more signature help

5 files changed, 109 insertions, 16 deletions

diff --git a/lsp-parse.c b/lsp-parse.c
index 339c490..c340d33 100644
--- a/lsp-parse.c
+++ b/lsp-parse.c
@@ -132,6 +132,18 @@ static void parse_capabilities(LSP *lsp, const JSON *json, JSONObject capabiliti
 	}
 }
 
+static JSONString get_markup_content(const JSON *json, JSONValue markup_value) {
+	// some fields are of type string | MarkupContent (e.g. completion documentation)
+	// this converts either one to a string.
+	if (markup_value.type == JSON_STRING) {
+		return markup_value.val.string;
+	} else if (markup_value.type == JSON_OBJECT) {
+		return json_object_get_string(json, markup_value.val.object, "value");
+	} else {
+		return (JSONString){0};
+	}
+}
+
 static bool parse_completion(LSP *lsp, const JSON *json, LSPResponse *response) {
 	// deal with textDocument/completion response.
 	// result: CompletionItem[] | CompletionList | null
@@ -229,16 +241,8 @@ static bool parse_completion(LSP *lsp, const JSON *json, LSPResponse *response)
 			item->text_edit.type = (LSPTextEditType)edit_type;
 		}
 		
-		JSONString documentation = {0};
 		JSONValue documentation_value = json_object_get(json, item_object, "documentation");
-		// the "documentation" field is either just a string or an object containing
-		// a type ("markdown" or "plaintext") and a string.
-		if (documentation_value.type == JSON_STRING) {
-			documentation = documentation_value.val.string;
-		} else if (documentation_value.type == JSON_OBJECT) {
-			documentation = json_object_get_string(json, documentation_value.val.object,
-				"value");
-		}
+		JSONString documentation = get_markup_content(json, documentation_value);
 		if (documentation.len) {
 			if (documentation.len > 1000) {
 				// rust has some docs which are *20,000* bytes long
@@ -292,6 +296,56 @@ static bool parse_completion(LSP *lsp, const JSON *json, LSPResponse *response)
 	return true;
 }
 
+static bool parse_signature_help(LSP *lsp, const JSON *json, LSPResponse *response) {
+	JSONObject result = json_force_object(json_get(json, "result"));
+	LSPResponseSignatureHelp *help = &response->data.signature_help;
+	
+	u32 active_signature = 0;
+	double active_signature_dbl = json_object_get_number(json, result, "activeSignature");
+	if (isnormal(active_signature_dbl))
+		active_signature = (u32)active_signature_dbl;
+	double active_signature_active_parameter = json_object_get_number(json, result, "activeParameter");
+	
+	JSONArray signatures = json_object_get_array(json, result, "signatures");
+	if (active_signature >= signatures.len)
+		active_signature = 0;
+	for (u32 s = 0; s < signatures.len; ++s) {
+		// parse SignatureInformation
+		LSPSignatureInformation *signature_out = arr_addp(help->signatures);
+		JSONObject signature_in = json_array_get_object(json, signatures, s);
+		JSONString label = json_object_get_string(json, signature_in, "label");
+		signature_out->label = lsp_response_add_json_string(response, json, label);
+		JSONString documentation = get_markup_content(json,
+			json_object_get(json, signature_in, "documentation"));
+		if (documentation.len)
+			signature_out->documentation = lsp_response_add_json_string(response, json, documentation);
+		
+		JSONArray parameters = json_object_get_array(json, signature_in, "parameters");
+		u32 active_parameter = U32_MAX;
+		double active_parameter_dbl = json_object_get_number(json, signature_in, "activeParameter");
+		if (isnormal(active_parameter_dbl)) {
+			active_parameter = (u32)active_parameter_dbl;
+		}
+		if (s == active_signature && active_parameter == U32_MAX &&
+			isnormal(active_signature_active_parameter)) {
+			active_parameter = (u32)active_parameter_dbl;
+		}
+		if (active_parameter < parameters.len) {
+			JSONObject parameter_info = json_array_get_object(json, parameters, active_parameter);
+			@TODO
+		}
+	}
+	
+	if (active_signature != 0) {
+		//make sure active signature is #0
+		LSPSignatureInformation active = help->signatures[active_signature];
+		arr_remove(help->signatures, active_signature);
+		arr_insert(help->signatures, 0, active);
+	}
+	
+	return true;
+}
+
 // fills request->id/id_string appropriately given the request's json
 // returns true on success
 static WarnUnusedResult bool parse_id(JSON *json, LSPRequest *request) {
@@ -425,6 +479,9 @@ static void process_message(LSP *lsp, JSON *json) {
 		case LSP_REQUEST_COMPLETION:
 			add_to_messages = parse_completion(lsp, json, &response);
 			break;
+		case LSP_REQUEST_SIGNATURE_HELP:
+			add_to_messages = parse_signature_help(lsp, json, &response);
+			break;
 		case LSP_REQUEST_INITIALIZE: {
 			// it's the response to our initialize request!
 			if (result.type == JSON_OBJECT) {
diff --git a/lsp-write.c b/lsp-write.c
index 835cfce..910eb1b 100644
--- a/lsp-write.c
+++ b/lsp-write.c
@@ -1,5 +1,3 @@
-
-
 static const char *lsp_language_id(Language lang) {
 	switch (lang) {
 	case LANG_CONFIG:
@@ -228,6 +226,13 @@ static void write_workspace_folders(JSONWriter *o, LSPDocumentID *workspace_fold
 	write_arr_end(o);
 }
 
+static void write_document_position(JSONWriter *o, LSPDocumentPosition pos) {
+	write_key_obj_start(o, "textDocument");
+		write_key_file_uri(o, "uri", pos.document);
+	write_obj_end(o);
+	write_key_position(o, "position", pos.pos);
+}
+
 static const char *lsp_request_method(LSPRequest *request) {
 	switch (request->type) {
 	case LSP_REQUEST_NONE: break;
@@ -454,10 +459,7 @@ static void write_request(LSP *lsp, LSPRequest *request) {
 	case LSP_REQUEST_COMPLETION: {
 		const LSPRequestCompletion *completion = &request->data.completion;
 		write_key_obj_start(o, "params");
-			write_key_obj_start(o, "textDocument");
-				write_key_file_uri(o, "uri", completion->position.document);
-			write_obj_end(o);
-			write_key_position(o, "position", completion->position.pos);
+			write_document_position(o, completion->position);
 			const LSPCompletionContext *context = &completion->context;
 			LSPCompletionTriggerKind trigger_kind = context->trigger_kind;
 			if (trigger_kind != LSP_TRIGGER_NONE) {
@@ -469,6 +471,12 @@ static void write_request(LSP *lsp, LSPRequest *request) {
 			}
 		write_obj_end(o);
 	} break;
+	case LSP_REQUEST_SIGNATURE_HELP: {
+		const LSPRequestSignatureHelp *help = &request->data.signature_help;
+		write_key_obj_start(o, "params");
+			write_document_position(o, help->position);
+		write_obj_end(o);
+	} break;
 	case LSP_REQUEST_DID_CHANGE_WORKSPACE_FOLDERS: {
 		const LSPRequestDidChangeWorkspaceFolders *w = &request->data.change_workspace_folders;
 		write_key_obj_start(o, "params");
diff --git a/lsp.c b/lsp.c
index 9ec7ad7..bd6348a 100644
--- a/lsp.c
+++ b/lsp.c
@@ -1,5 +1,5 @@
 // print server-to-client communication
-#define LSP_SHOW_S2C 0
+#define LSP_SHOW_S2C 1
 // print client-to-server communication
 #define LSP_SHOW_C2S 0
 
@@ -42,6 +42,7 @@ static void lsp_request_free(LSPRequest *r) {
 	case LSP_REQUEST_SHUTDOWN:
 	case LSP_REQUEST_EXIT:
 	case LSP_REQUEST_COMPLETION:
+	case LSP_REQUEST_SIGNATURE_HELP:
 	case LSP_REQUEST_DID_CLOSE:
 	case LSP_REQUEST_WORKSPACE_FOLDERS:
 		break;
@@ -74,6 +75,9 @@ static void lsp_response_free(LSPResponse *r) {
 	case LSP_REQUEST_COMPLETION:
 		arr_free(r->data.completion.items);
 		break;
+	case LSP_REQUEST_SIGNATURE_HELP:
+		arr_free(r->data.signature_help.signatures);
+		break;
 	default:
 		break;
 	}
@@ -130,6 +134,8 @@ static bool lsp_supports_request(LSP *lsp, const LSPRequest *request) {
 		return true;
 	case LSP_REQUEST_COMPLETION:
 		return cap->completion_support;
+	case LSP_REQUEST_SIGNATURE_HELP:
+		return cap->signature_help_support;
 	case LSP_REQUEST_DID_CHANGE_WORKSPACE_FOLDERS:
 		return cap->workspace_folders_support;
 	}
diff --git a/lsp.h b/lsp.h
index 1c75861..4491cd2 100644
--- a/lsp.h
+++ b/lsp.h
@@ -245,6 +245,26 @@ typedef struct {
 	LSPCompletionItem *items;
 } LSPResponseCompletion;
 
+typedef struct {
+	LSPString label;
+	LSPString documentation;
+	// NOTE: LSP gives us parameter information for *all*
+	// parameters, but we only really need it for the active parameter.
+	
+	// (UTF-16) indices into `label` indicating which
+	// part of it should be highlighted for the active parameter
+	u16 active_start;
+	u16 active_end;
+	// documentation for the active parameter
+	LSPString active_documentation;
+} LSPSignatureInformation;
+
+typedef struct {
+	// NOTE: the "active" signature will be the first one
+	// in this array.
+	LSPSignatureInformation *signatures;
+} LSPResponseSignatureHelp;
+
 
 typedef LSPRequestType LSPResponseType;
 typedef struct {
@@ -255,6 +275,7 @@ typedef struct {
 	char *string_data;
 	union {
 		LSPResponseCompletion completion;
+		LSPResponseSignatureHelp signature_help;
 	} data;
 } LSPResponse;
 
diff --git a/main.c b/main.c
index 3f028f6..3468577 100644
--- a/main.c
+++ b/main.c
@@ -6,6 +6,7 @@
      - go to definition using LSP
      - find usages
 - go through signature help capabilities
+- JSON syntax highlighting
 - separate signature-help setting (dont use trigger-characters)
 - check if there are any other non-optional/nice-to-have-support-for server-to-client requests
 - do something with lsp->error