local u = require("util.utils")
local l = require("logger")
local uci = require("uci").cursor()

local M = {}
local reconf = {}
local wifi
local reloadSilent

M.WWW_CAPTIVE_PATH = "/usr/share/lua/wifibox/www"
M.WWW_CAPTIVE_INDICATOR = "/www/.wifibox-inplace"
M.WWW_RENAME_NAME = "/www-regular"



local function reloadBit(dlist, itemname)
	if dlist[itemname] == nil then dlist[itemname] = "" end
	if dlist[itemname] == "" then dlist[itemname] = "r"
	elseif dlist[itemname] == "c" then dlist[itemname] = "b"
	end
end
local function commitBit(dlist, itemname)
	if dlist[itemname] == nil then dlist[itemname] = "" end
	if dlist[itemname] == "" then dlist[itemname] = "c"
	elseif dlist[itemname] == "r" then dlist[itemname] = "b"
	end
end
local function bothBits(dlist, itemname) dlist[itemname] = "b" end



function M.init(wifiInstance, reloadSilent)
	wifi = wifiInstance
	silent = reloadSilent or false
	return true
end

--- Switch configuration between AP and station modes
-- @param components	a table with components as keys with operations as values (add or remove)
-- Valid components (each with add and rm operation) are: apnet, staticaddr, dhcppool, wwwredir, dnsredir, wwwcaptive, natreflect.
-- and additionally: wifiiface/add, network/reload
function M.switchConfiguration(components)
	local dirtyList = {} -- laundry list, add config/script name as key with value c (commit), r (reload) or b (both)
	
	for k,v in pairs(components) do
		local fname = k .. "_" .. v
		if type(reconf[fname]) == "function" then
			l:debug("reconfiguring component '" .. k .. "' (" .. v .. ")")
			reconf[fname](dirtyList)
		else
			l:warn("unknown component or action '" .. fname .. "' skipped")
		end
	end
	
	-- first run all commits, then perform reloads
	for k,v in pairs(dirtyList) do
		if v == "c" or v == "b" then M.commitComponent(k) end
	end
	for k,v in pairs(dirtyList) do
		if v == "r" or v == "b" then M.reloadComponent(k, silent) end
	end
end

function M.commitComponent(c)
	l:info("committing component '" .. c .. "'")
	uci:commit(c)
end

function M.reloadComponent(c, silent)
	l:info("reloading component '" .. c .. "'")
	if silent ~= nil and silent then os.execute("/etc/init.d/" .. c .. " reload &> /dev/null")
	else os.execute("/etc/init.d/" .. c .. " reload") end
end

function M.uciTableSet(config, section, options)
	for k, v in pairs(options) do uci:set(config, section, k, v) end
end



--[[ Issue '/etc/init.d/network reload' command ]]
function reconf.network_reload(dirtyList) reloadBit(dirtyList, "network") end

--[[ Issue '/etc/init.d/wireless reload' command ]]
function reconf.wireless_reload(dirtyList) reloadBit(dirtyList, "wireless") end

--[[ Add wlan interface declaration to /etc/config/network ]]
function reconf.wifiiface_add(dirtyList)
	uci:set("network", wifi.NET, "interface")
	commitBit(dirtyList, "network")
end


--[[ Add/remove access point network ]]
function reconf.apnet_add_noreload(dirtyList) reconf.apnet_add(dirtyList, true) end
function reconf.apnet_add(dirtyList, noReload)
	local sname = nil
	uci:foreach("wireless", "wifi-iface", function(s)
		if s.ssid == wifi.AP_SSID then sname = s[".name"]; return false end
	end)
	if sname == nil then sname = uci:add("wireless", "wifi-iface") end
	
	M.uciTableSet("wireless", sname, {
		network = wifi.NET,
		ssid = wifi.AP_SSID,
		encryption = "none",
		device = "radio0",
		mode = "ap",
	})
	
	commitBit(dirtyList, "wireless")
	if noReload == nil or noReload == false then reloadBit(dirtyList, "network") end
end
function reconf.apnet_rm(dirtyList)
	local sname = nil
	uci:foreach("wireless", "wifi-iface", function(s)
		if s.ssid == wifi.AP_SSID then sname = s[".name"]; return false end
	end)
	if sname == nil then return l:info("AP network configuration does not exist, nothing to remove") end
	uci:delete("wireless", sname)
	reloadBit(dirtyList, "network"); commitBit(dirtyList, "wireless")
end


--[[ Switch between wireless static IP and DHCP ]]
function reconf.staticaddr_add(dirtyList)
	uci:set("network", wifi.NET, "interface")
	--TODO: remove ifname on wlan interface?
	--NOTE: 'type = "bridge"' should -not- be added as this prevents defining a separate dhcp pool (http://wiki.openwrt.org/doc/recipes/routedap)
	M.uciTableSet("network", wifi.NET, {
		proto = "static",
		ipaddr = wifi.AP_ADDRESS,
		netmask = wifi.AP_NETMASK
	})
	bothBits(dirtyList, "network")
end
--TODO: replace repeated deletes by M.uciTableDelete
function reconf.staticaddr_rm(dirtyList)
	uci:set("network", wifi.NET, "interface")
	uci:set("network", wifi.NET, "proto", "dhcp")
	uci:delete("network", wifi.NET, "ipaddr")
	uci:delete("network", wifi.NET, "netmask")
	--uci:delete("network", wifi.NET, "type") --do not remove since it is not added anymore
	bothBits(dirtyList, "network")
end


--[[ Add/remove DHCP pool for wireless net ]]
function reconf.dhcppool_add(dirtyList)
	uci:set("dhcp", wifi.NET, "dhcp") --create section
	M.uciTableSet("dhcp", wifi.NET, {
		interface = wifi.NET,
		start = "100",
		limit = "150",
		leasetime = "12h",
	})
	commitBit(dirtyList, "dhcp"); reloadBit(dirtyList, "dnsmasq")
end
function reconf.dhcppool_rm(dirtyList)
	uci:delete("dhcp", wifi.NET)
	commitBit(dirtyList, "dhcp"); reloadBit(dirtyList, "dnsmasq")
end


--[[ Add/remove webserver 404 redirection and denial of dirlisting ]]
function reconf.wwwredir_add(dirtyList)
	uci:set("uhttpd", "main", "error_page", "/admin/autowifi.html")
	uci:set("uhttpd", "main", "no_dirlist", "1")
	bothBits(dirtyList, "uhttpd")
end
function reconf.wwwredir_rm(dirtyList)
	uci:delete("uhttpd", "main", "error_page")
	uci:delete("uhttpd", "main", "no_dirlist")
	bothBits(dirtyList, "uhttpd")
end


--[[ Add/remove redirecton of all DNS requests to self ]]
function reconf.dnsredir_add(dirtyList)
	local redirText = "/#/" .. wifi.AP_ADDRESS
	local sname = u.getUciSectionName("dhcp", "dnsmasq")
	if sname == nil then return l:error("dhcp config does not contain a dnsmasq section") end
	if uci:get("dhcp", sname, "address") ~= nil then return l:debug("DNS address redirection already in place, not re-adding", false) end
	
	uci:set("dhcp", sname, "address", {redirText})
	commitBit(dirtyList, "dhcp"); reloadBit(dirtyList, "dnsmasq")
end
function reconf.dnsredir_rm(dirtyList)
	local sname = u.getUciSectionName("dhcp", "dnsmasq")
	if sname == nil then return l:error("dhcp config does not contain a dnsmasq section") end
	
	uci:delete("dhcp", sname, "address")
	commitBit(dirtyList, "dhcp"); reloadBit(dirtyList, "dnsmasq")
end


--TODO: handle os.rename() return values (nil+msg on error)
function reconf.wwwcaptive_add(dirtyList)
	if u.exists(M.WWW_CAPTIVE_INDICATOR) then
		return l:debug("WWW captive directory already in place, not redoing", false)
	end
	local rv,reason = os.rename("/www", M.WWW_RENAME_NAME)
	if rv == true then
		u.symlink(M.WWW_CAPTIVE_PATH, "/www")
		return true
	else
		return l:error("Could not rename /www to " .. M.WWW_RENAME_NAME .. "(" .. reason .. ")")
	end
end
function reconf.wwwcaptive_rm(dirtyList)
	if not u.exists(M.WWW_CAPTIVE_INDICATOR) then return l:debug("WWW captive directory not in place, not undoing", false) end
	os.remove("/www")
	if os.rename(M.WWW_RENAME_NAME, "/www") ~= true then
		return l:error("Could not rename " .. M.WWW_RENAME_NAME .. " to /www")
	end
	return true
end


--[[ Setup/remove NAT reflection to redirect all IPs ]]
function reconf.natreflect_add(dirtyList)
	uci:set("firewall", "portalreflect", "redirect");
	M.uciTableSet("firewall", "portalreflect", {
		src = "lan",
		proto = "tcp",
		src_dport = "80",
		dest_port = "80",
		dest_ip = wifi.AP_ADDRESS,
		target = "DNAT"
	})
	bothBits(dirtyList, "firewall")
end
function reconf.natreflect_rm(dirtyList)
	uci:delete("firewall", "portalreflect")
	bothBits(dirtyList, "firewall")
end

return M