#!/bin/bash

######################################################################
#                     The ASCII lightsaber                           #
#                                                                    #
#            By: Jansen Price <jansen.price@gmail.com>               #
#                      November 19, 2015                             #
#   ▁▁▁▁▁▁▁▁▁▁▁▁▁ ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁    #
#  |▍░▐░░▣░▒░▒░▒▕|                                               ▌   #
#   ▔▔▔▔▔▔▔▔▔▝▔▔▔ ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔    #
######################################################################

lsaberVersion="lsaber-1.0"

# Determine width and height of terminal
WIDTH=`tput cols`
HEIGHT=`tput lines`

HILT=(" ▁▁▁▁▁▁▁▁▁▁▁▁▁ " "▐▍░▐░░▣░▒░▒░▒▕|" " ▔▔▔▔▔▔▔▔▔▝▔▔▔ ")
BLADE=("▁" "█" "▔")
TIP=(" " "▌" " ")

COLORNAMES=("red" "green" "yellow" "blue" "purple" "cyan")
COLORCODES=("\E[31m" "\E[32m" "\E[33m" "\E[34m" "\E[35m" "\E[36m")

displayUsage() {
    echo "$lsaberVersion - An animated ASCII lightsaber"
    echo "Usage: lsaber [-l <length>] [message]"
    echo "  -l Length of the lightsaber"
    echo "  -c Color of blade (valid colors: ${COLORNAMES[@]})"
    echo
    echo "Example: lsaber -l 44 -c green 'May the force be with you'"
}

# Handle --help arg
if [ -n "$1" -a "$1" == "--help" ]; then
    displayUsage
    exit 1
fi

# Default blade length and color
bladeLength=55
bladeColor=red

# Process user options
while getopts "l:c:" opt; do
    case $opt in
        l)
            # Set the bladelength (option -l <length>)
            bladeLength=$OPTARG
            ;;
        c)
            # Set the color (option -c <color>)
            bladeColor=$OPTARG
            ;;
    esac
done

# Shift off the used args
shift $((OPTIND-1))

# Get message
if [ -n "$1" ]; then
    message="$@"
fi

# Define hilt length
hiltLength=${#HILT}

# Get blade length
maxSaberLength=$((($WIDTH-$hiltLength)/2))
isNumber='^[0-9]+$'
if ! [[ $bladeLength =~ $isNumber ]] ; then
    echo "Error: Blade length must be a number" >&2
    exit 1
fi
if [ "$bladeLength" -gt "$maxSaberLength" ]; then
    bladeLength=$maxSaberLength
fi

# Define saber length
saberLength=$((${#HILT}+$bladeLength))

# Get blade color
if [[ ${COLORNAMES[@]} =~ $bladeColor ]]; then
    for c in $(seq 0 $((${#COLORNAMES[@]} - 1))); do
        if [ "${COLORNAMES[c]}" == "$bladeColor" ]; then
            bladeColorCode=${COLORCODES[c]}
        fi
    done
else
    echo "Error: Invalid color name for blade" >&2; echo
    displayUsage
    exit 1
fi

drawHilt() {
    local row=$1
    local col=$2

    # Preserve whitespace in strings
    local IFS='%'

    tput cup $(($row-1)) $col
    echo ${HILT[0]}

    tput cup $row $col
    echo ${HILT[1]}

    tput cup $(($row+1)) $col
    echo ${HILT[2]}

    # Reset whitespace preserving directive
    unset IFS
}

animateBlade() {
    local row=$1
    local col=$2
    local hiltLength=$3
    local bladeLength=$4

    bladeStart=$(($col+$hiltLength))

    # Hide the cursor
    tput civis

    for (( i=0; i<$bladeLength; i++ ))
    do
        tput cup $(($row-1)) $(($bladeStart+$i)); echo ${BLADE[0]}
        tput cup $row $(($bladeStart+$i)); echo ${BLADE[1]}
        tput cup $(($row+1)) $(($bladeStart+$i)); echo ${BLADE[2]}

        tput cup $(($row-1)) $(($bladeStart+$i+1)); echo ${TIP[0]}
        tput cup $row $(($bladeStart+$i+1)); echo ${TIP[1]}
        tput cup $(($row+1)) $(($bladeStart+$i+1)); echo ${TIP[2]}

        sleep 0.001
    done

    # Display the cursor
    tput cnorm
}

showMessage() {
    local row=$1
    local message=$2

    messageLength=${#message}
    center=$((($WIDTH-$messageLength)/2))

    tput cup $(($row+3)) $center
    echo "$message"
}

# ------------------------------------------------------
# Main program execution

# Clear the screen
tput clear

# Calculate center of screen
centerRow=$(($HEIGHT/2))
centerCol=$((($WIDTH-$saberLength)/2))

drawHilt $centerRow $centerCol
printf "$bladeColorCode"
animateBlade $centerRow $centerCol $hiltLength $bladeLength
if [ -n "$message" ]; then
    showMessage $centerRow "$message"
fi

# Move cursor down to bottom of screen
tput cup $HEIGHT 0
tput op
exit 0