/*
  Copyright(C) 2015  Brazil
  Copyright(C) 2022  Sutou Kouhei <kou@clear-code.com>

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "../grn_ctx_impl.h"
#include <groonga/command.h>

#ifdef GRN_WITH_MRUBY
#include <mruby.h>
#include <mruby/class.h>
#include <mruby/data.h>
#include <mruby/value.h>
#include <mruby/string.h>

#include "mrb_ctx.h"
#include "mrb_command.h"

static struct mrb_data_type mrb_grn_command_type = {
  "Groonga::Command",
  NULL
};

mrb_value
mrb_grn_command_instantiate(grn_ctx *ctx, grn_obj *command)
{
  grn_mrb_data *data = &(ctx->impl->mrb);
  mrb_state *mrb = data->state;
  struct RClass *module = data->module;
  char name[GRN_TABLE_MAX_KEY_SIZE];
  int name_size;
  mrb_value mrb_name;
  struct RClass *command_class;
  struct RClass *target_command_class;
  mrb_value mrb_target_command_class;
  mrb_value mrb_arguments[1];

  name_size = grn_obj_name(ctx, command, name, GRN_TABLE_MAX_KEY_SIZE);
  mrb_name = mrb_str_new(mrb, name, name_size);

  command_class = mrb_class_get_under(mrb, module, "Command");
  mrb_target_command_class = mrb_funcall(mrb,
                                         mrb_obj_value(command_class),
                                         "find_class", 1, mrb_name);
  if (mrb_nil_p(mrb_target_command_class)) {
    target_command_class = command_class;
  } else {
    target_command_class = mrb_class_ptr(mrb_target_command_class);
  }
  mrb_arguments[0] = mrb_cptr_value(mrb, command);
  return mrb_obj_new(mrb, target_command_class, 1, mrb_arguments);
}

static void
mrb_grn_command_run_wrapper(grn_ctx *ctx,
                            grn_obj *command,
                            grn_command_input *input,
                            void *user_data)
{
  grn_mrb_data *data = &(ctx->impl->mrb);
  mrb_state *mrb = data->state;
  struct RClass *module = data->module;
  int arena_index;
  mrb_value mrb_command;
  mrb_value mrb_input;

  arena_index = mrb_gc_arena_save(mrb);
  mrb_command = mrb_grn_command_instantiate(ctx, command);
  {
    struct RClass *command_input_class;
    mrb_value mrb_arguments[1];
    command_input_class = mrb_class_get_under(mrb, module, "CommandInput");
    mrb_arguments[0] = mrb_cptr_value(mrb, input);
    mrb_input = mrb_obj_new(mrb, command_input_class, 1, mrb_arguments);
  }
  mrb_funcall(mrb, mrb_command, "run_internal", 1, mrb_input);
  if (ctx->rc == GRN_SUCCESS && mrb->exc) {
    char name[GRN_TABLE_MAX_KEY_SIZE];
    int name_size;
    name_size = grn_obj_name(ctx, command, name, GRN_TABLE_MAX_KEY_SIZE);
    if (mrb->exc == mrb->nomem_err) {
      MERR("failed to allocate memory in mruby: <%.*s>",
           name_size, name);
    } else {
      mrb_value reason;
      reason = mrb_funcall(mrb, mrb_obj_value(mrb->exc), "inspect", 0);
      ERR(GRN_COMMAND_ERROR,
          "failed to run command: <%*.s>: %.*s",
          name_size, name,
          (int)RSTRING_LEN(reason), RSTRING_PTR(reason));
    }
  }
  mrb_gc_arena_restore(mrb, arena_index);
}

static mrb_value
mrb_grn_command_class_register(mrb_state *mrb, mrb_value klass)
{
  grn_ctx *ctx = (grn_ctx *)mrb->ud;
  mrb_value mrb_name;
  mrb_value *mrb_arguments;
  mrb_int n_arguments;

  mrb_get_args(mrb, "Sa", &mrb_name, &mrb_arguments, &n_arguments);

  {
    grn_expr_var *vars;
    mrb_int i;

    for (i = 0; i < n_arguments; i++) {
      mrb_arguments[i] = mrb_convert_type(mrb, mrb_arguments[i],
                                          MRB_TT_STRING, "String", "to_str");
    }
    vars = GRN_MALLOCN(grn_expr_var, (size_t)n_arguments);
    for (i = 0; i < n_arguments; i++) {
      mrb_value mrb_argument = mrb_arguments[i];
      grn_expr_var *var = &vars[i];
      var->name = RSTRING_PTR(mrb_argument);
      var->name_size = RSTRING_LEN(mrb_argument);
      GRN_TEXT_INIT(&(var->value), 0);
    }

    grn_command_register(ctx,
                         RSTRING_PTR(mrb_name),
                         RSTRING_LEN(mrb_name),
                         mrb_grn_command_run_wrapper,
                         vars,
                         (unsigned int)n_arguments,
                         NULL);

    for (i = 0; i < n_arguments; i++) {
      grn_expr_var *var = &vars[i];
      GRN_OBJ_FIN(ctx, &(var->value));
    }
    GRN_FREE(vars);
  }

  grn_mrb_ctx_check(mrb);

  {
    grn_mrb_data *data = &(ctx->impl->mrb);
    struct RClass *command_class;
    command_class = mrb_class_get_under(mrb, data->module, "Command");
    mrb_funcall(mrb,
                mrb_obj_value(command_class),
                "register_class", 2, mrb_name, klass);
  }

  return mrb_nil_value();
}

static mrb_value
mrb_grn_command_initialize(mrb_state *mrb, mrb_value self)
{
  mrb_value mrb_command_ptr;

  mrb_get_args(mrb, "o", &mrb_command_ptr);
  DATA_TYPE(self) = &mrb_grn_command_type;
  DATA_PTR(self) = mrb_cptr(mrb_command_ptr);
  return self;
}

void
grn_mrb_command_init(grn_ctx *ctx)
{
  grn_mrb_data *data = &(ctx->impl->mrb);
  mrb_state *mrb = data->state;
  struct RClass *module = data->module;
  struct RClass *procedure_class;
  struct RClass *klass;

  procedure_class = mrb_class_get_under(mrb, module, "Procedure");
  klass = mrb_define_class_under(mrb, module, "Command", procedure_class);
  MRB_SET_INSTANCE_TT(klass, MRB_TT_DATA);

  mrb_define_class_method(mrb, klass, "register",
                          mrb_grn_command_class_register,
                          MRB_ARGS_REQ(2));

  mrb_define_method(mrb, klass, "initialize",
                    mrb_grn_command_initialize, MRB_ARGS_REQ(1));
}
#endif
