-- acf model for /etc/network/interfaces
-- Copyright(c) 2007 N. Angelacos - Licensed under terms of GPL2
local mymodule = {}

modelfunctions = require("modelfunctions")
fs = require("acf.fs")
format = require("acf.format")

local servicename = "networking"
local interfacesfile = "/etc/network/interfaces"

local array

-- iface is a local table with cfes for the various parts of interface definitions
-- Depending on the address family and corresponding method, different options are valid
local iface = require("alpine-baselayout/interfaces-definitions")

local followlink = function(path)
	local where = path
	while fs.is_link(where) do
		local link = posix.readlink(where)
		if link and not string.find(link, "^/") then
			link = posix.dirname(where).."/"..link
		end
		where = link
	end
	return where
end

local filename = followlink(interfacesfile)

-- Create an interface structure with all options
local get_blank_iface = function ()
	local f =  {}
	for name,table in pairs(iface.required) do
		f[name] = cfe(table)
	end

	for name,table in pairs(iface.optional) do
		f[name] = cfe(table)
	end

	return cfe({ type="group", value=f, label="Interface description" })
end

-- Get a reverse list of options valid for a given family / method
local get_options = function (family, method)
	local optional = {}
	if iface.method_options[family] and iface.method_options[family][method] then
		for i,o in ipairs(iface.method_options[family][method]) do
			optional[o] = true
		end
	end
	return optional
end

-- return the index of array entry matching "name"
local arrayindex = function (name)
	if name and #name > 0  then
		if array == nil then
			unpack_interfaces ()
		end

		for k,v in ipairs(array) do
			if name == v.value.name.value then
				return k
			end
		end
	end

	return nil
end

local appendentry  = function (self, value, prefix)
	self = self or ""
	-- if we already have some values, then append a newline
	if #self > 0  then self = self .. "\n" end
	-- strip the prefix
	local str = string.gsub(value, "^" .. ( prefix or "" ), "")
	-- and append
	return self .. str
end

local expandentry = function (self, prefix)
	if #self == 0 then
		return ""
	end
	-- force the string to end in a single linefeed
	self = string.gsub (self, "\r", "")
	self = string.gsub (self, "[\n]*$", "\n")
	local strings = {}
	for line in string.gmatch(self, "(.-)\n") do
		if #line > 0 then
			strings[#strings+1] = prefix .. line
		end
	end
	return table.concat(strings, "\n")
end

-- This function parses the interfaces file and creates array
local unpack_interfaces = function ()
	if array == nil then
		local filecontent = fs.read_file(filename) or ""
		-- make sure it has a terminating \n
		filecontent  = string.gsub (filecontent, "([^\n])$", "%1\n")

		array = {}
		local comment = ""
		local auto = {}

		for line in string.gmatch ( filecontent, "%s*([^\n]*%S)%s*\n?") do
			-- it can be #, auto, iface, or a parameter
			if string.match(line, "^#") then
				comment = appendentry(comment, line , "#%s*" )
			elseif string.match(line, "^auto") then
				local name = string.match(line, "auto%s+(%S+)")
				auto[name] = true
			elseif string.match(line, "^iface") then
				local name, family, method = string.match(line, "%S+%s+(%S+)%s+(%S+)%s+(%S+)")
				array[#array + 1] = get_blank_iface()
				local interface = array[#array].value
				interface.comment.value = comment
				comment = ""
				interface.name.value = name or ""
				interface.family.value = family or ""
				interface.method.value = method or ""
			elseif #array > 0 then
				-- it must be some kind of parameter
				local param, val =
					string.match(line, "(%S+)%s*(.*)$")
				if (param) then
					local interface = array[#array].value
					if comment ~= "" then
						interface.comment.value = appendentry(interface.comment.value, comment)
						comment = ""
					end
					if not (interface[param]) then
						interface.other.value = appendentry(interface.other.value, param.." "..val)
					else
						interface[param].value = appendentry(interface[param].value, val)
					end
				end
			end
		end
		for i,int in ipairs(array) do
			if auto[int.value.name.value] then
				int.value.auto.value = true
			end
		end
	end

	return array
end

-- This function takes array and writes the interfaces file (only writing options valid for the family/method combo)
local commit_interfaces = function()
	local str = ""
	local strings = {}
	local required = {}
	for name,value in pairs(iface.required) do
		-- Check for the ones handled by other means
		if name~="comment" and name~="name" and name~="family" and name~="method" and name~="auto" and name~="other" then
			required[name] = true
		end
	end
	for n,int in ipairs(array) do
		local me = int.value
		if me.comment.value ~= "" then
			strings[#strings+1] = expandentry(me.comment.value, "# ")
		end
		if me.auto.value then
			strings[#strings+1] = "auto " .. me.name.value
		end
		strings[#strings+1] = string.format("iface %s %s %s", me.name.value,
						me.family.value, me.method.value)
		local optional = get_options(me.family.value, me.method.value)
		for name,entry in pairs(me) do
			if (required[name] or optional[name]) and entry.value ~= "" then
				strings[#strings+1] = expandentry(entry.value, "\t"..name.." ")
			end
		end
		if me.other.value ~= "" then
			strings[#strings+1] = expandentry(me.other.value, "\t")
		end
		strings[#strings+1] = ""
	end

	local filecontent = table.concat(strings, "\n")
	fs.write_file(filename, filecontent)
end

-- Validate the interface (assuming valid family / method, will only validate the appropriate options)
local validate_interface = function (def)
	local success = true
	local optional = {}

	-- since the structure is different depending on the family and method, check them first
	success = modelfunctions.validateselect(def.value.family) and success
	success = modelfunctions.validateselect(def.value.method) and success
	if success then
		-- Validate the method (given the family)
		local method = cfe(iface.required.method)
		method.value = def.value.method.value
		method.option = {}
		if iface.family_methods[def.value.family.value] then
			method.option = iface.family_methods[def.value.family.value]
		end
		if not modelfunctions.validateselect(method) then
			def.value.method.errtxt = "Invalid method for this address family"
			success = false
		end

		-- Determine the list of valid options
		optional = get_options(def.value.family.value, def.value.method.value)
	end

	if #def.value.name.value == 0 then
		def.value.name.errtxt = "The interface must have a name"
		success = false
	elseif string.find(def.value.name.value, "%s") then
		def.value.name.errtxt = "Cannot contain spaces"
		success = false
	end

	-- More validation tests go here ---
	-- for optional fields, first check optional[name] to see if it should be validated

	if not success then
		def.errtxt = "Failed validation"
	end

	return success
end

local list_interfaces = function()
	local output = {}
	unpack_interfaces()
	for i,int in ipairs(array) do
		output[#output+1] = int.value.name.value
	end
	table.sort(output)
	return output
end

-------------------------------------------------------------------------------
-- Public Methods
-------------------------------------------------------------------------------

mymodule.get_all_interfaces = function(self, clientdata)
	unpack_interfaces()
	return cfe({ type="group", value=array, label="Interfaces" })
end

mymodule.get_iface_by_name = function(self, clientdata)
	-- if the name is blank, then return a blank iface with error
	local ret
	unpack_interfaces()
	local idx = arrayindex(clientdata.name or "")
	if not idx then
		ret = get_blank_iface()
		ret.value.name.value = name
		ret.value.name.errtxt = "Interface does not exist"
	else
		ret = array[idx]
	end
	ret.value.name.readonly = true
	return ret
end

mymodule.get_iface = function(self, clientdata)
	return get_blank_iface()
end

mymodule.create_iface = function(self, def)
	unpack_interfaces()
	local success = validate_interface( def )

	if success then
		idx = #array
		table.insert( array, idx+1, def )
		commit_interfaces()
	else
		def.errtxt = "Failed to create interface"
	end

	return def
end

mymodule.update_iface = function(self, def)
	unpack_interfaces()
	-- if the def by that name doesn't exist, fail
	local success
	local idx = arrayindex(def.value.name.value or "" )
	if not idx then
		def.value.name.errtxt = "This is an invalid interface name"
		success = false
	else
		success = validate_interface( def )
	end

	if success then
		array[idx] = def
		commit_interfaces()
	else
		def.errtxt = "Failed to update interface"
	end

	return def
end

mymodule.get_delete_iface_by_name = function(self, clientdata)
	local result = {}
	result.name = cfe({ type="select", value=clientdata.name or "", label="Interface Name", option=list_interfaces() })

	return cfe({ type="group", value=result, label="Interface Name" })
end

mymodule.delete_iface_by_name = function(self, deleterequest)
	local success = modelfunctions.validateselect(deleterequest.value.name)

	if success then
		unpack_interfaces()
		local idx = arrayindex(deleterequest.value.name.value)
		if idx then
			table.remove (array, idx )
			commit_interfaces()
			deleterequest.descr = "Interface deleted"
		else
			deleterequest.errtxt = "Interface not found"
		end
	else
		deleterequest.errtxt = "Failed to delete interface"
	end

	return deleterequest
end

mymodule.get_status = function ()
	local status = {}
	status.filename = cfe({ value=filename, label="Interfaces file" })
	status.iproute = cfe({ type="longtext", label="ip route" })
	status.ipaddr = cfe({ type="longtext", label="ip addr" })
	status.iptunnel = cfe({ type="longtext", label="ip tunnel" })

	if not fs.is_file(filename) then
		status.filename.errtxt = "File not found"
	end

	status.iproute.value, status.iproute.errtxt = modelfunctions.run_executable({"ip", "route"})
	status.ipaddr.value, status.ipaddr.errtxt = modelfunctions.run_executable({"ip", "addr"})
	status.iptunnel.value, status.iptunnel.errtxt = modelfunctions.run_executable({"ip", "tunnel"})

	return cfe({ type="group", value=status, label="Interfaces Status" })
end

mymodule.get_file = function ()
	return modelfunctions.getfiledetails(filename)
end

mymodule.write_file = function (self, newfile)
	array = nil
	return modelfunctions.setfiledetails(self, newfile, {filename})
end

mymodule.get_interfaces = function()
	local ipaddr = modelfunctions.run_executable({"ip", "addr"})
	-- now parse the result to find the interfaces
	local retval = {}
	for line in string.gmatch(ipaddr, "[^\n]*\n?") do
		if string.find(line, "^%d+:%s+") then
			local interface=string.match(line, "^%d+:%s+([^:@]+)")
			retval[#retval+1] = interface
		end
	end
	return cfe({ type="list", value=retval, label="IP Interfaces" })
end

mymodule.get_addresses = function()
	local ipaddr = modelfunctions.run_executable({"ip", "addr"})
	-- now parse the result to find the interfaces and IP addresses
	local retval = {}
	local interface
	for line in string.gmatch(ipaddr, "[^\n]*\n?") do
		if string.find(line, "^%d+:%s+") then
			interface=string.match(line, "^%d+:%s+([^:@]+)")
		elseif string.find(line, "^%s*inet%s") then
			table.insert(retval, {interface=interface, ipaddr=string.match(line, "^%s*inet%s+([%d%.]+)")})
		end
	end
	return cfe({ type="structure", value=retval, label="Interface IP Addresses" })
end

mymodule.get_ifup_by_name = function(self, clientdata)
	local result = {}
	result.name = cfe({ type="select", value=clientdata.name or "", label="Interface Name", option=list_interfaces() })

	return cfe({ type="group", value=result, label="Interface Name" })
end

mymodule.ifup_by_name = function (self, ifuprequest)
	local success = modelfunctions.validateselect(ifuprequest.value.name)
	if success then
		name = ifuprequest.value.name.value or ""
		ifuprequest.descr, ifuprequest.errtxt = modelfunctions.run_executable({"ifup", name}, true)

		if not ifuprequest.errtxt and ifuprequest.descr == "" then
			ifuprequest.descr = "Interface up"
		end
	else
		ifuprequest.errtxt = "Failed ifup"
	end

	return ifuprequest
end

mymodule.get_ifdown_by_name = function(self, clientdata)
	local result = {}
	result.name = cfe({ type="select", value=clientdata.name or "", label="Interface Name", option=list_interfaces() })

	return cfe({ type="group", value=result, label="Interface Name" })
end

mymodule.ifdown_by_name = function (self, ifdownrequest)
	local success = modelfunctions.validateselect(ifdownrequest.value.name)
	if success then
		name = ifdownrequest.value.name.value or ""
		ifdownrequest.descr, ifdownrequest.errtxt = modelfunctions.run_executable({"ifdown", name}, true)

		if not ifdownrequest.errtxt and ifdownrequest.descr == "" then
			ifdownrequest.descr = "Interface down"
		end
	else
		ifdownrequest.errtxt = "Failed ifup"
	end

	return ifdownrequest
end

mymodule.get_restartnetworking = function(self, clientdata)
	local actions = {}
	actions[1] = "restart"
	local service = cfe({ type="hidden", value=servicename, label="Service Name" })
	local startstop = cfe({ type="group", label="Restart Networking", value={servicename=service}, option=actions, descr="WARNING!!! Restarting networking may cause the ACF web interface to stop functioning. Try refreshing this page after restarting. If that fails, you may have to use terminal access to recover." })

	return startstop
end

mymodule.restartnetworking = function(self, startstop)
	return modelfunctions.startstop_service(startstop, "restart")
end

return mymodule