q

#!/usr/bin/env bash
# Copyright (C) 2016 Alexander Klapheke
# 
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
# DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
# OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.



# Simple academic paper queue, inspired by paperq <paperq.invergo.net>
# but with tab completion, and pandoc-citeproc as a more robust bibtex
# parser. Expects papers with the same filenames as their bibtex keys.
# Requires pandoc v1.16. Released under the MIT License.
#
# TODO: would be much faster if --list could parse all bibtex keys at once
# TODO: if a key is a prefix of an earlier key, you can't access it---try to match exact first?
# TODO: nicer errors if citation not found (esp. in bibshort() )
# TODO: replace biblong()/bibshort() voodoo with actual parser

# Options:
bibfile=$HOME/texmf/bibtex/bib/references.bib
paperdir=$HOME/Documents/Papers # no trailing slash
queue=$HOME/.config/qlist
default_action=list # remove, view, bib, list, zip, count, edit
view_program=xdg-open # program used to view PDFs
[[ -t 1 ]] && colors=1 # color output if running interactively



[[ -f "$queue" ]] || touch "$queue"

# color messages
message () { if [[ $colors ]]; then echo -e  "\e[1;30m${*}\e[0m" >&2; else echo "$*" >&2; fi }
error   () { if [[ $colors ]]; then echo -e  "\e[1;31m${*}\e[0m" >&2; else echo "$*" >&2; fi }

# color output
gray    () { if [[ $colors ]]; then sed $'s/.\+/\e[1;30m\\0\e[0m/' ; else sed -e ''; fi }
white   () { if [[ $colors ]]; then sed $'s/.\+/\e[1;37m\\0\e[0m/' ; else sed -e ''; fi }
plain   () { if [[ $colors ]]; then sed $'s/.\+/\e[0;37m\\0\e[0m/' ; else sed -e ''; fi }

# check to make sure all external commands can be called
executables=("pandoc" "pandoc-citeproc" "zip" "$view_program")
for ((i=0; i < ${#executables[@]}; i++)); do
	if [[ ! $(command -v ${executables[$i]}) ]]; then
		error "Executable not found: ${executables[$i]}"; exit
	fi
done

# format citations
biblong  () {
	echo "@$1" | pandoc --bibliography="$bibfile" -t plain --columns="$(tput cols)" | tail -n +3 | head -n -2;
}
bibshort () {
	echo "@$1" | pandoc --bibliography="$bibfile" -t plain --wrap=none   | # format citation
	white                                                                    | # color author+date
	sed '2,$s/.*\(“[^”]\+”\).*/\1/'                                          | # extract title
	tr '\n' ' '                                                              | # join lines
	sed "s/\(.\{$(($(tput cols)-(number_width-number_space)-6))\}\).*/\1.../"; # truncate
}

get_paper_id () {
	local id=${1:-1}
	if [[ $id =~ ^[[:digit:]]+$ ]]; then
		if [[ $id -le 0 || $id -gt $(queuelength) ]]; then
			error "Invalid index."
			exit 1
		fi
		id=$(sed -n "${id}p" "$queue")
	else
		if ! grep -q "$id" "$queue"; then
			error "Invalid index."
			exit 1
		fi
		id=$(sed -n "/${id}/{p;q}" "$queue")
	fi
	echo "$id"
}

queuelength () {
	wc -l "$queue" | cut -f 1 -d ' '
}

iterate () {
	if [[ $(queuelength) -eq 0 ]]; then
		message "Queue is empty! For help, run: $(basename "$0") --help"
		return 1
	fi
	local num=$(echo "$1" | bc)
	while read -r line; do
		if [[ "$line" = "" ]]; then continue; fi
		if [[ $num -ne 0 && $i -gt $num ]]; then break; fi
		echo "$line"
		i=$((i+1))
	done < "$queue"
}

addpaper () {
	local id=$1
	filename="$paperdir/$id.pdf"
	if [[ ! -r "$filename" ]]; then
		error "Could not read file $filename"
		return 1
	fi
	echo "$id" >> "$queue"
	message "Added paper:"
	biblong "$id"
}

removepaper () {
	local id=$(get_paper_id "$1")
	if [[ $id ]]; then
		sed -i "/${id}/{d;q}" "$queue"
		message "Removed paper:"
		biblong "$id"
	fi
}

viewpaper () {
	local id=$(get_paper_id "$1")
	if [[ $id ]]; then
		"$view_program" "$paperdir/$id.pdf" &> /dev/null
	fi
}

listpapers () {
	local i=1
	local num=$1
	
	# Width of list numbers (= log_10 of number of list items to show)
	number_width=$(echo "$(echo "l(${num:-$(queuelength)})/l(10)" | bc -l)/1" | bc) 
	# Width of space after numbers (bash counts the color codes as taking up width)
	number_space=$(if [[ $colors ]]; then echo 12; else echo 1; fi) 
	
	for id in $(iterate "${num:=0}"); do
		echo -e "$(printf "%-$((number_width+number_space))b" "$(echo -n $i | gray)") $(bibshort "$id")"
		i=$((i+1))
	done
}

zippapers () {
	local i=1
	local num=$1

	temp=$(mktemp -d)
	for id in $(iterate "${num:=0}"); do
		ln -T "${paperdir}/${id}.pdf" "${temp}/$(printf '%02d\n' "$i")-${id}.pdf"
		i=$((i+1))
	done
	zip -j ./q.zip "$temp"/*
	[[ -d "$temp" ]] && rm -rf "$temp"
}

if [[ $# -eq 0 ]]; then set "$1" "--$default_action"; fi

while [[ $# -gt 0 ]]; do
	opt="$1"; shift; if [[ ! "$1" =~ ^- ]]; then arg="$1"; shift; fi
	case "$opt" in
		'-a'|'--add'   ) addpaper "${arg:?Please specify a filename}" ;;
		'-r'|'--remove') removepaper "$arg"                           ;;
		'-v'|'--view'  ) viewpaper "$arg"                             ;;
		'-b'|'--bib'   ) biblong "$(get_paper_id "$arg")"             ;;
		'-l'|'--list'  ) listpapers "$arg"                            ;;
		'-z'|'--zip'   ) zippapers "$arg"                             ;;
		'-c'|'--count' ) queuelength | gray                           ;;
		'-e'|'--edit'  ) "$EDITOR" "$queue"                           ;;
		'-h'|'--help'  )
			echo "Reading queue"
			echo "Usage: $(basename "$0") [OPTIONS]"
			echo
			echo "  -h, --help         Print this message"
			echo
			echo "  -a, --add ID       Add (enqueue) file with BibTeX key ID to end of queue"
			echo "  -r, --remove [NUM] Remove (dequeue) file from queue (default: first)"
			echo "  -v, --view [NUM]   View file from queue (default: first)"
			echo "  -b, --bib [NUM]    View bibliography entry for file (default: first)"
			echo "  -l, --list [NUM]   List first NUM files (default: all)"
			echo "  -z, --zip [NUM]    Create archive of first NUM files (default: all)"
			echo "  -c, --count        Count files in queue"
			echo "  -e, --edit         Manually edit queue"
			echo
			echo "Options can be used in sequence. With no options, default action is ${default_action}."
			echo "A bare argument is interpreted as a file to be viewed."
			echo "-a completes a file base name with the extension .pdf."
			echo "-v, -b, -r also accept parts of filenames and select the first matching file."
			echo
			exit 0 ;;
		-*) error "Inalid option: $opt" ;;
		[^-]*) viewpaper "$opt" ;;
	esac
done

q_completion.sh

# Completion: Place the following completion file in /etc/bash_completion.d/:
_papers () {
	COMPREPLY=()
	local cur=${COMP_WORDS[COMP_CWORD]}
	local prev=${COMP_WORDS[COMP_CWORD-1]}

	local paperdir=$HOME/Documents/Papers # no trailing slash
	local queue=$HOME/.config/qlist

	if [[ "$cur" = -* ]]; then
		COMPREPLY=( $( compgen -W "-h --help -a --add -r --remove -v --view -b --bib -l --list -z --zip -c --count -e --edit" -- $cur ) )
	else
		case "$prev" in
			-a|--add) COMPREPLY=( $( compgen -W "$(ls "$paperdir" | xargs basename -s '.pdf')" -- $cur ) ) ;;
			-r|--remove|-v|--view|-b|--bib|q) COMPREPLY=( $( compgen -W "$(cat "$queue")" -- $cur ) ) ;;
		esac
	fi

}

complete -F _papers q