Separator: support Unicode / double width separator string

Fixes #504

src/modules/separator/separator.c

@@ -2,19 +2,34 @@
 #include "common/jsonconfig.h"
 #include "modules/separator/separator.h"
 #include "util/stringUtils.h"
+#include "util/mallocHelper.h"
+#include "util/wcwidth.h"
+
+static inline uint32_t max(uint32_t a, uint32_t b)
+{
+    return a > b ? a : b;
+}
+
+static inline uint32_t getWcsWidth(const FFstrbuf* mbstr, wchar_t* wstr, mbstate_t* state)
+{
+    const char* str = mbstr->chars;
+    uint32_t wstrLength = (uint32_t) mbsrtowcs(wstr, &str, mbstr->length, state);
+    int result = mk_wcswidth(wstr, wstrLength);
+    return result > 0 ? (uint32_t) result : mbstr->length;
+}
 
 void ffPrintSeparator(FFSeparatorOptions* options)
 {
-    uint32_t titleLength = instance.state.titleLength;
-    if (titleLength == 0)
-    {
-        // Title was not printed, should we support this case?
-        titleLength = instance.state.platform.userName.length + 1 + (instance.config.title.fqdn ?
-            instance.state.platform.domainName.length :
-            instance.state.platform.hostName.length
-        );
-    }
+    mbstate_t state = {};
+    bool fqdn = instance.config.title.fqdn;
+    const FFPlatform* platform = &instance.state.platform;
 
+    FF_AUTO_FREE wchar_t* wstr = malloc((max(
+        platform->userName.length, options->string.length) + 1) * sizeof(*wstr));
+
+    uint32_t titleLength = 1 // @
+        + getWcsWidth(&platform->userName, wstr, &state) // user name
+        + (fqdn ? platform->domainName.length : platform->hostName.length); // host name
     ffLogoPrintLine();
 
     if(options->string.length == 0)
@@ -23,13 +38,39 @@ void ffPrintSeparator(FFSeparatorOptions* options)
     }
     else
     {
+        uint32_t wcsLength = getWcsWidth(&options->string, wstr, &state);
+
+        int remaining = (int) titleLength;
         //Write the whole separator as often as it fits fully into titleLength
-        for(uint32_t i = 0; i < titleLength / options->string.length; i++)
+        for (; remaining >= (int) wcsLength; remaining -= (int) wcsLength)
             ffStrbufWriteTo(&options->string, stdout);
 
-        //Write as much of the separator as needed to fill titleLength
-        for(uint32_t i = 0; i < titleLength % options->string.length; i++)
-            putchar(options->string.chars[i]);
+        if (remaining > 0)
+        {
+            //Write as much of the separator as needed to fill titleLength
+            if (wcsLength != options->string.length)
+            {
+                // Unicode chars
+                for(int i = 0; remaining > 0; ++i)
+                {
+                    #ifdef __linux__
+                    // https://stackoverflow.com/questions/75126743/i-have-difficulties-with-putwchar-in-c#answer-75137784
+                    char wch[16] = "";
+                    uint32_t wchLength = (uint32_t) wcrtomb(wch, wstr[i], &state);
+                    fwrite(wch, wchLength, 1, stdout);
+                    #else
+                    putwchar(wstr[i]);
+                    #endif
+                    int width = mk_wcwidth(wstr[i]);
+                    remaining -= width < 0 ? 0 : width;
+                }
+            }
+            else
+            {
+                for(int i = 0; i < remaining; i++)
+                    putchar(options->string.chars[i]);
+            }
+        }
     }
     putchar('\n');
 }