From 41d1dfaa6617df3b2caf88bd55ab17a6bb0aef00 Mon Sep 17 00:00:00 2001
From: sergiotarxz <sergio.iglesias7890@gmail.com>
Date: Thu, 7 Jan 2021 16:02:34 +0100
Subject: [PATCH] Added support for calling javascript functions from perl.

---
 bin/js-pruebas                          |  20 +++--
 javascript_interpreter_xs/javascript.xs | 115 +++++++++++++-----------
 2 files changed, 75 insertions(+), 60 deletions(-)

diff --git a/bin/js-pruebas b/bin/js-pruebas
index 10d361d..ab65d63 100755
--- a/bin/js-pruebas
+++ b/bin/js-pruebas
@@ -8,13 +8,17 @@ use feature 'say';
 use Peertube::DL::Javascript;
 
 my $a = Peertube::DL::Javascript::_duk_create_heap_default();
-eval { Peertube::DL::Javascript::_duk_push_lstring( $a, "\"hola mundo\"" ); };
-if ($@) {
-    warn $@;
-    $@ = "";
-}
 if ( defined $a ) {
-Peertube::DL::Javascript::_duk_peval($a);
-say Peertube::DL::Javascript::_duk_get_lstring($a, -1);
-Peertube::DL::Javascript::_duk_destroy_heap($a);
+    eval {
+        my $return = Peertube::DL::Javascript::_duk_eval_wrapper(
+            $a,
+            "function a(nombre) { return 'Hello ' + nombre;  }; a('sergio');"
+        );
+        say $return;
+    };
+    if ($@) {
+        warn $@;
+    }
+    say Peertube::DL::Javascript::_duk_call_function( $a, "a", "sergio" );
+    Peertube::DL::Javascript::_duk_destroy_heap($a);
 }
diff --git a/javascript_interpreter_xs/javascript.xs b/javascript_interpreter_xs/javascript.xs
index b7c5595..9441baa 100644
--- a/javascript_interpreter_xs/javascript.xs
+++ b/javascript_interpreter_xs/javascript.xs
@@ -24,48 +24,80 @@ _duk_create_heap_default()
         RETVAL
 
 SV *
-_duk_push_lstring(SV *, SV *)
+_duk_eval_wrapper(SV *, SV *)
     CODE:
+        if (!ST(0)) {
+            croak("Javascript context undefined.", 0);
+        }
         duk_context *context = (duk_context *) SvUV(ST(0)); 
-        if(!context) {
-            croak("Javascript context undef.", 0);
+        if (!context) {
+            croak("Javascript context null on function call.");
         }
-        STRLEN len;
-        char * lstring = SvPV(ST(1), len);
-        if(!len) {
-            croak("Empty string on lstring push.");
+        duk_idx_t top_index;
+        if ( (top_index = duk_get_top_index(context)) != DUK_INVALID_INDEX) {
+            duk_pop_n(context, top_index + 1);
         }
-        duk_push_lstring(context, lstring, strlen(lstring));
-//
-//      * Example subroutine call
-//      dSP;
-//      ENTER;
-//      SAVETMPS;
-//      PUSHMARK(SP);
-//      EXTEND(SP, 1);
-//      PUSHs(sv_2mortal(newSVpv("Javascript context invalid.", 0)));
-//      PUTBACK;
-//
-//      call_sv(sv_2mortal(newSVpv("::die", 0)), G_DISCARD);
-//
-//      FREETMPS;
-//      LEAVE;
-//
-//
+        duk_require_stack(context, 2);
+        if (!ST(1)) {
+            croak("Code to eval is undef.");
+        }
+        STRLEN code_len;
+        char *code = SvPV(ST(1), code_len);
+        duk_push_lstring(context, code, strlen(code));
+        if ( duk_peval(context) != 0 ) {
+            croak("Eval failed:\n%s\n", duk_get_string(context, -1));
+        }
+        duk_size_t *lstring_len;
+        const char * lstring = duk_get_lstring(context, -1, lstring_len);
+        RETVAL = newSVpv(lstring, (size_t) lstring_len);
+        top_index = duk_get_top_index(context);
+        duk_pop_n(context, top_index+1);
     OUTPUT:
         RETVAL
 
-void
-_duk_peval(SV *)
+SV *
+_duk_call_function(SV *, SV *, ...) 
     CODE:
+        if (!ST(0)) {
+            croak("Context is undef.");
+        }
         duk_context *context = (duk_context *) SvUV(ST(0)); 
-        if(!context) {
-            croak("Javascript context undef.", 0);
+        if (!context) {
+            croak("Javascript context null on function call.");
         }
-
-        if(duk_peval(context) != 0) {
-            croak("Eval failed:\n%s\n", duk_safe_to_string(context, -1));
+        STRLEN function_name_len;
+        if (!ST(1)) {
+            croak("Function name must be defined.");
         }
+        char * function_name = SvPV(ST(1), function_name_len);
+        if ( function_name_len == 0 ) {
+            croak("Function name cannot be empty.");
+        }
+        duk_idx_t top_index;
+        if ( (top_index = duk_get_top_index(context)) != DUK_INVALID_INDEX ) {
+            duk_pop_n(context, top_index+1);
+        }
+        duk_require_stack(context, items+1);
+        (void) duk_get_global_lstring(context, function_name, strlen(function_name));
+        if (items > 2) {
+            for ( int i = 2; i < items; i++) {
+                SV *argument_SV = ST(i);
+                if (!argument_SV) {
+                    croak("Argument %d undefined.", i);
+                }
+                STRLEN argument_len;
+                char *argument = SvPV(argument_SV, argument_len);
+                duk_push_lstring(context, argument, strlen(argument));
+            }
+        }
+        duk_size_t *lstring_len;
+        duk_call(context, 1);
+        char * return_value = duk_get_lstring(context, -1, lstring_len);
+        top_index = duk_get_top_index(context);
+        duk_pop_n(context, top_index+1);
+        RETVAL = newSVpv(return_value, (size_t) lstring_len);
+    OUTPUT:
+        RETVAL
 
 void
 _duk_destroy_heap(SV *)
@@ -75,24 +107,3 @@ _duk_destroy_heap(SV *)
             croak("Cannot destroy something that is not a context.");
         }
         duk_destroy_heap(context);
-
-SV *
-_duk_get_lstring(SV *, SV *)
-    CODE:
-        duk_context *context = (duk_context *) SvUV(ST(0)); 
-        if (!context) {
-            croak("Unable to get lstring from no existing context.");
-        }
-        duk_idx_t idx = SvIV(ST(1));
-        if (!duk_is_string(context, idx)) {
-            croak("Idx is not a string.");
-        }
-        if (duk_is_symbol(context, idx)) {
-            croak("This is a symbol, not a string.");
-        }
-        duk_size_t *lstring_len;
-        const char * lstring = duk_get_lstring(context, idx, lstring_len);
-        RETVAL = newSVpv(lstring, (size_t) lstring_len);
-    OUTPUT:
-        RETVAL
-