From 617cdd89dea3d3ae3708ed14c72166f0fb89836a Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Tue, 23 Oct 2018 20:48:12 -0700
Subject: [PATCH] Implement textDocument/foldingRange

---
 CMakeLists.txt                            |  1 +
 src/messages/initialize.cc                |  4 +-
 src/messages/textDocument_foldingRange.cc | 61 +++++++++++++++++++++++
 3 files changed, 65 insertions(+), 1 deletion(-)
 create mode 100644 src/messages/textDocument_foldingRange.cc

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7c526d72..a16583e3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -220,6 +220,7 @@ target_sources(ccls PRIVATE
   src/messages/textDocument_completion.cc
   src/messages/textDocument_definition.cc
   src/messages/textDocument_did.cc
+  src/messages/textDocument_foldingRange.cc
   src/messages/textDocument_formatting.cc
   src/messages/textDocument_documentHighlight.cc
   src/messages/textDocument_documentSymbol.cc
diff --git a/src/messages/initialize.cc b/src/messages/initialize.cc
index c9aa4ce2..0836b436 100644
--- a/src/messages/initialize.cc
+++ b/src/messages/initialize.cc
@@ -160,6 +160,7 @@ struct lsServerCapabilities {
   bool renameProvider = true;
   // The server provides document link support.
   lsDocumentLinkOptions documentLinkProvider;
+  bool foldingRangeProvider = true;
   // The server provides execute command support.
   struct ExecuteCommandOptions {
     std::vector<std::string> commands{std::string(ccls_xref)};
@@ -184,7 +185,8 @@ MAKE_REFLECT_STRUCT(lsServerCapabilities, textDocumentSync, hoverProvider,
                     codeLensProvider, documentFormattingProvider,
                     documentRangeFormattingProvider,
                     documentOnTypeFormattingProvider, renameProvider,
-                    documentLinkProvider, executeCommandProvider, workspace);
+                    documentLinkProvider, foldingRangeProvider,
+                    executeCommandProvider, workspace);
 
 // Workspace specific client capabilities.
 struct lsWorkspaceClientCapabilites {
diff --git a/src/messages/textDocument_foldingRange.cc b/src/messages/textDocument_foldingRange.cc
new file mode 100644
index 00000000..31563695
--- /dev/null
+++ b/src/messages/textDocument_foldingRange.cc
@@ -0,0 +1,61 @@
+// Copyright 2017-2018 ccls Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#include "message_handler.h"
+#include "pipeline.hh"
+#include "project.h"
+#include "query_utils.h"
+#include "working_files.h"
+
+namespace ccls {
+namespace {
+MethodType foldingRange = "textDocument/foldingRange";
+
+struct In_textDocumentFoldingRange : public RequestMessage {
+  MethodType GetMethodType() const override { return foldingRange; }
+  struct Params {
+    lsTextDocumentIdentifier textDocument;
+  } params;
+};
+MAKE_REFLECT_STRUCT(In_textDocumentFoldingRange::Params, textDocument);
+MAKE_REFLECT_STRUCT(In_textDocumentFoldingRange, id, params);
+REGISTER_IN_MESSAGE(In_textDocumentFoldingRange);
+
+struct FoldingRange {
+  int startLine, startCharacter, endLine, endCharacter;
+  std::string kind = "region";
+};
+MAKE_REFLECT_STRUCT(FoldingRange, startLine, startCharacter, endLine, endCharacter, kind);
+
+struct Handler_textDocumentFoldingRange
+    : BaseMessageHandler<In_textDocumentFoldingRange> {
+  MethodType GetMethodType() const override { return foldingRange; }
+  void Run(In_textDocumentFoldingRange *request) override {
+    QueryFile *file;
+    if (!FindFileOrFail(db, project, request->id,
+                        request->params.textDocument.uri.GetPath(), &file,
+                        nullptr))
+      return;
+    WorkingFile *wfile =
+        working_files->GetFileByFilename(file->def->path);
+    if (!wfile)
+      return;
+    std::vector<FoldingRange> result;
+    std::optional<lsRange> ls_range;
+
+    for (auto [sym, refcnt] : file->symbol2refcnt)
+      if (refcnt > 0 && sym.extent.Valid() &&
+          (sym.kind == SymbolKind::Func || sym.kind == SymbolKind::Type) &&
+          (ls_range = GetLsRange(wfile, sym.extent))) {
+        FoldingRange &fold = result.emplace_back();
+        fold.startLine = ls_range->start.line;
+        fold.startCharacter = ls_range->start.character;
+        fold.endLine = ls_range->end.line;
+        fold.endCharacter = ls_range->end.character;
+      }
+    pipeline::Reply(request->id, result);
+  }
+};
+REGISTER_MESSAGE_HANDLER(Handler_textDocumentFoldingRange);
+} // namespace
+} // namespace ccls