Fix doc dependency link (#1078)

pkl-doc/src/main/kotlin/org/pkl/doc/DocPackageInfo.kt

@@ -23,6 +23,7 @@ import org.pkl.core.Member.SourceLocation
 import org.pkl.core.PModule
 import org.pkl.core.PObject
 import org.pkl.core.TypeAlias
+import org.pkl.core.packages.PackageUri
 
 /** API equivalent of standard library module `pkl.DocPackageInfo`. */
 data class DocPackageInfo(
@@ -198,6 +199,12 @@ data class DocPackageInfo(
   ) {
     internal val prefix = "$name."
 
+    val qualifiedName: String =
+      if (uri != null) {
+        val packageUri = PackageUri(uri)
+        "${uri.authority}${packageUri.pathWithoutVersion}"
+      } else name
+
     /** Note: Returns an absolute URI, or an URI relative to the current site. */
     internal fun getModuleDocUrl(moduleName: String): URI? =
       when {

pkl-doc/src/main/kotlin/org/pkl/doc/DocScope.kt

@@ -35,7 +35,7 @@ internal sealed class DocScope {
 
   abstract val parent: DocScope?
 
-  private val siteScope: SiteScope? by lazy {
+  val siteScope: SiteScope? by lazy {
     var scope = this
     while (scope !is SiteScope) {
       scope = scope.parent ?: return@lazy null
@@ -122,7 +122,7 @@ internal abstract class PageScope : DocScope() {
 
 // equality is identity
 internal class SiteScope(
-  docPackages: List<DocPackage>,
+  val docPackages: List<DocPackage>,
   private val overviewImports: Map<String, URI>,
   private val importResolver: (URI) -> ModuleSchema,
   outputDir: Path,
@@ -259,6 +259,11 @@ internal class PackageScope(
 
   override val url: URI by lazy { parent.url.resolve("./${name.pathEncoded}/$version/index.html") }
 
+  fun urlForVersionRelativeTo(scope: DocScope, version: String): URI {
+    val myVersion = parent.url.resolve("./${name.pathEncoded}/$version/index.html")
+    return IoUtils.relativize(myVersion, scope.url)
+  }
+
   override val dataUrl: URI by lazy {
     parent.url.resolve("./data/${name.pathEncoded}/$version/index.js")
   }

pkl-doc/src/main/kotlin/org/pkl/doc/PageGenerator.kt

@@ -525,15 +525,16 @@ internal abstract class PageGenerator<out S>(
         var first = true
         for (dep in dependencies) {
           if (first) first = false else +", "
-          a {
-            href =
-              dep.documentation?.toString()
-                ?: pageScope.relativeSiteUrl
-                  .resolve("${dep.name}/${dep.version}/index.html")
-                  .toString()
-            +dep.name
-            +":"
-            +dep.version
+          val link = getDependencyLink(dep)
+          if (link != null) {
+            a {
+              href = link
+              +dep.name
+              +":"
+              +dep.version
+            }
+          } else {
+            span { +"${dep.name}:${dep.version}" }
           }
         }
       }
@@ -556,6 +557,14 @@ internal abstract class PageGenerator<out S>(
     return result
   }
 
+  private fun getDependencyLink(dep: DocPackageInfo.PackageDependency): String? {
+    val siteScope = pageScope.siteScope ?: return null
+    return siteScope.packageScopes.values
+      .find { it.name == dep.qualifiedName }
+      ?.urlForVersionRelativeTo(pageScope, dep.version)
+      ?.toString()
+  }
+
   protected class MemberInfoKey(val name: String, val classes: Set<String> = setOf())
 
   protected fun collectMemberInfo(