/* Copyright JS Foundation and other contributors, http://js.foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <string.h>

#include "jerryscript.h"
#include "test-common.h"
#include "jerryscript-ext/module.h"

/* Load a module. */
const char eval_string1[] = "require ('my_custom_module');";

/* Load a module using a different resolver. */
const char eval_string2[] = "require ('differently-handled-module');";

/* Load a broken module using the built-in resolver. */
const char eval_string3[] =
"(function() {"
"  var theError;"
"  try {"
"    require ('my_broken_module');"
"  } catch (anError) {"
"    theError = anError;"
"  }"
"  return (((theError.message === 'Module on_resolve () must not be NULL') &&"
"    (theError.moduleName === 'my_broken_module') &&"
"    (theError instanceof TypeError)) ? 1 : 0);"
"}) ();";

/* Load a non-existent module. */
const char eval_string4[] =
"(function() {"
"  var theError;"
"  try {"
"    require ('some_missing_module_xyzzy');"
"  } catch (anError) {"
"    theError = anError;"
"  }"
"  return (((theError.message === 'Module not found') &&"
"    (theError.moduleName === 'some_missing_module_xyzzy')) ? 1 : 0);"
"}) ();";

/* Make sure the result of a module load is cached. */
const char eval_string5[] =
"(function() {"
"  var x = require('cache-check');"
"  var y = require('cache-check');"
"  return x === y ? 1 : 0;"
"}) ();";

/* Make sure the result of a module load is removed from the cache. */
const char eval_string6[] =
"(function() {"
"  var x = require('cache-check');"
"  clear_require_cache('cache-check');"
"  var y = require('cache-check');"
"  return x !== y ? 1 : 0;"
"}) ();";

/* Make sure the entire cache is cleared. */
const char eval_string7[] =
"(function() {"
"  var x = require('cache-check');"
"  clear_require_cache(undefined);"
"  var y = require('cache-check');"
"  return x !== y ? 1 : 0;"
"}) ();";

/*
 * Define a resolver for a module named "differently-handled-module" to check that custom resolvers work.
 */
static bool
resolve_differently_handled_module (const jerry_value_t name,
                                    jerry_value_t *result)
{
  jerry_size_t name_size = jerry_get_utf8_string_size (name);
  JERRY_VLA (jerry_char_t, name_string, name_size);
  jerry_string_to_utf8_char_buffer (name, name_string, name_size);

  if (!strncmp ((char *) name_string, "differently-handled-module", name_size))
  {
    (*result) = jerry_create_number (29);
    return true;
  }
  return false;
} /* resolve_differently_handled_module */

static jerryx_module_resolver_t differently_handled_module_resolver =
{
  NULL,
  resolve_differently_handled_module
};

/*
 * Define module "cache-check" via its own resolver as an empty object. Since objects are accessible only via references
 * we can strictly compare the object returned on subsequent attempts at loading "cache-check" with the object returned
 * on the first attempt and establish that the two are in fact the same object - which in turn shows that caching works.
 */
static bool
cache_check (const jerry_value_t name,
             jerry_value_t *result)
{
  jerry_size_t name_size = jerry_get_utf8_string_size (name);
  JERRY_VLA (jerry_char_t, name_string, name_size);
  jerry_string_to_utf8_char_buffer (name, name_string, name_size);

  if (!strncmp ((char *) name_string, "cache-check", name_size))
  {
    (*result) = jerry_create_object ();
    return true;
  }
  return false;
} /* cache_check */

static jerryx_module_resolver_t cache_check_resolver =
{
  NULL,
  cache_check
};

static const jerryx_module_resolver_t *resolvers[3] =
{
  &jerryx_module_native_resolver,
  &differently_handled_module_resolver,
  &cache_check_resolver
};

static jerry_value_t
handle_clear_require_cache (const jerry_value_t js_function,
                            const jerry_value_t this_val,
                            const jerry_value_t args_p[],
                            const jerry_length_t args_count)
{
  (void) js_function;
  (void) this_val;
  (void) args_count;

  TEST_ASSERT (args_count == 1);
  jerryx_module_clear_cache (args_p[0], resolvers, 3);

  return 0;
} /* handle_clear_require_cache */

static jerry_value_t
handle_require (const jerry_value_t js_function,
                const jerry_value_t this_val,
                const jerry_value_t args_p[],
                const jerry_length_t args_count)
{
  (void) js_function;
  (void) this_val;
  (void) args_count;

  jerry_value_t return_value = 0;

  TEST_ASSERT (args_count == 1);
  return_value = jerryx_module_resolve (args_p[0], resolvers, 3);

  return return_value;
} /* handle_require */

static void
assert_number (jerry_value_t js_value, double expected_result)
{
  TEST_ASSERT (!jerry_value_is_error (js_value));
  TEST_ASSERT (jerry_get_number_value (js_value) == expected_result);
} /* assert_number */

static void
eval_one (const char *the_string, double expected_result)
{
  jerry_value_t js_eval_result = jerry_eval ((const jerry_char_t *) the_string,
                                             strlen (the_string),
                                             JERRY_PARSE_STRICT_MODE);
  assert_number (js_eval_result, expected_result);
  jerry_release_value (js_eval_result);
} /* eval_one */

#ifndef ENABLE_INIT_FINI
extern void my_broken_module_register (void);
extern void my_custom_module_register (void);
#endif /* !ENABLE_INIT_FINI */

int
main (int argc, char **argv)
{
  (void) argc;
  (void) argv;
  jerry_value_t js_global = 0, js_function = 0, js_property_name = 0;
  jerry_value_t res;

#ifndef ENABLE_INIT_FINI
  my_broken_module_register ();
  my_custom_module_register ();
#endif /* !ENABLE_INIT_FINI */

  jerry_init (JERRY_INIT_EMPTY);

  js_global = jerry_get_global_object ();

  js_function = jerry_create_external_function (handle_require);
  js_property_name = jerry_create_string ((const jerry_char_t *) "require");
  res = jerry_set_property (js_global, js_property_name, js_function);
  TEST_ASSERT (!jerry_value_is_error (res));
  TEST_ASSERT (jerry_value_is_boolean (res) && jerry_get_boolean_value (res));
  jerry_release_value (res);
  jerry_release_value (js_property_name);
  jerry_release_value (js_function);

  js_function = jerry_create_external_function (handle_clear_require_cache);
  js_property_name = jerry_create_string ((const jerry_char_t *) "clear_require_cache");
  res = jerry_set_property (js_global, js_property_name, js_function);
  TEST_ASSERT (!jerry_value_is_error (res));
  TEST_ASSERT (jerry_value_is_boolean (res) && jerry_get_boolean_value (res));
  jerry_release_value (res);
  jerry_release_value (js_property_name);
  jerry_release_value (js_function);

  jerry_release_value (js_global);

  eval_one (eval_string1, 42);
  eval_one (eval_string2, 29);
  eval_one (eval_string3, 1);
  eval_one (eval_string4, 1);
  eval_one (eval_string5, 1);
  eval_one (eval_string6, 1);
  eval_one (eval_string7, 1);

  jerry_cleanup ();
} /* main */