#include "raylib.h"
#include "raymath.h"

#if defined(PLATFORM_WEB)
    #include <emscripten/emscripten.h>
#endif

typedef enum {
  O = 0, // nothing
  //P = 1, // player
  t = 2, // tree
  T = 3, // troll area
  B = 4, // bandit area
  T_B = 5, // troll base
  B_B = 6, // bandit base
  //G = 7, // gate (exit)
} MapSymbol;

typedef enum {
  AA_IDLE = 0,
  AA_CHARGE = 1,
  AA_ATTACK = 2,
} AttackAnimState;

typedef enum {
  T_IDLE = 0,
  T_FOLLOW = 1,
  T_AGGRO = 2,
} TrollState;

typedef enum {
  HA_IDLE = 0,
  HA_PLAY = 1,
} HitAnimState;

typedef struct ScuffString {
  char  *buffer;
  int len;
  int capacity;
} String;

typedef struct State {
  // how much scaling to apply from original asset resolution
  float render_scale;
  // game positions
  bool is_player_hit;
  Vector2 pixels_per_gridbox;
  Vector2 mouse_position;
  Vector2 player_position;
  Color player_tint;
  // @note: normally when we place a texture, the coordinates
  // are the top left coordinates. This will cause a disconnect
  // when moving the player with a point and click motion.
  // To fix that we calculate a new position so the player_coordinates
  // are in the center. This will make it so when the player clicks on the 
  // ground somewhere, the character sprite will be properly centered on that point.
  Rectangle player_render_rect;
  Vector2 player_position_target;

  Vector2 bandit_position;
  // troll state
  int troll_state;
  float troll_move_delta;
  Vector2 troll_position;
  Vector2 troll_last_player_position;
  Vector2 troll_move_dir;
  Vector2 troll_position_target;
  Rectangle troll_render_rect;
  Color troll_tint_base;
  Color troll_tint;
  // - troll attack
  bool troll_anim_attack_play;
  int troll_attack_anime_state;
  double t_troll_charge_anim_start;
  float t_troll_charge_anim_duration;
  float t_troll_anim_freq;
  float troll_attack_offset_max;
  float t_troll_attack_anim_start;
  float t_troll_attack_anim_duration;

  // player movement
  bool is_player_move;
  Vector2 player_move_dir;
  // @todo
  // direction player is being hit from, incorporate that into the gameplay code
  // For now, just update the player_move_dir to the player_hit_dir
  // Vector2 player_hit_dir; 
  float player_move_delta; // amount player will move
  // target position player will move to
  // 1. the player can move intentionally, in which case carry forward from player position target
  // 2. the player can move from feedback of being hit, NOT IMPLEMENTED YET
  int player_hit_anim_state;
  float player_hit_anim_speed;
  float t_player_hit_anim_duration;
  float t_player_hit_anim_start;
  Vector2 player_move_target; 

  // game sprites
  Texture2D *grass_sprite;
  Texture2D *player_sprite;

  Texture2D *troll_sprite;
  Texture2D *troll_weapon_sprite;
  Texture2D *bandit_sprite;
  Texture2D *bandit_weapon_sprite;

  Texture2D *troll_area_floor_sprite;
  Texture2D *bandit_area_floor_sprite;

  Texture2D *troll_base_sprite;
  Texture2D *bandit_base_sprite;

  String *action_log;
} State;

//----------------------------------------------------------------------------------
// Global Variables Definition
//----------------------------------------------------------------------------------
const int screenWidth = 1280;
const int screenHeight = 1024;
State mega_state = {};
// layer ground 
int floor_grid_map[8][8] = {{O, O, O, O, O, O, O, O},
                            {O, O, O, O, T, T, T, T},
                            {B, B, B, B, T, T, T, T},
                            {B, B, B, B, T, T, T, T},
                            {B, B, B, B, T, T, T, T},
                            {B, B, B, B, T, T, T, T},
                            {B, B, B, B, T, T, T, T},
                            {B, B, B, B, T, T, T, T}};
// vegetation grid 
int floor_cover_grid_map[8][8] = {{O, O,   O, O, O, O, O, O},
                                  {O, O,   O, O, O, O, O, O},
                                  {O, O,   O, O, O, O, O, O},
                                  {O, O,   O, O, O, O, O, O},
                                  {O, O,   O, O, O, O, O, T_B},
                                  {O, B_B, O, O, O, O, O, O},
                                  {O, O,   O, O, O, O, O, O},
                                  {O, O,   O, O, O, O, O, O}};
Vector2 grid_dims = {8, 8};
//----------------------------------------------------------------------------------
// Module functions declaration
//----------------------------------------------------------------------------------
void UpdateDrawFrame();     // Update and Draw one frame

int main(void)
{
  InitWindow(screenWidth, screenHeight, "raylib browser example");
  SetTargetFPS(60);
  Texture2D grass_sprite = LoadTexture("./assets/dungeon/floor/grass/grass_flowers_blue_1_new.png");
  Texture2D player_sprite = LoadTexture("./assets/player/base/human_male.png");
  Texture2D troll_sprite = LoadTexture("./assets/monster/hill_giant_old.png");
  Texture2D bandit_sprite = LoadTexture("./assets/monster/unique/maurice_new.png");
  Texture2D troll_area_floor_sprite = LoadTexture("./assets/dungeon/floor/dirt_northeast_new.png");
  Texture2D bandit_area_floor_sprite = LoadTexture("./assets/dungeon/floor/dirt_east_new.png");
  Texture2D bandit_base_sprite = LoadTexture("./assets/dungeon/floor/hive_3.png");
  Texture2D troll_base_sprite = LoadTexture("./assets/dungeon/floor/dirt_2_old.png");
  Texture2D troll_weapon_sprite = LoadTexture("./assets/item/weapon/club_old.png");

  mega_state.render_scale = 2.0f;
  mega_state.grass_sprite = &grass_sprite;
  mega_state.player_sprite = &player_sprite;
  mega_state.troll_sprite = &troll_sprite;
  mega_state.bandit_sprite = &bandit_sprite;
  mega_state.troll_area_floor_sprite = &troll_area_floor_sprite;
  mega_state.bandit_area_floor_sprite = &bandit_area_floor_sprite;
  mega_state.bandit_base_sprite = &bandit_base_sprite;
  mega_state.troll_base_sprite = &troll_base_sprite;
  mega_state.troll_weapon_sprite = &troll_weapon_sprite;
  mega_state.player_position = (Vector2){50.0f, 50.0f};
  mega_state.player_hit_anim_speed = 50.0f; // pixels per second;
  mega_state.t_player_hit_anim_duration = 0.2f;
  mega_state.player_render_rect = (Rectangle){.x=0,.y=0,.width=player_sprite.width,.height=player_sprite.height*mega_state.render_scale};
  mega_state.player_move_delta = 5.0f;
  mega_state.pixels_per_gridbox = (Vector2){screenWidth/grid_dims.x, screenHeight/grid_dims.y};
  mega_state.player_tint = (Color){255, 255, 255, 255};
  mega_state.troll_state = T_IDLE;

  mega_state.bandit_position = (Vector2){64.0f, 800.0f};
  mega_state.troll_position = (Vector2){1024.0f, 600.0f};
  mega_state.troll_move_delta = 2.0f;
  mega_state.t_troll_charge_anim_duration = 1.0f;
  mega_state.troll_tint_base = (Color){255, 255, 255, 255};
  mega_state.troll_tint = mega_state.troll_tint_base;
  mega_state.t_troll_attack_anim_duration = 0.4f;
  mega_state.troll_attack_offset_max = 100.0f;
  mega_state.troll_render_rect = (Rectangle){.x=0,.y=0,.width=troll_sprite.width*mega_state.render_scale,.height=troll_sprite.height*mega_state.render_scale};

  char *str_buffer = (char*)MemAlloc(512*sizeof(char));
  mega_state.action_log = &(String){.buffer=str_buffer, .capacity=512, .len=0};

  #if defined(PLATFORM_WEB)
    emscripten_set_main_loop(UpdateDrawFrame, 0, 1);
  #else
    SetTargetFPS(60);
    
    while(!WindowShouldClose())
    {
      UpdateDrawFrame();
    }
  #endif

  CloseWindow();

  return 0;
}

void DrawMapFloorTiles(float scale)
{
  // @note: testing this, might need lighting
  Color BlackTint = {128,128,128,255};
  Texture2D grass = *mega_state.grass_sprite;
  float winc = (float)grass.width * scale;
  float hinc = (float)grass.height * scale;
  Vector2 grid_pos = {0, 0};
  for (int ypos=0; ypos<screenHeight; ypos+=hinc)
  {
    grid_pos.y = ((float)ypos) / ((float)mega_state.pixels_per_gridbox.y);
    for (int xpos=0; xpos<screenWidth; xpos+=winc)
    {
      grid_pos.x = ((float)xpos) / ((float)mega_state.pixels_per_gridbox.x);
      Vector2 pixel_pos = {xpos, ypos};
      int grid_ele = floor_grid_map[(int)grid_pos.y][(int)grid_pos.x];
      Texture2D render_tex;
      switch (grid_ele) {
        case (O):
          {
            render_tex = *mega_state.grass_sprite;
          } break;
        case (B):
          {
            render_tex = *mega_state.bandit_area_floor_sprite;
          } break;
        case (T):
          {
            render_tex = *mega_state.troll_area_floor_sprite;
          } break;
        default:
          {
          } break;
      }
      DrawTextureEx(render_tex, pixel_pos, 0, scale, BlackTint);
    }
  }
}

void DrawFloorCoverTiles(float scale)
{
  // @note: testing this, might need lighting
  Color BlackTint = {128,128,128,255};
  Texture2D null_tex = *mega_state.player_sprite;
  float winc = (float)null_tex.width * scale;
  float hinc = (float)null_tex.height * scale;

  Vector2 grid_pos = {0, 0};
  for (int ypos=0; ypos<screenHeight; ypos+=hinc)
  {
    grid_pos.y = ((float)ypos) / ((float)mega_state.pixels_per_gridbox.y);
    for (int xpos=0; xpos<screenWidth; xpos+=winc)
    {
      grid_pos.x = ((float)xpos) / ((float)mega_state.pixels_per_gridbox.x);
      Vector2 pixel_pos = {xpos, ypos};
      int grid_ele = floor_cover_grid_map[(int)grid_pos.y][(int)grid_pos.x];
      Texture2D render_tex;
      switch (grid_ele) {
        case (B_B):
          {
            render_tex = *mega_state.bandit_base_sprite;
          } break;
        case (T_B):
          {
            render_tex = *mega_state.troll_base_sprite;
          } break;
        default:
          {
            render_tex = null_tex;
          } continue;
      }
      DrawTextureEx(render_tex, pixel_pos, 0, scale, BlackTint);
    }
  }
}

Vector2 GetSpriteCenterPosition(Texture2D sprite, Vector2 position, float render_scale)
{
  float centered_x = position.x - ((float)sprite.width)*render_scale/2.0f;
  float centered_y = position.y - ((float)sprite.height)*render_scale/2.0f;

  return (Vector2){.x = centered_x, .y = centered_y};
}

Vector2 GetRenderCenterFromTL(Rectangle render_rect, Vector2 position)
{
  float centered_x = position.x - ((float)render_rect.width)/2.0f;
  float centered_y = position.y - ((float)render_rect.height)/2.0f;

  return (Vector2){.x = centered_x, .y = centered_y};
}

void DrawCharacters(float scale)
{
  Rectangle src_rect, dest_rect;
  // draw Troll
  // - troll weapon
  Vector2 troll_weapon_centered = GetSpriteCenterPosition(*mega_state.troll_weapon_sprite, mega_state.troll_position, 1.0f);
  // move to left hand
  troll_weapon_centered.x -= mega_state.troll_sprite->width;
  src_rect = (Rectangle){.x=0, .y=0, .width=-mega_state.troll_weapon_sprite->width, .height=mega_state.troll_weapon_sprite->height};
  dest_rect = (Rectangle){.x=troll_weapon_centered.x, .y=troll_weapon_centered.y, 
                          .width=0.5f*scale*mega_state.troll_weapon_sprite->width, 
                          .height=0.5f*scale*mega_state.troll_weapon_sprite->height};
  DrawTexturePro(*mega_state.troll_weapon_sprite, src_rect, dest_rect,
                 (Vector2){0,0}, 0, RAYWHITE); 
  // - troll sprite
  DrawTextureEx(*mega_state.troll_sprite, (Vector2){mega_state.troll_render_rect.x, mega_state.troll_render_rect.y}, 0, scale, mega_state.troll_tint); 
  // draw collision box
  DrawRectangleLines(mega_state.troll_render_rect.x, mega_state.troll_render_rect.y, mega_state.troll_render_rect.width, mega_state.troll_render_rect.height, RED); 

  // draw Bandit
  Vector2 bandit_center = GetSpriteCenterPosition(*mega_state.bandit_sprite, mega_state.bandit_position, scale);
  src_rect = (Rectangle){.x=0, .y=0, .width=-mega_state.bandit_sprite->width, .height=mega_state.bandit_sprite->height};
  dest_rect = (Rectangle){.x=bandit_center.x, .y=bandit_center.y, 
                          .width=scale*mega_state.bandit_sprite->width, 
                          .height=scale*mega_state.bandit_sprite->height};
  DrawTexturePro(*mega_state.bandit_sprite, src_rect, dest_rect,
                 (Vector2){0,0}, 0, (Color){255, 128, 128, 255}); 
  // draw player
  Vector2 player_center = GetSpriteCenterPosition(*mega_state.player_sprite, mega_state.player_position, scale);
  DrawTextureEx(*mega_state.player_sprite, player_center, 0, scale, mega_state.player_tint); 
  //DrawTextureEx(*mega_state.player_sprite, (Vector2){mega_state.player_render_rect.x, mega_state.player_render_rect.y}, 0, scale, RAYWHITE); 
  DrawRectangleLines(mega_state.player_render_rect.x, mega_state.player_render_rect.y, mega_state.player_render_rect.width, mega_state.player_render_rect.height, RED); 
}

void UpdateDrawFrame(void)
{
  BeginDrawing();
  {
    // INPUT
    mega_state.mouse_position = GetMousePosition();
    if (IsMouseButtonPressed(MOUSE_BUTTON_LEFT) && mega_state.player_hit_anim_state != HA_PLAY)
    {
      mega_state.is_player_move = true;
      mega_state.player_position_target = mega_state.mouse_position;
      mega_state.player_move_dir = Vector2Normalize(Vector2Subtract(mega_state.player_position_target, mega_state.player_position));
    }
    if (IsMouseButtonPressed(MOUSE_BUTTON_RIGHT))
    {
      // @debug: cleaning up troll collision state
      mega_state.troll_attack_anime_state = AA_IDLE;
      mega_state.troll_tint = WHITE;
      mega_state.is_player_hit = false;
    }

    // PROCESSING
    if (mega_state.player_hit_anim_state == HA_PLAY)
    {
      float anim_length = GetTime() - mega_state.t_player_hit_anim_start;
      float ft = GetFrameTime();
      float pixel_per_second_per_ft = ft*mega_state.player_hit_anim_speed/mega_state.t_player_hit_anim_duration;
      mega_state.player_position = Vector2Add(mega_state.player_position, Vector2Scale(mega_state.player_move_dir, pixel_per_second_per_ft));
      mega_state.player_tint = (Color){255, 128, 128, 255};
      if (anim_length >= mega_state.t_player_hit_anim_duration)
      {
        mega_state.player_hit_anim_state = HA_IDLE;
      mega_state.player_tint = (Color){255, 255, 255, 255};
      }
    }
    if (mega_state.is_player_move)
    {
      mega_state.player_position = Vector2Add(mega_state.player_position, Vector2Scale(mega_state.player_move_dir, mega_state.player_move_delta));
      if (Vector2Distance(mega_state.player_position, mega_state.player_position_target) <= 5.0f)
      {
        mega_state.is_player_move = false;
      }
    }
    // calculate center positions
    Vector2 player_centered = GetRenderCenterFromTL(mega_state.player_render_rect, mega_state.player_position);
    mega_state.player_render_rect.x = player_centered.x;
    mega_state.player_render_rect.y = player_centered.y;

    // process enemies detecting the player
    // troll
    // get player location on map
    // map_world_to_grid
    Vector2 grid_pos = Vector2Divide(Vector2Multiply(mega_state.player_position, grid_dims), (Vector2){screenWidth, screenHeight});
    int tile_at_player = floor_grid_map[(int)grid_pos.y][(int)grid_pos.x];
    bool in_troll_area = true;
    bool troll_persue_player = true;
    if (tile_at_player != T)
    {
      in_troll_area = false;
      if (mega_state.troll_state != T_AGGRO)
      {
        mega_state.troll_attack_anime_state = AA_IDLE;
        troll_persue_player = false;
      }
    }

    float player_troll_dist = Vector2Distance(mega_state.player_position, mega_state.troll_position);
    bool troll_detect = false;
    bool troll_attack_start = false;
    float slow_multiplier = mega_state.troll_attack_anime_state == AA_CHARGE ? 0.2f : 1.0f;
    if (player_troll_dist < 200 && troll_persue_player)
    {
      troll_detect = true;
      mega_state.troll_state = T_FOLLOW;
      if (player_troll_dist < 80 && mega_state.troll_attack_anime_state == AA_IDLE)
      {
        troll_attack_start = true;
      }
    }
    if (troll_detect && mega_state.troll_attack_anime_state != AA_ATTACK)
    {
      mega_state.troll_last_player_position = mega_state.player_position;
      mega_state.troll_position_target = mega_state.troll_last_player_position;
      mega_state.troll_move_dir = Vector2Normalize(Vector2Subtract(mega_state.troll_position_target, mega_state.troll_position));
      if (player_troll_dist > 10.0f)
      {
        // @note: this actually might not even be needed
        // move only if both are more than 10pixels apart.
        // it becomes jarring other wise
        mega_state.troll_position = Vector2Add(mega_state.troll_position, Vector2Scale(mega_state.troll_move_dir, slow_multiplier*mega_state.troll_move_delta));
      }
    }
    Vector2 troll_centered = GetSpriteCenterPosition(*mega_state.troll_sprite, mega_state.troll_position, mega_state.render_scale);
    mega_state.troll_render_rect.x = troll_centered.x;
    mega_state.troll_render_rect.y = troll_centered.y;
    if (troll_attack_start)
    {
      // start attack animation
      mega_state.troll_anim_attack_play = true;
      mega_state.t_troll_charge_anim_start = GetTime();
      mega_state.troll_attack_anime_state = AA_CHARGE;
    }
    float charge_time = 0.0f;
    float charge_color_delta = 0.0f;
    if (mega_state.troll_attack_anime_state == AA_CHARGE)
    {
      // get color based on time
      float charge_progress = (GetTime() - mega_state.t_troll_charge_anim_start) / mega_state.t_troll_charge_anim_duration;
      mega_state.troll_tint.r = Clamp(mega_state.troll_tint_base.r - (charge_progress*mega_state.troll_tint_base.r), 0, 255);
      if (charge_progress >= 1.0f)
      {
        mega_state.troll_attack_anime_state = AA_ATTACK;
        mega_state.t_troll_attack_anim_start = GetTime();
      }
    } 
    else if (mega_state.troll_attack_anime_state == AA_ATTACK)
    {
      // maximum distance to attack jump in
      // mega_state.troll_attack_offset_max = 10.0f;
      // mega_state.troll_attack_anim_duration = 1.0f;
      float anim_length = GetTime() - mega_state.t_troll_attack_anim_start;
      float ft = GetFrameTime();
      float pixel_per_second_per_ft = ft*mega_state.troll_attack_offset_max/mega_state.t_troll_attack_anim_duration;
      mega_state.troll_position = Vector2Add(mega_state.troll_position, Vector2Scale(mega_state.troll_move_dir, pixel_per_second_per_ft));
      mega_state.troll_tint = (Color){255, 128, 255, 255};
      // get troll center position and check for collision with player
      // now check if colliding with player
      bool is_colliding = CheckCollisionRecs(mega_state.player_render_rect, mega_state.troll_render_rect);
      if (is_colliding)
      {
        mega_state.is_player_hit = true;
      }
      if (anim_length >= mega_state.t_troll_attack_anim_duration || is_colliding)
      {
        mega_state.troll_attack_anime_state = AA_IDLE;
        mega_state.troll_tint = mega_state.troll_tint_base;
        if (is_colliding)
        {
          // make player get hit
          mega_state.player_hit_anim_state = HA_PLAY;
          mega_state.t_player_hit_anim_start = GetTime();
          mega_state.player_move_dir = mega_state.troll_move_dir;
          mega_state.is_player_move = false; // disable walk check, stuff been thrown off
        }
      }
    }

    float player_bandit_delta = Vector2Distance(mega_state.player_position, mega_state.bandit_position);
    bool bandit_detect = false;
    if (player_bandit_delta < 200)
    {
      bandit_detect = true;
    }
    // RENDERING
    ClearBackground(RAYWHITE);
    DrawMapFloorTiles(2.0f);
    DrawFloorCoverTiles(2.0f);
    DrawCharacters(2.0f);

    // do text rendering at the end
    // draw mouse position for debugging
    if (mega_state.is_player_hit)
    {
      DrawText("player hit", 500, 20, 20, GREEN);
    }
    if (troll_detect)
    {
      DrawText("Detecting", mega_state.troll_position.x, mega_state.troll_position.y + mega_state.troll_sprite->height + 20, 20, GREEN);
    }
    if (bandit_detect)
    {
      DrawText("Detecting", mega_state.bandit_position.x, mega_state.bandit_position.y + mega_state.bandit_sprite->height + 20, 20, GREEN);
    }
    DrawText(TextFormat("FPS: %d", GetFPS()), 1200, 20, 20, GREEN);
    DrawText(TextFormat("Player Tile: %d", tile_at_player), 20, 20, 20, GREEN);
  }
  EndDrawing();
}