1 files changed, 75 insertions, 13 deletions

diff --git a/web/web_prompt.c b/web/web_prompt.c
index 69f4705..201bd7b 100644
--- a/web/web_prompt.c
+++ b/web/web_prompt.c
@@ -8,8 +8,68 @@
 
 #include <emscripten/emscripten.h>
 
+struct prompt_state {
+	char *msgl, *input, *msgr;
+};
+
+struct prompt_state prompt_buffered, prompt_flushed;
+
 enum prompt_mode pm;
 
+static inline void buffer_str(char *str, char **buffer, char *flushed)
+{
+	if (str == *buffer || (str && *buffer && !strcmp(str, *buffer)))
+		return;
+
+	if (*buffer && *buffer != flushed)
+		free(*buffer);
+
+	*buffer = str ? strdup(str) : NULL;
+}
+
+void prompt_set_msgl(char *str)
+{
+	buffer_str(str, &prompt_buffered.msgl, prompt_flushed.msgl);
+}
+
+void prompt_set_msgr(char *str)
+{
+	buffer_str(str, &prompt_buffered.msgr, prompt_flushed.msgr);
+}
+
+void prompt_set_input(char *str)
+{
+	buffer_str(str, &prompt_buffered.input, prompt_flushed.input);
+}
+
+static inline bool buffered_str_changed(char *buffered, char *flushed)
+{
+	return (!buffered != !flushed) ||
+		(buffered && flushed && strcmp(buffered, flushed));
+}
+
+static inline void free_flushed_str(char *flushed, char *buffered)
+{
+	if (flushed && flushed != buffered)
+		free(flushed);
+}
+
+void prompt_flush()
+{
+	if (buffered_str_changed(prompt_buffered.msgl, prompt_flushed.msgl))
+		EM_ASM({setPromptMsgL($0)}, prompt_buffered.msgl);
+	if (buffered_str_changed(prompt_buffered.msgr, prompt_flushed.msgr))
+		EM_ASM({setPromptMsgR($0)}, prompt_buffered.msgr);
+	if (buffered_str_changed(prompt_buffered.input, prompt_flushed.input))
+		EM_ASM({setPromptInput($0)}, prompt_buffered.input);
+
+	free_flushed_str(prompt_flushed.msgl, prompt_buffered.msgl);
+	free_flushed_str(prompt_flushed.msgr, prompt_buffered.msgr);
+	free_flushed_str(prompt_flushed.input, prompt_buffered.input);
+
+	prompt_flushed = prompt_buffered;
+}
+
 void set_prompt_mode(enum prompt_mode mode)
 {
 	pm = mode;
@@ -26,8 +86,8 @@ void set_prompt_mode(enum prompt_mode mode)
 void prompt_visit()
 {
 	set_prompt_mode(PM_VISIT);
-	EM_ASM({promptMsgL($0)}, "Enter points:");
-	EM_ASM({promptMsgR($0)}, "");
+	prompt_set_msgl("Enter points:");
+	prompt_set_msgr(NULL);
 	EM_ASM({setKeyLabel($0, $1)}, "submit", "OK");
 	EM_ASM({setKeyLabel($0, $1)}, "rem", "REMAINING");
 }
@@ -35,15 +95,15 @@ void prompt_visit()
 void prompt_bot_visit()
 {
 	set_prompt_mode(PM_DARTBOARD);
-	EM_ASM({promptMsgL($0)}, "Bot is throwing…");
-	EM_ASM({promptMsgR($0)}, "");
+	prompt_set_msgl("Bot is throwing…");
+	prompt_set_msgr(NULL);
 }
 
 void prompt_num_darts()
 {
 	set_prompt_mode(PM_NUM_DARTS);
-	EM_ASM({promptMsgL($0)}, "Darts needed?");
-	EM_ASM({promptMsgR($0)}, "");
+	prompt_set_msgl("Darts needed?");
+	prompt_set_msgr(NULL);
 	EM_ASM({setKeyLabel($0, $1)}, "submit", "OK");
 	EM_ASM({setKeyLabel($0, $1)}, "rem", "REMAINING");
 }
@@ -52,10 +112,10 @@ void prompt_end_match()
 {
 	EM_ASM(setPlayerActive()); // sets all inactive
 	set_prompt_mode(PM_END_MATCH);
-	EM_ASM({promptMsgL($0)},
+	prompt_set_msgl(
 		state->mode == M_PVC && state->legs[1]->rem <= 0 ? "Bot wins. :(" :
 			"You win! :)");
-	EM_ASM({promptMsgR($0)}, "");
+	prompt_set_msgr(NULL);
 	EM_ASM({setKeyLabel($0, $1)}, "submit", "END MATCH");
 	EM_ASM({setKeyLabel($0, $1)}, "rem", "REMATCH");
 }
@@ -69,8 +129,8 @@ void prompt_select_mode()
 	EM_ASM(clearVisits());
 
 	set_prompt_mode(PM_SELECT_MODE);
-	EM_ASM({promptMsgL($0)}, "Select match mode:");
-	EM_ASM({promptMsgR($0)}, "");
+	prompt_set_msgl("Select match mode:");
+	prompt_set_msgr(NULL);
 }
 
 bool is_key_active(char *k)
@@ -113,6 +173,8 @@ void prompt_handle_pre(char *command)
 
 void prompt_handle_on_change()
 {
+	prompt_flush();
+
 	if (pm != PM_VISIT)
 		return;
 
@@ -132,7 +194,7 @@ void prompt_handle_append(char *data)
 	if (len_str < 3) {
 		str = realloc(str, len_str + len_data + 1);
 		memcpy(str + len_str, data, len_data + 1);
-		EM_ASM({setPromptInput($0)}, str);
+		prompt_set_input(str);
 		prompt_handle_on_change();
 	}
 	free(str);
@@ -147,7 +209,7 @@ void prompt_handle_backspace()
 	size_t len_str = strlen(str);
 	if (len_str > 0) {
 		str[len_str-1] = 0;
-		EM_ASM({setPromptInput($0)}, str);
+		prompt_set_input(str);
 		prompt_handle_on_change();
 	}
 	free(str);
@@ -158,7 +220,7 @@ void prompt_handle_clear()
 	if (pm == PM_DARTBOARD)
 		return;
 
-	EM_ASM({setPromptInput($0)}, "");
+	prompt_set_input(NULL);
 	prompt_handle_on_change();
 }