#include <GLFW/glfw3.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>

#include "game.h"
#include "domino.h"
#include "characters.h"
#include "assets/white_and_blue_dominoes.h"
#include "assets/red_and_peach_dominoes.h"

#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)>(b))?(a):(b))
#define CLAMP(x,a,b) (MIN(MAX(x,a),b))

int mouse_x = 0, mouse_y = 0;

struct bricks bricks = {0};

struct brick hand[5];
size_t hand_count = 0;

struct brick active = {0};
bool has_active = 0;

struct brick preview[256] = {0};
size_t preview_count = 0;

int camera_x = 0;
int camera_y = 0;
bool is_dragging = 0;

#define DIRECTIONS 6
struct eye direction[DIRECTIONS] = {
  {.x =  0, .y = -1},
  {.x = -2, .y =  0},
  {.x =  1, .y =  0},
  {.x =  0, .y =  1},
  {.x = -1, .y = -1},
  {.x = -1, .y =  1},
};

void get_prewiews() {
  preview_count = 0;
  for (size_t i = 0; i < bricks.count * 2; i++) {
    struct eye e = bricks.items.eye[i];
    if (e.val != active.front.val && e.val != active.back.val) continue;

    struct brick p = active;

    p.front.x = e.x;
    p.front.y = e.y;
    p.back.x =  e.x + !active.front.vertical;
    p.back.y =  e.y +  active.front.vertical;

    struct brick previews[DIRECTIONS] = {0};
    for (size_t ii = 0; ii < DIRECTIONS; ii++) {
      int offset_x = active.front.vertical ? direction[ii].y : direction[ii].x;
      int offset_y = active.front.vertical ? direction[ii].x : direction[ii].y;
      previews[ii] = p;
      previews[ii].front.x += offset_x;
      previews[ii].front.y += offset_y;
      previews[ii].front.val = 0;

      previews[ii].back.x += offset_x;
      previews[ii].back.y += offset_y;

      for (size_t iii = 0; iii < bricks.count * 2; iii++) {
        previews[ii].front.val |= (
            (bricks.items.eye[iii].x == previews[ii].back.x && bricks.items.eye[iii].y == previews[ii].back.y) ||
            (bricks.items.eye[iii].x == previews[ii].front.x && bricks.items.eye[iii].y == previews[ii].front.y)
            || (e.val == active.front.val && direction[ii].x < 0)
            || (e.val == active.back.val  && direction[ii].x >= 0)
            );
      }
    }

    for (size_t ii = 0; ii < DIRECTIONS; ii++) {
      if (!previews[ii].front.val)
        preview[preview_count++] = previews[ii];
    }
  }
}

void print_brick(struct brick b) {
  struct eye *eyes = (struct eye*) &b;
  for (size_t i = 0; i < 2; i++) {
    printf("{.x = %d, .y =   %d, .val = %d, .vertical = %d}" , eyes[i].x, eyes[i].y, eyes[i].val, eyes[i].vertical); }
  printf("\n");
}

void key_callback(int key, int scancode, int action, int mods) {
  (void) scancode;
  (void) mods;

  if (action != GLFW_PRESS) return;
  switch (key) {
    case GLFW_KEY_R:
      if (active.front.vertical) {
        struct eye tmp = active.front;
        active.front.val = active.back.val;
        active.back.val = tmp.val;
      }
      active.front.vertical = !active.front.vertical;
      get_prewiews();
      printf("rotate\n");
      break;
    case GLFW_KEY_ENTER:
      break;
    case GLFW_KEY_BACKSPACE:
      break;
  }
}

void cursor_position_callback(int xpos, int ypos) {
  if (is_dragging) {
    camera_x += xpos - mouse_x;
    camera_y += ypos - mouse_y;
  }
  mouse_x = xpos;
  mouse_y = ypos;
}

void mouse_button_callback(int button, int action, int mods) {
  (void) mods;

  if (button == GLFW_MOUSE_BUTTON_RIGHT) {
    is_dragging = (action == GLFW_PRESS);
  }

  if (button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_PRESS) {
    // pick up brick from hand
    for (size_t i = 0; i < hand_count; i++) {
      struct brick *b = &hand[i];
      if (!has_active) {
        if (b->front.x <= mouse_x && mouse_x <= b->front.x + DOMINO_WIDTH &&
          b->front.y <= mouse_y && mouse_y <= b->front.y + DOMINO_HEIGHT
          ) {
          has_active = 1;
          active = *b;
          active.front.x -= mouse_x;
          active.front.y -= mouse_y;
        }
      } else {
        hand[i - 1] = hand[i];
      }
    }
    if (has_active) {
      hand_count--;
      get_prewiews();
    }
  }

  printf("click!\n");
  if (button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_RELEASE) {
    if (has_active) {
      has_active = 0;

      size_t min_dist = -1;
      for (size_t i = 0; i < preview_count; i++) {
        int active_x = active.front.x + mouse_x + DOMINO_WIDTH / 2;
        int active_y = active.front.y + mouse_y + DOMINO_HEIGHT / 2;
        int preview_x = camera_x + preview[i].front.x * EYE_SIZE + DOMINO_WIDTH / 2;
        int preview_y = camera_y + preview[i].front.y * EYE_SIZE + DOMINO_HEIGHT / 2;
        preview[i].front.val = (active_x - preview_x) * (active_x - preview_x) + (active_y - preview_y) * (active_y - preview_y);
        if (min_dist == (size_t)-1) min_dist = i;
        if (preview[i].front.val < preview[min_dist].front.val) min_dist = i;
      }

      if (preview[min_dist].front.val < EYE_SIZE * EYE_SIZE && preview_count) {
        preview[min_dist].front.val = active.front.val;
        preview[min_dist].front.vertical = active.front.vertical;
        preview[min_dist].back.val = active.back.val;
        bricks_append(&bricks, preview[min_dist]);
        for (size_t i = 0; i < bricks.count; i++) print_brick(bricks.items.brick[i]);
      } else {
        hand[hand_count++] = active;
      }
      printf("dist: %d\n", preview[min_dist].front.val);
      preview_count = 0;
    }
  }

}

void init(struct image canvas) {
  camera_x = canvas.width / 2;
  camera_y = canvas.height / 2;

  bricks_append(
      &bricks,
      (struct brick) {
        .front = {.x = 0, .y = 0, .val = 3},
        .back  = {.x = 1, .y = 0, .val = 2},
      }
      );

  hand[hand_count++] = (struct brick) {
        .front = {.val = 0},
        .back  = {.val = 3},
      };
  hand[hand_count++] = (struct brick) {
        .front = {.val = 4},
        .back  = {.val = 1},
      };
  hand[hand_count++] = (struct brick) {
        .front = {.val = 2},
        .back  = {.val = 5},
      };
  hand[hand_count++] = (struct brick) {
        .front = {.val = 2},
        .back  = {.val = 5},
      };
}

void draw( struct image canvas, struct image texture, size_t xpos, size_t ypos, bool vertical) {
  for (size_t y = 0; y < texture.height; y++) {
    for (size_t x = 0; x < texture.width; x++) {
      size_t canvas_y = vertical ? x : y;
      size_t canvas_x = vertical ? y : x;
      canvas.buf[(ypos + canvas_y) * canvas.width + xpos + canvas_x] = texture.buf[y * texture.width + x];
    }
  }
}

void draw_glyph( struct image canvas, uint32_t glyph, size_t xpos, size_t ypos, struct color color) {
  struct image texture = {
    .width = 5,
    .height = 6,
    .bufsize = 5 * 6,
    .buf = (uint32_t[30]) {0}
  };

  texture.buf = (uint32_t[30]) {0};

  for (size_t y = 0; y < texture.height; y++) {
    for (size_t x = 0; x < texture.width; x++) {
      if ((glyph >> ((texture.height - y - 1) * texture.width + (texture.width - x - 1))) & 1) {
        texture.color[y * texture.width + x] = color;
      }
    }
  }
  draw(canvas, texture, xpos, ypos, 0);
}

void print(struct image canvas, char *string, size_t xpos, size_t ypos, struct color color) {
  for (size_t i = 0; string[i]; i++) {
    uint32_t glyph = characters[string[i] - ' '];
    draw_glyph(canvas, glyph, xpos + i * 5, ypos, color);
  }
}

void render(struct image canvas) {
  for (size_t i = 0; i < canvas.bufsize; i++) canvas.buf[i] = 0;

  // domino playground
  for (size_t i = 0; i < bricks.count; i++) {
    struct brick *b = &bricks.items.brick[i];
    draw(canvas, red_and_peach_dominoes[b->back.val][b->front.val], camera_x + b->front.x * EYE_SIZE, camera_y + b->front.y * EYE_SIZE, b->front.vertical);
  }

  // preview
  for (size_t i = 0; i < preview_count; i++) {
    draw(canvas, white_and_blue_dominoes[active.back.val][active.front.val], camera_x + preview[i].front.x * EYE_SIZE, camera_y + preview[i].front.y * EYE_SIZE, active.front.vertical);
  }

  // hand
  for (size_t i = 0; i < hand_count; i++) {
    struct brick *b = &hand[i];
    b->front.x = (canvas.width - hand_count *(DOMINO_WIDTH + 4))/2 + i * (DOMINO_WIDTH + 4);
    b->front.y = canvas.height - DOMINO_WIDTH;
    draw(canvas, red_and_peach_dominoes[b->back.val][b->front.val], b->front.x, b->front.y, b->front.vertical);
  }

  draw_glyph(canvas, (uint32_t) 0b00011000111001100010000100011100, 50, 50, (struct color) {255, 255, 0, 255});

  // active
  if (has_active) {
    draw(canvas, red_and_peach_dominoes[active.back.val][active.front.val], CLAMP(mouse_x + active.front.x, 0, canvas.width), CLAMP(mouse_y + active.front.y, 0, canvas.height), active.front.vertical);
  }

  // character
  char title[] = "domino dungeon";
  char inventory[] = "Inventory";
  // print(canvas, title, (canvas.width - (sizeof(title)-1) * 5) / 2, 5, (struct color) {255, 255, 255, 255});
  print(canvas, inventory, (canvas.width - (sizeof(inventory)-1) * 5) / 2, canvas.height - DOMINO_WIDTH - 10, (struct color) {255, 255, 255, 255});
  print(canvas, "Drag Dominos from your inventory onto the chain to", 3, 2, (struct color) {255, 255, 255, 255});
  print(canvas, "reach the goal. Press [R] to rotate", 3, 9, (struct color) {255, 255, 255, 255});

}