--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- default-rsync.lua
--
--    Syncs with rsync ("classic" Lsyncd)
--    A (Layer 1) configuration.
--
-- Note:
--    this is infact just a configuration using Layer 1 configuration
--    like any other. It only gets compiled into the binary by default.
--    You can simply use a modified one, by copying everything into a
--    config file of yours and name it differently.
--
-- License: GPLv2 (see COPYING) or any later version
-- Authors: Axel Kittenberger <axkibe@gmail.com>
--
--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


if not default then
	error( 'default not loaded' )
end


if default.rsync then
	error( 'default-rsync already loaded' )
end


local rsync = { }
default.rsync = rsync

-- uses default collect

--
-- used to ensure there aren't typos in the keys
--
rsync.checkgauge = {

	-- unsets default user action handlers
	onCreate    =  false,
	onModify    =  false,
	onDelete    =  false,
	onStartup   =  false,
	onMove      =  false,

	delete      =  true,
	exclude     =  true,
	excludeFrom =  true,
	target      =  true,

	rsync  = {
		acls              =  true,
		archive           =  true,
		binary            =  true,
		bwlimit           =  true,
		checksum          =  true,
		compress          =  true,
		copy_links        =  true,
		cvs_exclude       =  true,
		dry_run           =  true,
		executability     =  true,
        group             =  true,
		hard_links        =  true,
		ignore_times      =  true,
		ipv4              =  true,
		ipv6              =  true,
		keep_dirlinks     =  true,
		links             =  true,
		one_file_system   =  true,
		owner             =  true,
		password_file     =  true,
		perms             =  true,
		protect_args      =  true,
		prune_empty_dirs  =  true,
		quiet             =  true,
		rsh               =  true,
		rsync_path        =  true,
		sparse            =  true,
		temp_dir          =  true,
		timeout           =  true,
        times             =  true,
		update            =  true,
		verbose           =  true,
        whole_file        =  true,
		xattrs            =  true,
		_extra            =  true,
	},
}


--
-- Spawns rsync for a list of events
--
-- Exlcusions are already handled by not having
-- events for them.
--
rsync.action = function( inlet )

	--
	-- gets all events ready for syncing
	--
	local elist = inlet.getEvents(
		function(event)
			return event.etype ~= 'Init' and event.etype ~= 'Blanket'
		end
	)

	--
	-- Replaces what rsync would consider filter rules by literals
	--
	local function sub( p )
		if not p then
			return
		end

		return p:
			gsub( '%?', '\\?' ):
			gsub( '%*', '\\*' ):
			gsub( '%[', '\\[' ):
			gsub( '%]', '\\]' )
	end

	--
	-- Gets the list of paths for the event list
	--
	-- Deletes create multi match patterns
	--
	local paths = elist.getPaths(
		function( etype, path1, path2 )
			if string.byte( path1, -1 ) == 47 and etype == 'Delete' then
				return sub( path1 )..'***', sub( path2 )
			else
				return sub( path1 ), sub( path2 )
			end
		end
	)

	--
	-- stores all filters by integer index
	--
	local filterI = { }

	--
	-- Stores all filters with path index
	--
	local filterP = { }

	--
	-- Adds one path to the filter
	--
	local function addToFilter( path )

		if filterP[ path ] then
			return
		end

		filterP[ path ] = true

		table.insert( filterI, path )
	end

	--
	-- Adds a path to the filter.
	--
	-- Rsync needs to have entries for all steps in the path,
	-- so the file for example d1/d2/d3/f1 needs following filters:
	-- 'd1/', 'd1/d2/', 'd1/d2/d3/' and 'd1/d2/d3/f1'
	--
	for _, path in ipairs( paths ) do

		if path and path ~= '' then

			addToFilter(path)

			local pp = string.match( path, '^(.*/)[^/]+/?' )

			while pp do
				addToFilter(pp)
				pp = string.match( pp, '^(.*/)[^/]+/?' )
			end

		end

	end

	local filterS = table.concat( filterI, '\n'   )
	local filter0 = table.concat( filterI, '\000' )

	log(
		'Normal',
		'Calling rsync with filter-list of new/modified files/dirs\n',
		filterS
	)

	local config = inlet.getConfig( )
	local delete = nil

	if config.delete == true or config.delete == 'running' then
		delete = { '--delete', '--ignore-errors' }
	end

	spawn(
		elist,
		config.rsync.binary,
		'<', filter0,
		config.rsync._computed,
		'-r',
		delete,
		'--force',
		'--from0',
		'--include-from=-',
		'--exclude=*',
		config.source,
		config.target
	)

end


--
-- Spawns the recursive startup sync
--
rsync.init = function(event)

	local config   = event.config
	local inlet    = event.inlet
	local excludes = inlet.getExcludes( )
	local delete   = nil
	local target   = config.target

	if not target then
		if not config.host then
			error('Internal fail, Neither target nor host is configured')
		end

		target = config.host .. ':' .. config.targetdir
	end

	if config.delete == true or config.delete == 'startup' then
		delete = { '--delete', '--ignore-errors' }
	end

	if #excludes == 0 then
		-- start rsync without any excludes
		log(
			'Normal',
			'recursive startup rsync: ',
			config.source,
			' -> ',
			target
		)

		spawn(
			event,
			config.rsync.binary,
			delete,
			config.rsync._computed,
			'-r',
			config.source,
			target
		)

	else
		-- start rsync providing an exclude list
		-- on stdin
		local exS = table.concat( excludes, '\n' )

		log(
			'Normal',
			'recursive startup rsync: ',
			config.source,
			' -> ',
			target,
			' excluding\n',
			exS
		)

		spawn(
			event,
			config.rsync.binary,
			'<', exS,
			'--exclude-from=-',
			delete,
			config.rsync._computed,
			'-r',
			config.source,
			target
		)
	end
end


--
-- Prepares and checks a syncs configuration on startup.
--
rsync.prepare = function(
	config,    -- the configuration
	level,     -- additional error level for inherited use ( by rsyncssh )
	skipTarget -- used by rsyncssh, do not check for target
)

	--
	-- First let default.prepare test the checkgauge
	--
	default.prepare( config, level + 6 )

	if not skipTarget and not config.target then
		error(
			'default.rsync needs "target" configured',
			level
		)
	end

	if config.rsyncOps then
		error(
			'"rsyncOps" is outdated please use the new rsync = { ... } syntax.',
			level
		)
	end

	if config.rsyncOpts and config.rsync._extra then
		error(
			'"rsyncOpts" is outdated in favor of the new rsync = { ... } syntax\n"' +
			'for which you provided the _extra attribute as well.\n"' +
			'Please remove rsyncOpts from your config.',
			level
		)
	end

	if config.rsyncOpts then
		log(
			'Warn',
			'"rsyncOpts" is outdated. Please use the new rsync = { ... } syntax."'
		)

		config.rsync._extra = config.rsyncOpts
		config.rsyncOpts = nil
	end

	if config.rsyncBinary and config.rsync.binary then
		error(
			'"rsyncBinary is outdated in favor of the new rsync = { ... } syntax\n"'+
			'for which you provided the binary attribute as well.\n"' +
			"Please remove rsyncBinary from your config.'",
			level
		)
	end

	if config.rsyncBinary then
		log(
			'Warn',
			'"rsyncBinary" is outdated. Please use the new rsync = { ... } syntax."'
		)

		config.rsync.binary = config.rsyncBinary
		config.rsyncOpts = nil
	end

	-- checks if the _computed argument exists already
	if config.rsync._computed then
		error(
			'please do not use the internal rsync._computed parameter',
			level
		)
	end

	--
	-- computes the rsync arguments into one list
	--
	local crsync = config.rsync;

	--
	-- everything implied by archive = true
	--
	local archiveFlags = {
		recursive   =  true,
		links       =  true,
		perms       =  true,
		times       =  true,
		group       =  true,
		owner       =  true,
		devices     =  true,
		specials    =  true,
		hard_links  =  false,
		acls        =  false,
		xattrs      =  false,
	}

	--
	-- if archive given the implications are filled in
	--
	if crsync.archive then
		for k, v in pairs( archiveFlags ) do
			if crsync[ k ] == nil then
				crsync[ k ] = v
			end
		end
	end


	crsync._computed = { true }
	local computed = crsync._computed
	local computedN = 2

	local shortFlags = {
		acls               = 'A',
		checksum           = 'c',
		compress           = 'z',
		copy_links         = 'L',
		cvs_exclude        = 'C',
		dry_run            = 'n',
		executability      = 'E',
        group              = 'g',
		hard_links         = 'H',
		ignore_times       = 'I',
		ipv4               = '4',
		ipv6               = '6',
		keep_dirlinks      = 'K',
		links              = 'l',
		one_file_system    = 'x',
		owner              = 'o',
		perms              = 'p',
		protect_args       = 's',
		prune_empty_dirs   = 'm',
		quiet              = 'q',
		sparse             = 'S',
        times              = 't',
		update             = 'u',
		verbose            = 'v',
        whole_file         = 'W',
		xattrs             = 'X',
	}

	local shorts = { '-' }
	local shortsN = 2

	if crsync._extra then
		for k, v in ipairs( crsync._extra ) do
			computed[ computedN ] = v
			computedN = computedN  + 1
		end
	end

	for k, flag in pairs( shortFlags ) do
		if crsync[ k ] then
			shorts[ shortsN ] = flag
			shortsN = shortsN + 1
		end
	end

	if crsync.devices and crsync.specials then
			shorts[ shortsN ] = 'D'
			shortsN = shortsN + 1
	else
		if crsync.devices then
			computed[ computedN ] = '--devices'
			computedN = computedN  + 1
		end

		if crsync.specials then
			computed[ computedN ] = '--specials'
			computedN = computedN  + 1
		end
	end
	
	if crsync.bwlimit then
		computed[ computedN ] = '--bwlimit=' .. crsync.bwlimit
		computedN = computedN  + 1
	end

	if crsync.password_file then
		computed[ computedN ] = '--password-file=' .. crsync.password_file
		computedN = computedN  + 1
	end

	if crsync.rsh then
		computed[ computedN ] = '--rsh=' .. crsync.rsh
		computedN = computedN  + 1
	end

	if crsync.rsync_path then
		computed[ computedN ] = '--rsync-path=' .. crsync.rsync_path
		computedN = computedN  + 1
	end

	if crsync.temp_dir then
		computed[ computedN ] = '--temp-dir=' .. crsync.temp_dir
		computedN = computedN  + 1
	end

	if crsync.timeout then
		computed[ computedN ] = '--timeout=' .. crsync.timeout
		computedN = computedN  + 1
	end

	if shortsN ~= 2 then
		computed[ 1 ] = table.concat( shorts, '' )
	else
		computed[ 1 ] = { }
	end

	-- appends a / to target if not present
	if not skipTarget and string.sub(config.target, -1) ~= '/' then
		config.target = config.target..'/'
	end

end


--
-- By default do deletes.
--
rsync.delete = true

--
-- Rsyncd exitcodes
--
rsync.exitcodes  = default.rsyncExitCodes

--
-- Calls rsync with this default options
--
rsync.rsync = {
	-- The rsync binary to be called.
	binary        = '/usr/bin/rsync',
	links         = true,
	times         = true,
	protect_args  = true
}


--
-- Default delay
--
rsync.delay = 15