assertEquals(
            module.path,
            onlyReference(symbolReference)
                .resolve()
                ?.containingFile
                ?.virtualFile
                ?.path,
        )
    }

    fun testConfiguredRootResolvesLoadFileFromConfiguredRoot() {
        val externalFile = configureRoot("external.jai" to "value :: 1;")
        val source = myFixture.addFileToProject("consumer.jai", "#load \"external.jai\";")

        val literal = literalWithText(source, "\"external.jai\"")

        assertEquals(
            externalFile.path,
            onlyReference(literal)
                .resolve()
                ?.containingFile
                ?.virtualFile
                ?.path,
        )
    }

    fun testConfiguredRootSuppliesImportAndLoadCompletion() {
        configureRoot(
            "Custom/module.jai" to "value :: 1;",
            "external.jai" to "value :: 1;",
        )

        val configuredRoots = JaiProjectSettings.getInstance(project).configuredRoots()
        assertEquals("expected one configured VFS root", 1, configuredRoots.size)
        assertNotNull("expected the configured module directory", configuredRoots.single().findChild("Custom"))

        myFixture.configureByText("import-consumer.jai", "#import \"Cus<caret>\";")
        myFixture.completeBasic()
        myFixture.checkResult("#import \"Custom\";")

        myFixture.configureByText("load-consumer.jai", "#load \"ext<caret>\";")
        myFixture.completeBasic()
        myFixture.checkResult("#load \"external.jai\";")
    }

    fun testReferencesSearchIncludesProjectUsagesForConfiguredExternalDeclaration() {
        val module = configureRoot("Custom/module.jai" to "Helper :: () {}")
        val source =
            myFixture.addFileToProject(
                "consumer.jai",
                """
                #import "Custom";
                main :: () { Helper(); }
                """.trimIndent(),
            )
        JaiProjectSettings.getInstance(project).refreshProjectRoots()
        val externalFile =
            PsiManager
                .getInstance(project)
                .findFile(module)
        assertNotNull("expected PSI for configured external module", externalFile)
        val declaration =
            PsiTreeUtil
                .findChildrenOfType(externalFile!!, JaiDeclName::class.java)
                .single { it.text == "Helper" }
        assertTrue(
            "configured Jai files should be indexed as library sources",
            com.intellij.openapi.roots.ProjectFileIndex
                .getInstance(project)
                .isInLibrarySource(module),
        )

        val usages = ReferencesSearch.search(declaration).findAll()

        assertEquals(
            "expected the project usage; scope=${declaration.useScope}, usages=$usages",
            1,
            usages.size,
        )
        assertEquals("Helper", usages.single().element.text)
        assertEquals(
            source.virtualFile.path,
            usages
                .single()
                .element.containingFile.virtualFile.path,
        )
    }

    private fun configureRoot(vararg files: Pair<String, String>): com.intellij.openapi.vfs.VirtualFile {
        val root = Files.createTempDirectory("jai-configured-root-").toAbsolutePath().normalize()
        temporaryRoot = root
        files.forEach { (relativePath, contents) ->
            val file = root.resolve(relativePath)
            Files.createDirectories(file.parent)
            Files.writeString(file, contents)
        }

        val virtualRoot = LocalFileSystem.getInstance().refreshAndFindFileByNioFile(root)
        assertNotNull("expected the configured root to be visible to VFS", virtualRoot)
        JaiProjectSettings.getInstance(project).setRootPaths(listOf(root.toString()))
        return virtualRoot!!.findFileByRelativePath(files.first().first)!!
    }

    private fun literalWithText(
        source: PsiFile,
        text: String,
    ): JaiLiteralExpr {
        val literal =
            PsiTreeUtil
                .findChildrenOfType(source, JaiLiteralExpr::class.java)
                .firstOrNull { it.text == text }
        assertNotNull("expected string literal $text", literal)
        return literal!!
    }

    private fun onlyReference(element: com.intellij.psi.PsiElement) =
        PsiReferenceService
            .getService()
            .getContributedReferences(element)
            .also { assertEquals("expected exactly one reference", 1, it.size) }
            .single()

    override fun tearDown() {
        try {
            super.tearDown()
        } finally {
            temporaryRoot?.toFile()?.deleteRecursively()
        }
    }
}