#!/usr/bin/env sh

# Standalone shell script to output various text styles

BASE_COLORS="black red green yellow blue magenta cyan white"
RGB_COLOR_NAMES="pink orange brown teal"
RGB_COLOR_VALUES="255;187;221 255;170;68 159;64;16 16;136;159"

RESET='\033[0m'
BOLD='\033[1m'
DIMMED='\033[2m'
ITALIC='\033[3m'
UNDERLINE='\033[4m'
BLINK='\033[5m'
INVERTED='\033[7m'
CONCEALED='\033[8m'
STRIKE='\033[9m'
GREEN_FG='\033[32m'
YELLOW_FG='\033[33m'
MAGENTA_BG='\033[45m'
CYAN_BG='\033[46m'

index() {
  shift "$1"
  echo "$2"
}

base_styles_line() {
  base_style="$1"
  name="$2"

  line="$name: ${base_style}Regular$RESET"
  line="$line ${base_style}$BOLD${GREEN_FG}Bold$RESET"
  line="$line ${base_style}$ITALIC$YELLOW_FG${MAGENTA_BG}Italic$RESET"
  line="$line ${base_style}$BOLD$CYAN_BG${ITALIC}Bold+Italic$RESET"
  line="$line ${base_style}${STRIKE}Strike$RESET"
  echo "$line"
}

base_colors_line() {
  start_code="$1"
  underline_oddity="$2"

  line=""
  for i in $(seq 0 7); do
    color=$((i + start_code))
    decor=""
    if [ $((i % 2)) -eq "$underline_oddity" ]; then
      decor="$UNDERLINE"
    fi
    line=$line'\033['$color'm'$decor$(index "$i" $BASE_COLORS)$RESET' '
    if [ "$3" = "1" ]; then
      line=$line'\033['$color'm'$UNDERLINE$ITALIC$(index "$i" $BASE_COLORS)"/italic"$RESET' '
    fi
  done
  echo "$line"
}

ansi_colors_line() {
  line=""

  for i in $(seq 16 231); do
    fg_color="\033[37m" # white
    col=$(((i - 16) % 36))
    if [ "$col" -gt 18 ]; then
      fg_color="\033[30m" # black
    fi
    line=$line'\033[38;5;'$i'm!\033[0m'$fg_color'\033[48;5;'$i'm?\033[0m'

    if [ "$1" != "1" ] && [ "$col" -eq 35 ]; then
      echo "$line"
      line=""
    fi
  done
  if [ "$1" = "1" ]; then
    echo "$line"
  fi
}

ansi_grayscale_line() {
  line=""
  for i in $(seq 232 255); do
    fg_color="\033[37m" # white
    if [ "$i" -ge 244 ]; then
      fg_color="\033[30m" # black
    fi
    line=$line'\033[38;5;'$i'm!\033[0m'$fg_color'\033[48;5;'$i'm?\033[0m'
  done
  echo "$line"
}

rgb_colors_line() {
  line=""
  for i in $(seq 0 3); do
    name=$(index "$i" $RGB_COLOR_NAMES)
    value=$(index "$i" $RGB_COLOR_VALUES)
    line=$line'\033[38;2;'$value'm'$name'\033[0m '
  done
  echo "$line"
}

if [ "$1" = "--short" ]; then
  echo "Base styles:"
  base_styles_line ''             "     None"
  base_styles_line "$DIMMED"      "   Dimmed"
  base_styles_line "$UNDERLINE"   "Underline"
  base_styles_line "$BLINK"       "    Blink"
  base_styles_line "$CONCEALED"   "Concealed"
  base_styles_line "$INVERTED"    " Inverted"
  base_styles_line '\033[30m\033[47m' "  With bg"

  echo "Partial switches (<ESC>[2x):"
  printf ' \033[1m''bold \033[3m''italic\033[22m \033[4m''underline\033[23m\033[5m\033[32m blink \033[7m\033[24m'
  printf 'reversed \033[25m\033[8m\033[9m''concealed\033[27m\033[28m\n'
  printf ' \033[45m''strikethrough\033[29m\033[39m\033[49m regular\033[0m\n'
fi

long_lines=""
if [ "$1" = "--long-lines" ]; then
  long_lines=1
fi

echo "Base colors:"
base_colors_line 30 0 "$long_lines"
base_colors_line 90 1 "$long_lines"
echo "Base colors (bg):"
base_colors_line 40 2
base_colors_line 100 2

if [ "$1" = "--short" ]; then
  exit 0
fi

echo "ANSI color palette:"
ansi_colors_line $long_lines
echo "ANSI grayscale palette:"
ansi_grayscale_line

echo "24-bit colors:"
rgb_colors_line