From c6d99559b547dcb4546363389bc0c5f8b63ff92d Mon Sep 17 00:00:00 2001
From: Adrien Bourmault <neox@os-k.eu>
Date: Mon, 12 Jul 2021 19:58:09 +0200
Subject: [PATCH] Better cli : arrows and edition

---
 src/cli.c    | 79 ++++++++++++++++++++++++++++++++++++++++++++--------
 src/server.c |  3 ++
 2 files changed, 70 insertions(+), 12 deletions(-)

diff --git a/src/cli.c b/src/cli.c
index 45f63b3..9276db0 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -39,8 +39,16 @@
 #define KEY_DIRECTIONS 91
 #define KEY_ARROW_UP 65
 #define KEY_ARROW_DOWN 66
+#define KEY_ARROW_RIGHT 67
+#define KEY_ARROW_LEFT 68
 #define KEY_DELETE 127
 
+#define C_CLEARLINE "\e[2K"
+#define C_CURSORLEFT "\e[1D"
+#define C_CURSORRIGHT "\e[1C"
+#define C_SAVE_CURSORPOS "\e7"
+#define C_RESTORE_CURSORPOS "\e8"
+
 static char getch(void)
 {
     char buf = 0;
@@ -90,7 +98,7 @@ void connectedCommunication(int sockfd)
     int historyIndex = 0, historyModifier;
 
     char curChar;
-    int curLineLength, continueReadLine, answerLength;
+    int curLineLength, curPosition, continueReadLine, answerLength;
 
     char *exitCommand = "exit";
     char *promptString = "gem-graph console> ";
@@ -102,9 +110,10 @@ void connectedCommunication(int sockfd)
 
         // Read command from terminal
         curLineLength = 0;
+        curPosition = 0;
         continueReadLine = 1;
         historyModifier = -1;
-        while (continueReadLine && (curChar = getch())) { //TODO empty line in history
+        while (continueReadLine && (curChar = getch())) {
 
             switch (curChar) {
 
@@ -114,17 +123,31 @@ void connectedCommunication(int sockfd)
                 break;
 
             case KEY_DELETE:
-
-                if (!strlen(sendBuff))
+                if (strlen(sendBuff) == 0)
                     break;
 
                 // Delete last char
-                sendBuff[--curLineLength] = 0;
+                sendBuff[--curPosition] = 0;
+                curLineLength--;
 
-                printf("\33[2K\r%s%s",
+                if (curLineLength >= 0) {
+
+                    printf("%s", C_SAVE_CURSORPOS);
+
+                    memmove(sendBuff + curPosition, sendBuff + curPosition + 1,
+                            SEND_BUFFER_SIZE);
+
+                    //sendBuff[curLineLength--] = 0;
+
+                    printf("%s\r%s%s",
+                        C_CLEARLINE,
                         promptString,
                         sendBuff
                        );
+
+                    printf("%s", C_RESTORE_CURSORPOS);
+                    printf("%s", C_CURSORLEFT);
+                }
                 break;
 
             case KEY_ESCAPE:
@@ -137,7 +160,8 @@ void connectedCommunication(int sockfd)
                             break;
                         historyModifier = (historyModifier + 1)
                             % (historyIndex + 1);
-                        printf("\33[2K\r%s%s",
+                        printf("%s\r%s%s",
+                                C_CLEARLINE,
                                 promptString,
                                 &historyBuff[
                                     (historyIndex - historyModifier - 1)
@@ -149,15 +173,16 @@ void connectedCommunication(int sockfd)
                                * SEND_BUFFER_SIZE
                                ], SEND_BUFFER_SIZE);
                         curLineLength = strlen(sendBuff);
+                        curPosition = curLineLength;
                         break;
 
                     case KEY_ARROW_DOWN:
-
                         if (historyIndex <= 0)
                             break;
                         historyModifier = (historyModifier + historyIndex)
                             % (historyIndex + 1);
-                        printf("\33[2K\r%s%s",
+                        printf("%s\r%s%s",
+                                C_CLEARLINE,
                                 promptString,
                                 &historyBuff[
                                     (historyIndex - historyModifier - 1)
@@ -169,16 +194,46 @@ void connectedCommunication(int sockfd)
                                * SEND_BUFFER_SIZE
                                ], SEND_BUFFER_SIZE);
                         curLineLength = strlen(sendBuff);
+                        curPosition = curLineLength;
+                        break;
+
+                    case KEY_ARROW_LEFT:
+                        if (curPosition > 0) {
+                            printf("%s", C_CURSORLEFT);
+                            curPosition--;
+                        }
+                        break;
+
+                    case KEY_ARROW_RIGHT:
+                        if (curPosition < curLineLength) {
+                            printf("%s", C_CURSORRIGHT);
+                            curPosition++;
+                        }
                         break;
                     }
                 }
                 break;
 
             default:
-                sendBuff[curLineLength++] = curChar;
-                printf("%c", curChar);
-                break;
+                if (curLineLength < SEND_BUFFER_SIZE) {
+                    printf("%s", C_SAVE_CURSORPOS);
 
+                    memmove(sendBuff + curPosition + 1, sendBuff + curPosition,
+                            SEND_BUFFER_SIZE);
+
+                    sendBuff[curPosition++] = curChar;
+                    curLineLength++;
+
+                    printf("%s\r%s%s",
+                        C_CLEARLINE,
+                        promptString,
+                        sendBuff
+                    );
+
+                    printf("%s", C_RESTORE_CURSORPOS);
+                    printf("%s", C_CURSORRIGHT);
+                }
+                break;
             }
 
             fflush(stdout);
diff --git a/src/server.c b/src/server.c
index af13a26..90a953c 100644
--- a/src/server.c
+++ b/src/server.c
@@ -87,6 +87,9 @@ void *serverCommunicationInstance(void *server)
                  clientPort,
                  receiveBuff);
 
+        if (receiveBuff[0] == '\0')
+            break;
+
         // get args in an array
         tokenIndex = 0;
         argv = (char**) realloc(argv, 1 * sizeof(char*));