feat(rust): add RustFileContextBuilder for file context

Add a new file `RustFileContextBuilder.kt` in the `cc.unitmesh.rust.context` package. This file contains the implementation of the `RustFileContextBuilder` class, which is responsible for building the file context for Rust files. The `getFileContext` method extracts relevant information from the `PsiFile` object, such as path, imports, structures, and functions, and creates a `FileContext` object.

Author: phodal

rust/src/main/kotlin/cc/unitmesh/rust/context/RustFileContextBuilder.kt

@@ -0,0 +1,22 @@
+package cc.unitmesh.rust.context
+
+import cc.unitmesh.devti.context.FileContext
+import cc.unitmesh.devti.context.builder.FileContextBuilder
+import com.intellij.psi.PsiFile
+import com.intellij.psi.util.PsiTreeUtil
+import org.rust.lang.core.psi.RsFile
+import org.rust.lang.core.psi.RsStructItem
+import org.rust.lang.core.psi.RsUseItem
+
+class RustFileContextBuilder : FileContextBuilder {
+    override fun getFileContext(psiFile: PsiFile): FileContext? {
+        if (psiFile !is RsFile) return null
+
+        val path = psiFile.virtualFile.path
+        val imports = PsiTreeUtil.getChildrenOfTypeAsList(psiFile, RsUseItem::class.java)
+        val structures = PsiTreeUtil.getChildrenOfTypeAsList(psiFile, RsStructItem::class.java)
+        val functions = emptyList<PsiFile>()
+
+        return FileContext(psiFile, psiFile.name, path, null, imports, structures, functions)
+    }
+}

rust/src/main/resources/cc.unitmesh.rust.xml

@@ -3,11 +3,12 @@
     <dependencies>
         <plugin id="com.intellij.clion"/>
         <plugin id="com.intellij.cidr.base"/>
-
         <module name="org.rust.lang"/>
     </dependencies>
 
     <extensions defaultExtensionNs="cc.unitmesh">
+        <fileContextBuilder language="Rust"
+                            implementationClass="cc.unitmesh.rust.context.RustFileContextBuilder"/>
         <classContextBuilder language="Rust"
                              implementationClass="cc.unitmesh.rust.context.RustClassContextBuilder"/>
         <methodContextBuilder language="Rust"