/*  SSNES - A Super Nintendo Entertainment System (SNES) Emulator frontend for libsnes.
 *  Copyright (C) 2010-2011 - Hans-Kristian Arntzen
 *
 *  Some code herein may be based on code found in BSNES.
 * 
 *  SSNES 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.
 *
 *  SSNES 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 SSNES.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

// Loader for external API plugins.

#define SSNES_DLL_IMPORT
#include "ext/ssnes_video.h"
#include <stdbool.h>
#include <stdlib.h>
#include <stdint.h>
#include "dynamic.h"
#include "general.h"

static bool g_input_dead = true;
static bool g_video_dead = true;
static dylib_t g_lib = NULL;

/////////// Input hook

typedef struct
{
   const ssnes_input_driver_t *driver;
   void *handle;
} input_ext_t;

static void* input_ext_init(void)
{
   g_input_dead = false;
   return calloc(1, sizeof(input_ext_t));
}

static void input_ext_poll(void *data)
{
   input_ext_t *ext = data;
   ext->driver->poll(ext->handle);
}

static int16_t input_ext_input_state(void *data, const struct snes_keybind **snes_keybinds, bool port, unsigned device, unsigned index, unsigned id)
{
   input_ext_t *ext = data;

   unsigned player = 0;
   if (device == SNES_DEVICE_MULTITAP)
      player = (port == SNES_PORT_1) ? 1 : index + 2;
   else
      player = (port == SNES_PORT_1) ? 1 : 2;

   const struct snes_keybind *ssnes_bind = NULL;

   for (unsigned i = 0; g_settings.input.binds[player - 1][i].id != -1; i++)
   {
      if (g_settings.input.binds[player - 1][i].id == id)
      {
         ssnes_bind = &g_settings.input.binds[player - 1][i];
         break;
      }
   }

   if (ssnes_bind)
   {
      struct ssnes_keybind bind = {
         .key = ssnes_bind->key,
         .joykey = ssnes_bind->joykey,
         .joyaxis = ssnes_bind->joyaxis
      };

      return ext->driver->input_state(ext->handle, &bind, player);
   }
   else
      return 0;
}

static bool input_ext_key_pressed(void *data, int key)
{
   input_ext_t *ext = data;

   const struct snes_keybind *ssnes_bind = NULL;
   for (unsigned i = 0; g_settings.input.binds[0][i].id != -1; i++)
   {
      if (g_settings.input.binds[0][i].id == key)
      {
         ssnes_bind = &g_settings.input.binds[0][i];
         break;
      }
   }

   if (ssnes_bind)
   {
      struct ssnes_keybind bind = {
         .key = ssnes_bind->key,
         .joykey = ssnes_bind->joykey,
         .joyaxis = ssnes_bind->joyaxis
      };

      return ext->driver->input_state(ext->handle, &bind, 1);
   }
   else
      return false;
}

static void input_ext_free(void *data)
{
   input_ext_t *ext = data;
   if (ext)
   {
      if (ext->driver && ext->handle)
         ext->driver->free(ext->handle);

      if (g_video_dead)
      {
         dylib_close(g_lib);
         g_lib = NULL;
      }

      g_input_dead = true;

      free(ext);
   }
}

static const input_driver_t input_ext = {
   .init = input_ext_init,
   .poll = input_ext_poll,
   .input_state = input_ext_input_state,
   .key_pressed = input_ext_key_pressed,
   .free = input_ext_free,
   .ident = "ext"
};


//////////// Video hook
typedef struct
{
   const ssnes_video_driver_t *driver;
   void *handle;
} ext_t;

static void video_ext_free(void *data)
{
   ext_t *ext = data;
   if (ext)
   {
      if (ext->driver && ext->handle)
         ext->driver->free(ext->handle);

      if (g_input_dead)
      {
         dylib_close(g_lib);
         g_lib = NULL;
      }

      g_video_dead = true;

      free(ext);
   }
}

static bool video_ext_focus(void *data)
{
   ext_t *ext = data;
   return ext->driver->focus(ext->handle);
}

static bool video_ext_alive(void *data)
{
   ext_t *ext = data;
   return ext->driver->alive(ext->handle);
}

static void video_ext_set_nonblock_state(void *data, bool state)
{
   ext_t *ext = data;
   ext->driver->set_nonblock_state(ext->handle, state);
}

static bool video_ext_frame(void *data, const void *frame, unsigned width, unsigned height, unsigned pitch, const char *msg)
{
   ext_t *ext = data;
   return ext->driver->frame(ext->handle, frame, width, height, pitch, msg);
}

static void* setup_input(ext_t *ext, const ssnes_input_driver_t *driver)
{
   int joypad_index[5];
   for (unsigned i = 0; i < 5; i++)
      joypad_index[i] = g_settings.input.joypad_map[i] == SSNES_NO_JOYPAD ? -1 : g_settings.input.joypad_map[i];

   void *handle = driver->init(joypad_index, g_settings.input.axis_threshold);
   if (!handle)
      return NULL;

   input_ext_t *wrap_handle = input_ext.init();
   if (!wrap_handle)
      return NULL;

   wrap_handle->handle = handle;
   wrap_handle->driver = driver;

   return wrap_handle;
}

static bool setup_video(ext_t *ext, const video_info_t *video, const input_driver_t **input, void **input_data)
{
   SSNES_LOG("Loaded driver: \"%s\"\n", ext->driver->ident ? ext->driver->ident : "Unknown");

   if (SSNES_GRAPHICS_API_VERSION != ext->driver->api_version)
   {
      SSNES_ERR("API version mismatch detected!\n");
      SSNES_ERR("Required API version: %d, Library version: %d\n", SSNES_GRAPHICS_API_VERSION, ext->driver->api_version);
      return false;
   }

   ssnes_video_info_t info = {
      .width = video->width,
      .height = video->height,
      .fullscreen = video->fullscreen,
      .vsync = video->vsync,
      .force_aspect = video->force_aspect,
      .aspect_ratio = g_settings.video.aspect_ratio,
      .smooth = video->smooth,
      .input_scale = video->input_scale,
      .color_format = video->rgb32 ? SSNES_COLOR_FORMAT_ARGB8888 : SSNES_COLOR_FORMAT_XRGB1555,
      .xml_shader = g_settings.video.bsnes_shader_path,
      .cg_shader = g_settings.video.cg_shader_path,
      .ttf_font = *g_settings.video.font_path ? g_settings.video.font_path : NULL,
      .ttf_font_size = g_settings.video.font_size
   };

   const ssnes_input_driver_t *input_driver = NULL;
   ext->handle = ext->driver->init(&info, &input_driver);
   if (!ext->handle)
      return false;

   *input = input_driver ? &input_ext : NULL;
   if (input_driver)
      *input_data = setup_input(ext, input_driver);
   else
      *input_data = NULL;

   return true;
}

static void* video_ext_init(const video_info_t *video, const input_driver_t **input, void **input_data)
{
   ext_t *ext = calloc(1, sizeof(*ext));
   if (!ext)
      return NULL;

   if (!(*g_settings.video.external_driver))
   {
      SSNES_ERR("External driver needs video_external_driver path to be set!\n");
      goto error;
   }

   g_lib = dylib_load(g_settings.video.external_driver);
   if (!g_lib)
   {
      SSNES_ERR("Failed to open library: \"%s\"\n", g_settings.video.external_driver);
      goto error;
   }

   const ssnes_video_driver_t* (*video_init)(void) = dylib_proc(g_lib, "ssnes_video_init");
   if (!video_init)
   {
      SSNES_ERR("Couldn't find function ssnes_video_init in library ...\n");
      goto error;
   }

   ext->driver = video_init();
   if (!ext->driver)
   {
      SSNES_ERR("External driver returned invalid driver handle.\n");
      goto error;
   }

   if (!setup_video(ext, video, input, input_data))
   {
      SSNES_ERR("Failed to start driver.\n");
      goto error;
   }

   g_video_dead = false;
   return ext;

error:
   video_ext_free(ext);
   return NULL;
}

const video_driver_t video_ext = {
   .init = video_ext_init,
   .frame = video_ext_frame,
   .alive = video_ext_alive,
   .set_nonblock_state = video_ext_set_nonblock_state,
   .focus = video_ext_focus,
   .free = video_ext_free,
   .ident = "ext"
};