/* Copyright 2014-2015 Samsung Electronics Co., Ltd.
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "jerry.h"
#include "jrt/jrt.h"

/**
 * Maximum command line arguments number
 */
#define JERRY_MAX_COMMAND_LINE_ARGS (64)

/**
 * Maximum size of source code / snapshots buffer
 */
#define JERRY_BUFFER_SIZE (1048576)

/**
 * Standalone Jerry exit codes
 */
#define JERRY_STANDALONE_EXIT_CODE_OK   (0)
#define JERRY_STANDALONE_EXIT_CODE_FAIL (1)

static uint8_t buffer[ JERRY_BUFFER_SIZE ];

static const jerry_api_char_t *
read_sources (const char *script_file_names[],
              int files_count,
              size_t *out_source_size_p)
{
  int i;
  uint8_t *source_buffer_tail = buffer;

  for (i = 0; i < files_count; i++)
  {
    const char *script_file_name = script_file_names[i];

    FILE *file = fopen (script_file_name, "r");

    if (file == NULL)
    {
      break;
    }

    int fseek_status = fseek (file, 0, SEEK_END);

    if (fseek_status != 0)
    {
      break;
    }

    long script_len = ftell (file);

    if (script_len < 0)
    {
      fclose (file);
      break;
    }

    rewind (file);

    const size_t current_source_size = (size_t)script_len;

    if (source_buffer_tail + current_source_size >= buffer + sizeof (buffer))
    {
      fclose (file);
      break;
    }

    size_t bytes_read = fread (source_buffer_tail, 1, current_source_size, file);
    if (bytes_read < current_source_size)
    {
      fclose (file);
      break;
    }

    fclose (file);

    source_buffer_tail += current_source_size;
  }

  if (i < files_count)
  {
    JERRY_ERROR_MSG ("Failed to read script N%d\n", i + 1);

    return NULL;
  }
  else
  {
    const size_t source_size = (size_t) (source_buffer_tail - buffer);

    *out_source_size_p = source_size;

    return (const jerry_api_char_t *) buffer;
  }
} /* read_sources */

static bool
read_snapshot (const char *snapshot_file_name_p,
               size_t *out_snapshot_size_p)
{
  JERRY_ASSERT (snapshot_file_name_p != NULL);
  JERRY_ASSERT (out_snapshot_size_p != NULL);

  *out_snapshot_size_p = 0;

  FILE *file = fopen (snapshot_file_name_p, "r");

  if (file == NULL)
  {
    return false;
  }

  int fseek_status = fseek (file, 0, SEEK_END);

  if (fseek_status != 0)
  {
    fclose (file);
    return false;
  }

  long snapshot_len = ftell (file);

  if (snapshot_len < 0)
  {
    fclose (file);
    return false;
  }

  rewind (file);

  if ((size_t) snapshot_len > sizeof (buffer))
  {
    fclose (file);
    return false;
  }

  size_t bytes_read = fread (buffer, 1u, (size_t) snapshot_len, file);
  if (bytes_read < (size_t) snapshot_len)
  {
    fclose (file);
    return false;
  }

  *out_snapshot_size_p = (size_t) snapshot_len;

  fclose (file);
  return true;
} /* read_snapshot */

/**
 * Provide the 'assert' implementation for the engine.
 *
 * @return true - if only one argument was passed and the argument is a boolean true.
 */
static bool
assert_handler (const jerry_api_object_t *function_obj_p __attr_unused___, /** < function object */
                const jerry_api_value_t *this_p __attr_unused___, /** < this arg */
                jerry_api_value_t *ret_val_p __attr_unused___, /** < return argument */
                const jerry_api_value_t args_p[], /** < function arguments */
                const jerry_api_length_t args_cnt) /** < number of function arguments */
{
  if (args_cnt == 1
      && args_p[0].type == JERRY_API_DATA_TYPE_BOOLEAN
      && args_p[0].v_bool == true)
  {
    return true;
  }
  else
  {
    JERRY_ERROR_MSG ("Script assertion failed\n");
    exit (JERRY_STANDALONE_EXIT_CODE_FAIL);
  }
} /* assert_handler */

int
main (int argc,
      char **argv)
{
  if (argc > JERRY_MAX_COMMAND_LINE_ARGS)
  {
    JERRY_ERROR_MSG ("Too many command line arguments : %d. Current maximum is %d (JERRY_MAX_COMMAND_LINE_ARGS)\n",
                      argc, JERRY_MAX_COMMAND_LINE_ARGS);

    return JERRY_STANDALONE_EXIT_CODE_FAIL;
  }

  const char *file_names[JERRY_MAX_COMMAND_LINE_ARGS];
  int i;
  int files_counter = 0;

  size_t max_data_bss_size, max_stack_size;
  jerry_get_memory_limits (&max_data_bss_size, &max_stack_size);

  // FIXME:
  //  jrt_set_mem_limits (max_data_bss_size, max_stack_size);

  jerry_flag_t flags = JERRY_FLAG_EMPTY;

  const char *exec_snapshot_file_names[JERRY_MAX_COMMAND_LINE_ARGS];
  int exec_snapshots_count = 0;

  bool is_dump_snapshot_mode = false;
  bool is_dump_snapshot_mode_for_global_or_eval = false;
  const char *dump_snapshot_file_name_p = NULL;

  bool is_repl_mode = false;

#ifdef JERRY_ENABLE_LOG
  const char *log_file_name = NULL;
#endif /* JERRY_ENABLE_LOG */
  for (i = 1; i < argc; i++)
  {
    if (!strcmp ("-v", argv[i]))
    {
      printf ("Build date: \t%s\n", jerry_build_date);
      printf ("Commit hash:\t%s\n", jerry_commit_hash);
      printf ("Branch name:\t%s\n", jerry_branch_name);
      printf ("\n");
    }
    else if (!strcmp ("--mem-stats", argv[i]))
    {
      flags |= JERRY_FLAG_MEM_STATS;
    }
    else if (!strcmp ("--mem-stats-per-opcode", argv[i]))
    {
      flags |= JERRY_FLAG_MEM_STATS_PER_OPCODE;
    }
    else if (!strcmp ("--mem-stats-separate", argv[i]))
    {
      flags |= JERRY_FLAG_MEM_STATS_SEPARATE;
    }
    else if (!strcmp ("--parse-only", argv[i]))
    {
      flags |= JERRY_FLAG_PARSE_ONLY;
    }
    else if (!strcmp ("--show-opcodes", argv[i]))
    {
      flags |= JERRY_FLAG_SHOW_OPCODES;
    }
    else if (!strcmp ("--dump-snapshot-for-global", argv[i])
             || !strcmp ("--dump-snapshot-for-eval", argv[i]))
    {
      is_dump_snapshot_mode = true;
      is_dump_snapshot_mode_for_global_or_eval = !strcmp ("--dump-snapshot-for-global", argv[i]);

      flags |= JERRY_FLAG_PARSE_ONLY;

      if (dump_snapshot_file_name_p == NULL
          && ++i < argc)
      {
        dump_snapshot_file_name_p = argv[i];
      }
      else
      {
        JERRY_ERROR_MSG ("Error: wrong format of the arguments\n");
        return JERRY_STANDALONE_EXIT_CODE_FAIL;
      }
    }
    else if (!strcmp ("--exec-snapshot", argv[i]))
    {
      if (++i < argc)
      {
        JERRY_ASSERT (exec_snapshots_count < JERRY_MAX_COMMAND_LINE_ARGS);
        exec_snapshot_file_names[exec_snapshots_count++] = argv[i];
      }
      else
      {
        JERRY_ERROR_MSG ("Error: wrong format of the arguments\n");
        return JERRY_STANDALONE_EXIT_CODE_FAIL;
      }
    }
    else if (!strcmp ("--log-level", argv[i]))
    {
      flags |= JERRY_FLAG_ENABLE_LOG;
      if (++i < argc && strlen (argv[i]) == 1 && argv[i][0] >='0' && argv[i][0] <= '3')
      {
#ifdef JERRY_ENABLE_LOG
        jerry_debug_level = argv[i][0] - '0';
#endif /* JERRY_ENABLE_LOG */
      }
      else
      {
        JERRY_ERROR_MSG ("Error: wrong format or invalid argument\n");
        return JERRY_STANDALONE_EXIT_CODE_FAIL;
      }
    }
    else if (!strcmp ("--log-file", argv[i]))
    {
      flags |= JERRY_FLAG_ENABLE_LOG;
      if (++i < argc)
      {
#ifdef JERRY_ENABLE_LOG
        log_file_name = argv[i];
#endif /* JERRY_ENABLE_LOG */
      }
      else
      {
        JERRY_ERROR_MSG ("Error: wrong format of the arguments\n");
        return JERRY_STANDALONE_EXIT_CODE_FAIL;
      }
    }
    else if (!strcmp ("--abort-on-fail", argv[i]))
    {
      flags |= JERRY_FLAG_ABORT_ON_FAIL;
    }
    else
    {
      file_names[files_counter++] = argv[i];
    }
  }

  if (is_dump_snapshot_mode)
  {
    if (files_counter == 0)
    {
      JERRY_ERROR_MSG ("--dump-snapshot argument is passed, but no script was specified on command line\n");
      return JERRY_STANDALONE_EXIT_CODE_FAIL;
    }

    if (exec_snapshots_count != 0)
    {
      JERRY_ERROR_MSG ("--dump-snapshot and --exec-snapshot options can't be passed simultaneously\n");
      return JERRY_STANDALONE_EXIT_CODE_FAIL;
    }
  }

  if (files_counter == 0
      && exec_snapshots_count == 0)
  {
    is_repl_mode = true;
  }

#ifdef JERRY_ENABLE_LOG
  if (log_file_name)
  {
    jerry_log_file = fopen (log_file_name, "w");
    if (jerry_log_file == NULL)
    {
      JERRY_ERROR_MSG ("Failed to open log file: %s\n", log_file_name);
      return JERRY_STANDALONE_EXIT_CODE_FAIL;
    }
  }
  else
  {
    jerry_log_file = stdout;
  }
#endif /* JERRY_ENABLE_LOG */

  jerry_init (flags);

  jerry_api_object_t *global_obj_p = jerry_api_get_global ();
  jerry_api_object_t *assert_func_p = jerry_api_create_external_function (assert_handler);
  jerry_api_value_t assert_value;
  assert_value.type = JERRY_API_DATA_TYPE_OBJECT;
  assert_value.v_object = assert_func_p;

  bool is_assert_added = jerry_api_set_object_field_value (global_obj_p,
                                                           (jerry_api_char_t *) "assert",
                                                           &assert_value);

  jerry_api_release_value (&assert_value);
  jerry_api_release_object (global_obj_p);

  if (!is_assert_added)
  {
    JERRY_ERROR_MSG ("Failed to register 'assert' method.");
  }

  jerry_completion_code_t ret_code = JERRY_COMPLETION_CODE_OK;

  bool is_ok = true;
  for (int i = 0; i < exec_snapshots_count; i++)
  {
    size_t snapshot_size;

    if (!read_snapshot (exec_snapshot_file_names[i], &snapshot_size))
    {
      ret_code = JERRY_COMPLETION_CODE_UNHANDLED_EXCEPTION;
    }
    else
    {
      jerry_api_value_t ret_value;
      ret_code = jerry_exec_snapshot ((void *) buffer,
                                      snapshot_size,
                                      true,
                                      &ret_value);
      JERRY_ASSERT (ret_value.type == JERRY_API_DATA_TYPE_UNDEFINED);
    }

    if (ret_code != JERRY_COMPLETION_CODE_OK)
    {
      is_ok = false;

      break;
    }
  }

  if (is_ok)
  {
    size_t source_size;
    const jerry_api_char_t *source_p = NULL;

    if (files_counter != 0)
    {
      source_p = read_sources (file_names, files_counter, &source_size);

      if (source_p == NULL)
      {
        return JERRY_STANDALONE_EXIT_CODE_FAIL;
      }
    }

    if (source_p != NULL)
    {
      if (is_dump_snapshot_mode)
      {
        static uint8_t snapshot_dump_buffer[ JERRY_BUFFER_SIZE ];

        size_t snapshot_size = jerry_parse_and_save_snapshot (source_p,
                                                              source_size,
                                                              is_dump_snapshot_mode_for_global_or_eval,
                                                              snapshot_dump_buffer,
                                                              JERRY_BUFFER_SIZE);
        if (snapshot_size == 0)
        {
          ret_code = JERRY_COMPLETION_CODE_UNHANDLED_EXCEPTION;
        }
        else
        {
          FILE *snapshot_file_p = fopen (dump_snapshot_file_name_p, "w");
          fwrite (snapshot_dump_buffer, sizeof (uint8_t), snapshot_size, snapshot_file_p);
          fclose (snapshot_file_p);
        }
      }
      else
      {
        if (!jerry_parse (source_p, source_size))
        {
          /* unhandled SyntaxError */
          ret_code = JERRY_COMPLETION_CODE_UNHANDLED_EXCEPTION;
        }
        else if ((flags & JERRY_FLAG_PARSE_ONLY) == 0)
        {
          ret_code = jerry_run ();
        }
      }
    }
  }

  if (is_repl_mode)
  {
    const char *prompt = "jerry> ";
    bool is_done = false;

    jerry_api_object_t *global_obj_p = jerry_api_get_global ();
    jerry_api_value_t print_function;

    if (!jerry_api_get_object_field_value (global_obj_p, (jerry_api_char_t *) "print", &print_function))
    {
      return JERRY_STANDALONE_EXIT_CODE_FAIL;
    }

    if (!jerry_api_is_function (print_function.v_object))
    {
      return JERRY_STANDALONE_EXIT_CODE_FAIL;
    }

    while (!is_done)
    {
      uint8_t *source_buffer_tail = buffer;
      size_t len = 0;

      printf ("%s", prompt);

      // input a line
      while (true)
      {
        if (fread (source_buffer_tail, 1, 1, stdin) != 1 && len == 0)
        {
          is_done = true;
          break;
        }
        if (*source_buffer_tail == '\n')
        {
          break;
        }
        source_buffer_tail ++;
        len ++;
      }
      *source_buffer_tail = 0;

      if (len > 0)
      {
        // evaluate the line
        jerry_api_value_t ret_val;
        ret_code = jerry_api_eval (buffer, len, false, false, &ret_val);

        if (ret_code == JERRY_COMPLETION_CODE_OK)
        {
          // print return value
          const jerry_api_value_t args[] = {ret_val};
          jerry_api_value_t ret_val_print;
          if (jerry_api_call_function (print_function.v_object, NULL, &ret_val_print, args, 1))
          {
            jerry_api_release_value (&ret_val_print);
          }
        }
        else
        {
          printf ("JERRY_COMPLETION_CODE_UNHANDLED_EXCEPTION\n");
        }

        jerry_api_release_value (&ret_val);
      }
    }

    jerry_api_release_object (global_obj_p);
    jerry_api_release_value (&print_function);
  }

  jerry_cleanup ();

#ifdef JERRY_ENABLE_LOG
  if (jerry_log_file && jerry_log_file != stdout)
  {
    fclose (jerry_log_file);
    jerry_log_file = NULL;
  }
#endif /* JERRY_ENABLE_LOG */

  if (ret_code == JERRY_COMPLETION_CODE_OK)
  {
    return JERRY_STANDALONE_EXIT_CODE_OK;
  }
  else
  {
    return JERRY_STANDALONE_EXIT_CODE_FAIL;
  }
} /* main */