/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *
 *  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 "filter.h"
#include "filters/softfilter.h"
#include "../dynamic.h"
#include "../conf/config_file.h"
#include "../general.h"
#include "../file_path.h"
#include "../file_ext.h"
#include "../performance.h"
#include <stdlib.h>

struct rarch_soft_plug
{
#ifdef HAVE_DYLIB
   dylib_t lib;
#endif
   const struct softfilter_implementation *impl;
};

#ifdef HAVE_THREADS
#include "../thread.h"

struct filter_thread_data
{
   sthread_t *thread;
   const struct softfilter_work_packet *packet;
   scond_t *cond;
   slock_t *lock;
   void *userdata;
   bool die;
   bool done;
};

static void filter_thread_loop(void *data)
{
   struct filter_thread_data *thr = (struct filter_thread_data*)data;

   for (;;)
   {
      slock_lock(thr->lock);
      while (thr->done && !thr->die)
         scond_wait(thr->cond, thr->lock);
      bool die = thr->die;
      slock_unlock(thr->lock);

      if (die)
         break;

      if (thr->packet && thr->packet->work)
         thr->packet->work(thr->userdata, thr->packet->thread_data);

      slock_lock(thr->lock);
      thr->done = true;
      scond_signal(thr->cond);
      slock_unlock(thr->lock);
   }
}
#endif

struct rarch_softfilter
{
   config_file_t *conf;

   const struct softfilter_implementation *impl;
   void *impl_data;

   struct rarch_soft_plug *plugs;
   unsigned num_plugs;

   unsigned max_width, max_height;
   enum retro_pixel_format pix_fmt, out_pix_fmt;

   struct softfilter_work_packet *packets;
   unsigned threads;

#ifdef HAVE_THREADS
   struct filter_thread_data *thread_data;
#endif
};

const struct softfilter_implementation *softfilter_find_implementation(rarch_softfilter_t *filt, const char *ident)
{
   unsigned i;
   for (i = 0; i < filt->num_plugs; i++)
   {
      if (!strcmp(filt->plugs[i].impl->short_ident, ident))
         return filt->plugs[i].impl;
   }

   return NULL;
}

struct softfilter_userdata
{
   config_file_t *conf;
   const char *prefix[2];
};

static int softfilter_get_float(void *userdata, const char *key_str, float *value, float default_value)
{
   struct softfilter_userdata *filt = (struct softfilter_userdata*)userdata;

   char key[2][256];
   snprintf(key[0], sizeof(key[0]), "%s_%s", filt->prefix[0], key_str);
   snprintf(key[1], sizeof(key[1]), "%s_%s", filt->prefix[1], key_str);

   bool got = config_get_float(filt->conf, key[0], value);
   got = got || config_get_float(filt->conf, key[1], value);

   if (!got)
      *value = default_value;
   return got;
}

static int softfilter_get_int(void *userdata, const char *key_str, int *value, int default_value)
{
   struct softfilter_userdata *filt = (struct softfilter_userdata*)userdata;

   char key[2][256];
   snprintf(key[0], sizeof(key[0]), "%s_%s", filt->prefix[0], key_str);
   snprintf(key[1], sizeof(key[1]), "%s_%s", filt->prefix[1], key_str);

   bool got = config_get_int(filt->conf, key[0], value);
   got = got || config_get_int(filt->conf, key[1], value);

   if (!got)
      *value = default_value;
   return got;
}

#define softfilter_get_array_setup() \
   struct softfilter_userdata *filt = (struct softfilter_userdata*)userdata; \
 \
   char key[2][256]; \
   snprintf(key[0], sizeof(key[0]), "%s_%s", filt->prefix[0], key_str); \
   snprintf(key[1], sizeof(key[1]), "%s_%s", filt->prefix[1], key_str); \
 \
   char *str = NULL; \
   bool got = config_get_string(filt->conf, key[0], &str); \
   got = got || config_get_string(filt->conf, key[1], &str);

#define softfilter_get_array_body(T) \
   if (got) \
   { \
      unsigned i; \
      struct string_list *list = string_split(str, " "); \
      *values = (T*)calloc(list->size, sizeof(T)); \
      for (i = 0; i < list->size; i++) \
         (*values)[i] = (T)strtod(list->elems[i].data, NULL); \
      *out_num_values = list->size; \
      string_list_free(list); \
      return true; \
   } \
   else \
   { \
      *values = (T*)calloc(num_default_values, sizeof(T)); \
      memcpy(*values, default_values, sizeof(T) * num_default_values); \
      *out_num_values = num_default_values; \
      return false; \
   }

static int softfilter_get_float_array(void *userdata, const char *key_str,
      float **values, unsigned *out_num_values,
      const float *default_values, unsigned num_default_values)
{
   softfilter_get_array_setup()
   softfilter_get_array_body(float)
}

static int softfilter_get_int_array(void *userdata, const char *key_str,
      int **values, unsigned *out_num_values,
      const int *default_values, unsigned num_default_values)
{
   softfilter_get_array_setup()
   softfilter_get_array_body(int)
}

static int softfilter_get_string(void *userdata, const char *key_str,
      char **output, const char *default_output)
{
   softfilter_get_array_setup()

   if (got)
   {
      *output = str;
      return true; 
   }
   else
   {
      *output = strdup(default_output);
      return false;
   }
}

static void softfilter_free(void *ptr)
{
   free(ptr);
}

static const struct softfilter_config softfilter_config = {
   softfilter_get_float,
   softfilter_get_int,
   softfilter_get_float_array,
   softfilter_get_int_array,
   softfilter_get_string,
   softfilter_free,
};


static bool create_softfilter_graph(rarch_softfilter_t *filt,
      enum retro_pixel_format in_pixel_format,
      unsigned max_width, unsigned max_height,
      softfilter_simd_mask_t cpu_features,
      unsigned threads)
{
   unsigned input_fmts, input_fmt, output_fmts;
   char key[64];
   struct softfilter_userdata userdata;

   snprintf(key, sizeof(key), "filter");

   char name[64];
   if (!config_get_array(filt->conf, key, name, sizeof(name)))
      return false;

   filt->impl = softfilter_find_implementation(filt, name);
   if (!filt->impl)
      return false;

   userdata.conf = filt->conf;
   userdata.prefix[0] = key; // Index-specific configs take priority over ident-specific.
   userdata.prefix[1] = filt->impl->short_ident;

   // Simple assumptions.
   filt->pix_fmt = in_pixel_format;
   input_fmts = filt->impl->query_input_formats();

   switch (in_pixel_format)
   {
      case RETRO_PIXEL_FORMAT_XRGB8888:
         input_fmt = SOFTFILTER_FMT_XRGB8888;
         break;
      case RETRO_PIXEL_FORMAT_RGB565:
         input_fmt = SOFTFILTER_FMT_RGB565;
         break;
      default:
         return false;
   }

   if (!(input_fmt & input_fmts))
   {
      RARCH_ERR("Softfilter does not support input format.\n");
      return false;
   }

   output_fmts = filt->impl->query_output_formats(input_fmt);
   if (output_fmts & input_fmt) // If we have a match of input/output formats, use that.
      filt->out_pix_fmt = in_pixel_format;
   else if (output_fmts & SOFTFILTER_FMT_XRGB8888)
      filt->out_pix_fmt = RETRO_PIXEL_FORMAT_XRGB8888;
   else if (output_fmts & SOFTFILTER_FMT_RGB565)
      filt->out_pix_fmt = RETRO_PIXEL_FORMAT_RGB565;
   else
   {
      RARCH_ERR("Did not find suitable output format for softfilter.\n");
      return false;
   }

   filt->max_width = max_width;
   filt->max_height = max_height;

   filt->impl_data = filt->impl->create(&softfilter_config, input_fmt, input_fmt, max_width, max_height,
         threads != RARCH_SOFTFILTER_THREADS_AUTO ? threads : rarch_get_cpu_cores(), cpu_features,
         &userdata);
   if (!filt->impl_data)
   {
      RARCH_ERR("Failed to create softfilter state.\n");
      return false;
   }

   threads = filt->impl->query_num_threads(filt->impl_data);
   if (!threads)
   {
      RARCH_ERR("Invalid number of threads.\n");
      return false;
   }

   RARCH_LOG("Using %u threads for softfilter.\n", threads);

   filt->packets = (struct softfilter_work_packet*)calloc(threads, sizeof(*filt->packets));
   if (!filt->packets)
   {
      RARCH_ERR("Failed to allocate softfilter packets.\n");
      return false;
   }

#ifdef HAVE_THREADS
   filt->thread_data = (struct filter_thread_data*)calloc(threads, sizeof(*filt->thread_data));
   if (!filt->thread_data)
      return false;
   filt->threads = threads;

   unsigned i;
   for (i = 0; i < threads; i++)
   {
      filt->thread_data[i].userdata = filt->impl_data;
      filt->thread_data[i].done = true;

      filt->thread_data[i].lock = slock_new();
      if (!filt->thread_data[i].lock)
         return false;
      filt->thread_data[i].cond = scond_new();
      if (!filt->thread_data[i].cond)
         return false;
      filt->thread_data[i].thread = sthread_create(filter_thread_loop, &filt->thread_data[i]);
      if (!filt->thread_data[i].thread)
         return false;
   }
#endif

   return true;
}

#ifdef HAVE_DYLIB
static bool append_softfilter_plugs(rarch_softfilter_t *filt, struct string_list *list)
{
   unsigned i;
   softfilter_simd_mask_t mask = rarch_get_cpu_features();

   for (i = 0; i < list->size; i++)
   {
      dylib_t lib = dylib_load(list->elems[i].data);
      if (!lib)
         continue;

      softfilter_get_implementation_t cb = (softfilter_get_implementation_t)dylib_proc(lib, "softfilter_get_implementation");
      if (!cb)
      {
         dylib_close(lib);
         continue;
      }

      const struct softfilter_implementation *impl = cb(mask);
      if (!impl)
      {
         dylib_close(lib);
         continue;
      }

      if (impl->api_version != SOFTFILTER_API_VERSION)
      {
         dylib_close(lib);
         continue;
      }

      struct rarch_soft_plug *new_plugs = (struct rarch_soft_plug*)realloc(filt->plugs, sizeof(*filt->plugs) * (filt->num_plugs + 1));
      if (!new_plugs)
      {
         dylib_close(lib);
         return false;
      }

      RARCH_LOG("[SoftFilter]: Found plug: %s (%s).\n", impl->ident, impl->short_ident);
      
      filt->plugs = new_plugs;
      filt->plugs[filt->num_plugs].lib = lib;
      filt->plugs[filt->num_plugs].impl = impl;
      filt->num_plugs++;
   }

   return true;
}
#else
extern const struct softfilter_implementation *blargg_ntsc_snes_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *lq2x_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *phosphor2x_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *twoxbr_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *epx_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *twoxsai_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *supereagle_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *supertwoxsai_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *twoxbr_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *darken_get_implementation(softfilter_simd_mask_t simd);
extern const struct softfilter_implementation *scale2x_get_implementation(softfilter_simd_mask_t simd);

static const softfilter_get_implementation_t soft_plugs_builtin[] = {
   blargg_ntsc_snes_get_implementation,
   lq2x_get_implementation,
   phosphor2x_get_implementation,
   twoxbr_get_implementation,
   darken_get_implementation,
   twoxsai_get_implementation,
   supertwoxsai_get_implementation,
   supereagle_get_implementation,
   epx_get_implementation,
   scale2x_get_implementation,
};

static bool append_softfilter_plugs(rarch_softfilter_t *filt)
{
   unsigned i;
   softfilter_simd_mask_t mask = rarch_get_cpu_features();

   filt->plugs = (struct rarch_soft_plug*)calloc(ARRAY_SIZE(soft_plugs_builtin), sizeof(*filt->plugs));
   if (!filt->plugs)
      return false;
   filt->num_plugs = ARRAY_SIZE(soft_plugs_builtin);

   for (i = 0; i < ARRAY_SIZE(soft_plugs_builtin); i++)
   {
      filt->plugs[i].impl = soft_plugs_builtin[i](mask);
      if (!filt->plugs[i].impl)
         return false;
   }

   return true;
}
#endif




rarch_softfilter_t *rarch_softfilter_new(const char *filter_config,
      unsigned threads,
      enum retro_pixel_format in_pixel_format,
      unsigned max_width, unsigned max_height)
{
#if defined(HAVE_DYLIB)
   char basedir[PATH_MAX];
#endif
   softfilter_simd_mask_t cpu_features = rarch_get_cpu_features();
   struct string_list *plugs = NULL;

   rarch_softfilter_t *filt = (rarch_softfilter_t*)calloc(1, sizeof(*filt));
   if (!filt)
      return NULL;

   filt->conf = config_file_new(filter_config);
   if (!filt->conf)
   {
      RARCH_ERR("[SoftFilter]: Did not find config: %s\n", filter_config);
      goto error;
   }

#if defined(HAVE_DYLIB)
   fill_pathname_basedir(basedir, filter_config, sizeof(basedir));

   plugs = dir_list_new(basedir, EXT_EXECUTABLES, false);
   if (!plugs)
      goto error;

   if (!append_softfilter_plugs(filt, plugs))
      goto error;

   string_list_free(plugs);
   plugs = NULL;
#else
   if (!append_softfilter_plugs(filt))
      goto error;
#endif

   if (!create_softfilter_graph(filt, in_pixel_format,
            max_width, max_height, cpu_features, threads))
      goto error;

   return filt;

error:
   string_list_free(plugs);
   rarch_softfilter_free(filt);
   return NULL;
}

void rarch_softfilter_free(rarch_softfilter_t *filt)
{
   unsigned i = 0;
   (void)i;

   if (!filt)
      return;

   free(filt->packets);
   if (filt->impl && filt->impl_data)
      filt->impl->destroy(filt->impl_data);

#ifdef HAVE_DYLIB
   for (i = 0; i < filt->num_plugs; i++)
   {
      if (filt->plugs[i].lib)
         dylib_close(filt->plugs[i].lib);
   }
   free(filt->plugs);
#endif

#ifdef HAVE_THREADS
   for (i = 0; i < filt->threads; i++)
   {
      if (!filt->thread_data[i].thread)
         continue;
      slock_lock(filt->thread_data[i].lock);
      filt->thread_data[i].die = true;
      scond_signal(filt->thread_data[i].cond);
      slock_unlock(filt->thread_data[i].lock);
      sthread_join(filt->thread_data[i].thread);
      slock_free(filt->thread_data[i].lock);
      scond_free(filt->thread_data[i].cond);
   }
   free(filt->thread_data);
#endif
   free(filt);
}

void rarch_softfilter_get_max_output_size(rarch_softfilter_t *filt,
      unsigned *width, unsigned *height)
{
   rarch_softfilter_get_output_size(filt, width, height, filt->max_width, filt->max_height);
}

void rarch_softfilter_get_output_size(rarch_softfilter_t *filt,
      unsigned *out_width, unsigned *out_height,
      unsigned width, unsigned height)
{
   if (filt && filt->impl && filt->impl->query_output_size)
      filt->impl->query_output_size(filt->impl_data, out_width, out_height, width, height);
}

enum retro_pixel_format rarch_softfilter_get_output_format(rarch_softfilter_t *filt)
{
   return filt->out_pix_fmt;
}

void rarch_softfilter_process(rarch_softfilter_t *filt,
      void *output, size_t output_stride,
      const void *input, unsigned width, unsigned height, size_t input_stride)
{
   unsigned i;

   if (filt && filt->impl && filt->impl->get_work_packets)
      filt->impl->get_work_packets(filt->impl_data, filt->packets,
            output, output_stride, input, width, height, input_stride);
   
#ifdef HAVE_THREADS
   // Fire off workers
   for (i = 0; i < filt->threads; i++)
   {
      //RARCH_LOG("Firing off filter thread %u ...\n", i);
      filt->thread_data[i].packet = &filt->packets[i];
      slock_lock(filt->thread_data[i].lock);
      filt->thread_data[i].done = false;
      scond_signal(filt->thread_data[i].cond);
      slock_unlock(filt->thread_data[i].lock);
   }

   // Wait for workers
   for (i = 0; i < filt->threads; i++)
   {
      //RARCH_LOG("Waiting for filter thread %u ...\n", i);
      slock_lock(filt->thread_data[i].lock);
      while (!filt->thread_data[i].done)
         scond_wait(filt->thread_data[i].cond, filt->thread_data[i].lock);
      slock_unlock(filt->thread_data[i].lock);
   }
#else
   for (i = 0; i < filt->threads; i++)
      filt->packets[i].work(filt->impl_data, filt->packets[i].thread_data);
#endif
}