#!/usr/bin/env bash

# clockascii (around 30x30 chars, depending on aspect)

# Written mostly by chatgpt in 2025

#### mine
# hide cursor
tput civis

# reshow cursor
cleanup () {
  tput cnorm
  exit 0
}

trap cleanup EXIT SIGTERM SIGINT 

clear # just once
#### end mine

ROWS=30
BASE_COLS=30
CX=14.5
CY=14.5
RADIUS=14
HOUR_LEN=9
MIN_LEN=11
ASPECT=0.398   # smaller = wider circle; 0.5 fits most terminals

MINCHAR="●"
HOURCHAR="■"
TICKCHAR="⬤"
MIDDLECHAR=" "

# scale width to compensate
COLS=$(awk -v c="$BASE_COLS" -v a="$ASPECT" 'BEGIN{print int(c / a + 0.5)}')

# doCenter () {
#     columns="$(tput cols)"
#     pad="$((( columns - COLS ) / 2 ))"
#     (( pad < 0 )) && pad=0
# }

doCenter () {
    columns="$(tput cols)"
    # Adjust for true visual center
    true_center_offset=$(awk -v cx="$CX" -v a="$ASPECT" -v c="$COLS" 'BEGIN{print int((cx/a) - (c/2))}')
    pad="$((( columns - COLS ) / 2 - true_center_offset ))"
    (( pad < 0 )) && pad=0
}


everything () {
    read -r H M S < <(date '+%H %M %S')

    MD=$(awk -v m="$M" -v s="$S" 'BEGIN{print m*6 + s*0.1}')
    HD=$(awk -v h="$H" -v m="$M" -v s="$S" 'BEGIN{print (h%12)*30 + m*0.5 + s*(0.5/60)}')

    #clear
    tput cup 0 0

    awk -v rows="$ROWS" -v cols="$COLS" \
        -v cx="$CX" -v cy="$CY" -v r="$RADIUS" \
        -v aspect="$ASPECT" \
        -v hd="$HD" -v md="$MD" \
        -v hlen="$HOUR_LEN" -v mlen="$MIN_LEN" \
        -v H="$H" -v M="$M" -v S="$S" \
        -v MINCHAR="$MINCHAR" -v HOURCHAR="$HOURCHAR" -v TICKCHAR="$TICKCHAR" -v MIDDLECHAR="$MIDDLECHAR" '

    BEGIN {
      PI = 3.141592653589793

      # init grid
      y = 0
      while (y < rows) {
        x = 0
        while (x < cols) {
          grid[y, x] = " "
          x++
        }
        y++
      }

      # draw circle
      y = 0
      while (y < rows) {
        x = 0
        while (x < cols) {
          # map to corrected coords (stretch horizontally)
          dx = (x - cx/aspect) * aspect
          dy = cy - y
          dist = sqrt(dx*dx + dy*dy)
          if (dist >= r - 0.3 && dist <= r + 0.3)
            grid[y, x] = " "
          x++
        }
        y++
      }

      # hour ticks
      k = 0
      while (k < 12) {
        deg = k * 30
        rad = (90 - deg) * PI / 180
        tx = (cx/aspect) + ((r - 1) / aspect) * cos(rad)
        ty = cy - (r - 1) * sin(rad)
        #gx = int(tx + 0.5)
        gx = int(tx)
        #gy = int(ty + 0.5)
        gy = int(ty)
        if (gy >= 0 && gy < rows && gx >= 0 && gx < cols)
          grid[gy, gx] = TICKCHAR
        k++
      }

      # minute hand
      mrad = (90 - md) * PI / 180
      t = 0
      while (t <= mlen) {
        px = (cx/aspect) + (t / aspect) * cos(mrad)
        py = cy - t * sin(mrad)
        #gx = int(px + 0.5)
        gx = int(px)
        #gy = int(py + 0.5)
        gy = int(py)
        if (gx >= 0 && gx < cols && gy >= 0 && gy < rows)
          grid[gy, gx] = (t >= mlen - 1 ? MINCHAR : MINCHAR)
        t += 0.5
      }

      hour hand
      hrad = (90 - hd) * PI / 180
      t = 0
      while (t <= hlen) {
        px = (cx/aspect) + (t / aspect) * cos(hrad)
        py = cy - t * sin(hrad)
        #gx = int(px + 0.5)
        gx = int(px)
        #gy = int(py + 0.5)
        gy = int(py)
        if (gx >= 0 && gx < cols && gy >= 0 && gy < rows)
          grid[gy, gx] = HOURCHAR
        t += 0.5
      }

      # hour hand      # hrad=(90-hd)*PI/180
      # t=0
      # 
      # while(t<=hlen){
      #     px=(cx/aspect)+(t/aspect)*cos(hrad)
      #     py=cy-t*sin(hrad)
      #     #gx=int(px+0.5)
      #     gx=int(px)
      #     gy=int(py+0.5)
      #     if(gx>=0 && gx<cols && gy>=0 && gy<rows) {
      #         grid[gy,gx]="■"
      #         # extra horizontal width
      #         if(gx+1<cols) grid[gy,gx+1]="■"
      #         if(gx-1>=0)   grid[gy,gx-1]="■"
      #     }
      #     t+=0.5
      # }


      grid[int(cy), int(cx/aspect)] = MIDDLECHAR

      # print
      y = 0
      while (y < rows) {
        x = 0
        while (x < cols) {
          printf("%s", grid[y, x])
          x++
        }
        printf("\n")
        y++
      }
      #printf("\n     %02d:%02d:%02d\n", H, M, S)
    }'

}


while true; do
  
  doCenter # get new $pad variable

  (( oldpad != pad )) && clear

  everything | pr -T -o "$pad"
  #echo "oldpad=$oldpad, newpad=$pad, offset=$true_center_offset" # debug
  sleep 10
    
  oldpad="$pad"

done