local sys = require "luci.sys"
local util = require "luci.util"
local fs = require "nixio.fs"
local dispatcher = require "luci.dispatcher"
local i18n = require "luci.i18n"
local uci = require("luci.model.uci").cursor()

local packageName = "https-dns-proxy"
local providers_dir = "/usr/lib/lua/luci/" .. packageName .. "/providers/"
local helperText = ""

function getPackageVersion()
	local opkgFile = "/usr/lib/opkg/status"
	local line
	local flag = false
	for line in io.lines(opkgFile) do
		if flag then
			return line:match('[%d%.$-]+') or ""
		elseif line:find("Package: " .. packageName:gsub("%-", "%%%-")) then
			flag = true
		end
	end
	return ""
end

function createHelperText()
	local initText = "<br />" .. translate("For more information on different options check") .. " "
	for filename in fs.dir(providers_dir) do
		local p_func = loadfile(providers_dir .. filename)
		setfenv(p_func, { _ = i18n.translate })
		local p = p_func()
		if p.help_link then
			local url, domain
			url = p.help_link
			domain = p.help_link_text or url:match('^%w+://([^/]+)')
			if not helperText:find(domain) then
				if helperText == "" then
					helperText = initText
				else
					helperText = helperText .. ", "
				end
				helperText = helperText .. [[<a href="]] .. url .. [[" target="_blank">]] .. domain .. [[</a>]]
			end
		end
	end
	if helperText ~= "" then
		local a = helperText:gsub('(.*),%s.*$', '%1')
		helperText = a .. " " .. translate("and") .. helperText:sub(#a + 2) .. "."
	end
end

function getProviderName(value)
	for filename in fs.dir(providers_dir) do
		local p_func = loadfile(providers_dir .. filename)
		setfenv(p_func, { _ = i18n.translate })
		local p = p_func()
		value = value:gsub('[%p%c%s]', '')
		p.url_match = p.resolver_url:gsub('[%p%c%s]', '')
		if value:match(p.url_match) then
			return p.label
		end
	end
	return translate("Unknown Provider")
end

local packageStatus, packageStatusCode
local ubusStatus = util.ubus("service", "list", { name = packageName })
local packageVersion = getPackageVersion()

if packageVersion == "" then
	packageStatusCode = -1
	packageStatus = translatef("%s is not installed or not found", packageName)
else  
	if not ubusStatus or not ubusStatus[packageName] then
		packageStatusCode = 0
		packageStatus = translate("Stopped")
		if not sys.init.enabled(packageName) then
			packageStatus = packageStatus .. " (" .. translate("disabled") .. ")"
		end
	else
		packageStatusCode, packageStatus = 1, ""
		for n = 1,1000 do
			if ubusStatus and ubusStatus[packageName] and 
				 ubusStatus[packageName]["instances"] and 
				 ubusStatus[packageName]["instances"]["instance" .. n] and 
				 ubusStatus[packageName]["instances"]["instance" .. n]["running"] then
				local value, k, v, url, url_flag, la, la_flag, lp, lp_flag
				for k, v in pairs(ubusStatus[packageName]["instances"]["instance" .. n]["command"]) do
					if la_flag then la, la_flag = v, false end
					if lp_flag then lp, lp_flag = v, false end
					if url_flag then url, url_flag = v, false end
					if v == "-a" then la_flag = true end
					if v == "-p" then lp_flag = true end
					if v == "-r" then url_flag = true end
				end
				la = la or "127.0.0.1"
				lp = lp or n + 5053
				packageStatus = packageStatus .. translatef("Running: %s DoH at %s:%s", getProviderName(url), la, lp) .. "\n"
			else
				break
			end
		end
	end
end

m = Map("https-dns-proxy", translate("DNS HTTPS Proxy Settings"))

h = m:section(TypedSection, "_dummy", translatef("Service Status [%s %s]", packageName, packageVersion))
h.template = "cbi/nullsection"
ss = h:option(DummyValue, "_dummy", translate("Service Status"))
if packageStatusCode == -1 then
	ss.template = packageName .. "/status"
	ss.value = packageStatus
else
		if packageStatusCode == 0 then
			ss.template = packageName .. "/status"
		else
			ss.template = packageName .. "/status-textarea"
		end
	ss.value = packageStatus
	buttons = h:option(DummyValue, "_dummy")
	buttons.template = packageName .. "/buttons"
end

createHelperText()
s3 = m:section(TypedSection, "https-dns-proxy", translate("Instances"), 
	translatef("When you add/remove any instances below, they will be used to override the 'DNS forwardings' section of %sDHCP and DNS%s.", "<a href=\"" .. dispatcher.build_url("admin/network/dhcp") .. "\">", "</a>") .. helperText)
s3.template = "cbi/tblsection"
s3.sortable  = false
s3.anonymous = true
s3.addremove = true

prov = s3:option(ListValue, "resolver_url", translate("Resolver"))
for filename in fs.dir(providers_dir) do
	local p_func = loadfile(providers_dir .. filename)
	setfenv(p_func, { _ = i18n.translate })
	local p = p_func()
	prov:value(p.resolver_url, p.label)
	if p.default then
		prov.default = p.resolver_url
	end
end
prov.forcewrite = true
prov.write = function(self, section, value)
	if not value then return end
	for filename in fs.dir(providers_dir) do
		local p_func = loadfile(providers_dir .. filename)
		setfenv(p_func, { _ = i18n.translate })
		local p = p_func()
		value = value:gsub('[%p%c%s]', '')
		p.url_match = p.resolver_url:gsub('[%p%c%s]', '')
		if value:match(p.url_match) then
			uci:set(packageName, section, "bootstrap_dns", p.bootstrap_dns)
			uci:set(packageName, section, "resolver_url", p.resolver_url)
		end
	end
	uci:save(packageName)
end

la = s3:option(Value, "listen_addr", translate("Listen address"))
la.datatype    = "host"
la.placeholder = "127.0.0.1"
la.rmempty     = true

local n = 0
uci:foreach(packageName, packageName, function(s)
		if s[".name"] == section then
				return false
		end
		n = n + 1
end)

lp = s3:option(Value, "listen_port", translate("Listen port"))
lp.datatype = "port"
lp.value    = n + 5053

ps = s3:option(Value, "proxy_server", translate("Proxy server"))
ps.rmempty  = true

return m