#!/bin/bash

######################################################################
# Program:	mkthumbnail
# Purpose:	Generates HTML code for thumbnails.
# Arguments:	See usage.
# Author:	Perette Barella
# Version:	@(#) $Id: mkthumbnails,v 1.16 2008/12/12 21:26:07 perette Exp $
#---------------------------------------------------------------------

######################################################################
# Function:	usage
# Purpose:	Displays the usage of this command.
# Author:	Perette Barella
#---------------------------------------------------------------------
function usage
{
	echo "Usage: $arg0 [options] images-per-line max-width max-height [file ....]"
	echo "       $arg0 [options] images-per-line max-width max-height [file ...]"
	echo "Options:"
	echo "  -c file         Read captions from file"
	echo "  -o              Insert image in order listed in caption file."
	echo "  -s attributes   Create single image and include specified HTML attributes"
	echo "                  Images-per-line is left out when using -s option."
	echo "  -q percent      Image quality, 1 = crap and 99=great"
	exit 1
}
##### End of function usage #####




######################################################################
# Function:	parse_arguments
# Purpose:	Parses the command line arguments
# Arguments:	The command line arguments.
# Returns:	Number of arguments parsed.
# Author:	Perette Barella
#---------------------------------------------------------------------
function parse_arguments
{
	typeset option
	single=false
	captions=""
	ordered=false
	comments=""
	quality=50

	while getopts 's:oc:q:?' option
	do
	    case "$option" in
		c)	captions="$OPTARG"
			if [ ! -e "$captions" ]
			then
				echo "`pwd`/$captions: caption file not found." 1>&2
				exit 1
			fi ;;
		o)	ordered=true ;;
		s)	single=true
			comments="$OPTARG" ;;
		q)	quality="$OPTARG"
			if ! expr "$quality" : '[0-9]\{1,2\}$' >/dev/null
			then
				usage
			fi ;;
		*)	usage ;;
	    esac
	done
	if $ordered && [ "$captions" = "" ]
	then
		echo "$arg0: Need provide caption file for ordered thumbnails" 1>&2
		exit 1
	fi
	return $((OPTIND - 1))
}
##### End of function parse_arguments #####





######################################################################
# Function:	resize_this
# Purpose:	Calculates the destination size given the actual
#		image sizes.  Generates the HTML.
# Arguments:	$1 - width
#		$2 - height
#		$3 - filename
# Returns:	0 on success, non-0 on failure.
#		newwidth, newheight - size the image must result in.
# Author:	Perette Barella
#---------------------------------------------------------------------
function resize_this
{
	typeset x="$1" y="$2" file="$3" thumbfile="$4" status=0 alternate=""
	if ! expr "$x $y" : "[0-9][0-9]* [0-9][0-9]*\$" >/dev/null
	then
		echo "$arg0: width or height of $file screwed up: $x" 1>&2
		return 1
	fi
	# calculate the adjustment for width and height as a per thousand.
	adjwidth=9999
	adjheight=9999
	[ "$destwidth" != "-" ] && let adjwidth="(destwidth * 1000) / $x"
	[ "$destheight" != "-" ] && let adjheight="(destheight * 1000) / $y"

	typeset adjust=$adjwidth
	[ $adjheight -lt $adjwidth ] && let adjust=$adjheight
	let newwidth="(x * adjust) / 1000"
	let newheight="(y * adjust) / 1000"
	if $single
	then
		echo "<A HREF=\"${file}\">_IMAGE(\`\`$thumbfile'', \`\`$comments'')</A>" |
		sed 's/"/\"/g'
	else
		alternate=""
		if [ "$captions" != "" ]
		then
			alternate=$(grep "^$file" "$captions" | cut -f2- | head -1)
		fi
		if [ "$alternate" = "" ] && ! expr "$file" : "\(.*/\)\{0,\}[A-Z0-9]\{0,3\}[0-9][0-9]*\.[a-z]*\$" >/dev/null
		then
			alternate=$(echo "$file" |
				sed -e 's/[0-9]*\.[a-z][a-z]*$//g' \
				-e 's&/&: &' -e 's/[^:a-zA-Z0-9]/ /'g)
		fi
		[ "$alternate" = "" ] && alternate="Thumbnail."
		[ $count -eq 0 ] && echo "<TR>"
		let "count=count+1"
		echo "<TD ALIGN=CENTER VALIGN=MIDDLE><A HREF=\"${file}\">_IMAGE(\`\`$thumbfile'', \`\`ALT=\"$alternate\" TITLE=\"$alternate\"'')</A></TD>"
		[ $count -eq $imagecount ] && echo "</TR>" && count=0
	fi
	return 0
}
##### End of function resize_this #####




######################################################################
# Function:	resize_jpeg
# Purpose:	Resize a jpeg (making a thumbnail) and write out the new file.
# Arguments:	$1 - the file to resize.
# Returns:	0 on success, non-0 on error
# Author:	Perette Barella
#---------------------------------------------------------------------
function resize_jpeg
{
	typeset file="$1" SIZE x y z thumbfile thumb_x thumb_y dirname exif
	dirname=$(dirname "$file")
	[ ! -d "$dirname/Thumbnails" ] && mkdir "$dirname/Thumbnails"
	thumbfile=$dirname/Thumbnails/$(basename "$file")
	set $(identify -format "%w %h %[EXIF:Orientation] 1" "$file") || exit 1
	x="$1"
	y="$2"
	exif="$3"
	[ "$exif" = "unknown" ] && exif=1

	# EXIF orientation values:
	# 1: natural orientation - N
	# 2: Flip Horizontal - N
	# 3: Rotate 180 deg clockwise = Flip V+H - N
	# 4: Flip vertical = rotate 180 + flip horizontal - N
	# 5: Rotate 90 deg clockwise + flip horizontal - X
	# 6: Rotate 90 deg clockwise - X
	# 7: Rotate 270 deg clockwise + flip horizontal - X
	# 8: Rotate 270 deg clockwise - X

	# Identify returns the size of the image as encoded.
	# If the image is rotated via the EXIF data, we need to
	# swap the X and Y coordinates to reflect this presentation.
	swap=false
	if [ $exif -ge 5 ]
	then
		z="$x" ; x="$y"; y="$z"
	fi

	resize_this "$x" "$y" "$file" "$thumbfile" || return $?
	if [ -f "$thumbfile" -a "$thumbfile" -nt "$file" ] &&
	   set $(identify -format "%w %h" "$thumbfile")
	then
		thumb_x="$1"
		thumb_y="$2"
		# The size may be off by +1.  This seems to be
		# the convert utility trying to maintain proportions.
		margin=2
		[ $thumb_x -ge $((newwidth - margin)) -a \
		  $thumb_x -le $((newwidth + margin)) -a \
		  $thumb_y -ge $((newheight - margin)) -a \
		  $thumb_y -le $((newheight + margin)) ] &&
			echo "Using existing $thumbfile" 1>&2 &&
			return 0
	fi
	echo "Creating $thumbfile" 1>&2 &&
	if [ "$exif" -ge 5 ]
	then
		z="$newwidth"
		newwidth="$newheight"
		newheight="$z"
	fi
	convert -quality $quality -geometry ${newwidth}x${newheight} "$file" "$thumbfile"
	return $?
}
##### End of function resize_jpeg #####



##### Start of main #####

arg0=$(basename $0)

parse_arguments "$@"
shift $?

if [ \( "$single" = "false" -a $# -lt 3 \) -o \
     \( "$single" = "true"  -a $# -lt 2 \) ]
then
	echo "$arg0: Too few parameters."
	usage
fi
imagecount="$1"
$single || shift
destwidth="$1"
destheight="$2"
shift 2

if $single
then
	imagecount=2
	if qualitystr=$(expr "$comments" : '.*QUALITY=\([0-9]\{1,2\}\)')
	then
		quality="$qualitystr"
		comments=$(echo "$comments" | sed 's/QUALITY=[0-9]* *//')
	fi
elif $ordered
then
	set $(cut -s -f1 "$captions" | egrep -v '^[ 	]*$|^[ 	]*#')
	if [ $# -eq 0 ]
	then
		echo "$captions: No images specified in file." 1>&2
		exit 3
	fi
fi

status=0
count=0

for file in "$@"
do
	# if it's already a thumbnail, skip it.
	if [ ! -e "$file" ]
	then
		echo "$arg0: $file does not exist" 1>&2
		status=1
		continue
	fi

	case "$file" in
		*/Thumbnails/*|Thumbnails/*)
			# Silently skip things that are already thumbnails.
			: ;;
		*)
			# ImageMagick handles most formats -- just pass
			# everyting off to it.
			resize_jpeg $file
			status=$?
			;;
	esac
done

[ $count -ne 0 ] && echo "</TR>"
exit $status



##### End of main #####