#include "state_lib.h"

void rb_json_state_indent(state, json, depth)
  VALUE state, json;
  long depth;
{
  VALUE indent = rb_json_state_get_intent(state);
  char* c_indent = StringValueCStr(indent);
  // Incrementing the depth
  char* full_indent;
  long i;
  for(i=0; i<depth; i++) {
    strcat(full_indent, c_indent);
  }
  rb_str_cat2(json, full_indent);
}

VALUE rb_to_json(rb_target, rb_state, rb_indent)
  VALUE rb_target, rb_state, rb_indent;
{
  VALUE args = rb_ary_new2(3);
  rb_ary_store (args, 0, rb_target);
  rb_ary_store (args, 1, rb_state);
  rb_ary_store (args, 2, rb_indent);
  return rb_rescue(call_to_json, args, to_json_exception, rb_target);
}

VALUE rb_json_should_shift(state, object_nl)
  VALUE state, object_nl;
{
  if(state == Qnil) return Qfalse;
  if(RSTRING(object_nl)->len == 0) return Qfalse;
  return Qtrue;
}

/**
 * Creates a State object from _opts_, which ought to be Hash to create a
 * new State instance configured by opts, something else to create an
 * unconfigured instance. If _opts_ is a State object, it is just returned.
 */
VALUE rb_json_from_state(self, opts)
  VALUE self, opts;
{
  if(rb_obj_is_kind_of(opts, rb_cJsonState)) {
    return opts;
  }
  else if(rb_obj_is_kind_of(opts, rb_cHash)) {
    return rb_funcall(self, rb_intern("new"), 1, opts);
  }
  else {
    return rb_funcall(self, rb_intern("new"), 0);
  }
}

/**
 * Returns _true_, if _object_ was already seen during this Unparsing run.
 */
VALUE rb_json_state_seen(self, object)
  VALUE self, object;
{
  VALUE seen_ivar = rb_ivar_get(self, rb_intern("@seen"));
  return rb_hash_aref(seen_ivar, rb_obj_id(object));
}

/**
 * Remember _object_, to find out if it was already encountered (to find out
 * if a cyclic data structure is unparsed).
 */
VALUE rb_json_state_remember(self, object)
  VALUE self, object;
{
  VALUE seen_ivar = rb_ivar_get(self, rb_intern("@seen"));
  rb_hash_aset(seen_ivar, rb_obj_id(object), Qtrue);
}

/**
 * Forget _object_ for this Unparsing run.
 */
VALUE rb_json_state_forget(self, object)
  VALUE self, object;
{
  VALUE seen_ivar = rb_ivar_get(self, rb_intern("@seen"));
  rb_hash_delete(seen_ivar, rb_obj_id(object));
}

/** Static **/

static VALUE call_to_json(args)
  VALUE args;
{
  VALUE rb_target = rb_ary_entry(args, 0);
  VALUE rb_state = rb_ary_entry(args, 1);
  VALUE rb_indent = rb_ary_entry(args, 2);
  return rb_funcall(rb_target, rb_intern("to_json"), 2, rb_state, rb_indent);
}

static VALUE to_json_exception(rb_target, rb_error)
  VALUE rb_target, rb_error;
{
  VALUE rb_error_class = rb_obj_class(rb_error);
  if(rb_error_class == rb_eArgError) {
    return rb_funcall(rb_target, rb_intern("to_json"), 0);
  }
  else {
    rb_exc_raise(rb_error);
  }
}