/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2018      - misson20000
 *  Copyright (C) 2018      - m4xw
 *
 *  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 <stdio.h>
#include <string.h>
#include <malloc.h>

#include <retro_inline.h>
#include <retro_math.h>
#include <formats/image.h>

#include <formats/image.h>
#include <gfx/scaler/scaler.h>
#include <gfx/scaler/pixconv.h>
#include <gfx/video_frame.h>

#include <switch.h>

#ifdef HAVE_CONFIG_H
#include "../../config.h"
#endif

#ifdef HAVE_MENU
#include "../../menu/menu_driver.h"
#endif

#include "../font_driver.h"

#include "../../configuration.h"
#include "../../command.h"
#include "../../driver.h"

#include "../../retroarch.h"
#include "../../verbosity.h"

#include "../common/switch_common.h"

#ifndef HAVE_THREADS
#include "../../tasks/tasks_internal.h"
#endif

/* (C) libtransistor */
static int pdep(uint32_t mask, uint32_t value)
{
    uint32_t out = 0;
    for (int shift = 0; shift < 32; shift++)
    {
        uint32_t bit = 1u << shift;
        if (mask & bit)
        {
            if (value & 1)
                out |= bit;
            value >>= 1;
        }
    }
    return out;
}

static uint32_t swizzle_x(uint32_t v) { return pdep(~0x7B4u, v); }
static uint32_t swizzle_y(uint32_t v) { return pdep(0x7B4, v); }

void gfx_slow_swizzling_blit(uint32_t *buffer, uint32_t *image, int w, int h, int tx, int ty, bool blend)
{
    uint32_t *dest = buffer;
    uint32_t *src = image;
    int x0 = tx;
    int y0 = ty;
    int x1 = x0 + w;
    int y1 = y0 + h;
    const uint32_t tile_height = 128;
    const uint32_t padded_width = 128 * 10;

    /* we're doing this in pixels - should just shift the swizzles instead */
    uint32_t offs_x0 = swizzle_x(x0);
    uint32_t offs_y = swizzle_y(y0);
    uint32_t x_mask = swizzle_x(~0u);
    uint32_t y_mask = swizzle_y(~0u);
    uint32_t incr_y = swizzle_x(padded_width);

    /* step offs_x0 to the right row of tiles */
    offs_x0 += incr_y * (y0 / tile_height);

    uint32_t x, y;
    for (y = y0; y < y1; y++)
    {
        uint32_t *dest_line = dest + offs_y;
        uint32_t offs_x = offs_x0;

        for (x = x0; x < x1; x++)
        {
            uint32_t pixel = *src++;
            if (blend) /* supercheap masking */
            {
                uint32_t dst = dest_line[offs_x];
                uint8_t src_a = ((pixel & 0xFF000000) >> 24);

                if (src_a > 0)
                    pixel &= 0x00FFFFFF;
                else
                    pixel = dst;
            }

            dest_line[offs_x] = pixel;

            offs_x = (offs_x - x_mask) & x_mask;
        }

        offs_y = (offs_y - y_mask) & y_mask;
        if (!offs_y)
            offs_x0 += incr_y; /* wrap into next tile row */
    }
}

void gfx_cpy_dsp_buf(uint32_t *buffer, uint32_t *image, int w, int h, uint32_t stride, bool blend)
{
    uint32_t *dest = buffer;
    uint32_t *src = image;
    for (uint32_t y = 0; y < h; y ++)
    {
        for (uint32_t x = 0; x < w; x ++)
        {
            uint32_t pos = y * stride / sizeof(uint32_t) + x;
            uint32_t pixel = *src;

            if (blend) /* supercheap masking */
            {
                uint32_t dst = dest[pos];
                uint8_t src_a = ((pixel & 0xFF000000) >> 24);

                if (src_a > 0)
                    pixel &= 0x00FFFFFF;
                else
                    pixel = dst;
            }

            dest[pos] = pixel;

            src++;
        }
    }
}

/* needed to clear surface completely as hw scaling doesn't always scale to full resoution perflectly */
static void clear_screen(switch_video_t *sw)
{
    nwindowSetDimensions(sw->win, sw->vp.full_width, sw->vp.full_height);

    uint32_t stride;

    uint32_t *out_buffer = (uint32_t*)framebufferBegin(&sw->fb, &stride);

    memset(out_buffer, 0, stride * 720);

    framebufferEnd(&sw->fb);
}

static void *switch_init(const video_info_t *video,
      input_driver_t **input, void **input_data)
{
    void  *switchinput = NULL;
    switch_video_t *sw = (switch_video_t *)calloc(1, sizeof(*sw));
    if (!sw)
        return NULL;

   sw->win = nwindowGetDefault();

   framebufferCreate(&sw->fb, sw->win, 1280, 720, PIXEL_FORMAT_RGBA_8888, 2);
   framebufferMakeLinear(&sw->fb);

    sw->vp.x            = 0;
    sw->vp.y            = 0;
    sw->vp.width        = sw->o_width = video->width;
    sw->vp.height       = sw->o_height = video->height;
    sw->overlay_enabled = false;
    sw->overlay         = NULL;
#ifdef HAVE_MENU
    sw->in_menu         = false;
#endif

    sw->vp.full_width   = 1280;
    sw->vp.full_height  = 720;

    /* Sanity check */
    sw->vp.width = MIN(sw->vp.width, sw->vp.full_width);
    sw->vp.height = MIN(sw->vp.height, sw->vp.full_height);

    sw->vsync = video->vsync;
    sw->rgb32 = video->rgb32;
    sw->keep_aspect = true;
    sw->should_resize = true;
    sw->o_size = true;
    sw->is_threaded = video->is_threaded;
    sw->smooth = video->smooth;
    sw->menu_texture.enable = false;

    /* Autoselect driver */
    if (input && input_data)
    {
        settings_t *settings = config_get_ptr();
        switchinput          = input_driver_init_wrap(&input_switch,
              settings->arrays.input_joypad_driver);
        *input               = switchinput ? &input_switch : NULL;
        *input_data          = switchinput;
    }

    font_driver_init_osd(sw,
          video,
          false,
          video->is_threaded,
          FONT_DRIVER_RENDER_SWITCH);

    clear_screen(sw);

    return sw;
}

static void switch_update_viewport(switch_video_t *sw,
            video_frame_info_t *video_info)
{
    settings_t *settings = config_get_ptr();
    int x                = 0;
    int y                = 0;
    float desired_aspect = 0.0f;
    float width          = sw->vp.full_width;
    float height         = sw->vp.full_height;

    if (sw->o_size)
    {
        width = sw->o_width;
        height = sw->o_height;
        sw->vp.x = (int)(((float)sw->vp.full_width - width)) / 2;
        sw->vp.y = (int)(((float)sw->vp.full_height - height)) / 2;

        sw->vp.width = width;
        sw->vp.height = height;

        return;
    }

    desired_aspect = video_driver_get_aspect_ratio();

    if (settings->bools.video_scale_integer)
    {
        video_viewport_get_scaled_integer(&sw->vp, sw->vp.full_width, sw->vp.full_height, desired_aspect, sw->keep_aspect);
    }
    else if (sw->keep_aspect)
    {
#if defined(HAVE_MENU)
        if (settings->uints.video_aspect_ratio_idx == ASPECT_RATIO_CUSTOM)
        {
            sw->vp.x = sw->vp.y = 0;
            sw->vp.width = width;
            sw->vp.height = height;
        }
        else
#endif
        {
            float delta;
            float device_aspect = ((float)sw->vp.full_width) / sw->vp.full_height;

            if (fabsf(device_aspect - desired_aspect) < 0.0001f)
            {
                /*
                    * If the aspect ratios of screen and desired aspect
                    * ratio are sufficiently equal (floating point stuff),
                    * assume they are actually equal.
                */
            }
            else if (device_aspect > desired_aspect)
            {
                delta = (desired_aspect / device_aspect - 1.0f) / 2.0f + 0.5f;
                x = (int)roundf(width * (0.5f - delta));
                width = (unsigned)roundf(2.0f * width * delta);
            }
            else
            {
                delta = (device_aspect / desired_aspect - 1.0f) / 2.0f + 0.5f;
                y = (int)roundf(height * (0.5f - delta));
                height = (unsigned)roundf(2.0f * height * delta);
            }
        }

        sw->vp.x = x;
        sw->vp.y = y;

        sw->vp.width = width;
        sw->vp.height = height;
    }
    else
    {
        sw->vp.x = sw->vp.y = 0;
        sw->vp.width = width;
        sw->vp.height = height;
    }
}

static void switch_set_aspect_ratio(void *data, unsigned aspect_ratio_idx)
{
    settings_t *settings = config_get_ptr();
    switch_video_t *sw   = (switch_video_t *)data;

    if (!sw)
        return;

    sw->keep_aspect      = true;
    sw->o_size           = false;

    switch (aspect_ratio_idx)
    {
       case ASPECT_RATIO_CORE:
          sw->o_size      = true;
          sw->keep_aspect = false;
          break;

       case ASPECT_RATIO_CUSTOM:
          if (settings->bools.video_scale_integer)
          {
             video_driver_set_viewport_core();
             sw->o_size      = true;
             sw->keep_aspect = false;
          }
          break;

       default:
          break;
    }


    sw->should_resize = true;
}

static bool switch_frame(void *data, const void *frame,
      unsigned width, unsigned height,
      uint64_t frame_count, unsigned pitch,
      const char *msg, video_frame_info_t *video_info)
{
   uint32_t stride;
   switch_video_t   *sw = data;
   uint32_t *out_buffer = NULL;
   bool       ffwd_mode = video_info->input_driver_nonblock_state;
#ifdef HAVE_MENU
   bool menu_is_alive   = video_info->menu_is_alive;
#endif
   struct font_params 
      *osd_params       = (struct font_params *)&video_info->osd_stat_params;
   bool statistics_show = video_info->statistics_show;

   if (!frame)
      return true;

   if (ffwd_mode && !sw->is_threaded)
   {
      /* render every 4th frame when in ffwd mode and not threaded */
      if ((frame_count % 4) != 0)
         return true;
   }

   if (  sw->should_resize || 
         width  != sw->last_width || 
         height != sw->last_height)
   {
      switch_update_viewport(sw, video_info);

      /* Sanity check */
      sw->vp.width  = MIN(sw->vp.width, sw->vp.full_width);
      sw->vp.height = MIN(sw->vp.height, sw->vp.full_height);

      scaler_ctx_gen_reset(&sw->scaler);

      sw->scaler.in_width  = width;
      sw->scaler.in_height = height;
      sw->scaler.in_stride = pitch;
      sw->scaler.in_fmt    = sw->rgb32 
         ? SCALER_FMT_ARGB8888 
         : SCALER_FMT_RGB565;

      if (!sw->smooth)
      {
         sw->scaler.out_width = sw->vp.width;
         sw->scaler.out_height = sw->vp.height;
         sw->scaler.out_stride = sw->vp.full_width * sizeof(uint32_t);
      }
      else
      {
         sw->scaler.out_width = width;
         sw->scaler.out_height = height;
         sw->scaler.out_stride = width * sizeof(uint32_t);

         float screen_ratio = (float)sw->vp.full_width / sw->vp.full_height;
         float tgt_ratio = (float)sw->vp.width / sw->vp.height;

         sw->hw_scale.width = ceil(screen_ratio / tgt_ratio * sw->scaler.out_width);
         sw->hw_scale.height = sw->scaler.out_height;
         sw->hw_scale.x_offset = ceil((sw->hw_scale.width - sw->scaler.out_width) / 2.0);
#ifdef HAVE_MENU
         if (!menu_is_alive)
#endif
         {
            clear_screen(sw);
            nwindowSetDimensions(sw->win, sw->hw_scale.width, sw->hw_scale.height);
         }
      }
      sw->scaler.out_fmt = SCALER_FMT_ABGR8888;

      sw->scaler.scaler_type = SCALER_TYPE_POINT;

      if (!scaler_ctx_gen_filter(&sw->scaler))
         return false;

      sw->last_width = width;
      sw->last_height = height;

      sw->should_resize = false;
   }

   out_buffer     = (uint32_t *)framebufferBegin(&sw->fb, &stride);
   sw->out_buffer = out_buffer;
   sw->stride     = stride;

#ifdef HAVE_MENU
   if (sw->in_menu && !menu_is_alive && sw->smooth)
   {
      memset(out_buffer, 0, stride * sw->vp.full_height);
      nwindowSetDimensions(sw->win, sw->hw_scale.width, sw->hw_scale.height);
   }

   sw->in_menu = menu_is_alive;

   if (sw->menu_texture.enable)
   {
      menu_driver_frame(menu_is_alive, video_info);

      if (sw->menu_texture.pixels)
      {
         memset(out_buffer, 0, stride * sw->vp.full_height);
         scaler_ctx_scale(&sw->menu_texture.scaler, sw->tmp_image + ((sw->vp.full_height - sw->menu_texture.tgth) / 2) * sw->vp.full_width + ((sw->vp.full_width - sw->menu_texture.tgtw) / 2), sw->menu_texture.pixels);
         gfx_cpy_dsp_buf(out_buffer, sw->tmp_image, sw->vp.full_width, sw->vp.full_height, stride, true);
      }
   }
   else
#endif
      if (sw->smooth) /* bilinear */
      {
         int w, h;
         unsigned x, y;
         struct scaler_ctx *ctx = &sw->scaler;
         scaler_ctx_scale_direct(ctx, sw->image, frame);
         w = sw->scaler.out_width;
         h = sw->scaler.out_height;

         for (y = 0; y < h; y++)
            for (x = 0; x < w; x++)
               out_buffer[y * stride / sizeof(uint32_t) + (x + sw->hw_scale.x_offset)] = sw->image[y * w + x];
      }
      else
      {
         struct scaler_ctx *ctx = &sw->scaler;
         scaler_ctx_scale(ctx, sw->image + (sw->vp.y * sw->vp.full_width) + sw->vp.x, frame);
         gfx_cpy_dsp_buf(out_buffer, sw->image, sw->vp.full_width, sw->vp.full_height, stride, false);
      }

   if (statistics_show && !sw->smooth)
   {
      if (osd_params)
         font_driver_render_msg(sw, video_info->stat_text,
               osd_params, NULL);
   }

   if (msg)
      font_driver_render_msg(sw, msg, NULL, NULL);

   framebufferEnd(&sw->fb);

   return true;
}

static void switch_set_nonblock_state(void *data, bool toggle, bool c, unsigned d)
{
    switch_video_t *sw = data;
    sw->vsync = !toggle;
}

static bool switch_alive(void *data) { return true; }
static bool switch_focus(void *data) { return true; }
static bool switch_suppress_screensaver(void *data, bool enable) { return false; }
static bool switch_has_windowed(void *data) { return false; }

static void switch_free(void *data)
{
    switch_video_t *sw = data;

    framebufferClose(&sw->fb);

    if (sw->menu_texture.pixels)
        free(sw->menu_texture.pixels);

    free(sw);
}

static bool switch_set_shader(void *data,
            enum rarch_shader_type type, const char *path)
{
    (void)data;
    (void)type;
    (void)path;

    return false;
}

static void switch_set_rotation(void *data, unsigned rotation)
{
    switch_video_t *sw = data;
    if (!sw)
        return;
    sw->rotation = rotation;
}

static void switch_viewport_info(void *data, struct video_viewport *vp)
{
    switch_video_t *sw = data;
    *vp = sw->vp;
}

static void switch_set_texture_frame(
    void *data, const void *frame, bool rgb32,
    unsigned width, unsigned height, float alpha)
{
    switch_video_t *sw = data;
    size_t sz = width * height * (rgb32 ? 4 : 2);

    if (!sw->menu_texture.pixels ||
        sw->menu_texture.width != width ||
        sw->menu_texture.height != height)
    {
        int xsf, ysf, sf;
        struct scaler_ctx *sctx = NULL;

        if (sw->menu_texture.pixels)
            sw->menu_texture.pixels = realloc(sw->menu_texture.pixels, sz);
        else
            sw->menu_texture.pixels = malloc(sz);

        if (!sw->menu_texture.pixels)
            return;

        xsf = 1280 / width;
        ysf = 720 / height;
        sf  = xsf;

        if (ysf < sf)
            sf = ysf;

        sw->menu_texture.width  = width;
        sw->menu_texture.height = height;
        sw->menu_texture.tgtw   = width * sf;
        sw->menu_texture.tgth   = height * sf;

        sctx                    = &sw->menu_texture.scaler;
        scaler_ctx_gen_reset(sctx);

        sctx->in_width          = width;
        sctx->in_height         = height;
        sctx->in_stride         = width * (rgb32 ? 4 : 2);
        sctx->in_fmt            = rgb32 ? SCALER_FMT_ARGB8888 : SCALER_FMT_RGB565;
        sctx->out_width         = sw->menu_texture.tgtw;
        sctx->out_height        = sw->menu_texture.tgth;
        sctx->out_stride        = 1280 * 4;
        sctx->out_fmt           = SCALER_FMT_ABGR8888;

        sctx->scaler_type       = SCALER_TYPE_POINT;

        if (!scaler_ctx_gen_filter(sctx))
            return;
    }

    memcpy(sw->menu_texture.pixels, frame, sz);
}

static void switch_apply_state_changes(void *data)
{
    (void)data;
}

static void switch_set_texture_enable(void *data, bool enable, bool full_screen)
{
    switch_video_t *sw = data;
    if (!sw->menu_texture.enable && enable)
        nwindowSetDimensions(sw->win, sw->vp.full_width, sw->vp.full_height);
    else if (!enable && sw->menu_texture.enable && sw->smooth)
    {
        clear_screen(sw);
        nwindowSetDimensions(sw->win, sw->hw_scale.width, sw->hw_scale.height);
    }
    sw->menu_texture.enable = enable;
    sw->menu_texture.fullscreen = full_screen;
}

#ifdef HAVE_OVERLAY
static void switch_overlay_enable(void *data, bool state)
{
    switch_video_t *swa = (switch_video_t *)data;

    if (!swa)
        return;

    swa->overlay_enabled = state;
}

static bool switch_overlay_load(void *data,
            const void *image_data, unsigned num_images)
{
    switch_video_t          *swa = (switch_video_t *)data;
    struct texture_image *images = (struct texture_image *)image_data;

    if (!swa)
        return false;

    swa->overlay         = images;
    swa->overlay_enabled = true;

    return true;
}

static void switch_overlay_tex_geom(void *data,
            unsigned idx, float x, float y, float w, float h) { }
static void switch_overlay_vertex_geom(void *data,
            unsigned idx, float x, float y, float w, float h) { }
static void switch_overlay_full_screen(void *data, bool enable) { }
static void switch_overlay_set_alpha(void *data, unsigned idx, float mod) { }

static const video_overlay_interface_t switch_overlay = {
    switch_overlay_enable,
    switch_overlay_load,
    switch_overlay_tex_geom,
    switch_overlay_vertex_geom,
    switch_overlay_full_screen,
    switch_overlay_set_alpha,
};

void switch_overlay_interface(void *data, const video_overlay_interface_t **iface)
{
    switch_video_t *swa = (switch_video_t *)data;
    if (!swa)
        return;
    *iface = &switch_overlay;
}

#endif

static const video_poke_interface_t switch_poke_interface = {
    NULL,                       /* get_flags */
    NULL,                       /* load_texture */
    NULL,                       /* unload_texture */
    NULL,                       /* set_video_mode */
    NULL,                       /* get_refresh_rate */
    NULL,                       /* set_filtering */
    NULL,                       /* get_video_output_size */
    NULL,                       /* get_video_output_prev */
    NULL,                       /* get_video_output_next */
    NULL,                       /* get_current_framebuffer */
    NULL,                       /* get_proc_address */
    switch_set_aspect_ratio,    /* set_aspect_ratio */
    switch_apply_state_changes, /* apply_state_changes */
    switch_set_texture_frame,
    switch_set_texture_enable,
    font_driver_render_msg,
    NULL, /* show_mouse */
    NULL, /* grab_mouse_toggle */
    NULL, /* get_current_shader */
    NULL, /* get_current_software_framebuffer */
    NULL, /* get_hw_render_interface */
};

static void switch_get_poke_interface(void *data,
            const video_poke_interface_t **iface)
{
    (void)data;
    *iface = &switch_poke_interface;
}

video_driver_t video_switch = {
    switch_init,
    switch_frame,
    switch_set_nonblock_state,
    switch_alive,
    switch_focus,
    switch_suppress_screensaver,
    switch_has_windowed,
    switch_set_shader,
    switch_free,
    "switch",
    NULL, /* set_viewport */
    switch_set_rotation,
    switch_viewport_info,
    NULL, /* read_viewport  */
    NULL, /* read_frame_raw */
#ifdef HAVE_OVERLAY
    switch_overlay_interface, /* switch_overlay_interface */
#endif
#ifdef HAVE_VIDEO_LAYOUT
  NULL,
#endif
    switch_get_poke_interface,
};

/* vim: set ts=3 sw=3 */
