module(..., package.seeall)

-- Load libraries
require("posix")
require("json")
require("modelfunctions")
fs = require("acf.fs")

-- Set variables
local packagename = "awall"

local etcpath = "/etc/awall/"
local etcoptionalpath = "/etc/awall/optional/"
local usrpath = "/usr/share/awall/mandatory/"
local usroptionalpath = "/usr/share/awall/optional/"

-- ################################################################################
-- LOCAL FUNCTIONS

local findfiles = function(where)
	local files = {}
	for d in posix.files(where) do
		if string.find(d, "%.json$") then
			if fs.is_file(where .. d) and string.find(d, "%.json$") then
				files[#files+1] = where..d
			elseif fs.is_link(where .. d) then
				-- awall will use links, but we want to drop the links from /etc/awall/ to one of the optional dirs
				-- because those are the ones handled by enable/disable
				local link = posix.dirname(posix.readlink(where..d) or "").."/"
logevent("link = "..link)
				if where == etcpath and (string.find(link, "^"..etcoptionalpath.."$") or string.find(link, "^"..usroptionalpath.."$")) then
					-- do nothing
				else
					files[#files+1] = where..d
				end

			end
		end
	end
	return files
end

local validatefiledetails = function(filedetails)
	local success = true
	local res, err = pcall(function()
        	local jsonoutput, count = json.decode(filedetails.value.filecontent.value)
        end)
	if not res and err then
		success = false
	end

	if not success then
		filedetails.value.filecontent.errtxt = "Invalid json code\n"..(err or "")
	end
	return success, filedetails
end

local validateeditablefile = function(filename)
	-- get/setfiledetails only work for files (not links), this prevents editing/deleting the enable links
	local dir = posix.dirname(filename or "").."/"
	if fs.is_file(filename) and string.find(filename, "%.json$") and (dir==etcpath or dir==etcoptionalpath) then
		return true
	else
		return false
	end
end

-- ################################################################################
-- PUBLIC FUNCTIONS

function getstatus()
	return modelfunctions.getstatus(nil, packagename, "AWall Status")
end

function get_startstop(self, clientdata)
        local actions = {"Verify", "Translate", "Activate"}
	return cfe({ type="group", label="Management", value={}, option=actions })
end

function startstop_service(self, startstop, action)        
	if not action then
		startstop.errtxt = "Invalid Action"
	else
		local cmd = {"awall"}
		if action == "Verify" then
			cmd[#cmd+1] = "translate"
			cmd[#cmd+1] = "-V"
		elseif action == "Translate" then
			cmd[#cmd+1] = "translate"
		else
			cmd[#cmd+1] = "activate"
			cmd[#cmd+1] = "-f"
		end
		startstop.descr, startstop.errtxt = modelfunctions.run_executable(cmd, true)
		if not startstop.errtxt and startstop.descr == "" then
			startstop.descr = "Success"
		end
	end
	return startstop
end

function list_policies()
	-- core-router     disabled  BSN core router
	local policies = {}
	local reversepolicies = {}
	local errtxt
	local f = modelfunctions.run_executable({"awall", "list"}, true)
	for l in string.gmatch(f, "[^\n]+") do
		local a,b,c = string.match(l, "(%S+)%s+(%S+)%s*(.*)")
		if a and a == "/usr/bin/lua:" then
			errtxt = b.." "..c
			break
		end
		if a then
			policies[#policies+1] = {name=a, status=b, description=c}
			reversepolicies[a] = #policies
		end
	end
	-- Since awall seems to crash (and not give results) when there is any error
	-- Let's show the actual files too
	local addfiles = function(files, editable, mandatory)
		for i,d in ipairs(files) do
			local name = string.match(d, "([^/]*)%.json$")
			if reversepolicies[name] then
				policies[reversepolicies[name]].filename = d
				policies[reversepolicies[name]].editable = editable
				if mandatory then policies[reversepolicies[name]].status = "mandatory" end
			else
				policies[#policies+1] = {name=name, filename=d, editable=editable}
				if mandatory then policies[#policies].status = "mandatory" end
				reversepolicies[name] = #policies
			end
		end
	end

	local files = findfiles(usroptionalpath)
	addfiles(files, false, false)
	files = findfiles(etcoptionalpath)
	addfiles(files, true, false)
	files = findfiles(usrpath)
	addfiles(files, false, true)
	files = findfiles(etcpath)
	addfiles(files, true, true)

	table.sort(policies, function(a,b) return a.name < b.name end)

	return cfe({ type="list", value=policies, label="Policies", errtxt=errtxt })
end

function get_newpolicy()
	local newpolicy = {}
	newpolicy.name = cfe({ label="Name", seq=1 })
	newpolicy.optional = cfe({ type="boolean", label="Optional", seq=2 })
	return cfe({ type="group", value=newpolicy, label="New Policy" })
end

function create_policy(self, newpolicy)
	local success = true
	local name = newpolicy.value.name.value

	if name == "" then
		newpolicy.value.name.errtxt = "Invalid name"
		success = false
	else
		local policies = list_policies()
		for i,pol in ipairs(policies.value) do
			if pol.name == newpolicy.value.name.value then
				newpolicy.value.name.errtxt = "Name already exists"
				success = false
				break
			end
		end
	end

	if success then
		local path
		if newpolicy.value.optional.value then
			path = etcoptionalpath
		else
			path = etcpath
		end
		path = path..name..".json"
		if posix.stat(path) then
			newpolicy.value.name.errtxt = path.." already exists"
			success = false
		else
			fs.write_file(path, "{}")
		end
	end

	if not success then
		newpolicy.errtxt = "Failed to create policy file"
	end

	return newpolicy
end

function get_delete_policy(self, clientdata)
	retval = {}
	retval.filename = cfe({ value=clientdata.filename or "", label="File Name" })
	return cfe({ type="group", value=retval, label="Delete Policy File" })
end

function delete_policy(self, delpolicy)
	if validateeditablefile(delpolicy.value.filename.value) then
		os.remove(delpolicy.value.filename.value)
	else
		delpolicy.errtxt = "Failed to delete policy"
		delpolicy.value.filename.errtxt="Policy not found"
	end

	return delpolicy
end

function read_policyfile(self, clientdata)
	-- Can read from all 4 locations
	return modelfunctions.getfiledetails(clientdata.filename, function(filename)
		local dir = posix.dirname(filename or "").."/"
		if string.find(filename, "%.json$") and (dir==etcpath or dir==etcoptionalpath or dir==usrpath or dir==usroptionalpath) then
			return true
		else
			return false
		end
		end)
end

function get_policyfile(self, clientdata)
	-- Can only get (for editing) from /etc/ locations
	return modelfunctions.getfiledetails(clientdata.filename, validateeditablefile)
end

function update_policyfile(self, filedetails)
	return modelfunctions.setfiledetails(self, filedetails, validateeditablefile, validatefiledetails)
end

function get_enablepolicy(self, clientdata)
	local policy = {}
	policy.name = cfe({ value=clientdata.name or "", label="Name", seq=1 })
	return cfe({ type="group", value=policy, label="Policy" })
end

function enable_policy(self, enable)
	enable.descr, enable.errtxt = modelfunctions.run_executable({"awall", "enable", enable.value.name.value}, true)
	return enable
end

function disable_policy(self, disable)
	disable.descr, disable.errtxt = modelfunctions.run_executable({"awall", "disable", disable.value.name.value}, true)
	return disable
end