#!/bin/bash
_help() {
    echo '
2FA code viewer

Usage:
- Create a (possible encrypted) folder for your service keys
- When the service presents you the QRCode, you typically can
  view the actual code as text. It looks something like:
  I5XXIY3IMEWCA3LBMRSSA6LPOUQGY33PNMQQU===
- Store this piece of text in a file: "Service name".key
- Run 2fa-view command in the folder

Viewer:
- Codes and service names are printed on the screen
- The upper timer shows the 30 second interval when
  the code changes
- The lower timer shows time left before the program exits

Options:
  --light    to disable animations
  --color X  to prefer a color for the skull. Choose color from:
             k r g b c m y w K R G B C M Y W
    '


    exit
}

for (( i=1; i<=$#; i++ )); do
  value=${!i}
  j=$(( i + 1 ))
  [[ "$value" = "--help" ]] && _help
  [[ "$value" = "--light" ]] && { LIGHT=1; continue; }
  [[ "$value" = "--color" ]] && {
      TFA_COLOR_TITLE="${!j}"
      ((i++))
      continue;
  }
  [[ "${value}" = "-"* ]] && {
    [[ "$value" =~ -.*h ]] && { _help; }
    continue
  }
done


timeadjust=0
update_frequency=30
exit_timeout=120
if [ "$1" = "light" ]; then LIGHT=1; fi
shopt -s nullglob
. qolop

picture="                ..;;;::;:;::;;:;,.
          .:::::;;;:;:::::::;;;;::;:;:.
        .::::;;::;::;:;::::::::::;:;::;::.
       ,::::;:::::::;;;::;:;;::::;::::::::.
       ';:::::::::::::::;;;;;;;:::;;::;;;:..
       ';;::::',',',;:::;:;;;,'.;::::;;:;...
         .'.  .        .,:,..           ..
         '       @    .::;:;.     @      ..
         .:'        .;:     .::.       .::.
         ..,;;;:;:;;:'        ,;,'';;,..,,'
           .      .;;.  ..  .,::,     .
                 ';:;;;::;;:::..:::
                 ,:::...;:.   . .,,
                    ..
"
picture_colors="kkKKwwbm$TFA_COLOR_TITLE$TFA_COLOR_TITLE$TFA_COLOR_TITLE$TFA_COLOR_TITLE$TFA_COLOR_TITLE$TFA_COLOR_TITLE"
picture_color_codes=()
for x in $( seq 0 $(( ${#picture_colors} - 1 )) ); do
  picture_color_codes+=( $( _qCol ${picture_colors:$x:1} ) )
done
picture_eye=$( _qCol R )

_skull() {
  if [ "$LIGHT" = 1 ]; then return; fi
  _qPos abs 4 1
  for x in $( seq 1 ${#picture} ); do
    chr="${picture:$x:1}"
    if [ "$chr" = " " ]; then _qPos right 1; continue; fi
    color="${picture_color_codes[$(( $RANDOM % ${#picture_colors} ))]}"
    if [ "$chr" = "@" ]; then color="$picture_eye"; chr="o"; fi
    printf "%s%s" \
      "$color" \
      "$chr"
  done

  _qCol z
}

flame=( )
for x in $( seq 1 $(( 44 * 8 )) ); do
  flame+=( 0 )
done
flame_mask_array=( \
  "11111000000000000000000000000000000000001111" \
  "11000000000000000000000000000000000000000001" \
  "00000000000000000000000000000000000000000000" \
  "00000000000000000000000000000000000000000000" \
  "10000000000001110110111111001110000000000001" \
  "11100000010111111111011110111101100000000111" \
  "11100000011111111111111111111111110000000111" \
  "11110001111111111111111111111111110100011111" \
)
flame_mask=( )
for y in {0..7}; do
  for x in {0..43}; do
    flame_mask+=( ${flame_mask_array[$y]:$x:1} )
  done
done
flame_chars="   .:##@"
flame_colors="zzzmryYY"
flame_color_codes=()
for x in $( seq 0 $(( ${#flame_colors} - 1 )) ); do
  flame_color_codes+=( $( _qCol ${flame_colors:$x:1} ) )
done
flame_next=$( _qPos right 1 )
flame_corner=$( _qPos abs 1 1 )

_flames() {
  if [ "$LIGHT" = 1 ]; then return; fi
  width=43
  height=7
  seq_x=$( seq 0 $width )
  for x in $seq_x; do
    pos=$(( ( $height ) * ( $width + 1 ) + $x ))
    flame[$pos]=$(( $RANDOM % 256 ))
  done

  for y in $( seq 0 $(( $height - 1 )) ); do
    for x in $seq_x; do
      if [ $x -eq $width ]; then continue; fi
      if [ $x -eq 0 ]; then continue; fi
      pos=$(( $y * ( $width + 1 ) + $x ))
      pos_under=$(( ( $y + 1 ) * ( $width + 1 ) + $x ))
      new_value=$(( ( ( \
        ${flame[$(( $pos_under ))]} + \
        ${flame[$(( $pos_under + 1 ))]} + \
        ${flame[$(( $pos_under - 1 ))]} \
       ) * 17 ) / 48 ))

       if [ $new_value -gt 255 ]; then
         new_value=255
       fi
       flame[$pos]=$new_value
    done
  done
  flame_buffer="${flame_corner}${flame_next}${flame_next}${flame_next}"
  for x in $( seq 0 $(( ( $width + 1 ) * ( $height + 1 ) - 1 )) ); do
    if [ $(( $x % ( $width + 1 ) )) -eq $width ]; then flame_buffer+="\n${flame_next}${flame_next}${flame_next}"; fi
    if [ ${flame_mask[$x]} -eq 1 ]; then flame_buffer+="${flame_next}"; continue; fi
    print_value=$(( flame[$x] / 32 ))
    flame_buffer+="${flame_color_codes[${print_value}]}${flame_chars:${print_value}:1}"
  done
  printf "$flame_buffer"
  _qPos abs 1 1
}

_stars() {
  if [ "$LIGHT" = 1 ]; then return; fi
  wall_chars="                                                                                 ,.'\`"
  wall_colors="kkkKKKzzzr"
  wall_color_codes=()
  for x in $( seq 0 $(( ${#wall_colors} - 1 )) ); do
    wall_color_codes+=( $( _qCol ${wall_colors:$x:1} ) )
  done

  lines=$(( 25 + $KEY_FILES ))
  _qPos abs 1 1
  seq_x=$( seq 1 50 )
  for y in $( seq 1 $lines ); do
    for x in $seq_x; do
      chr="${wall_chars:$(( $RANDOM % ${#wall_chars} )):1}"
      if [ "$chr" = " " ]; then _qPos right 1; continue; fi
      color="${wall_color_codes[$(( $RANDOM % ${#wall_colors} ))]}"
      printf "%s%s" \
        "$color" \
        "$chr"
    done
    printf "\n"
  done
  _qCol z
}

_exit() {
  clear
  _skull
  _qPos down 4
  exit
}
_get_code() {
  oathtool -b --totp $( cat "$1" | tr -dc '[:print:]' )
}
_print_codes() {
    #~ printf 'L%.0s' $( seq -1 $update_frequency )
    if [ "$LIGHT" = 1 ]; then
        _qPos abs 3 1;
    else
        _qPos abs 20 1
    fi
    even=0
    for k in *key; do
      if [ $even -eq 0 ]; then
        _qCol z Y
      else
        _qCol z G
      fi
      name=${k%.key}
      name=${name//_/ }
      _qPos right 6
      printf "[ %s ]%s %s \n" \
        $( _get_code "$k" ) \
        $( _qCol s ) \
        "$name"
      even=$(( 1 - $even ))
    done
    _qCol z
}

_show_clock() {
    for foo in {1..1}; do
        i=$(( ( $( date +%s ) - $timeadjust ) % $update_frequency ))
        l=$(( $update_frequency - $i ))
        if [ "$LIGHT" = 1 ]; then
            _qPos abs $(( $KEY_FILES + 5 )) 1
        else
            _qPos abs $(( $KEY_FILES + 22 )) 1
        fi
        _qCol CLREND z g;_qPos right 5; date
        # seconds to code update
        _qCol z g
        printf "\r"; _qPos right 4; printf "[";
        printf ' %.0s' $( seq 1 $update_frequency )
        printf ']\r'; _qPos right 5
        if [ $l -gt 8 ]; then _qCol z G;
        elif [ $l -gt 3 ]; then _qCol z Y;
        else _qCol z R;
        fi
        printf '=%.0s' $( seq 1 $l )
        _qCol z c
        # seconds to this client shutdown
        left=$(( $update_frequency * ( $exit_timeout - $SECONDS ) / $exit_timeout ))
        printf "\n\r"; _qPos right 4; printf "[";
        printf ' %.0s' $( seq 1 $update_frequency )
        printf ']\r'; _qPos right 5
        if [ $left -gt 8 ]; then _qCol z c;
        elif [ $left -gt 3 ]; then _qCol z y;
        else _qCol z r;
        fi
        printf '#%.0s' $( seq 1 $left )
        _qCol z; printf "\n"
        _qCol CLREND
        # die if key pressed, or client open for exit_timeout length
        wait_for_second=$SECONDS
        for i in {1..10}; do
          read -t 0.1 foo
          [[ "$?" -eq 0 ]] && _exit
          [[ $SECONDS -gt $exit_timeout ]] && _exit
          _flames
          if [ $SECONDS -gt $wait_for_second ]; then break; fi
        done
    done
}
if [ -f "$1" ]; then _get_code "$1"; _get_code "$1" | xclip; exit; fi
for key in *key; do ((KEY_FILES++)); done
clear
_print_codes
_skull
_flames; _flames; _flames; _flames

while :;do
    set -e
    new_codes=$( _print_codes )
    set +e
    [[ ! "$new_codes" = "$codes" ]] && {
      # print codes only if they change, this keeps selection in shell intact
      _stars
      codes=$new_codes
      echo -e "$codes"
      echo ''
    }
    _show_clock
done