#!/bin/bash
# fzfShowU8var.sh - Dump UTF-8 by 16x16 table side-by-side w/VARIATION SELECTORS
# (C) 2024-2025 Felix Hauri - felix@f-hauri.ch
# No arguments. 
# Use arrow Up/Down to browse UTF-8
# Use arrow Left/Right to browse VARIATION SELECTORS
# Use <tab> to select table to show when exit.
# Note: Exiting fzf, table are shown with better alignment.
#  Better shown in a minumum 86 columns wide mate-terminal or gnome-terminal

showU8 () {
    local _i _a _f _e _t
    printf -v _f '%*s' 16 ''
    _t=${_f// /--}
    printf -v _t '%s  %s  %s\n' ${_t::6} ${_t:1}{,}
    _f="${_f// / %b}"
    printf -v _e '\\U%X' $(($1>16?$1+917743:$1+65023))
    _e="${_f//b/b$_e}"
    printf 'Show UTF8 table using: VARIATION SELECTOR-%d (U+%X)\n' \
	    $1 $(($1>16?$1+917743:$1+65023))
    shift
    for _a; do
	printf "U%03Xyx $_f $_e\n%s" 0x${_a} {,}{{0..9},{A..F}} "$_t"
	for _i in {0..9} {A..F}; do
	    (( 16#$_a == 0 )) && (( ( 16#$_i & 7 )  < 2 )) &&
		printf 'U%04Xx%68s\n' 0x$_a$_i '' && continue	
	    printf "U%04Xx $_f $_e\n"  0x$_a$_i \
		   "\\U$_a$_i"{,}{{0..9},{A..F}}
	done
    done
}

showU8c () {
    local _i _a _f _e _t
    printf -v _t '%31s' ''
    _t=${_t// /-}
    printf -v _t '%s    %s  %s\n' ${_t::6} $_t{,}
    printf -v _f '%%%ds%%%%b\\\\r' {40..10..-2}
    printf -v _f "$_f"
    _f=${_f// /$'\UA0'}
    printf -v _e '%%%%%%ds%%%%%%%%b\\\\U%X\\\\\\\\r' \
	    $(($1>16?$1+917743:$1+65023))
    printf -v _e "$_e" {73..43..-2}
    printf -v _e "$_e"
    printf 'Show UTF8 table using: VARIATION SELECTOR-%d (U+%X)\n' \
	    $1 $(($1>16?$1+917743:$1+65023))
    shift
    for _a; do
	printf "$_e${_f}U%03Xyx\n%s" {,}{{F..A..-1},{9..0..-1}} 0x${_a} "$_t"
	for _i in {0..9} {A..F}; do
	    (( 16#$_a == 0 )) && (( ( 16#$_i & 7 )  < 2 )) &&
		printf 'U%04Xx%68s\n' 0x$_a$_i '' && continue	
	    printf "$_e${_f}U%04Xx\n" \
		   "\\U$_a$_i"{,}{{F..A..-1},{9..0..-1}} 0x$_a$_i
	done
    done
}
tmpfile=$(mktemp)
echo ${mod:-16} >$tmpfile

aList=( {0..215} {249..282} {284..293} {303..308} {324..326} {360..363} \
   {366..367} {392..396} {431..434} {444..444} {463..474} {479..482} {487..489}\
   {492..494} {496..507} {512..747} {760..762} {768..787} {3584..3585} )
res="$(
    fzf -m < <(printf '%04X\n' ${aList[@]}) --preview \
	"$(declare -f showU8);showU8 \$(<$tmpfile) {}" --preview-window 74 \
	--bind "left:execute| mod=\$(<$tmpfile) ; echo > $tmpfile \$(( \
	       mod > 1 ? mod - 1 : 256 ))|+refresh-preview" \
	--bind "right:execute| echo > $tmpfile \$(( mod=\$(<$tmpfile), \
	       mod < 256 ? mod + 1 : 1 ))|+refresh-preview"
)"
showU8c $(<$tmpfile) $res
rm $tmpfile