tint

#!/usr/bin/env bash
#=========================================================================================
# HEADER
#=========================================================================================
#  IMPLEMENTATION
#
#     title           tint
#     description     The ANSI/VT100 terminals and terminal emulators can display colors
#                     and formatted text using escape sequences. Instead of using the raw
#                     ANSI escape sequences, we use the tput command which is ensures
#                     portability between various terminals and terminal emulators.
#     version         0.3
#     author          Djordje Ungar <https://www.djordjeungar.com/>
#     collaborator    Heitor Moreira da Silva <heitormoreira@yahoo.com.br>
#     copyright       Copyright (c) 2018 ArtBIT
#     license         MIT License
#
#=========================================================================================
#  HISTORY
#     2018-04-19 : ArtBIT       : Script creation
#     2020-03-01 : heitormsilva : Add -c and -l options and improvements
# 
#=========================================================================================
#  DEBUG OPTION
#    set -n  # Uncomment to check your syntax, without execution.
#    set -x  # Uncomment to debug this shell script
#
#=========================================================================================
# END_OF_HEADER
#=========================================================================================

# Returns the position of the matching closing bracket in the string
# Note: $2 specifies the position of a open bracket to find the match for
_bash_tint__get_closing_bracket_position() {
    local text="$1"
    local position=${2:-0}
    local counter=0
    local ch prev_ch
    local closing_bracket_position=
    for (( j=position; j<${#text}; j++ )); do
        ch="${text:$j:1}"
        if [[ "$ch" == '(' ]]; then
            ((counter++))
        elif [[ "$ch" == ')' ]] && [[ "$prev_ch" != '\' ]]; then
            ((counter--))
        fi
        if [[ $counter -eq 0 ]]; then
            closing_bracket_position=$j
            return $j
        fi
        prev_ch="$ch"
    done
    return 0
}

_debug() {
    [[ -z "$DEBUG" ]] && return
    echo >&2 "$@"
}

# Echoes the resulting transform
_bash_tint__parse() {
    local text="$1"
    local context
    eval "declare -A context="${2#*=}

    local i char word cmd result content
    word_char_regex="[a-zA-Z0-9_]"
    word=""
    result=""
    for (( i=0; i<"${#text}"; i++ )); do
        char="${text:$i:1}"
        if [[ "$char" =~ $word_char_regex ]]; then
            word="${word}${char}"
        else 
            if [[ ! -z "$word" ]]; then
                if [[ "$char" == '(' ]]; then
                    _bash_tint__get_closing_bracket_position "${text:$i}"
                    local closing_bracket_position=$?
                    if [[ $closing_bracket_position -gt 0 ]]; then
                        # copy context
                        context_string=$(declare -p context)
                        eval "declare -A child_context="${context_string#*=}

                        content="${text:$(( i + 1)):$(( closing_bracket_position - 1 ))}"

                        ctx=
                        cmd=
                        # re-match brackets for commands that return functions, i.e. color(123)(text)
                        rematch=
                        case "$word" in
                            # Text effects
                            bold)               cmd="bold"    ctx="$word" ;;
                            dim)                cmd="dim"     ctx="$word" ;;
                            underline)          cmd="smul"    ctx="$word" ;;
                            standout)           cmd="smso"    ctx="$word" ;;
                            blink)              cmd="blink"   ctx="$word" ;;
                            invert)             cmd="rev"     ctx="$word" ;;
                            hidden)             cmd="invis"   ctx="$word" ;;

                            # Foreground colors
                            light_red)          cmd="setaf 9"  ctx="fg" ;;
                            light_green)        cmd="setaf 10" ctx="fg" ;;
                            light_yellow)       cmd="setaf 228" ctx="fg" ;;
                            light_blue)         cmd="setaf 12" ctx="fg" ;;
                            light_magenta)      cmd="setaf 13" ctx="fg" ;;
                            light_cyan)         cmd="setaf 14" ctx="fg" ;;
                            light_gray | light_grey) 
                                                cmd="setaf 15" ctx="fg" ;;
                            light_orange)       cmd="setaf 11" ctx="fg" ;;
                            black)              cmd="setaf 0"  ctx="fg" ;;
                            red)                cmd="setaf 1"  ctx="fg" ;;
                            green)              cmd="setaf 2"  ctx="fg" ;;
                            yellow)             cmd="setaf 226"  ctx="fg" ;;
                            blue)               cmd="setaf 4"  ctx="fg" ;;
                            magenta)            cmd="setaf 5"  ctx="fg" ;;
                            cyan)               cmd="setaf 6"  ctx="fg" ;;
                            white)              cmd="setaf 7"  ctx="fg" ;;
                            gray | grey)        cmd="setaf 8"  ctx="fg" ;;
                            orange)             cmd="setaf 3"  ctx="fg" ;;

                            # Background colors
                            Light_red)          cmd="setab 9" ctx="bg" ;;
                            Light_green)        cmd="setab 10" ctx="bg" ;;
                            Light_yellow)       cmd="setab 228" ctx="bg" ;;
                            Light_blue)         cmd="setab 12" ctx="bg" ;;
                            Light_magenta)      cmd="setab 13" ctx="bg" ;;
                            Light_cyan)         cmd="setab 14" ctx="bg" ;;
                            Light_gray | Light_grey) 
                                                cmd="setab 15" ctx="bg" ;;
                            Light_orange)       cmd="setab 11" ctx="bg" ;;
                            Black)              cmd="setab 0" ctx="bg" ;;
                            Red)                cmd="setab 1" ctx="bg" ;;
                            Green)              cmd="setab 2" ctx="bg" ;;
                            Yellow)             cmd="setab 226" ctx="bg" ;;
                            Blue)               cmd="setab 4" ctx="bg" ;;
                            Magenta)            cmd="setab 5" ctx="bg" ;;
                            Cyan)               cmd="setab 6" ctx="bg" ;;
                            White)              cmd="setab 7" ctx="bg" ;;
                            Gray | Grey)        cmd="setab 8" ctx="bg" ;;
                            Orange)             cmd="setab 3" ctx="bg" ;;

                            # Commands
                            reset)              cmd="sgr0"    ;;
                            clear)              cmd="clear"   ;;
                            save_cursor)        cmd="sc"      ;;
                            restore_cursor)     cmd="rc"      ;;
                            move_cursor)
                                IFS=$',' read -r X Y <<< "$content"
                                cmd="cup $Y $X"
                                ;;
                            color)  
                                if [[ "$content" =~ ^[0-9]+$ ]]; then
                                    cmd="setaf $content"
                                    ctx="fg"
                                    rematch=1
                                fi
                                ;;
                            Color) 
                                if [[ "$content" =~ ^[0-9]+$ ]]; then
                                    cmd="setab $content"
                                    ctx="bg"
                                    rematch=1
                                fi
                                ;;
                        esac

                        if [ ! -z "$cmd" ]; then
                            (( i+=closing_bracket_position ))
                            if [[ ! -z "$ctx" ]]; then
                                if [[ ! -z "$rematch" ]]; then
                                    content="${text:$(( i + 1))}"
                                    _bash_tint__get_closing_bracket_position "$content"
                                    closing_bracket_position=$?
                                    content="${content:1:$(( closing_bracket_position - 1 ))}"
                                    (( i+=closing_bracket_position + 1))
                                fi
                                # reset all contexts then set all the active contexts
                                local tputargs="sgr0" 
                                for context_name in fg bg bold dim underline standout blink invert hidden; do
                                    if [ ! -z "${context[$context_name]}" ]; then
                                        tputargs="${tputargs}\n${context[$context_name]}"
                                    fi
                                done
                                child_context["$ctx"]="$cmd"
                                content="$(_bash_tint__parse "$content" "$(declare -p child_context)")"
                                # if the sub content ends with a context reset, we truncate it, since the same thing is
                                # going to happen in this step as well
                                # sed 's,\x1B(B\x1B\[m\(\x1B\[[^m]\+m\)\+$,,g'
                                re="(.*)\(B\[m(\[[^m]+m)*$";
                                while [[ "$content" =~ $re ]]; do
                                  content="${BASH_REMATCH[1]}"
                                done
                                if [ "$clearText" != "true" ]; then
                                    result="${result}$(tput $cmd)${content}$(printf -- "$tputargs" | tput -S)"
                                else
                                    result="${result}${content}"
                                fi
                            else 
                                # No need to reset context
                                if [ "$clearText" != "true" ]; then
                                    result="${result}$(tput $cmd)"
                                fi
                            fi
                        fi
                    else
                        result="${result}${word}${char}"
                    fi
                    word=
                    char=
                fi
                result="${result}${word}${char}"
                word=""
            else
                result="${result}${char}"
                word=""
            fi
        fi
    done
    result="${result}${word}"
    printf -- "$result"
}

_bash_tint__exec_command() {
    local cmd=
    local content="$2"
}

_bash_tint__logo() {
    colors=(Red Green Yellow Magenta Blue Cyan Orange)
    regex="#"
    while IFS= read -r line; do
        while true; do
            if ! [[ "$line" =~ $regex ]]; then
                break;
            fi
            color="${colors[$RANDOM % ${#colors[@]}]}"
            line=${line/\#\#/$color(  )}
        done
        tint "$line"
    done < <(cat <<-'EOF'
	##########  ######  ####    ##  ##########
	    ##        ##    ##  ##  ##      ##    
	    ##        ##    ##    ####      ##    
	    ##      ######  ##      ##      ##    
	EOF
    )
}

tint_usage() {
    usage=$(cat <<"HELP_USAGE"
Usage: tint [-c -n] <string>
Options:
  -c                            Remove all tint tag marks from the text and 
                                returns it cleared.
  -l                            List available colours codes to be used in 
                                color\(123)(text) format.
  -n                            Do not put a new line character at the end of text.

String format:                  String can contain one or more tint functions.
Functions:                      Result:
  Effects:
    bold\(text)                   bold(text)
    underline\(text)              underline(text)
    invert\(text)                 invert(text)
    blink\(text)                  blink(text)
    hidden\(text)                 hidden(text)
  Foreground colors:
    black\(text)                  black(text)
    red\(text)                    red(text)
    green\(text)                  green(text)
    yellow\(text)                 yellow(text)
    orange\(text)                 orange(text)
    blue\(text)                   blue(text)
    magenta\(text)                magenta(text)
    cyan\(text)                   cyan(text)
    white\(text)                  white(text)
    gray\(text)                   gray(text)
    light_red\(text)              light_red(text)
    light_green\(text)            light_green(text)
    light_yellow\(text)           light_yellow(text)
    light_orange\(text)           light_orange(text)
    light_blue\(text)             light_blue(text)
    light_magenta\(text)          light_magenta(text)
    light_cyan\(text)             light_cyan(text)
    light_gray\(text)             light_gray(text)
  Background colors:
    Black\(text)                  Black(text)
    Red\(text)                    Red(text)
    Green\(text)                  Green(text)
    Yellow\(text)                 Yellow(text)
    Orange\(text)                 Orange(text)
    Blue\(text)                   Blue(text)
    Magenta\(text)                Magenta(text)
    Cyan\(text)                   Cyan(text)
    White\(text)                  White(text)
    Gray\(text)                   Gray(text)
    Light_red\(text)              Light_red(text)
    Light_green\(text)            Light_green(text)
    Light_yellow\(text)           Light_yellow(text)
    Light_orange\(text)           Light_orange(text)
    Light_blue\(text)             Light_blue(text)
    Light_magenta\(text)          Light_magenta(text)
    Light_cyan\(text)             Light_cyan(text)
    Light_gray\(text)             Light_gray(text)
Example:
    tint "white\(Cyan\(T)Magenta\(I)Yellow\(N)Black\(T)) is fun!"
Outputs:
    bold(Cyan(T)Magenta(I)Yellow(N)Black(T)) is fun!
    
HELP_USAGE
)
    _bash_tint__logo
    tint "$usage"
}

listColours() {
    tput init
    local end=$(( $(tput colors)-1 ))
    local w=8
    for c in $(seq 0 $end); do
        eval "$(printf "tput setaf %3s   " "$c")"; echo -n "$_"
        [[ $c -ge $(( w*2 )) ]] && offset=2 || offset=0
        [[ $(((c+offset) % (w-offset))) -eq $(((w-offset)-1)) ]] && echo
    done
    tput init
}

tint() {
    if [ "$1" == "--help" ]; then
        tint -h
        return
    fi
 
    local clearText="false"
    local newLine="true"

    OPTIND=1 #reset getops index
	while getopts ":chln" opt $@; do
        case $opt in
            c)
                clearText=true
                ;;
            h)
                tintf "$@"
                return
                ;;
            l)
                listColours
                return
                ;;
            n)
                newLine="false"
                ;;
            \?)
                echo "Invalid option: '-${OPTARG}'" >&2
                #exit 1
                ;;
            :)
                echo "Option -$OPTARG requires an argument." >&2
                #exit 1
                ;;
        esac
        shift $((--OPTIND))
    done

    if [ "$newLine" = "true" ]; then
        tintf "$@"
        printf "\n"
    else
        tintf "$@"
    fi
}

tintf() {
    if [ "$1" == "-h" -o "$1" == "--help" ]; then
        tint_usage
        return
    fi
    # trailing newlines are removed with command substitution, to circumvent this, we add a trailing dot to the input string
    # and then remove the last character from the result string
    input="$1."
    shift

    # This is the initial context
    declare -A context
    context=( ["fg"]= ["bg"]= ["bold"]= ["dim"]= ["underline"]= ["standout"]= ["blink"]= ["invert"]= ["hidden"]= )
    result="$(_bash_tint__parse "$(printf -- "$input" "${@}")" "$(declare -p context)")"
    result="${result//\\(/(}"
    result="${result//\\)/)}"

    printf -- "${result::-1}"
}

tint "${@}"