/************************************************

  coverband_ext.c -

  $Author: $

  Copyright (c) 2014 Dan Mayer

************************************************/

#include <ruby.h>

static int
any_ignore_patterns( VALUE rb_ignore_patterns, const char *srcfile ) {
  int ignore_patterns_len = RARRAY_LEN(rb_ignore_patterns);
  VALUE * ignore_patterns = RARRAY_PTR(rb_ignore_patterns);
  char * ignore_pattern;
  int i;
  for(i = 0; i < ignore_patterns_len; i++) {
    ignore_pattern  = StringValueCStr(ignore_patterns[i]);
    if (strstr(srcfile, ignore_pattern)) {
      return 1;
    }
  }
  return 0;
}

// TODO I read below do I need to do this for my variables below?
// If you create a Ruby object from C and store it in a C global variable without exporting it to Ruby, you must at least tell the garbage collector about it, lest ye be reaped inadvertently:
// VALUE obj;
// obj = rb_ary_new();
// rb_global_variable(obj);

static void trace_line_handler_ext(VALUE rb_event_flag_t, VALUE data, VALUE self, ID id, VALUE klass);

static void
trace_line_handler_ext(VALUE rb_event_flag_t, VALUE data, VALUE self, ID id, VALUE klass)
{
  VALUE currentCoverbandBase = rb_funcall(rb_path2class("Coverband::Base"), rb_intern("instance"), 0);
  const char *srcfile = rb_sourcefile();
  VALUE proj_dir = rb_iv_get(currentCoverbandBase, "@project_directory");
  const char * c_str_proj_dir = StringValueCStr(proj_dir);

  if((strstr(srcfile, "gems") == NULL) &&
     (strstr(srcfile, "internal:prelude") == NULL) &&
     (strstr(srcfile, c_str_proj_dir) != NULL) &&
     (!any_ignore_patterns( rb_iv_get(currentCoverbandBase, "@ignore_patterns"), srcfile))
    ) {
    rb_funcall(currentCoverbandBase, rb_intern("add_file_without_checks"), 2, rb_str_new2(srcfile), INT2NUM(rb_sourceline()));
  }

}

static VALUE
cb_extended(VALUE self) {
  return Qtrue;
}

static VALUE
cb_set_tracer(VALUE self) {
  if(!rb_iv_get(self, "@tracer_set")) {
    // NOTE: We are using rb_add_event_hook opposed to rb_tracepoint_new for 1.9.X compat
    // not using higher level C functions of set_trace_func to avoid extra overhead we don't need since we only need the RUBY_EVENT_LINE hook as well as only needing file / line number opposed to everything else.
    rb_thread_add_event_hook(rb_thread_current(), trace_line_handler_ext, RUBY_EVENT_LINE, 0);
    rb_iv_set(self, "@tracer_set", Qtrue);
  }
  return Qnil;
}

static VALUE
cb_unset_tracer(VALUE self) {
  if(rb_iv_get(self, "@tracer_set")) {
    rb_thread_remove_event_hook(rb_thread_current(), trace_line_handler_ext);
    rb_iv_set(self, "@tracer_set", Qfalse);
  }
  return Qnil;
}

void Init_coverband_ext(void)
{
  VALUE coverbandBase = rb_path2class("Coverband::Base");
  rb_define_method(coverbandBase, "extended?", cb_extended, 0);
  rb_define_method(coverbandBase, "set_tracer", cb_set_tracer, 0);
  rb_define_method(coverbandBase, "unset_tracer", cb_unset_tracer, 0);
}