#!/bin/bash
#
# Copy a booke to cello-friendly form. Bass clef, transposed down
# 1 or 2 octaves.
#
# It would be easier to do with transpose in dottes.fmt, but I can't get
# that to work properly for a 2 octave downward transpose.
#
# This relies on abcm2ps >= 6.0 but does not check for it.

if [ $# != 1 ]; then
    echo "Usage: makeCello.sh <book dir name>"
    exit 1
fi

# Return 0 if we should transpose down 2 octaves, 1 if just one
# octave. $2 is highest note, $3 is lowest note.
#
# If range is G to d', transpose down 2 octaves.
# Otherwise calculate the distance above d for the highest note on a one
# octave transposition, and the distance below C on a two octave
# transposition. Find the smallest, and use the corresponding
# transposition, preferring 2 octaves in case of a tie.
transposedowntwo()
{
    if (($3 >= 104 && $2 <= 115)); then
        return 0;
    fi
    over=$(($2 - 108))
    if (($over < 0)); then
        over=0
    fi
    under=$((100 - $3))
    if (($under < 0)); then
        under=0
    fi
    if (($over < $under)); then
        return 1;
    fi

    return 0;
}

dir=`pwd`

booke=$dir/$1
outdir=$dir/$1-Cello

mkdir -p $outdir

# Copy book component items.
cp $booke/*.txt $outdir

echo "Cello" > $outdir/instrument.txt

find $booke -name "*.abc" | sort |
    while read filename
    do
        name=`basename $filename .abc`
        range=`./abcrange.py $filename`

        # Move down either one octave or two, depending on the range
        # of the tune.
        middle="D"
        if transposedowntwo $range; then
            middle="d"
        fi

        sed -e "/^ *K:/s/$/ clef=bass middle=$middle/" $filename > $outdir/$name.abc
    done