#!/bin/bash

set -e

if printf '%s\n' "$0" | grep / >/dev/null 2>/dev/null; then
    export PATH="$(printf '%s\n' "$0" | tr '/\n' '\n/' | sed \$d | tr '/\n' '\n/'):${PATH}"
fi

pid=$$
o='0 0 0 0'
E='1 1 1 1'

x=x; y=y; z=z
ciexyy=0
zflag=
grey=0
keep=0

usage () {
	xyy="-z x1 y1 x2 y2 x3 y3 [white-x white-y]"
	xyz="X1 Y1 Z1 X2 Y2 Z2 X3 Y3 Z3 [white-X white-Y white-Z]"
	printf 'usage: %s [-1 | -2 | -3] [-gk] [%s | %s]\n' "$0" "$xyy" "$xyz" >&2
	exit 1
}

while ! test $# = 0; do
	if test "$1" = --; then
		shift 1
		break
	elif test "${1::1}" = -; then
		arg="${1:1}"
		shift 1
		while test -n "${arg::1}"; do
			flag="${arg::1}"
			arg="${arg:1}"
			if test "$flag" = 1; then
				x=x; y=y; z=z
			elif test "$flag" = 2; then
				x=y; y=z; z=x
			elif test "$flag" = 3; then
				x=z; y=x; z=y
			elif test "$flag" = g; then
				grey=1
			elif test "$flag" = k; then
				keep=1
			elif test "$flag" = z; then
				ciexyy=1
			else
				usage
			fi  
		done
	else
		break
	fi
done

a=$(( ( 3 - $ciexyy ) * 3 ))
b=$(( ( 3 - $ciexyy ) * 4 ))
if test $# != 0 && test $# != $a && test $# != $b; then
	usage
elif test $ciexyy = 1 && test $# = 0; then
	usage
fi

read frames width height pixfmt < <(blind-read-head)

if test $# = 0; then
	convert () { cat; }
	unconvert () { cat; }
else
	if test $ciexyy = 1; then
		zflag=-z
	fi
	convert () {
		blind-affine-colour -al \
			<(blind-colour-matrix -F "$pixfmt" $zflag -- "$@" | \
				blind-tee \
					>(blind-invert-matrix -e | \blind-to-named -a blind-${pid}-invmat) | \
					blind-repeat inf -)
	}
	unconvert () {
		blind-affine-colour -al \
			<(blind-from-named -a blind-${pid}-invmat \
				./blind-arithm -xyz max <(./blind-single-colour -w 3 -h 3 1) | \
				blind-repeat inf -)
	}
fi

if test $keep = 0; then
	primary () { blind-from-named -a blind-${pid}-$x "$@"; }
	keep_primary () { "$@"; }
else
	primary () {
		blind-from-named -a blind-${pid}-$x \
			blind-tee >(blind-to-named -a blind-${pid}-k) | \
			"$@"
	}
	keep_primary () {
		if test $x = x; then
		    X=; Y=y; Z=z
		elif test $x = y; then
		    X=x; Y=; Z=z
		else
		    X=x; Y=y; Z=
		fi
		blind-from-named -f 7 -a blind-${pid}-k \
			blind-arithm -a$X$Y$Z add /dev/fd/7 | \
			"$@"
	}
fi

if test $grey = 0; then
	finalise () { unconvert; }
else
	finalise () {
		unconvert | blind-set-saturation <(blind-single-colour -f inf -w $width -h $height 0)
	}
fi

(blind-write-head $frames $width $height "$pixfmt" ; cat) | \
	convert "$@" | \
	blind-split-chans -c \
		>(blind-to-named -a blind-${pid}-x) \
		>(blind-to-named -a blind-${pid}-y) \
		>(blind-to-named -a blind-${pid}-z) \
		- | \
	blind-arithm mul \
		<(blind-single-colour -f inf -w $width -h $height 0 0 0 1 | \
			blind-arithm sub \
				<(primary blind-affine-colour -l \
					<(printf '%s %s %s %s\n' \
						1 4 4 xyza \
						$o $o $o $o \
						$o $o $o $o \
						$o $o $o $o \
						$E $E $E $o | \
						blind-from-text | \
						blind-repeat inf -))) | \
	keep_primary \
	blind-from-named -f 8 -a blind-${pid}-$y blind-arithm add /dev/fd/8 | \
	blind-from-named -f 9 -a blind-${pid}-$z blind-arithm add /dev/fd/9 | \
	finalise