#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <curses.h>
#include <string.h>

#define UP (1)
#define DOWN (2)

#ifndef TRUE
  #define TRUE 1
#endif

#ifndef FALSE
  #define FALSE 0
#endif

int
help()
{
  puts("Program Flags:");
  printf("\t--tickTime [integer]\n\t\tWill change the time waited between frame updates in miliseconds\n\n");
  printf("\t--streanLen [integer]\n\t\tChanges the vertical length of the stream in characters\n");
  return 1;
}

int
main(int argc, char **argv)
{
  int time = 15;
  int initTailLen = 20;
  for(int i=1; i<argc; i++) {
    if(strcmp(argv[i],"--help") == 0 || strcmp(argv[i], "-h") == 0) {
      endwin();
      help();
      return 1;
    } else {
      if(strcmp(argv[i],"--tickTime") == 0) {
        time=atoi(argv[i+1]);
        i++;
      } else {
        if(strcmp(argv[i],"--streamLen") == 0) {
          initTailLen=atoi(argv[i+1]);
          i++;
        } else {
          endwin();
          printf("[ERROR] Invalid flag\n\n");
          help();
          return -1;
        }
      }
    }
  }

  WINDOW *term = initscr();
  start_color();
  init_pair(1,COLOR_GREEN,COLOR_BLACK);
  attron(COLOR_PAIR(1));
  noecho();
  if(nodelay(term,TRUE)==ERR) {
    puts("[ERROR] could not enter no-delay mode");
    return ERR;
  }
  timeout(time);

  int maxX = COLS;
  int maxY = LINES;

  int tailLen[maxX];

  for(int i=0; i<maxX; i++) {
    int num=rand()%2;
    if(num>1) {
      tailLen[i]=initTailLen+(rand()%(4%initTailLen));
    } else {
      if(num<=1) {
        tailLen[i]=initTailLen-(rand()%initTailLen);
      }
    }
  }
  int cascade[maxX];
  int tail[maxX];
  int jmpTail[maxX];

  for(int i=0; i<maxX; i++)
    cascade[i]=ERR;

  int pause = 0;
  int dir = DOWN;
  int limit = maxY;
  int startPos = 0;
  int get = getch();
  while(get!='q') {
    if(get=='s') {
      pause=TRUE;
    }
    int xPos = rand()%maxX;//get random x position for the stream
    if(cascade[xPos]==ERR) {//make sure the stream is set to active
      cascade[xPos]=startPos;
    }
    for(int i=0; i<maxX; i++) {//move the streams up/down
      if(!pause) {
        if(cascade[i]!=ERR) {
          if(dir==DOWN) {
            tail[i] = cascade[i]-tailLen[i];
          } else {
            tail[i] = cascade[i]+tailLen[i];
          }
          if(cascade[i]==limit) {//check if the position is at the bottom of the screen
            cascade[i]=ERR;//set the position to ERR if it is at the bottom
          } else {
            if(rand()%10==1) {//check if the stream will jump
              if(!(jmpTail[i]<=maxY)) {
                if(dir==DOWN) {
                  cascade[i]=cascade[i]+rand()%8;
                  jmpTail[i]=cascade[i]-tailLen[i];
                } else {
                  cascade[i]=cascade[i]-rand()%8;
                  jmpTail[i]=cascade[i]+tailLen[i];
                }
              }
            } else {
              if(dir==DOWN) {
                cascade[i]++;//increase the position
              } else {
                cascade[i]--;
              }
            }
          }
        }
      }
      if(tail[i]!=limit) {//keep iterating the tail intill it is at the limit
        if(dir==DOWN) {
          tail[i]++;
        } else {
          tail[i]--;
        }
      }
      if(jmpTail[i]==maxY || jmpTail[i]==0) {
        jmpTail[i]=OK;
      } else {
        if(dir==DOWN) {
          jmpTail[i]++;
        } else {
          jmpTail[i]--;
        }
      }
      mvaddch(jmpTail[i],i,' ');
      mvaddch(tail[i],i,' ');
      mvaddch(cascade[i],i,(rand()%60)+65);
    }
    refresh();
    if(!pause) {
      timeout(time);
    } else {
      timeout(-1);
      get=getch();
      switch (get) {
      case 's':
        pause=!pause;
        break;
      case 'r':
        pause=FALSE;
        if(dir==DOWN) {
          dir=UP;
          limit=0;
          startPos=maxY;
        } else {
          dir=DOWN;
          limit=maxY;
          startPos=0;
        }
        break;
      case 'q':
        get='q';
        break;
      }
      timeout(time);
    }
    if(get!='q') {
      get=getch();
    }
  }
  endwin();
  return 1;
}