/*
  VitaShell
  Copyright (C) 2015-2018, TheFloW

  This program 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 Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "main.h"
#include "browser.h"
#include "archive.h"
#include "photo.h"
#include "file.h"
#include "theme.h"
#include "utils.h"

static vita2d_texture *loadImage(const char *file, int type, char *buffer) {
  vita2d_texture *tex = NULL;

  if (isInArchive()) {
    int size = 0;

    if (isInArchive()) {
      size = ReadArchiveFile(file, buffer, BIG_BUFFER_SIZE);
    } else {
      size = ReadFile(file, buffer, BIG_BUFFER_SIZE);
    }

    if (size <= 0) {
      return NULL;
    }

    switch (type) {
      case FILE_TYPE_BMP:
        tex = vita2d_load_BMP_buffer(buffer);
        break;
      
      case FILE_TYPE_PNG:
        tex = vita2d_load_PNG_buffer(buffer);
        break;
        
      case FILE_TYPE_JPEG:
        tex = vita2d_load_JPEG_buffer(buffer, size);
        break;
    }
  } else {
    switch (type) {
      case FILE_TYPE_BMP:
        tex = vita2d_load_BMP_file(file);
        break;
      
      case FILE_TYPE_PNG:
        tex = vita2d_load_PNG_file(file);
        break;
        
      case FILE_TYPE_JPEG:
        tex = vita2d_load_JPEG_file(file);
        break;
    }
  }

  // Set bilinear filter
  if (tex)
    vita2d_texture_set_filters(tex, SCE_GXM_TEXTURE_FILTER_LINEAR, SCE_GXM_TEXTURE_FILTER_LINEAR);

  return tex;
}

static int isHorizontal(float rad) {
  return ((int)sinf(rad) == 0) ? 1 : 0;
}

static void photoMode(float *zoom, float width, float height, float rad, int mode) {
  int horizontal = isHorizontal(rad);
  float h = horizontal ? height : width;
  float w = horizontal ? width : height;

  switch (mode) {
    case MODE_CUSTOM:
      break;
      
    case MODE_PERFECT: // this is only used for showing image the first time
      if (h > SCREEN_HEIGHT) { // first priority, fit height
        *zoom = SCREEN_HEIGHT / h;
      } else if (w > SCREEN_WIDTH) { // second priority, fit screen
        *zoom = SCREEN_WIDTH / w;
      } else { // otherwise, original size
        *zoom = 1.0f;
      }

      break;
    
    case MODE_ORIGINAL:
      *zoom = 1.0f;
      break;
      
    case MODE_FIT_HEIGHT:
      *zoom = SCREEN_HEIGHT / h;
      break;
      
    case MODE_FIT_WIDTH:
      *zoom = SCREEN_WIDTH / w;
      break;
  }
}

static int getNextZoomMode(float *zoom, float width, float height, float rad, int mode) {
  float next_zoom = ZOOM_MAX, smallest_zoom = ZOOM_MAX;;
  int next_mode = MODE_ORIGINAL, smallest_mode = MODE_ORIGINAL;

  int i = 0;
  while (i < 3) {
    if (mode == MODE_CUSTOM || mode == MODE_PERFECT || mode == MODE_FIT_WIDTH) {
      mode = MODE_ORIGINAL;
    } else {
      mode++;
    }

    float new_zoom = 0.0f;
    photoMode(&new_zoom, width, height, rad, mode);

    if (new_zoom < smallest_zoom) {
      smallest_zoom = new_zoom;
      smallest_mode = mode;
    }

    if (new_zoom > *zoom && new_zoom < next_zoom) {
      next_zoom = new_zoom;
      next_mode = mode;
    }

    i++;
  }

  // Get smallest then
  if (next_zoom == ZOOM_MAX) {
    next_zoom = smallest_zoom;
    next_mode = smallest_mode;
  }

  *zoom = next_zoom;
  return next_mode;
}

static void resetImageInfo(vita2d_texture *tex, float *width, float *height, float *x, float *y, float *rad, float *zoom, int *mode, uint64_t *time) {
  *width = vita2d_texture_get_width(tex);
  *height = vita2d_texture_get_height(tex);

  *x = *width/2.0f;
  *y = *height/2.0f;

  *rad = 0;
  *zoom = 1.0f;

  *mode = MODE_PERFECT;
  photoMode(zoom, *width, *height, *rad, *mode);

  *time = 0;
}

int photoViewer(const char *file, int type, FileList *list, FileListEntry *entry, int *base_pos, int *rel_pos) {
  char *buffer = memalign(4096, BIG_BUFFER_SIZE);
  if (!buffer)
    return VITASHELL_ERROR_NO_MEMORY;

  vita2d_texture *tex = loadImage(file, type, buffer);
  if (!tex) {
    free(buffer);
    return VITASHELL_ERROR_NO_MEMORY;
  }

  // Variables
  float width = 0.0f, height = 0.0f, x = 0.0f, y = 0.0f, rad = 0.0f, zoom = 1.0f;
  int mode = MODE_PERFECT;
  uint64_t time = 0;

  // Reset image
  resetImageInfo(tex, &width, &height, &x, &y, &rad, &zoom, &mode, &time);

  while (1) {
    readPad();

    // Cancel
    if (pressed_pad[PAD_CANCEL]) {
      break;
    }

    // Previous/next image.
    if (pressed_pad[PAD_LEFT] || pressed_pad[PAD_RIGHT]) {
      int available = 0;

      int old_base_pos = *base_pos;
      int old_rel_pos = *rel_pos;
      FileListEntry *old_entry = entry;

      int previous = pressed_pad[PAD_LEFT];
      while (previous ? entry->previous : entry->next) {
        entry = previous ? entry->previous : entry->next;

        if (previous) {
          if (*rel_pos > 0) {
            (*rel_pos)--;
          } else if (*base_pos > 0) {
            (*base_pos)--;
          }
        } else {
          if ((*rel_pos + 1) < list->length) {
            if ((*rel_pos + 1) < MAX_POSITION) {
              (*rel_pos)++;
            } else if ((*base_pos + *rel_pos + 1) < list->length) {
              (*base_pos)++;
            }
          }
        }

        if (!entry->is_folder) {
          char path[MAX_PATH_LENGTH];
          snprintf(path, MAX_PATH_LENGTH, "%s%s", list->path, entry->name);
          int type = getFileType(path);
          if (type == FILE_TYPE_BMP || type == FILE_TYPE_JPEG || type == FILE_TYPE_PNG) {
            vita2d_wait_rendering_done();
            vita2d_free_texture(tex);
            
            tex = loadImage(path, type, buffer);
            if (!tex) {
              free(buffer);
              return VITASHELL_ERROR_NO_MEMORY;
            }

            // Reset image
            resetImageInfo(tex, &width, &height, &x, &y, &rad, &zoom, &mode, &time);
            available = 1;
            break;
          }
        }
      }

      if (!available) {
        *base_pos = old_base_pos;
        *rel_pos = old_rel_pos;
        entry = old_entry;
      }
    }

    // Photo mode
    if (pressed_pad[PAD_ENTER]) {
      time = sceKernelGetProcessTimeWide();

      x = width / 2.0f;
      y = height / 2.0f;

      // Find next mode
      mode = getNextZoomMode(&zoom, width, height, rad, mode);
    }

    // Rotate
    if (pressed_pad[PAD_LTRIGGER]) {
      rad -= M_PI_2;
      if (rad < 0)
        rad += M_TWOPI;

      photoMode(&zoom, width, height, rad, mode);
    } else if (pressed_pad[PAD_RTRIGGER]) {
      rad += M_PI_2;
      if (rad >= M_TWOPI)
        rad -= M_TWOPI;

      photoMode(&zoom, width, height, rad, mode);
    }

    // Zoom
    if (current_pad[PAD_RIGHT_ANALOG_DOWN]) {
      time = sceKernelGetProcessTimeWide();
      mode = MODE_CUSTOM;
      zoom /= ZOOM_FACTOR;
    } else if (current_pad[PAD_RIGHT_ANALOG_UP]) {
      time = sceKernelGetProcessTimeWide();
      mode = MODE_CUSTOM;
      zoom *= ZOOM_FACTOR;
    }

    if (zoom < ZOOM_MIN) {
      zoom = ZOOM_MIN;
    }

    if (zoom > ZOOM_MAX) {
      zoom = ZOOM_MAX;
    }

    // Move
    if (pad.lx < (ANALOG_CENTER - ANALOG_SENSITIVITY) || pad.lx > (ANALOG_CENTER + ANALOG_SENSITIVITY)) {
      float d = ((pad.lx - ANALOG_CENTER) / MOVE_DIVISION) / zoom;

      if (isHorizontal(rad)) {
        x += cosf(rad) * d;
      } else {
        y += -sinf(rad) * d;
      }
    }

    if (pad.ly < (ANALOG_CENTER - ANALOG_SENSITIVITY) || pad.ly > (ANALOG_CENTER + ANALOG_SENSITIVITY)) {
      float d = ((pad.ly - ANALOG_CENTER) / MOVE_DIVISION) / zoom;

      if (isHorizontal(rad)) {
        y += cosf(rad) * d;
      } else {
        x += sinf(rad) * d;
      }
    }

    // Limit
    int horizontal = isHorizontal(rad);
    float w = horizontal ? SCREEN_HALF_WIDTH : SCREEN_HALF_HEIGHT;
    float h = horizontal ? SCREEN_HALF_HEIGHT : SCREEN_HALF_WIDTH;

    if ((zoom *  width) > 2.0f * w) {
      if (x < (w / zoom)) {
        x = w / zoom;
      } else if (x > (width - w / zoom)) {
        x = width - w / zoom;
      }
    } else {
      x = width / 2.0f;
    }

    if ((zoom * height) > 2.0f * h) {
      if (y < (h / zoom)) {
        y = h / zoom;
      } else if (y > (height - h / zoom)) {
        y = height - h/zoom;
      }
    } else {
      y = height / 2.0f;
    }

    // Start drawing
    startDrawing(bg_photo_image);

    // Photo
    vita2d_draw_texture_scale_rotate_hotspot(tex, SCREEN_HALF_WIDTH, SCREEN_HALF_HEIGHT, zoom, zoom, rad, x, y);

    // Zoom text
    if ((sceKernelGetProcessTimeWide() - time) < ZOOM_TEXT_TIME)
      pgf_draw_textf(SHELL_MARGIN_X, SCREEN_HEIGHT - 3.0f * SHELL_MARGIN_Y, PHOTO_ZOOM_COLOR, "%.0f%%", zoom * 100.0f);

    // End drawing
    endDrawing();
  }

  vita2d_wait_rendering_done();
  vita2d_free_texture(tex);

  free(buffer);

  return 0;
}