fix handling of TextEdit[]

i hate microsoft so much

11 files changed, 118 insertions, 28 deletions

diff --git a/buffer.c b/buffer.c
index 1214fa4..9fa4ee5 100644
--- a/buffer.c
+++ b/buffer.c
@@ -1850,11 +1850,55 @@ LSPRange buffer_selection_as_lsp_range(TextBuffer *buffer) {
 	}
 }
 
-void buffer_apply_lsp_text_edit(TextBuffer *buffer, const LSPResponse *response, const LSPTextEdit *edit) {
-	BufferPos start = buffer_pos_from_lsp(buffer, edit->range.start);
-	BufferPos end = buffer_pos_from_lsp(buffer, edit->range.end);
-	buffer_delete_chars_between(buffer, start, end);
-	buffer_insert_utf8_at_pos(buffer, start, lsp_response_string(response, edit->new_text));
+void buffer_apply_lsp_text_edits(TextBuffer *buffer, const LSPResponse *response, const LSPTextEdit *lsp_edits, size_t n_edits) {
+	typedef struct {
+		BufferPos pos;
+		BufferPos end;
+		const char *new_text;
+	} Edit;
+	Edit *edits = calloc(n_edits, sizeof *edits);
+	for (size_t i = 0; i < n_edits; ++i) {
+		Edit *edit = &edits[i];
+		edit->pos = buffer_pos_from_lsp(buffer, lsp_edits[i].range.start);
+		edit->end = buffer_pos_from_lsp(buffer, lsp_edits[i].range.end);
+		edit->new_text = lsp_response_string(response, lsp_edits[i].new_text);
+	}
+	for (size_t i = 0; i < n_edits; ++i) {
+		Edit *edit = &edits[i];
+		buffer_delete_chars_between(buffer, edit->pos, edit->end);
+		buffer_insert_utf8_at_pos(buffer, edit->pos, edit->new_text);
+		// a TextEdit[] is annoyingly *not* applied one edit at a time,
+		// instead all the edits happen "at once"
+		//  (see https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textEditArray)
+		// so we need to adjust the positions of subsequent edits
+		size_t inserted_newlines = str_count_char(edit->new_text, '\n');
+		i32 line_diff = (i32)inserted_newlines
+			- (i32)(edit->end.line - edit->pos.line);
+		i32 index_diff = 0;
+		const char *last_newline = strrchr(edit->new_text, '\n');
+		if (last_newline) {
+			index_diff = (i32)unicode_utf32_len(last_newline + 1) - (i32)edit->end.index;
+		} else {
+			index_diff = (i32)unicode_utf32_len(edit->new_text) + (i32)edit->pos.index - (i32)edit->end.index;
+		}
+		// see how nightmarish this is? thanks a lot, microsoft.
+		for (size_t j = i + 1; j < n_edits; ++j) {
+			Edit *edit2 = &edits[j];
+			BufferPos bounds[2] = {edit2->pos, edit2->end};
+			for (u32 k = 0; k < 2; ++k) {
+				BufferPos *pos = &bounds[k];
+				if (buffer_pos_cmp(*pos, edit->pos) < 0)
+					continue;
+				
+				if (pos->line <= edit->end.line)
+					pos->index += (u32)index_diff;
+				pos->line += (u32)line_diff;
+			}
+			edit2->pos = bounds[0];
+			edit2->end = bounds[1];
+		}
+	}
+	free(edits);
 }
 
 static void buffer_send_lsp_did_change(LSP *lsp, TextBuffer *buffer, BufferPos pos,
diff --git a/ide-format.c b/ide-format.c
index 70103c7..8cc0059 100644
--- a/ide-format.c
+++ b/ide-format.c
@@ -58,10 +58,11 @@ void format_process_lsp_response(Ted *ted, const LSPResponse *response) {
 	if (buffer_lsp_document_id(buffer) != request->data.formatting.document)
 		return; // switched document
 
+	buffer_deselect(buffer);
 	const LSPResponseFormatting *f = &response->data.formatting;
-	arr_foreach_ptr(f->edits, const LSPTextEdit, edit) {
-		buffer_apply_lsp_text_edit(buffer, response, edit);
-	}
+	buffer_start_edit_chain(buffer);
+	buffer_apply_lsp_text_edits(buffer, response, f->edits, arr_len(f->edits));
+	buffer_end_edit_chain(buffer);
 }
 
 void format_quit(Ted *ted) {
diff --git a/ide-rename-symbol.c b/ide-rename-symbol.c
index c32f984..53a6467 100644
--- a/ide-rename-symbol.c
+++ b/ide-rename-symbol.c
@@ -136,7 +136,7 @@ void rename_symbol_process_lsp_response(Ted *ted, const LSPResponse *response) {
 	
 	arr_foreach_ptr(data->changes, const LSPWorkspaceChange, change) {
 		switch (change->type) {
-		case LSP_CHANGE_EDIT: {
+		case LSP_CHANGE_EDITS: {
 			const LSPWorkspaceChangeEdit *change_data = &change->data.edit;
 			const char *path = lsp_document_path(lsp, change_data->document);
 			if (!ted_open_file(ted, path)) goto done;
@@ -152,7 +152,7 @@ void rename_symbol_process_lsp_response(Ted *ted, const LSPResponse *response) {
 				goto done;
 			}
 			
-			buffer_apply_lsp_text_edit(buffer, response, &change_data->edit);
+			buffer_apply_lsp_text_edits(buffer, response, change_data->edits, arr_len(change_data->edits));
 			}
 			break;
 		case LSP_CHANGE_RENAME: {
diff --git a/lsp-parse.c b/lsp-parse.c
index 61e44c4..e941f1a 100644
--- a/lsp-parse.c
+++ b/lsp-parse.c
@@ -832,12 +832,12 @@ static bool parse_workspace_edit(LSP *lsp, LSPResponse *response, const JSON *js
 			LSPDocumentID document = 0;
 			if (!parse_document_uri(lsp, json, uri, &document))
 				return false;
+			LSPWorkspaceChange *change = arr_addp(edit->changes);
+			change->type = LSP_CHANGE_EDITS;
+			change->data.edit.document = document;
 			for (u32 e = 0; e < edits.len; ++e) {
-				LSPWorkspaceChange *change = arr_addp(edit->changes);
-				change->type = LSP_CHANGE_EDIT;
-				change->data.edit.document = document;
 				JSONValue text_edit = json_array_get(json, edits, e);
-				if (!parse_text_edit(lsp, response, json, text_edit, &change->data.edit.edit))
+				if (!parse_text_edit(lsp, response, json, text_edit, arr_addp(change->data.edit.edits)))
 					return false;
 			}
 		}
@@ -854,12 +854,12 @@ static bool parse_workspace_edit(LSP *lsp, LSPResponse *response, const JSON *js
 			if (!parse_document_uri(lsp, json, json_object_get(json, text_document, "uri"), &document))
 				return false;
 			JSONArray edits = json_object_get_array(json, change, "edits");
-			for (u32 e = 0; e < edits.len; ++e) {
-				LSPWorkspaceChange *out = arr_addp(edit->changes);
-				out->type = LSP_CHANGE_EDIT;
-				out->data.edit.document = document;
-				JSONValue text_edit = json_array_get(json, edits, e);
-				if (!parse_text_edit(lsp, response, json, text_edit, &out->data.edit.edit))
+			LSPWorkspaceChange *out = arr_addp(edit->changes);
+			out->type = LSP_CHANGE_EDITS;
+			out->data.edit.document = document;
+			for (u32 i = 0; i < edits.len; ++i) {
+				JSONValue text_edit = json_array_get(json, edits, i);
+				if (!parse_text_edit(lsp, response, json, text_edit, arr_addp(out->data.edit.edits)))
 					return false;
 			}
 		} else if (kind.type == JSON_STRING) {
diff --git a/lsp.c b/lsp.c
index 0ab78a8..e8cb630 100644
--- a/lsp.c
+++ b/lsp.c
@@ -159,9 +159,15 @@ void lsp_response_free(LSPResponse *r) {
 	case LSP_REQUEST_WORKSPACE_SYMBOLS:
 		arr_free(r->data.workspace_symbols.symbols);
 		break;
-	case LSP_REQUEST_RENAME:
+	case LSP_REQUEST_RENAME: {
+		LSPResponseRename *rename = &r->data.rename;
+		arr_foreach_ptr(rename->changes, LSPWorkspaceChange, c) {
+			if (c->type == LSP_CHANGE_EDITS) {
+				arr_free(c->data.edit.edits);
+			}
+		}
 		arr_free(r->data.rename.changes);
-		break;
+		} break;
 	case LSP_REQUEST_HIGHLIGHT:
 		arr_free(r->data.highlight.highlights);
 		break;
diff --git a/lsp.h b/lsp.h
index 832d3d4..395f5ee 100644
--- a/lsp.h
+++ b/lsp.h
@@ -482,7 +482,14 @@ typedef struct {
 } LSPResponseWorkspaceSymbols;
 
 typedef enum {
-	LSP_CHANGE_EDIT = 1,
+	// yes, we do need to store multiple edits in a single workspace change;
+	//   doing a workspace change with TextEdit[] t1
+	//   followed by a workspace change with TextEdit[] t2
+	//   is different from a workspace change with t1+t2
+	// (see https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textEditArray,
+	//      https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocumentEdit)
+	// because microsoft is a bunch of idiots
+	LSP_CHANGE_EDITS = 1,
 	LSP_CHANGE_CREATE,
 	LSP_CHANGE_RENAME,
 	LSP_CHANGE_DELETE
@@ -490,7 +497,7 @@ typedef enum {
 
 typedef struct {
 	LSPDocumentID document;
-	LSPTextEdit edit;
+	LSPTextEdit *edits;
 } LSPWorkspaceChangeEdit;
 
 typedef struct {
@@ -859,7 +866,7 @@ void lsp_write_quit(void);
 /// print server-to-client communication
 #define LSP_SHOW_S2C 0
 /// print client-to-server communication
-#define LSP_SHOW_C2S 0
+#define LSP_SHOW_C2S 1
 
 #endif // LSP_INTERNAL
 
diff --git a/main.c b/main.c
index a0b6e67..7506c08 100644
--- a/main.c
+++ b/main.c
@@ -1,6 +1,5 @@
 /*
 TODO:
-- figure out what's wrong with format-selection with clangd
 - figure out what's wrong with godot language server
 - automatically restart server
 FUTURE FEATURES:
diff --git a/ted-internal.h b/ted-internal.h
index 6868895..498516b 100644
--- a/ted-internal.h
+++ b/ted-internal.h
@@ -458,8 +458,8 @@ LSPPosition buffer_cursor_pos_as_lsp_position(TextBuffer *buffer);
 ///
 /// Returns `(LSPRange){0}` if nothing is selected.
 LSPRange buffer_selection_as_lsp_range(TextBuffer *buffer);
-/// Apply LSP TextEdit from response
-void buffer_apply_lsp_text_edit(TextBuffer *buffer, const LSPResponse *response, const LSPTextEdit *edit);
+/// Apply LSP TextEdit[] from response
+void buffer_apply_lsp_text_edits(TextBuffer *buffer, const LSPResponse *response, const LSPTextEdit *edits, size_t n_edits);
 /// Get the cursor position as an LSPDocumentPosition.
 LSPDocumentPosition buffer_cursor_pos_as_lsp_document_position(TextBuffer *buffer);
 /// highlight an \ref LSPRange in this buffer.
diff --git a/unicode.h b/unicode.h
index 8765164..cd6a965 100644
--- a/unicode.h
+++ b/unicode.h
@@ -187,6 +187,22 @@ static size_t unicode_utf16_len(const char *str) {
 	return len;
 }
 
+// get the number of UTF-32 codepoints needed to encode `str`.
+///
+// returns `(size_t)-1` on bad UTF-8
+static size_t unicode_utf32_len(const char *str) {
+	size_t len = 0;
+	uint32_t c = 0;
+	while (*str) {
+		size_t n = unicode_utf8_to_utf32(&c, str, 4);
+		if (n >= (size_t)-2)
+			return (size_t)-1;
+		++len;
+		str += n;
+	}
+	return len;
+}
+
 /// returns the UTF-8 offset from `str` which corresponds to a UTF-16 offset of
 /// `utf16_offset` (rounds down if `utf16_offset` is in the middle of a codepoint).
 ///
diff --git a/util.c b/util.c
index bdeb687..89b3dc2 100644
--- a/util.c
+++ b/util.c
@@ -262,6 +262,21 @@ void str_trim(char *str) {
 	str_trim_start(str);
 }
 
+size_t str_count_char(const char *s, char c) {
+	const char *p = s;
+	size_t count = 0;
+	while (1) {
+		p = strchr(p, c);
+		if (p) {
+			++count;
+			++p;
+		} else {
+			break;
+		}
+	}
+	return count;
+}
+
 char *a_sprintf(PRINTF_FORMAT_STRING const char *fmt, ...) ATTRIBUTE_PRINTF(1, 2);
 char *a_sprintf(const char *fmt, ...) {
 	// idk if you can always just pass NULL to vsnprintf
diff --git a/util.h b/util.h
index 97db6fd..edbcbe3 100644
--- a/util.h
+++ b/util.h
@@ -103,6 +103,8 @@ void str_trim_start(char *str);
 void str_trim_end(char *str);
 /// trim whitespace from both sides of a string
 void str_trim(char *str);
+/// count occurences of `c` in `s`
+size_t str_count_char(const char *s, char c);
 /// equivalent to GNU function asprintf (like sprintf, but allocates the string with malloc).
 char *a_sprintf(const char *fmt, ...);
 /// convert binary number to string. make sure `s` can hold at least 65 bytes!!