#include<stdlib.h>
#include<string.h>
#include<time.h>
#include<cglm/cglm.h>
#include"mino.h"
#include"graph.h"
#include"input.h"
#include"core.h"

#define DELAY_FALL 0.2
#define DELAY_BAKE 1.0
#define GRID_W 10
#define GRID_H 20
#define GRID_X 32
#define GRID_Y 32
#define CELL_W 32
#define CELL_H 32
_ mat4 proj;
_ S8 grid[GRID_H][GRID_W]={0};/*indexes into tetros,-1 for nothing*/
_ Tetro tetros[]={
  {0,{0,0},{1.5,1.5}, {{0,1},{1,1},{2,1},{3,1}}},
  {1,{0,0},{1,1},     {{0,0},{0,1},{1,1},{2,1}}},
  {2,{0,0},{1,1},     {{2,0},{0,1},{1,1},{2,1}}},
  {3,{0,0},{1,1},     {{1,0},{0,1},{1,1},{2,1}}},
  {4,{0,0},{1,1},     {{1,0},{2,0},{0,1},{1,1}}},
  {5,{0,0},{1,1},     {{0,0},{1,0},{1,1},{2,1}}},
  {6,{0,0},{0.5,0.5}, {{0,0},{1,0},{0,1},{1,1}}}};
_ C tetros_c[]="IJLTSZO";
_ vec4 tetros_col[]={{0,1,1,1},{0,0,1,1},{1,0.5,0,1},{1,0,1,1},{1,0,0,1},{0,1,0,1},{1,1,0,1}};

_ U32 tex_cell_grid,tex_cell_mino,tex_cell_soon;
_ U32 shader_tetro;
_ IM C shader_tetro_vert[]=GRAPH_GLSL(
  layout (location=0) in vec3 pos;
  layout (location=1) in vec2 tex;
  out vec2 Tex;
  uniform mat4 proj;
  uniform mat4 model;
  void main(){gl_Position=proj*model*vec4(pos,1);Tex=tex;});
_ IM C shader_tetro_frag[]=GRAPH_GLSL(
  out vec4 Frag;
  in vec2 Tex;
  uniform vec4 col;
  uniform sampler2D buf;
  void main(){Frag=texture(buf,Tex)*col;});
_ V shader_tetro_init(V){
  shader_tetro=graph_shader_create(shader_tetro_vert,shader_tetro_frag),
  graph_shader_use(shader_tetro),
  graph_shader_setM4("proj",proj),
  graph_shader_setV4("col",(vec4){1,1,1,1}),
  graph_shader_setI("buf",0);}

_ V tetro_trans(Tetro*t,vec2 m){
  glm_vec2_add(t->pos,m,t->pos);}
_ V tetro_rot(Tetro*t,S8 c){U8 i;vec2 a;
  for(i=0;i<4;++i){
    glm_vec2_sub(t->org,t->v[i],a),
    glm_vec2_rotate(a,GLM_PI_2*(2-c),a),
    glm_vec2_add(a,t->org,a),
    glm_vec2_copy(a,t->v[i]);}}
_ V tetro_bake(Tetro t){U8 i;vec2 a;
  glm_vec2_sub(t.pos,(vec2){GRID_X,GRID_Y},a),
  glm_vec2_div(a,(vec2){CELL_W,CELL_H},a);
  for(i=0;i<4;++i)grid[(U32)(a[1]+t.v[i][1])][(U32)(a[0]+t.v[i][0])]=t.i;}
_ V tetro_draw_col(Tetro t,vec4 c){U8 i;vec2 a;vec2 z={CELL_W,CELL_H};
  graph_shader_use(shader_tetro),
  graph_tex_use(tex_cell_mino,0),
  graph_shader_setM4("proj",proj),
  graph_shader_setV4("col",c);
  for(i=0;i<4;++i){
    glm_vec2_mul(t.v[i],z,a),
    glm_vec2_add(t.pos,a,a),
    graph_quad(a,z);}}
_ V tetro_draw(Tetro t){tetro_draw_col(t,tetros_col[t.i]);}

_ Tetro bag[14];
_ U8 bag_i=14;
_ V tetro_next(Tetro*t){U8 i,j;Tetro u;
  Q(bag_i>=13,bag_i=0,memcpy(bag,tetros,SZ tetros),memcpy(bag+7,tetros,SZ tetros);
    for(i=0;i<13;++i)j=i+rand()/(RAND_MAX/(14-i)+1),u=bag[j],bag[j]=bag[i],bag[i]=u;)
  OR ++bag_i;*t=bag[bag_i],t->pos[0]=GRID_X+CELL_W*4,t->pos[1]=GRID_Y+CELL_H*(GRID_H-1);}
_ U8 tetro_in_floor(Tetro t){U8 i;U32 w,x;vec2 a;
  glm_vec2_sub(t.pos,(vec2){GRID_X,GRID_Y},a),
  glm_vec2_div(a,(vec2){CELL_W,CELL_H},a);
  for(i=0;i<4;++i){w=a[1]+t.v[i][1],x=a[0]+t.v[i][0];Q(w>=GRID_H||w<0,R 1)Q(-1!=grid[w][x],R 1)}
  R 0;}
_ V tetro_fall(Tetro*t,F64 dt){_ F64 et=0;U8 q;
  t->pos[1]-=CELL_H,q=tetro_in_floor(*t),t->pos[1]+=CELL_H;
  Q(q,Q(et>=DELAY_BAKE,tetro_bake(*t),tetro_next(t),et=0)OR et+=dt)
  OR tetro_trans(t,(vec2){0,-32});}

_ V grid_draw(V){U8 i,j;S8 c;vec2 z={CELL_W,CELL_H},pos={GRID_X,GRID_Y};
  graph_shader_use(shader_tetro),
  graph_shader_setM4("proj",proj);
  for(i=0;i<GRID_H;++i,pos[1]+=CELL_H,pos[0]=CELL_W)
    for(j=0;j<GRID_W;++j,pos[0]+=CELL_W){
      if(-1==(c=grid[i][j]))
        graph_tex_use(tex_cell_soon,0),
        graph_shader_setV4("col",(vec4){0.5,0.5,0.5,1});
      OR
        graph_tex_use(tex_cell_mino,0),
        graph_shader_setV4("col",tetros_col[c]);
      graph_quad(pos,z);}}

_ Tetro held;
V core_init(V){
  glm_ortho(0,graph_win_w,0,graph_win_h,0,4,proj),
  srand(time(0)),
  shader_tetro_init(),
  tex_cell_grid=graph_tex_create("res/tex/cell_grid.png"),
  tex_cell_mino=graph_tex_create("res/tex/cell_mino.png"),
  tex_cell_soon=graph_tex_create("res/tex/cell_soon.png"),
  memset(grid,-1,GRID_W*GRID_H);
  tetro_next(&held);}
V core_tick(InputPoint p,InputButtons b,F64 dt){_ F64 et=0;
  glm_ortho(0,graph_win_w,0,graph_win_h,0,4,proj);
  grid_draw();
  tetro_draw(held);
  Q((et+=dt)>=DELAY_FALL,tetro_fall(&held,et),et=0)
  Q(IB_Z&b.p,tetro_rot(&held, 1))
  Q(IB_X&b.p,tetro_rot(&held,-1))
  Q(IB_C&b.p,tetro_next(&held))
  Q(IB_L&b.p,tetro_trans(&held,(vec2){-32, 0}))
  Q(IB_R&b.p,tetro_trans(&held,(vec2){ 32, 0}))
  Q(IB_U&b.p,tetro_trans(&held,(vec2){ 0, 32}))
  Q(IB_D&b.p,tetro_trans(&held,(vec2){ 0,-32}))
  Q(IB_1&b.p,tetro_bake(held))}