#!/bin/sh

#
# This is a regression test for a bug seen where mosh-client's
# prediction code would sometimes show "gück" when "glück" was typed.
# mosh-client would output a predicted Unicode input character
# first as an 8-bit character containing the lowest 8 bits of the
# Unicode code point, then redraw it correctly with its UTF-8 sequence
# when the prediction is validated.  For many accented Latin
# characters, the 8-bit character is an illegal UTF-8 code sequence.
# Most terminal emulators will output the Unicode replacement
# character, which is only visible until validation.  urxvt, however,
# draws no character and does not change the cursor location on an
# illegal UTF-8 sequence, causing this bug to be visible as ongoing
# display corruption.  A subset of wide characters (including CJK)
# will show display corruption with all terminal emulators, because a
# narrow replacement character will be drawn when a wide character
# should have been.
#
# tmux draws a replacement character for invalid UTF-8, and we
# depend on that in this test.
#
# Another similar failing case is typing "faĩl".  In this case the "ĩ"
# would be predicted as ")" before being replaced by the
# correct character.
#
fail()
{
    printf "$@" 2>&1
    exit 99
}



PATH=$PATH:.:$srcdir
# Top-level wrapper.
if [ $# -eq 0 ]; then
    e2e-test $0 tmux baseline mosh-args post
    exit
fi

sleepf()
{
    (sleep .1 || sleep 1) > /dev/null 2>&1
}

seq()
{
    if [ $# -lt 1 -o $# -gt 3 ]; then
	echo "bad args" >&2
    fi
    first=$1
    incr=1
    last=0
    case $# in
	3)
	    incr=$2
	    last=$3
	    ;;
	2)
	    last=$2
	    ;;
	1)
	    ;;
    esac
    while :; do
	printf '%d\n' $first
	first=$(expr $first + $incr)
	if [ $first -gt $last ]; then
	    break
	fi
    done
}

chr()
{
    printf "\\$(printf %03o $1)"
}

utf8cp()
{
    local c=$1
    if [ $c -gt $((0x10ffff)) ]; then
	fail "illegal Unicode code point %x\n" $c
    elif [ $c -lt $((0x80)) ]; then
	chr $c
    elif [ $c -lt $((0x800)) ]; then
	chr $(( (($c >>  6) & 0x1f) | 0xc0 ))
	chr $(( ($c & 0x3f)         | 0x80 ))
    elif [ $c -lt $((0x10000)) ]; then
	chr $(( (($c >> 12) & 0x0f) | 0xe0 ))
	chr $(( (($c >>  6) & 0x3f) | 0x80 ))
	chr $(( ($c & 0x3f)         | 0x80 ))
    elif [ $c -lt $((0x200000)) ]; then
	chr $(( (($c >> 18) & 0x03) | 0xf0 ))
	chr $(( (($c >> 12) & 0x3f) | 0x80 ))
	chr $(( (($c >>  6) & 0x3f) | 0x80 ))
	chr $(( ($c & 0x3f)         | 0x80 ))
    fi
}

tmux_commands()
{
    for x in $(seq 1 5); do
	for y in $(seq 1 5); do 
	    for i in g l ü c k " " f a ĩ l " "; do
		printf "send-keys '%s'\n" "$i"
		sleepf
	    done
	done
	printf "send-keys 0x0d\n"
    done
    printf "send-keys 0x0d\n"
    sleep 1
    printf "send-keys 0x04\n"
    sleep 10
} 

tmux_stdin()
{
    tmux_commands | "$@"
    exit
}

baseline()
{
    # Just receive and toss input in canonical mode.
    cat > /dev/null
}

post()
{
    # Look for bad output: ')' or \374
    if [ -n "$(env -u LC_ALL -u LC_CTYPE -u LANGUAGE LANG=C egrep "%output %0 (\)|$(printf \\374))" $(basename $0).d/baseline.tmux.log)" ]; then
        exit 1
    fi
    exit 0
}

case $1 in
    tmux)
	shift;
	tmux_stdin "$@";;
    baseline)
	baseline;;
    mosh-args)
	printf "%s\n" "--predict=always";;
    post)
	post;;
    *)
	fail "unknown test argument %s\n" $1;;
esac