refactor: make php language injector play nice with phpdocs

src/main/kotlin/com/github/tempest/framework/views/injection/PHPLanguageInjector.kt

@@ -1,5 +1,6 @@
 package com.github.tempest.framework.views.injection
 
+import com.github.tempest.framework.TempestFrameworkUtil
 import com.intellij.lang.injection.MultiHostInjector
 import com.intellij.lang.injection.MultiHostRegistrar
 import com.intellij.lang.tree.util.children
@@ -8,75 +9,83 @@ import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiLanguageInjectionHost
 import com.intellij.psi.html.HtmlTag
 import com.intellij.psi.impl.source.html.HtmlRawTextImpl
+import com.intellij.psi.impl.source.xml.XmlAttributeValueImpl
+import com.intellij.psi.impl.source.xml.XmlTextImpl
+import com.intellij.psi.util.PsiTreeUtil
 import com.intellij.psi.xml.XmlAttribute
-import com.intellij.psi.xml.XmlAttributeValue
-import com.intellij.psi.xml.XmlText
 import com.intellij.psi.xml.XmlToken
 import com.jetbrains.php.lang.PhpLanguage
+import com.jetbrains.php.lang.documentation.phpdoc.psi.PhpDocComment
 
 class PHPLanguageInjector : MultiHostInjector {
-    val tagsMap = mapOf(
-        "{!!" to "!!}",
-        "{{" to "}}",
-    )
+    companion object {
+        private val templateTags = mapOf(
+            "{!!" to "!!}",
+            "{{" to "}}",
+        )
+    }
 
-    override fun getLanguagesToInject(
-        registrar: MultiHostRegistrar,
-        element: PsiElement
-    ) {
-        when (element) {
-            is XmlAttributeValue -> {
-                val attribute = element.parent as? XmlAttribute ?: return
+    override fun elementsToInjectIn() = listOf(
+        XmlAttributeValueImpl::class.java,
+        XmlTextImpl::class.java,
+        HtmlTag::class.java,
+    )
 
-                if (!attribute.name.startsWith(':')) return
+    override fun getLanguagesToInject(registrar: MultiHostRegistrar, element: PsiElement) {
+        val file = element.containingFile ?: return
+        if (!file.name.endsWith(TempestFrameworkUtil.TEMPLATE_SUFFIX)) return
 
-                val injectableHost = element as? PsiLanguageInjectionHost ?: return
+        when (element) {
+            is XmlAttributeValueImpl -> injectIntoAttribute(element, registrar)
+            is XmlTextImpl -> injectIntoText(element, registrar)
+            is HtmlTag -> injectIntoHtmlTag(element, registrar)
+        }
+    }
 
-                registrar
-                    .startInjecting(PhpLanguage.INSTANCE ?: return)
-                    .addPlace("<?=", "?>", injectableHost, TextRange(0, injectableHost.textLength))
-                    .doneInjecting()
-            }
+    private fun injectIntoAttribute(element: XmlAttributeValueImpl, registrar: MultiHostRegistrar) {
+        val attribute = element.parent as? XmlAttribute ?: return
+        if (!attribute.name.startsWith(':')) return
 
-            is HtmlTag -> {
-                element.children
-                    .mapNotNull { it as? HtmlRawTextImpl }
-                    .forEach { child ->
-                        injectIntoText(HtmlTextInjectionHostWrapper(child), registrar)
-                    }
-            }
+        val variableDeclarations = collectVariableDeclarations(element)
+        registrar
+            .startInjecting(PhpLanguage.INSTANCE)
+            .addPlace("$variableDeclarations<?=", "?>", element, element.textRange.shiftLeft(element.startOffset))
+            .doneInjecting()
+    }
 
-            is XmlText -> {
-//                println("element: ${element.text}, ${element.javaClass.name} ${element is PsiLanguageInjectionHost}")
-                val injectableHost = element as? PsiLanguageInjectionHost ?: return
-                injectIntoText(injectableHost, registrar)
-            }
-        }
+    private fun injectIntoHtmlTag(element: HtmlTag, registrar: MultiHostRegistrar) {
+        element.children
+            .filterIsInstance<HtmlRawTextImpl>()
+            .forEach { injectIntoText(HtmlTextInjectionHostWrapper(it), registrar) }
     }
 
-    private fun injectIntoText(
-        element: PsiLanguageInjectionHost,
-        registrar: MultiHostRegistrar
-    ) {
-        val children = element.node.children().toList()
+    private fun injectIntoText(element: PsiLanguageInjectionHost, registrar: MultiHostRegistrar) {
+        val tokens = element.node.children()
             .filter { it is XmlToken }
-            .apply { if (size < 2) return }
+            .toList()
+            .takeIf { it.size >= 2 } ?: return
+
+        val openTag = tokens.find { it.text in templateTags }?.psi ?: return
+        val closeTag = tokens.find { it.text == templateTags[openTag.text] }?.psi ?: return
+        val range = TextRange(openTag.textRangeInParent.endOffset, closeTag.startOffsetInParent)
 
-//        println("children: $children")
-        val openTag = children.find { tagsMap.containsKey(it.text) }?.psi ?: return
-        val closeTag = children.find { it.text == tagsMap[openTag.text] }?.psi ?: return
+        val variableDeclarations = collectVariableDeclarations(element)
 
-//        println("openTag: ${openTag.text}, closeTag: ${closeTag?.text}")
-        val textRange = TextRange(openTag.textRangeInParent.endOffset, closeTag.startOffsetInParent)
-//            println("injecting ${language} into $element, $textRange")
-        registrar.startInjecting(PhpLanguage.INSTANCE)
-            .addPlace("<?=", "?>", element, textRange)
+        registrar
+            .startInjecting(PhpLanguage.INSTANCE)
+            .addPlace("$variableDeclarations<?=", "?>", element, range)
             .doneInjecting()
     }
 
-    override fun elementsToInjectIn() = listOf(
-        XmlAttributeValue::class.java,
-        XmlText::class.java,
-        HtmlTag::class.java,
-    )
+    private fun collectVariableDeclarations(element: PsiElement): String? {
+        val file = element.containingFile ?: return null
+
+        val searchFile = file.viewProvider.getPsi(PhpLanguage.INSTANCE) ?: file
+        val variableDeclarations = PsiTreeUtil.findChildrenOfType(searchFile, PhpDocComment::class.java)
+            .filter { "@var" in it.text }
+            .joinToString("\n") { it.text }
+            .ifEmpty { return null }
+
+        return "<?php $variableDeclarations ?>"
+    }
 }