From ad1a8e0d95c6171ab28ce27f794ebe9afe260a3a Mon Sep 17 00:00:00 2001
From: Myzel394 <50424412+Myzel394@users.noreply.github.com>
Date: Sat, 7 Sep 2024 21:02:43 +0200
Subject: [PATCH] feat(aliases): Add support for prepare rename

---
 .../lsp/text-document-prepare-rename.go       | 45 +++++++++++++++++++
 root-handler/handler.go                       |  9 ++++
 root-handler/text-document-prepare-rename.go  | 38 ++++++++++++++++
 3 files changed, 92 insertions(+)
 create mode 100644 handlers/aliases/lsp/text-document-prepare-rename.go
 create mode 100644 root-handler/text-document-prepare-rename.go

diff --git a/handlers/aliases/lsp/text-document-prepare-rename.go b/handlers/aliases/lsp/text-document-prepare-rename.go
new file mode 100644
index 0000000..2b2d03e
--- /dev/null
+++ b/handlers/aliases/lsp/text-document-prepare-rename.go
@@ -0,0 +1,45 @@
+package lsp
+
+import (
+	"config-lsp/handlers/aliases"
+	"config-lsp/handlers/aliases/ast"
+	"config-lsp/handlers/aliases/handlers"
+
+	"github.com/tliron/glsp"
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentPrepareRename(context *glsp.Context, params *protocol.PrepareRenameParams) (any, error) {
+	d := aliases.DocumentParserMap[params.TextDocument.URI]
+	character := params.Position.Character
+	line := params.Position.Line
+
+	rawEntry, found := d.Parser.Aliases.Get(line)
+
+	if !found {
+		return nil, nil
+	}
+
+	entry := rawEntry.(*ast.AliasEntry)
+
+	if character >= entry.Key.Location.Start.Character && character <= entry.Key.Location.End.Character {
+		return entry.Key.Location.ToLSPRange(), nil
+	}
+
+	if entry.Values != nil && character >= entry.Values.Location.Start.Character && character <= entry.Values.Location.End.Character {
+		rawValue := handlers.GetValueAtCursor(character, entry)
+
+		if rawValue == nil {
+			return nil, nil
+		}
+
+		switch (*rawValue).(type) {
+		case ast.AliasValueUser:
+			userValue := (*rawValue).(ast.AliasValueUser)
+
+			return userValue.Location.ToLSPRange(), nil
+		}
+	}
+
+	return nil, nil
+}
diff --git a/root-handler/handler.go b/root-handler/handler.go
index 9b74ea4..9dff13c 100644
--- a/root-handler/handler.go
+++ b/root-handler/handler.go
@@ -30,6 +30,7 @@ func SetUpRootHandler() {
 		TextDocumentDefinition:  TextDocumentDefinition,
 		WorkspaceExecuteCommand: WorkspaceExecuteCommand,
 		TextDocumentRename:      TextDocumentRename,
+		TextDocumentPrepareRename: TextDocumentPrepareRename,
 	}
 
 	server := server.NewServer(&lspHandler, lsName, false)
@@ -41,6 +42,14 @@ func initialize(context *glsp.Context, params *protocol.InitializeParams) (any,
 	capabilities := lspHandler.CreateServerCapabilities()
 	capabilities.TextDocumentSync = protocol.TextDocumentSyncKindFull
 
+	if (*params.Capabilities.TextDocument.Rename.PrepareSupport) == true {
+		// Client supports rename preparation
+		prepareRename := true
+		capabilities.RenameProvider = protocol.RenameOptions{
+			PrepareProvider: &prepareRename,
+		}
+	}
+
 	return protocol.InitializeResult{
 		Capabilities: capabilities,
 		ServerInfo: &protocol.InitializeResultServerInfo{
diff --git a/root-handler/text-document-prepare-rename.go b/root-handler/text-document-prepare-rename.go
new file mode 100644
index 0000000..fc4489b
--- /dev/null
+++ b/root-handler/text-document-prepare-rename.go
@@ -0,0 +1,38 @@
+package roothandler
+
+import (
+	"github.com/tliron/glsp"
+	aliases "config-lsp/handlers/aliases/lsp"
+
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+func TextDocumentPrepareRename(context *glsp.Context, params *protocol.PrepareRenameParams) (any, error) {
+	language := rootHandler.GetLanguageForDocument(params.TextDocument.URI)
+
+	if language == nil {
+		showParseError(
+			context,
+			params.TextDocument.URI,
+			undetectableError,
+		)
+
+		return nil, undetectableError.Err
+	}
+
+	switch *language {
+	case LanguageHosts:
+		return nil, nil
+	case LanguageSSHDConfig:
+		return nil, nil
+	case LanguageFstab:
+		return nil, nil
+	case LanguageWireguard:
+		return nil, nil
+	case LanguageAliases:
+		return aliases.TextDocumentPrepareRename(context, params)
+	}
+
+	panic("root-handler/TextDocumentPrepareRename: unexpected language" + *language)
+}
+