#!/bin/sh
# Author: Jens Getreu
# 16.2.2016
# license: MIT

### CONFIGURATION SECTION START

LaunchViewer () {
	# WARNING: if the environment variable ADOC_VIEWER is defined
	# the following code is never executed!
	
	# Note: we need & at the end of the line!
	# Uncomment one line only!
	# Chromium Asciidoctor-plugin follows your changes without "reload".
	#chromium "file:///$1" &
	# Alternative:
	#chrome "file:///$1" &
	# Extra package needed for this example: apt-get install uni2ascii
	#chromium "--app=file:$(echo "$1"|uni2ascii -aJ)" &
	# Press "reload current page" in firefox to see your changes.
	firefox  "file:///$1" &
	# If your editor has an integrated viewer (like Atom)
	# do not uncomment any line above, but we need this:
	return 0
}

LaunchEditor () {
	# WARNING: if the environment variable ADOC_EDITOR is defined
	# the following code is never executed!

	# Note there is no & in this function. The editor should not fork!
	# Uncomment one line only!

	# Very simple Linux editor.
	leafpad "$1"
	# Linux geany. Optional: enable autosave in geany's save plugin.
	#geany "$1"
	# Alternatively run gvim.
	#gvim --nofork "$1"
	return 0
}

### CONFIGURATION SECTION END



Readlink () {
	# Path=$(readlink -f "$1") # not available in busybox
	# We actually only need absolute paths so the following will do.
	local Path
	Path="$(echo "$(cd "$(dirname "$1")" && pwd -P)"/"$(basename "$1")")"
	# return global variable
	Readlink="$Path"
}




Main () {
	if  [ "-h" = "$1" ]; then
		echo "\n${0} creates, edits or views an asciidoc note."
		echo "\nusage:"
		echo "\n   $_ [-h][-ro|-so|-eo] | [<File.adoc>|<Dir>|<File>]"
		echo "\n<Dir>|<File>: directory where the new note file will be created"
		echo "(current directory if none)."
		echo "If <File> is given a new adoc note will be created next to that file."
		echo "If <File.adoc> is given the file is edited."
		echo "Filename of <File> is changed when not in sync with title."
		echo "\nOptions:"
		echo "-ro\tDo not open editor, open viewer only."
		echo "-eo\tDo not open viewer, only new note or, sync filename and edit."
		echo "-so\tDo not open editor or viewer, only new note or sync filename."
		exit 0
	fi

	local Path
	local Option
	if  [ "-ro" = "$1" ] || [ "-so" = "$1" ] || [ "-eo" = "$1" ] ; then
		Option="$1"
		Readlink "$2"
	else
		Option=""
		Readlink "$1"
	fi
	Path="$Readlink"


	# If file extension is not .adoc then create a new note.
	if [ ! -n "$Path" ] || \
	 [ !  "$(echo "$Path"|awk -F . '{print $NF}')" = "adoc" ]  ; then
		AdocNewNote "$Path"  || exit 1
		Path="$AdocNewNote"
	fi

	if [ -f "$Path" ] ; then
		if  [ ! "-ro" = "$Option" ] ; then
			SyncFilename "$Path"
			Path="$SyncFilename"
		fi
		if  [ ! "-eo" = "$Option" ] && \
			[ ! "-so" = "$Option" ] ; then
			AdocView "$Path"
		fi
		if  [ ! "-ro" = "$Option" ] && \
			[ ! "-so" = "$Option" ] ; then
			AdocEdit "$Path"
			SyncFilename "$AdocEdit"
			Path="$SyncFilename"
		fi
		echo "$Path"
		exit 0
	else
		echo "Error: Can not open '$Path'." >&2
		exit 1
	fi
}

SanitizeFilename () {
	# line 1:   tab -> space
	# line 2:   Delete control characters.
	# line 3:   :\\/|?~,;=   ->  _
	# line 4:
	#   Exclude NTFS critical characters:       <>:"\\/|?*
	#   https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247%28v=vs.85%29.aspx
	#   Exclude restricted in fat32:        +,;=[]
	#   https://en.wikipedia.org/wiki/Filename#Reserved_characters_and_words
	#   These are considered unsafe in URLs:    <>#%{}|\^~[]`
	#   https://perishablepress.com/stop-using-unsafe-characters-in-urls/
	# line 5:   Strip all until the first alpha char at the beginning
	#       and all spaces and _ at the end of the line.
	# line 6:   Remove spaces and _ before and after --.
	# Return global variable
	SanitizeFilename="$(echo "$1"| \
		tr -s '[:blank:]'   ' '| \
		tr -d '[:cntrl:]' | \
		tr -s ':\\/|?~,;='   '_'| \
		tr -s '<>:"\\/|?*<>#%{}|\^~[]+,;=[]`[:blank:]'    ' '| \
		sed -e 's/[[:blank:]_]*\(.*\)/\1/g; s/[[:blank:]_]*$//g' \
			-e 's/[[:blank:]_]*--[[:blank:]_]*/--/g'
		)"
}


SyncFilename () {
	# Pathname of the asciidoc-file
	local Path
	Path="$1"

	# Change filename according to the title in the
	# first line of the .adoc file.
	
	# Extract title from the first line of the .adoc file
	local FirstLine
	FirstLine="$(head -n 1 "$Path")" || exit 1
	local Title
	# line 1: stream string
	# line 2: omit BOM and =
	# line 3: splitt title and subtitle, then concat with -- in between
	Title="$(echo "$FirstLine" | \
			sed -e 's/[^=]*=[[:blank:]]*\(.*\)/\1/' \
				-e 's/:[[:blank:]]*$//g; s/\(.*\):\(.*\)/\1--\2/g' )"
	# A title was found when Title <> FirstLine
	if [ ! "$FirstLine" = "$Title" ] ; then

		# extract leading numbers including "-" and "_"
		# example  "20150912-hallo.adoc" -> "20150912-"
		# example  "01-abstract.adoc" -> "01-"
		# example  "04-01_03-abstract.adoc" -> "04-01_03-"
		# example  "hallo02-abstract.adoc" -> ""
		local BaseName
		BaseName="$(basename "$Path")"
		local LeadingNumbers
		LeadingNumbers="$(echo "$BaseName" | \
			sed -e 's/\([[:digit:]_-]*\)\(.*\)/\1/')"
		# if no leading numbers found the following equals
		if [ "$BaseName" = "$LeadingNumbers" ] ; then
			LeadingNumbers="" #no leading no. found
		fi

		# Substitute special chars with _
		SanitizeFilename "$Title"
		local FileTitle
		FileTitle="$(echo "$SanitizeFilename"|
				sed -e 's/\([[:digit:]_-]*\)\(.*\)/\2/')"

		# Construct new name
		local DirName
		DirName="$(dirname "$Path")"
		local NewPath="${DirName}/${LeadingNumbers}${FileTitle}.adoc"
		mv -n "$Path" "$NewPath" >/dev/null 2>&1
		Path="$NewPath"
	fi

	# Return global variable
	SyncFilename="$Path"
}




AdocNewNote () {
	local Suffix="Notes"
	local TitleSuffix=" : $Suffix"
	local FileSuffix="--$Suffix"
	local Dir
	local Basename
	local DocRef
	local NewFileName
	if [ -n "$1" ] && [ -f "$1" ] ; then
		Dir="$(dirname "$1")"
		Basename="$(basename "$1")"
		DocRef="Annotations on file: link:++$Basename++[]"
		SanitizeFilename "$Basename"
		NewFileName="$Dir/${SanitizeFilename}${FileSuffix}.adoc"
	elif [ -n "$1" ] && [ -d "$1" ] ; then
		Dir="$1"
		Basename="$(basename "$1")"
		DocRef=""
		# omit leading numbers, "-" and "_"
		Basename="$(echo "$Basename"| \
			sed -e 's/\([[:digit:]_-]*\)\(.*\)/\2/')"
		SanitizeFilename "$Basename"
		NewFileName="$Dir/$(date +%Y%m%d)-${SanitizeFilename}${FileSuffix}.adoc"
	else
		Dir="$(pwd)"
		Basename="$(basename "$Dir")"
		DocRef=""
		# omit leading numbers, "-" and "_"
		Basename="$(echo "$Basename"| \
			sed -e 's/\([[:digit:]_-]*\)\(.*\)/\2/')"
		SanitizeFilename "$Basename"
		NewFileName="$Dir/$(date +%Y%m%d)-${SanitizeFilename}${FileSuffix}.adoc"
	fi
	local Datestr
	Datestr="$(date +%x)"

	if  [ ! -e "$NewFileName" ] ; then

		# Create new file according to template (with unicode BOM)
		printf  "\357\273\277= ${Basename}${TitleSuffix}
$USER
v1.0, $Datestr
:numbered!:
:toc!:
:pagenums:

$DocRef

" > "$NewFileName"

	else
		echo "$NewFileName already exists. No new document created.">&2
	fi
	# return global variable
	AdocNewNote="$NewFileName"
}




AdocEdit () {
	AdocEdit="$1"
	if [ -n "$ADOC_EDITOR" ]; then
		"$ADOC_EDITOR" "$AdocEdit"
	else
		LaunchEditor "$AdocEdit"
	fi
	# Return global variable AdocEdit
}




AdocView () {
	AdocView="$1"
	if [ -n "$ADOC_VIEWER" ]; then
		"$ADOC_VIEWER" "$ADOC_VIEWER_OPT$AdocView" &
	else
		LaunchViewer "$AdocView"
	fi
	# Return global variable AdocView
}



Main "$1" "$2"