/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2015 - Daniel De Matteis
 *  Copyright (C) 2012-2015 - Michael Lelli
 *
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include <boolean.h>
#include "libretro.h"
#include "dynamic.h"
#include "libretro_version_1.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include "general.h"
#include "retroarch.h"
#include "performance.h"
#include "input/keyboard_line.h"
#include "audio/audio_utils.h"
#include "retroarch_logger.h"
#include "intl/intl.h"

#ifdef HAVE_NETPLAY
#include "netplay.h"
#endif

/**
 * video_frame:
 * @data                 : pointer to data of the video frame.
 * @width                : width of the video frame.
 * @height               : height of the video frame.
 * @pitch                : pitch of the video frame.
 *
 * Video frame render callback function.
 **/
static void video_frame(const void *data, unsigned width,
      unsigned height, size_t pitch)
{
   const char *msg = NULL;

   if (!driver.video_active)
      return;

   g_extern.frame_cache.data   = data;
   g_extern.frame_cache.width  = width;
   g_extern.frame_cache.height = height;
   g_extern.frame_cache.pitch  = pitch;

   if (g_extern.system.pix_fmt == RETRO_PIXEL_FORMAT_0RGB1555 &&
         data && data != RETRO_HW_FRAME_BUFFER_VALID)
   {
      RARCH_PERFORMANCE_INIT(video_frame_conv);
      RARCH_PERFORMANCE_START(video_frame_conv);
      driver.scaler.in_width = width;
      driver.scaler.in_height = height;
      driver.scaler.out_width = width;
      driver.scaler.out_height = height;
      driver.scaler.in_stride = pitch;
      driver.scaler.out_stride = width * sizeof(uint16_t);

      scaler_ctx_scale(&driver.scaler, driver.scaler_out, data);
      data = driver.scaler_out;
      pitch = driver.scaler.out_stride;
      RARCH_PERFORMANCE_STOP(video_frame_conv);
   }

   /* Slightly messy code,
    * but we really need to do processing before blocking on VSync
    * for best possible scheduling.
    */
   if (driver.recording_data && (!g_extern.filter.filter
            || !g_settings.video.post_filter_record || !data
            || g_extern.record_gpu_buffer)
      )
      rarch_recording_dump_frame(data, width, height, pitch);

   msg = msg_queue_pull(g_extern.msg_queue);
   driver.current_msg = msg;

   if (g_extern.filter.filter && data)
   {
      unsigned owidth  = 0, oheight = 0, opitch = 0;

      rarch_softfilter_get_output_size(g_extern.filter.filter,
            &owidth, &oheight, width, height);

      opitch = owidth * g_extern.filter.out_bpp;

      RARCH_PERFORMANCE_INIT(softfilter_process);
      RARCH_PERFORMANCE_START(softfilter_process);
      rarch_softfilter_process(g_extern.filter.filter,
            g_extern.filter.buffer, opitch,
            data, width, height, pitch);
      RARCH_PERFORMANCE_STOP(softfilter_process);

      if (driver.recording_data && g_settings.video.post_filter_record)
         rarch_recording_dump_frame(g_extern.filter.buffer,
               owidth, oheight, opitch);

      data = g_extern.filter.buffer;
      width = owidth;
      height = oheight;
      pitch = opitch;
   }

   if (!driver.video->frame(driver.video_data, data, width, height, pitch, msg))
      driver.video_active = false;
}

/*
 * readjust_audio_input_rate:
 *
 * Readjust the audio input rate.
 */
static void readjust_audio_input_rate(void)
{
   int avail = driver.audio->write_avail(driver.audio_data);

   //RARCH_LOG_OUTPUT("Audio buffer is %u%% full\n",
   //      (unsigned)(100 - (avail * 100) / g_extern.audio_data.driver_buffer_size));

   unsigned write_idx = g_extern.measure_data.buffer_free_samples_count++ &
      (AUDIO_BUFFER_FREE_SAMPLES_COUNT - 1);
   int      half_size   = g_extern.audio_data.driver_buffer_size / 2;
   int      delta_mid   = avail - half_size;
   double   direction   = (double)delta_mid / half_size;
   double   adjust      = 1.0 + g_settings.audio.rate_control_delta *
      direction;

   g_extern.measure_data.buffer_free_samples[write_idx] = avail;
   g_extern.audio_data.src_ratio = g_extern.audio_data.orig_src_ratio * adjust;

   //RARCH_LOG_OUTPUT("New rate: %lf, Orig rate: %lf\n",
   //      g_extern.audio_data.src_ratio, g_extern.audio_data.orig_src_ratio);
}

/**
 * retro_flush_audio:
 * @data                 : pointer to audio buffer.
 * @right                : amount of samples to write.
 *
 * Writes audio samples to audio driver. Will first
 * perform DSP processing (if enabled) and resampling.
 *
 * Returns: true (1) if audio samples were written to the audio
 * driver, false (0) in case of an error.
 **/
bool retro_flush_audio(const int16_t *data, size_t samples)
{
   const void *output_data        = NULL;
   unsigned output_frames         = 0;
   size_t   output_size           = sizeof(float);
   struct resampler_data src_data = {0};
   struct rarch_dsp_data dsp_data = {0};

   if (driver.recording_data)
   {
      struct ffemu_audio_data ffemu_data = {0};
      ffemu_data.data                    = data;
      ffemu_data.frames                  = samples / 2;

      if (driver.recording && driver.recording->push_audio)
         driver.recording->push_audio(driver.recording_data, &ffemu_data);
   }

   if (g_extern.is_paused || g_settings.audio.mute_enable)
      return true;
   if (!driver.audio_active || !g_extern.audio_data.data)
      return false;

   RARCH_PERFORMANCE_INIT(audio_convert_s16);
   RARCH_PERFORMANCE_START(audio_convert_s16);
   audio_convert_s16_to_float(g_extern.audio_data.data, data, samples,
         g_extern.audio_data.volume_gain);
   RARCH_PERFORMANCE_STOP(audio_convert_s16);

   src_data.data_in               = g_extern.audio_data.data;
   src_data.input_frames          = samples >> 1;

   dsp_data.input                 = g_extern.audio_data.data;
   dsp_data.input_frames          = samples >> 1;

   if (g_extern.audio_data.dsp)
   {
      RARCH_PERFORMANCE_INIT(audio_dsp);
      RARCH_PERFORMANCE_START(audio_dsp);
      rarch_dsp_filter_process(g_extern.audio_data.dsp, &dsp_data);
      RARCH_PERFORMANCE_STOP(audio_dsp);

      if (dsp_data.output)
      {
         src_data.data_in      = dsp_data.output;
         src_data.input_frames = dsp_data.output_frames;
      }
   }

   src_data.data_out = g_extern.audio_data.outsamples;

   if (g_extern.audio_data.rate_control)
      readjust_audio_input_rate();

   src_data.ratio = g_extern.audio_data.src_ratio;
   if (g_extern.is_slowmotion)
      src_data.ratio *= g_settings.slowmotion_ratio;

   RARCH_PERFORMANCE_INIT(resampler_proc);
   RARCH_PERFORMANCE_START(resampler_proc);
   rarch_resampler_process(driver.resampler,
         driver.resampler_data, &src_data);
   RARCH_PERFORMANCE_STOP(resampler_proc);

   output_data   = g_extern.audio_data.outsamples;
   output_frames = src_data.output_frames;

   if (!g_extern.audio_data.use_float)
   {
      RARCH_PERFORMANCE_INIT(audio_convert_float);
      RARCH_PERFORMANCE_START(audio_convert_float);
      audio_convert_float_to_s16(g_extern.audio_data.conv_outsamples,
            (const float*)output_data, output_frames * 2);
      RARCH_PERFORMANCE_STOP(audio_convert_float);

      output_data = g_extern.audio_data.conv_outsamples;
      output_size = sizeof(int16_t);
   }

   if (driver.audio->write(driver.audio_data, output_data,
            output_frames * output_size * 2) < 0)
   {
      RARCH_ERR(RETRO_LOG_AUDIO_WRITE_FAILED);

      driver.audio_active = false;
      return false;
   }

   return true;
}

/**
 * audio_sample:
 * @left                 : value of the left audio channel.
 * @right                : value of the right audio channel.
 *
 * Audio sample render callback function.
 **/
static void audio_sample(int16_t left, int16_t right)
{
   g_extern.audio_data.conv_outsamples[g_extern.audio_data.data_ptr++] = left;
   g_extern.audio_data.conv_outsamples[g_extern.audio_data.data_ptr++] = right;

   if (g_extern.audio_data.data_ptr < g_extern.audio_data.chunk_size)
      return;

   retro_flush_audio(g_extern.audio_data.conv_outsamples, g_extern.audio_data.data_ptr);

   g_extern.audio_data.data_ptr = 0;
}

/**
 * audio_sample_batch:
 * @data                 : pointer to audio buffer.
 * @frames               : amount of audio frames to push.
 *
 * Batched audio sample render callback function.
 *
 * Returns: amount of frames sampled. Will be equal to @frames
 * unless @frames exceeds (AUDIO_CHUNK_SIZE_NONBLOCKING / 2).
 **/
static size_t audio_sample_batch(const int16_t *data, size_t frames)
{
   if (frames > (AUDIO_CHUNK_SIZE_NONBLOCKING >> 1))
      frames = AUDIO_CHUNK_SIZE_NONBLOCKING >> 1;

   retro_flush_audio(data, frames << 1);

   return frames;
}

/**
 * audio_sample_rewind:
 * @left                 : value of the left audio channel.
 * @right                : value of the right audio channel.
 *
 * Audio sample render callback function (rewind version). This callback
 * function will be used instead of audio_sample when rewinding is activated.
 **/
static void audio_sample_rewind(int16_t left, int16_t right)
{
   g_extern.audio_data.rewind_buf[--g_extern.audio_data.rewind_ptr] = right;
   g_extern.audio_data.rewind_buf[--g_extern.audio_data.rewind_ptr] = left;
}

/**
 * audio_sample_batch_rewind:
 * @data                 : pointer to audio buffer.
 * @frames               : amount of audio frames to push.
 *
 * Batched audio sample render callback function (rewind version). This callback
 * function will be used instead of audio_sample_batch when rewinding is activated.
 *
 * Returns: amount of frames sampled. Will be equal to @frames
 * unless @frames exceeds (AUDIO_CHUNK_SIZE_NONBLOCKING / 2).
 **/
static size_t audio_sample_batch_rewind(const int16_t *data, size_t frames)
{
   size_t i;
   size_t samples = frames << 1;

   for (i = 0; i < samples; i++)
      g_extern.audio_data.rewind_buf[--g_extern.audio_data.rewind_ptr] = data[i];

   return frames;
}

/**
 * input_apply_turbo:
 * @port                 : user number
 * @id                   : identifier of the key
 * @res                  : boolean return value. FIXME/TODO: to be refactored.
 *
 * Apply turbo button if activated.
 *
 * If turbo button is held, all buttons pressed except
 * for D-pad will go into a turbo mode. Until the button is
 * released again, the input state will be modulated by a 
 * periodic pulse defined by the configured duty cycle. 
 *
 * Returns: 1 (true) if turbo button is enabled for this
 * key ID, otherwise the value of @res will be returned.
 *
 **/
static bool input_apply_turbo(unsigned port, unsigned id, bool res)
{
   if (res && g_extern.turbo_frame_enable[port])
      g_extern.turbo_enable[port] |= (1 << id);
   else if (!res)
      g_extern.turbo_enable[port] &= ~(1 << id);

   if (g_extern.turbo_enable[port] & (1 << id))
      return res && ((g_extern.turbo_count % g_settings.input.turbo_period)
            < g_settings.input.turbo_duty_cycle);
   return res;
}

/**
 * input_state:
 * @port                 : user number.
 * @device               : device identifier of user.
 * @idx                  : index value of user.
 * @id                   : identifier of key pressed by user.
 *
 * Input state callback function.
 *
 * Returns: Non-zero if the given key (identified by @id) was pressed by the user
 * (assigned to @port).
 **/
static int16_t input_state(unsigned port, unsigned device,
      unsigned idx, unsigned id)
{
   int16_t res = 0;

   static const struct retro_keybind *libretro_input_binds[MAX_USERS] = {
      g_settings.input.binds[0],
      g_settings.input.binds[1],
      g_settings.input.binds[2],
      g_settings.input.binds[3],
      g_settings.input.binds[4],
      g_settings.input.binds[5],
      g_settings.input.binds[6],
      g_settings.input.binds[7],
      g_settings.input.binds[8],
      g_settings.input.binds[9],
      g_settings.input.binds[10],
      g_settings.input.binds[11],
      g_settings.input.binds[12],
      g_settings.input.binds[13],
      g_settings.input.binds[14],
      g_settings.input.binds[15],
   };

   device &= RETRO_DEVICE_MASK;

   if (g_extern.bsv.movie && g_extern.bsv.movie_playback)
   {
      int16_t ret;
      if (bsv_movie_get_input(g_extern.bsv.movie, &ret))
         return ret;

      g_extern.bsv.movie_end = true;
   }

   if (g_settings.input.remap_binds_enable)
   {
      if (id < RARCH_FIRST_CUSTOM_BIND)
         id = g_settings.input.remap_ids[port][id];
   }

   if (!driver.block_libretro_input)
   {
      if (((id < RARCH_FIRST_META_KEY) || (device == RETRO_DEVICE_KEYBOARD)))
         res = driver.input->input_state(driver.input_data, libretro_input_binds, port,
               device, idx, id);

#ifdef HAVE_OVERLAY
      if (port == 0)
      {
         switch (device)
         {
            case RETRO_DEVICE_JOYPAD:
               if (driver.overlay_state.buttons & (UINT64_C(1) << id))
                  res |= 1;
               break;
            case RETRO_DEVICE_KEYBOARD:
               if (id < RETROK_LAST)
               {
                  if (OVERLAY_GET_KEY(&driver.overlay_state, id))
                     res |= 1;
               }
               break;
            case RETRO_DEVICE_ANALOG:
               {
                  unsigned base = 0;
                  
                  if (idx == RETRO_DEVICE_INDEX_ANALOG_RIGHT)
                     base = 2;
                  if (id == RETRO_DEVICE_ID_ANALOG_Y)
                     base += 1;
                  if (driver.overlay_state.analog[base])
                     res = driver.overlay_state.analog[base];
               }
               break;
         }
      }
#endif
   }

   /* flushing_input will be cleared in rarch_main_iterate. */
   if (driver.flushing_input)
      res = 0;

   /* Don't allow turbo for D-pad. */
   if (device == RETRO_DEVICE_JOYPAD && (id < RETRO_DEVICE_ID_JOYPAD_UP ||
            id > RETRO_DEVICE_ID_JOYPAD_RIGHT))
      res = input_apply_turbo(port, id, res);

   if (g_extern.bsv.movie && !g_extern.bsv.movie_playback)
      bsv_movie_set_input(g_extern.bsv.movie, res);

   return res;
}


#ifdef HAVE_OVERLAY
/*
 * input_poll_overlay:
 *
 * Poll pressed buttons/keys on currently active overlay.
 **/
static inline void input_poll_overlay(void)
{
   input_overlay_state_t old_key_state;
   unsigned i, j, device;
   uint16_t key_mod = 0;
   bool polled = false;

   memcpy(old_key_state.keys, driver.overlay_state.keys,
         sizeof(driver.overlay_state.keys));
   memset(&driver.overlay_state, 0, sizeof(driver.overlay_state));

   device = input_overlay_full_screen(driver.overlay) ?
      RARCH_DEVICE_POINTER_SCREEN : RETRO_DEVICE_POINTER;

   for (i = 0;
         driver.input->input_state(driver.input_data, NULL, 0, device, i,
            RETRO_DEVICE_ID_POINTER_PRESSED);
         i++)
   {
      input_overlay_state_t polled_data;
      int16_t x = driver.input->input_state(driver.input_data, NULL, 0,
            device, i, RETRO_DEVICE_ID_POINTER_X);
      int16_t y = driver.input->input_state(driver.input_data, NULL, 0,
            device, i, RETRO_DEVICE_ID_POINTER_Y);

      input_overlay_poll(driver.overlay, &polled_data, x, y);

      driver.overlay_state.buttons |= polled_data.buttons;

      for (j = 0; j < ARRAY_SIZE(driver.overlay_state.keys); j++)
         driver.overlay_state.keys[j] |= polled_data.keys[j];

      /* Fingers pressed later take prio and matched up
       * with overlay poll priorities. */
      for (j = 0; j < 4; j++)
         if (polled_data.analog[j])
            driver.overlay_state.analog[j] = polled_data.analog[j];

      polled = true;
   }

   if (OVERLAY_GET_KEY(&driver.overlay_state, RETROK_LSHIFT) ||
         OVERLAY_GET_KEY(&driver.overlay_state, RETROK_RSHIFT))
      key_mod |= RETROKMOD_SHIFT;

   if (OVERLAY_GET_KEY(&driver.overlay_state, RETROK_LCTRL) ||
    OVERLAY_GET_KEY(&driver.overlay_state, RETROK_RCTRL))
      key_mod |= RETROKMOD_CTRL;

   if (OVERLAY_GET_KEY(&driver.overlay_state, RETROK_LALT) ||
         OVERLAY_GET_KEY(&driver.overlay_state, RETROK_RALT))
      key_mod |= RETROKMOD_ALT;

   if (OVERLAY_GET_KEY(&driver.overlay_state, RETROK_LMETA) ||
         OVERLAY_GET_KEY(&driver.overlay_state, RETROK_RMETA))
      key_mod |= RETROKMOD_META;

   /* CAPSLOCK SCROLLOCK NUMLOCK */
   for (i = 0; i < ARRAY_SIZE(driver.overlay_state.keys); i++)
   {
      if (driver.overlay_state.keys[i] != old_key_state.keys[i])
      {
         uint32_t orig_bits = old_key_state.keys[i];
         uint32_t new_bits  = driver.overlay_state.keys[i];

         for (j = 0; j < 32; j++)
            if ((orig_bits & (1 << j)) != (new_bits & (1 << j)))
               input_keyboard_event(new_bits & (1 << j), i * 32 + j, 0, key_mod);
      }
   }

   /* Map "analog" buttons to analog axes like regular input drivers do. */
   for (j = 0; j < 4; j++)
   {
      unsigned bind_plus  = RARCH_ANALOG_LEFT_X_PLUS + 2 * j;
      unsigned bind_minus = bind_plus + 1;

      if (driver.overlay_state.analog[j])
         continue;

      if (driver.overlay_state.buttons & (1ULL << bind_plus))
         driver.overlay_state.analog[j] += 0x7fff;
      if (driver.overlay_state.buttons & (1ULL << bind_minus))
         driver.overlay_state.analog[j] -= 0x7fff;
   }

   /* Check for analog_dpad_mode.
    * Map analogs to d-pad buttons when configured. */
   switch (g_settings.input.analog_dpad_mode[0])
   {
      case ANALOG_DPAD_LSTICK:
      case ANALOG_DPAD_RSTICK:
      {
         float analog_x, analog_y;
         unsigned analog_base = 2;

         if (g_settings.input.analog_dpad_mode[0] == ANALOG_DPAD_LSTICK)
            analog_base = 0;

         analog_x = (float)driver.overlay_state.analog[analog_base + 0] / 0x7fff;
         analog_y = (float)driver.overlay_state.analog[analog_base + 1] / 0x7fff;

         if (analog_x <= -g_settings.input.axis_threshold)
            driver.overlay_state.buttons |= (1ULL << RETRO_DEVICE_ID_JOYPAD_LEFT);
         if (analog_x >=  g_settings.input.axis_threshold)
            driver.overlay_state.buttons |= (1ULL << RETRO_DEVICE_ID_JOYPAD_RIGHT);
         if (analog_y <= -g_settings.input.axis_threshold)
            driver.overlay_state.buttons |= (1ULL << RETRO_DEVICE_ID_JOYPAD_UP);
         if (analog_y >=  g_settings.input.axis_threshold)
            driver.overlay_state.buttons |= (1ULL << RETRO_DEVICE_ID_JOYPAD_DOWN);
         break;
      }

      default:
         break;
   }

   if (polled)
      input_overlay_post_poll(driver.overlay);
   else
      input_overlay_poll_clear(driver.overlay);
}
#endif

/**
 * input_poll:
 *
 * Input polling callback function.
 **/
static void input_poll(void)
{
   driver.input->poll(driver.input_data);

#ifdef HAVE_OVERLAY
   if (driver.overlay)
      input_poll_overlay();
#endif

#ifdef HAVE_COMMAND
   if (driver.command)
      rarch_cmd_poll(driver.command);
#endif
}

/**
 * retro_set_default_callbacks:
 * @data           : pointer to retro_callbacks object
 *
 * Binds the libretro callbacks to default callback functions.
 **/
void retro_set_default_callbacks(void *data)
{
   struct retro_callbacks *cbs = (struct retro_callbacks*)data;

   if (!cbs)
      return;

   cbs->frame_cb        = video_frame;
   cbs->sample_cb       = audio_sample;
   cbs->sample_batch_cb = audio_sample_batch;
   cbs->state_cb        = input_state;
   cbs->poll_cb         = input_poll;
}

/**
 * retro_init_libretro_cbs:
 * @data           : pointer to retro_callbacks object
 *
 * Initializes libretro callbacks, and binds the libretro callbacks 
 * to default callback functions.
 **/
void retro_init_libretro_cbs(void *data)
{
   struct retro_callbacks *cbs = (struct retro_callbacks*)data;

   if (!cbs)
      return;

   pretro_set_video_refresh(video_frame);
   pretro_set_audio_sample(audio_sample);
   pretro_set_audio_sample_batch(audio_sample_batch);
   pretro_set_input_state(input_state);
   pretro_set_input_poll(input_poll);

   retro_set_default_callbacks(cbs);

#ifdef HAVE_NETPLAY
   if (!driver.netplay_data)
      return;

   if (g_extern.netplay_is_spectate)
   {
      pretro_set_input_state(
            (g_extern.netplay_is_client ?
             input_state_spectate_client : input_state_spectate)
            );
   }
   else
   {
      pretro_set_video_refresh(video_frame_net);
      pretro_set_audio_sample(audio_sample_net);
      pretro_set_audio_sample_batch(audio_sample_batch_net);
      pretro_set_input_state(input_state_net);
   }
#endif
}

/**
 * retro_set_rewind_callbacks:
 *
 * Sets the audio sampling callbacks based on whether or not
 * rewinding is currently activated.
 **/
void retro_set_rewind_callbacks(void)
{
   if (g_extern.frame_is_reverse)
   {
      pretro_set_audio_sample(audio_sample_rewind);
      pretro_set_audio_sample_batch(audio_sample_batch_rewind);
   }
   else
   {
      pretro_set_audio_sample(audio_sample);
      pretro_set_audio_sample_batch(audio_sample_batch);
   }
}