#include "image_viewer.h"
#include "cursor.h"
#include "direction.h"
#include "display_utils.h"
#include "image.h"
#include "input.h"
#include "logger.h"
#include "image_loader.h"
#include "coords.h"
#include <time.h>
#include <stdlib.h>

#define COMMANDS_NUM 30
#define CURSOR_SHOW_DURATION 3 // seconds

#define MAX_ZOOM 10
#define MIN_ZOOM 0.02

image_viewer_t image_viewer_create(char *filename, display_t *display, logger_t *logger) {
  image_viewer_t viewer = {
    .display = display,
    .image = image_create(filename),
    .cursor = cursor_create(),
    .logger = logger,
    .display_region = image_region_create(0, 0, DISPLAY_WIDTH, DISPLAY_HEIGHT),
    .image_region = image_region_create(0, 0, 0, 0),
  };

  viewer.error = image_loader_load(&viewer.image);

  if (viewer.error == IMERR_SUCCESS) {
    viewer.image_region =
        image_region_create(0, 0, viewer.image.width, viewer.image.height);
    viewer.scale = image_get_initial_zoom(&viewer.image);
    cursor_center(&viewer.cursor, viewer.image_region);
  }

  return viewer;
}

void image_viewer_destroy(image_viewer_t *viewer) {
  image_destroy(&viewer->image);
}

void command_handler_move_cursor(void *data, direction_t direction, int amount) {
  image_viewer_t *viewer = (image_viewer_t *)data;

  cursor_hide(&viewer->cursor, &viewer->image, viewer->scale, viewer->display);
  if (!cursor_move(&viewer->cursor,
                   image_get_zoom_region(&viewer->image, viewer->scale),
                   direction, amount / viewer->scale.scale)) {
    direction_move_xy(direction, (int32_t*)&viewer->scale.x, (int32_t*)&viewer->scale.y, amount / viewer->scale.scale);
    cursor_move(&viewer->cursor,
                image_get_zoom_region(&viewer->image, viewer->scale), direction,
                amount / viewer->scale.scale);
    image_viewer_display_image(viewer);
  }

  cursor_show(&viewer->cursor, &viewer->image, viewer->scale, viewer->display);
  display_render(viewer->display);
}

void command_handler_move_left(void *data, int amount) {
  image_viewer_t *viewer = (image_viewer_t*)data;
  logger_debug(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
               "Moving cursor to left by %d", amount);
  command_handler_move_cursor(data, LEFT, amount);
}

void command_handler_move_right(void *data, int amount) {
  image_viewer_t *viewer = (image_viewer_t *)data;
  logger_debug(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
               "Moving cursor to right by %d", amount);
  command_handler_move_cursor(data, RIGHT, amount);
}

void command_handler_move_up(void *data, int amount) {
  image_viewer_t *viewer = (image_viewer_t *)data;
  logger_debug(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
               "Moving cursor up by %d", amount);
  command_handler_move_cursor(data, UP, amount);
}

void command_handler_move_down(void *data, int amount) {
  image_viewer_t *viewer = (image_viewer_t *)data;
  logger_debug(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
               "Moving cursor down by %d", amount);
  command_handler_move_cursor(data, DOWN, amount);
}


void command_handler_exit(void *data, int amount) {
  image_viewer_t *viewer = (image_viewer_t *)data;
  viewer->running = false;
}

void zoom(image_viewer_t *viewer, int amount) {
  double zoom = viewer->scale.scale;
  double new_zoom = zoom * (1 + amount * 0.05);

  if (new_zoom > MAX_ZOOM) {
    logger_warn(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
                "Cannot zoom more than %f", MAX_ZOOM);
    new_zoom = MAX_ZOOM;
  }

  if (new_zoom < MIN_ZOOM) {
    logger_warn(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
                "Cannot zoom less than %f", MIN_ZOOM);
    new_zoom = MIN_ZOOM;
  }

  image_zoom_t tmp = {
    .scale = new_zoom,
    .x = viewer->scale.x,
    .y = viewer->scale.y,
  };

  image_region_t current_region = image_get_zoom_region(&viewer->image, viewer->scale);
  image_region_t new_region =
      image_get_zoom_region(&viewer->image, tmp);

  uint16_t scaled_w = (uint16_t)(zoom * viewer->image.width),
    scaled_h = (uint16_t)(zoom * viewer->image.height);

  int32_t beg_x = ((double)DISPLAY_WIDTH - (double)(scaled_w)) / 2;
  int32_t beg_y = ((double)DISPLAY_HEIGHT - (double)(scaled_h)) / 2;

  if (beg_x < 0) {
    beg_x = 0;
  }

  if (beg_y < 0) {
    beg_y = 0;
  }

  if (scaled_w > DISPLAY_WIDTH) {
    scaled_w = DISPLAY_WIDTH;
  }

  if (scaled_h > DISPLAY_HEIGHT) {
    scaled_h = DISPLAY_HEIGHT;
  }

  int32_t diff_w = current_region.width - new_region.width;
  int32_t diff_h = current_region.height - new_region.height;

  double side_percentage_x =
      (double)(viewer->cursor.x - current_region.x) / current_region.width;
  double side_percentage_y =
      (double)(viewer->cursor.y - current_region.y) / current_region.height;

  tmp.x += side_percentage_x * diff_w;
  tmp.y += side_percentage_y * diff_h;
  viewer->scale = tmp;

  image_viewer_display_image(viewer);
  cursor_show(&viewer->cursor, &viewer->image, viewer->scale, viewer->display);
}

// TODO: implement zoom functions
void command_handler_zoom_in(void *data, int amount) {
  // hide cursor, zoom, show cursor
  image_viewer_t *viewer = (image_viewer_t *)data;
  logger_debug(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
               "Zooming in by %d", amount);

  zoom(viewer, amount);
}

void command_handler_zoom_out(void *data, int amount) {
  image_viewer_t *viewer = (image_viewer_t *)data;
  logger_debug(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
               "Zooming out by %d", amount);

  zoom(viewer, -amount);
}

void command_handler_zoom_reset(void *data, int amount) {
  image_viewer_t *viewer = (image_viewer_t *)data;
  logger_debug(viewer->logger, __FILE__, __FUNCTION__, __LINE__,
               "Zoom reset by %d", amount);
  viewer->scale = image_get_initial_zoom(&viewer->image);
  image_viewer_display_image(viewer);
  cursor_center(&viewer->cursor, viewer->image_region);
  cursor_show(&viewer->cursor, &viewer->image, viewer->scale, viewer->display);
}

void image_viewer_register_commands(image_viewer_t *viewer, commands_t *commands) {
  commands_register(commands, IN_KEYBOARD, 'h', &command_handler_move_left,
                    viewer);
  commands_register(commands, IN_KEYBOARD, 'j', &command_handler_move_down,
                    viewer);
  commands_register(commands, IN_KEYBOARD, 'k', &command_handler_move_up,
                    viewer);
  commands_register(commands, IN_KEYBOARD, 'l', &command_handler_move_right,
                    viewer);

  commands_register(commands, IN_KEYBOARD, 'e', &command_handler_exit,
                    viewer);

  commands_register(commands, IN_KEYBOARD, 'z', &command_handler_zoom_in,
                    viewer);
  commands_register(commands, IN_KEYBOARD, 'x', &command_handler_zoom_out,
                    viewer);
  commands_register(commands, IN_KEYBOARD, 'r', &command_handler_zoom_reset,
                    viewer);

  commands_register(commands, IN_ENCODER_ROTATE, 0, &command_handler_move_right,
                    viewer);
  commands_register(commands, IN_ENCODER_ROTATE, 1,
                    &command_handler_move_down, viewer);
  commands_register(commands, IN_ENCODER_ROTATE, 2, &command_handler_zoom_in,
                    viewer);

  commands_register(commands, IN_ENCODER_CLICK, 0, &command_handler_exit,
                    viewer);

  commands_register(commands, IN_ENCODER_CLICK, 2, &command_handler_zoom_reset,
                    viewer);
}

void image_viewer_start_loop(image_viewer_t *viewer, void *reg_knobs_base) {
  command_t command_array[COMMANDS_NUM];
  commands_t commands = commands_create(command_array, COMMANDS_NUM, reg_knobs_base);

  image_viewer_register_commands(viewer, &commands);

  viewer->running = true;
  time_t now = time(NULL);
  while (viewer->running) {
    // Main loop
    commands_check_input(&commands);
    now = time(NULL);

    if (viewer->cursor.shown && difftime(now, viewer->cursor.shown_at) >= CURSOR_SHOW_DURATION) {
      cursor_hide(&viewer->cursor, &viewer->image, viewer->scale, viewer->display);
      display_render(viewer->display);
    }
  }
}

void image_viewer_display_image(image_viewer_t *viewer) {
  cursor_hide(&viewer->cursor, &viewer->image, viewer->scale, viewer->display);
  viewer->scale = image_write_to_display(&viewer->image, viewer->display, viewer->scale);
  display_render(viewer->display);
}