#!/bin/bash
# Generate a collage with the covers of your favorite albums according to your last.fm profile.
# Inspired by Gijsco's Last.fm Desktop Generator (http://build.last.fm/item/37) and Jamie Zawinski's webcollage (http://www.jwz.org/webcollage/)
# Requires imagemagick and xsltproc (fairly standard)
# Also requires parse_pictures.xsl which you should find wherever you found this script.
#
# Usage:
# Copy the script and parse_pictures.xsl in a directory of your choice.
# Running the script from the command line will use the default values.
# Use ./lastCollage -u yourlastfmusername to make the collage with your profile and default values. See output for a description of the parameters.
# You can delete the sub-directory lccache if you want to start afresh. It'll be re-created.
#
# More explanations at http://ledazibao.free.fr/lastCollage
#
# Koant (http://www.last.fm/user/Koant/) 
# Thu 15 May 2008 
#
# Possible improvements, if you feel like it:
# . better random; RANDOM produces extremely correlated numbers. Had to re-seed after each use.
# . use other feeds than top albums
# . speed things up

# Default Settings
username='Koant' 	# last.fm username
type='overall' 		# 3month, 6month, 12month or overall

AlbumSize=300		# size of each album cover, in pixel
Final=1280x1024		# dimension of the final image, in pixel
AlbumOpacity=80 	# from 0 to 100 (100 is completely opaque, the cover won't blend into the background)
GradientSize=20 	# in pixel. Transparency gradient size for an album. The bigger the larger the area of the cover is transparent.
ImageOpacity=70 	# darken the final image, from 0 to 100 (0 is completely black)
iteration=1		# Number of times the algorithm is run. 2 is usually enough
cache='lccache' 	# name of cache directory

# Checking out dependencies (bc, ImageMagick and xsltproc)
if which bc > /dev/null; then echo "bc is installed." 
else 
	echo 	
	echo "	bc is not installed! I can't proceed."
	exit 
fi
if which convert > /dev/null; then echo "ImageMagick is installed." 
else 
	echo	
	echo "	ImageMagick is not installed! I can't proceed."
	exit 
fi

if which xsltproc > /dev/null; then echo "xsltproc is installed." 
else 
	echo
	echo "	xsltproc is not installed! I can't proceed."
	exit 
fi

# Reading out parameters
# from http://www.ibm.com/developerworks/library/l-bash-parameters.html by Ian Shields

while getopts ":u:O:o:n:f:c:a:t:g:i:" optval "$@"
    do
      case "$optval" in
        "u")
		username=$OPTARG	
          ;;
        "O")
		ImageOpacity=$OPTARG
          ;;
	"o")
		AlbumOpacity=$OPTARG		
	;;
	"n")
		imagename=$OPTARG
	;;
	"f")
		Final=$OPTARG
	;;
	"c")
		Canvas=$OPTARG
	;;
	"a")
		AlbumSize=$OPTARG
	;;
	"t")
		type=$OPTARG
	;;
	"g")
		GradientSize=$OPTARG
	;;
	"i")
		iteration=$OPTARG
	;;
	"?")
          echo "Unknown option $OPTARG, ignored."
          ;;
        ":")
          echo "No argument value for option $OPTARG"
          ;;
 	*)       
        # Should not occur
          echo "Unknown error while processing options"
          ;;
      esac
done

# processing and reverting to default if needs be
imagename=${imagename:-"$username"} # Default imagename is username
Canvas=${Canvas:-"$Final"} # Default Canvas size is Final's

FinalWidth=$(echo $Final | cut -d'x' -f1)
FinalHeight=$(echo $Final | cut -d'x' -f2)
CanvasWidth=$(echo $Canvas | cut -d'x' -f1)
CanvasHeight=$(echo $Canvas | cut -d'x' -f2)

echo "I'll be using the following parameters:-"
echo "	(u) Username: $username "
echo "	(t) How far back: $type (should be one of '3month', '6month' or '12month')"
echo "	(n) Name of the picture: $imagename.jpg"
echo "	(c) Size of the canvas: "$CanvasWidth"x"$CanvasHeight
echo "	(f) Size of the final image: "$FinalWidth"x"$FinalHeight
echo "	(a) Album size: $AlbumSize pixels"
echo "	(o) Album opacity: $AlbumOpacity (in [0 100]. 100 means no transparency)"
echo "	(g) Gradient size: $GradientSize pixels (should be between 1 and half the album size)" 
echo "	(O) Darkness of final image: $ImageOpacity (in [0 100]. 0 makes the image completely black)"
echo "	(i) Number of iterations: $iteration"
echo "(use the letter in parentheses to change the value, as argument to the script)"

# URL
URL="http://ws.audioscrobbler.com/1.0/user/$username/topalbums.xml?type=$type"

# Make script crontab friendly:
cd $(dirname $0)

# Create cache if doesn't exist already
if test ! -d $cache
	then
	mkdir $cache
fi

# returns a random integer between $1 and $2
function get_rand { 
	RANDOM=$(dd if=/dev/urandom count=2 2> /dev/null | cksum | cut -f1 -d" ") # re-seed
	l=`expr $2 - $1`	
	r=`echo "r=($l+1)* ($RANDOM/32767); if (r<1) print 0 else print r" |bc -l |cut -d'.' -f1`
	echo `expr $r + $1`
}

#add + sign if needs be
function add_sign { 
	if ! echo $1 | grep -e "-" >/dev/null
	then
	echo +$1
	else 
	echo $1
	fi
}

# Create picture log if doesn't exist already
# (list of all URL of pics that have been downloaded)
if test ! -f $cache/pixlog
	then
	touch $cache/pixlog
	chmod a+w $cache/pixlog
	echo "http://cdn.last.fm/depth/catalogue/noimage/cover_med.gif" >> $cache/pixlog # empty album cover, won't be dl.
fi

# fetching the list
echo "Fetching the list of albums..."
rm -f albumlist.xml
wget -q -O albumlist.xml "$URL"


# Download new pictures only
echo "Downloading new pictures..."
urllist=$(xsltproc parse_pictures.xsl albumlist.xml  2> /dev/null)
touch filelist
for url in $urllist
do	
	if ! grep "$url" $cache/pixlog > /dev/null # check whether it's already in the cache 
	then # download and add to the list if need be
		echo $url
		wget -q -P $cache  "$url" && echo $url >> $cache/temp.log
		cat $cache/temp.log >> $cache/pixlog		
		rm -f $cache/temp.log
	fi
done


# list of pictures to actually use, in random order
echo "Preparing the list of pictures..."
rm -f tempfilelist
touch tempfilelist
for url in $urllist # shuflles the list of pictures
	do
		x=$(get_rand 1000 9999)
		echo $x ${url##*/} >> tempfilelist
	done
sort tempfilelist | cut -d' ' -f2 > filelist
rm -f tempfilelist

# Useful quantities
Dx=`echo "r=($CanvasWidth - $FinalWidth)/2; if (r*r<1) print 0 else print r" |bc -l |cut -d'.' -f1`
Dy=`echo "r=($CanvasHeight - $FinalHeight)/2; if (r*r<1) print 0 else print r" |bc -l |cut -d'.' -f1`
startx=`expr 0 - $Dx`
starty=`expr 0 - $Dy`
rangex=`expr $FinalWidth + $Dx - $AlbumSize`
rangey=`expr $FinalHeight + $Dy - $AlbumSize`

# prepare the mask
echo "Preparing the mask..."

intensity=`echo "254*($AlbumOpacity/100)+1" | bc -l | cut -d'.' -f1`
ln=`expr $AlbumSize - $GradientSize`
convert -size "$AlbumSize"x"$AlbumSize" xc:black -stroke rgb\($intensity,$intensity,$intensity\) -fill rgb\($intensity,$intensity,$intensity\) -draw "roundRectangle $GradientSize,$GradientSize $ln,$ln $GradientSize,$GradientSize" -gaussian "$GradientSize"x"$GradientSize" mask.png

# make the background
echo "Preparing the background..."
if test -f $imagename.jpg # use former image as background if exists. Resize if necessary
	then
	echo "$imagename.jpg exists, I'll paste the new collage on it."
	convert $imagename.jpg -resize "$FinalWidth"x"$FinalHeight"! background.png
else	
	convert -size "$FinalWidth"x"$FinalHeight" xc:black background.png
fi

# add images from list
echo "Add images (might take a while)..."

for ((i=1;i<=$iteration;i+=1));
do
	echo "	iteration $i of $iteration"
	while read fn
	do
		if test -f $cache/$fn
		then
	#	echo $cache/$fn
		convert -resize "$AlbumSize"x"$AlbumSize"! $cache/$fn mask.png +matte -compose CopyOpacity -composite  temp.png

		x=$(add_sign $(get_rand $startx $rangex))
		y=$(add_sign $(get_rand $starty $rangey))
		convert background.png \( temp.png -repage "$x""$y" \)  -flatten background.png
		fi
	done < filelist
done

# darken and jpg
echo "Darken the final image..."
intensity=`echo "254*($ImageOpacity/100)+1" |bc -l | cut -d'.' -f1`
convert background.png \( -size "$FinalWidth"x"$FinalHeight" xc:rgb\($intensity,$intensity,$intensity\) \) +matte -compose Multiply -composite $imagename.jpg

# cleaning up
rm -f background.png mask.png temp.png filelist albumlist.xml

echo "Finished! Image saved in $imagename.jpg"