#!/usr/bin/lua
--[[

	Part of AREDN -- Used for creating Amateur Radio Emergency Data Networks
	Copyright (C) 2018 Darryl Quinn
	See Contributors file for additional contributors

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation version 3 of the License.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.	If not, see <http://www.gnu.org/licenses/>.

	Additional Terms:

	Additional use restrictions exist on the AREDN(TM) trademark and logo.
		See AREDNLicense.txt for more info.

	Attributions to the AREDN Project must be retained in the source code.
	If importing this code into a new or existing project attribution
	to the AREDN project must be added to the source code.

	You must not misrepresent the origin of the material contained within.

	Modified versions must be modified to attribute to the original source
	and be marked in reasonable ways as differentiate it from the original
	version

--]]

require("uci")
require("aredn.uci")
require("aredn.utils")
require("aredn.http")
local aredn_olsr = require("aredn.olsr")
local aredn_info = require("aredn.info")
require("nixio")
local json = require("luci.jsonc")
require("iwinfo")
local nettools = require("aredn.nettools")

local API_VERSION="1.5"

-- Function extensions
os.capture = capture


function getSysinfo()
	local info={}
	info['api_version']=API_VERSION
	info['node']=aredn_info.getNodeName()
	info['tactical']=aredn_info.getTacticalName()
	info['description']=aredn_info.getNodeDescription()
	info['firmware_version']=aredn_info.getFirmwareVersion()
	info['model']=aredn_info.getModel()
	--
	info['date']=aredn_info.getDate()
	info['time']=aredn_info.getTime()
	--
	info['uptime']=aredn_info.getUptime()
	info['loads']=aredn_info.getLoads()
	info['first_boot']=aredn_info.getFirstBoot()
	info['target_type']=aredn_info.getTargetType()
	return info
end

function getAlerts()
	local info={}
	info['aredn']=aredn_info.getArednAlert()
	info['local']=aredn_info.getLocalAlert()
	return info
end

function getStatusMeshRF()
	local info={}
	local dev = aredn_info.getMeshRadioDevice()
	if dev ~= "" then
		info['device']= dev
		info['ssid']=aredn_info.getSSID()
		info['channel']=aredn_info.getChannel(info['device'])
		info['chanbw']=aredn_info.getChannelBW(info['device'])
		info['band']=aredn_info.getBand(info['device'])
		info['frequency']=aredn_info.getFreq(info['device'])
	end
	return info
end

function getStatusIp()
	local info={}
	info['gateway']=aredn_info.getDefaultGW()
	info['wifi']=aredn_info.getInterfaceIPAddress('wifi')
	info['lan']=aredn_info.getInterfaceIPAddress('lan')
	info['wan']=aredn_info.getInterfaceIPAddress('wan')
	return info
end

function getLocationInfo()
	local info={}
	local lat, lon= aredn_info.getLatLon()
	local gs= aredn_info.getGridSquare()
	info['lat']=lat
	info['lon']=lon
	info['gridsquare']=gs
	return info
end

function getFreeMemory()
	local info = aredn_info.getFreeMemory()
	return info
end


function get_key_for_value( t, value )
  for k,v in pairs(t) do
    if v==value then return k end
  end
  return nil
end

function getRemoteNodes()
	local info = {}
	local neighbors = {}
	for _, v in ipairs(aredn_olsr.getOLSRLinks())
	do
		local remoteIP = v.remoteIP
		neighbors[remoteIP] = true
		local name = nixio.getnameinfo(remoteIP)
		if name then
			local cname = name:match("^dtdlink%.(.*)$") or name:match("^mid%d+%.(.*)$")
			if cname then
				local addrs = nixio.getaddrinfo(cname)
				if addrs then
					neighbors[addrs[1].address] = true
				end
			end
		end
	end
	local routeetx = {}
	for _, v in ipairs(aredn_olsr.getOLSRRoutes())
	do
		routeetx[v.destination] = string.format("%.2f", v.etx)
	end
	for line in io.lines("/var/run/hosts_olsr.stable")
	do
		local ip, hostname = line:match("^(%d+%.%d+%.%d+%.%d+)%s+(%S+)%s+#.*$")
		if ip and not neighbors[ip] and not (hostname:match("^dtdlink%.") or hostname:match("^mid%d+%.")) then
			local etx = routeetx[ip]
			if etx then
				info[#info + 1] = {
					name = hostname,
					ip = ip,
					etx = etx
				}
			end
		end
	end
	table.sort(info, function(a,b) return tonumber(a.etx) < tonumber(b.etx) end)
	return info
end

-- gets signal and noise data from either iwinfo (realtime = true) or the files archived in /tmp/snrlog (realtime = false)
-- the files in /tmp/snrlog are written once per minute by the script /usr/local/bin/snrlog
function getSignal(realtime)
	local defnoise=-95
	local dpa={}  -- datapoint table/array
	local dirname="/tmp/snrlog"

	local datepattern="(%d+)/(%d+)/(%d+)%s(%d+):(%d+):(%d+)"

	local parms={}
	parms=parsecgi(nixio.getenv("QUERY_STRING") or "")

	-- make sure snrlog dir is created
	if dir_exists(dirname) then
		nixio.fs.mkdir(dirname)
	end

	-- get wifi ifname
	local wifiiface=get_ifname("wifi")

	-- get bandwidth
	local radio=aredn_info.getMeshRadioDevice()
	local bandwidth=aredn_info.getChannelBW(radio)

	local timestamp_s=os.time()
	local signal_dbm, noise_dbm, tx_rate_mbps, rx_rate_mbps, tx_rate_mcs_index, rx_rate_mcs_index

	--[[
		-- insertResult() transforms data from iwinfo (realtime) and snrlog (archive) so that the responses are always the same.
		-- the front end expects data points that look like this:
		{
			timestamp: string;
			signal_dbm: number;
			noise_dbm: number;
			tx_rate_mbps: number;
			rx_rate_mbps: number;
			tx_rate_mcs_index: number | undefined;
			rx_rate_mcs_index: number | undefined;
		}
	]]--

	function insertResult(timestamp_s_epoch, signal_dbm, noise_dbm, tx_rate_mbps, rx_rate_mbps, tx_rate_mcs_index, rx_rate_mcs_index)
		local dp={} -- datapoint
		local timestamp

		-- snrlog sometimes has the string "null" for signal/noise, if so then assume they are zero
		if signal_dbm=="null" then
			signal_dbm = -95
		end
		if noise_dbm=="null" then
			noise_dbm = -95
		end

		-- signal and noise might also be nil, so convert them to numbers
		signal_dbm = tonumber(signal_dbm or -95)
		noise_dbm = tonumber(noise_dbm or -95)

		--snrlog sometimes has -1 for mcs indices, if so then make them undefined
		if tx_rate_mcs_index == -1 or tx_rate_mcs_index == "-1" then
			tx_rate_mcs_index = nil
		end
		if rx_rate_mcs_index == -1 or rx_rate_mcs_index == "-1" then
			rx_rate_mcs_index = nil
		end

		-- convert from seconds since epoch to iso 8601 format
		timestamp=os.date("%Y-%m-%dT%H:%M:%SZ", timestamp_s_epoch)

		dp.timestamp = timestamp
		dp.signal_dbm=signal_dbm
		dp.noise_dbm=noise_dbm
		dp.tx_rate_mbps=tonumber(tx_rate_mbps or 0)
		dp.rx_rate_mbps=tonumber(rx_rate_mbps or 0)
		dp.tx_rate_mcs_index=tonumber(tx_rate_mcs_index)
		dp.rx_rate_mcs_index=tonumber(rx_rate_mcs_index)
		table.insert(dpa,dp)
	end

	if realtime then
		-- REALTIME
		if (parms.device=="strongest" or parms.device=="" or (not parms.device)) then
			-- REALTIME/STRONGEST SIGNAL
			signal_dbm=iwinfo["nl80211"].signal(wifiiface)
			noise_dbm=iwinfo["nl80211"].noise(wifiiface)
		else
			-- REALTIME/SPECIFIC SIGNAL
			-- split out device to mac-host
			local mac,host=string.match(parms.device,"([^-]*)-(.*)")
			local macinfo=iwinfo["nl80211"].assoclist(wifiiface)[mac:upper()]
			if macinfo then
				signal_dbm=macinfo.signal
				noise_dbm=macinfo.noise
				tx_rate_mbps=macinfo.tx_rate/1000
				tx_rate_mbps=adjust_rate(tx_rate_mbps,bandwidth)
				rx_rate_mbps=macinfo.rx_rate/1000
				rx_rate_mbps=adjust_rate(rx_rate_mbps,bandwidth)
				tx_rate_mcs_index=macinfo.tx_mcs
				rx_rate_mcs_index=macinfo.rx_mcs
			end
		end
		insertResult(timestamp_s, signal_dbm, noise_dbm, tx_rate_mbps, rx_rate_mbps, tx_rate_mcs_index, rx_rate_mcs_index )
	else
		-- ARCHIVE
		local filename
		if not parms.device or parms.device=="" then
			-- get the first file from dirlist
			for maclist in nixio.fs.glob(dirname.."/".."*") do
				filename=maclist
				parms.device=maclist
				break
			end
		else
			filename=dirname.."/"..parms.device
		end

		if filename then
			for line in io.lines(filename) do
				local timestamp
				timestamp,signal_dbm,noise_dbm,tx_rate_mcs_index,tx_rate_mbps,rx_rate_mcs_index,rx_rate_mbps=line:match("(.*)%,(.*)%,(.*),(.*),(.*),(.*),(.*)")

				-- convert the timestamp to seconds since epoch
				local dtm,dtd,dty,dth,dtmin,dts=timestamp:match(datepattern)
				timestamp_s = os.time({month=dtm,day=dtd,year=dty,hour=dth,min=dtmin,sec=dts})

				insertResult(timestamp_s, signal_dbm, noise_dbm, tx_rate_mbps, rx_rate_mbps, tx_rate_mcs_index, rx_rate_mcs_index)
			end
		end
	end
	return dpa
end

function getScanList()
	local device = aredn_info.getMeshRadioDevice()
	local scanlist = iwinfo["nl80211"].scanlist(device)
	return scanlist
end

function getFreqList()
	local device = aredn_info.getMeshRadioDevice()
	local freqlist = iwinfo["nl80211"].freqlist(device)
	return freqlist
end

-- ==== MAIN =====
ctx = uci.cursor()
if not ctx then
	error("Failed to get uci cursor")
end

info={}
info['api_version'] = API_VERSION

-- get/process query string
local qsset={}
if (arg[1]==nil and arg[2]==nil) then
	qs=nixio.getenv("QUERY_STRING")
	if qs~="" then
		qsset=parseQueryString(qs)
	else
		-- maybe default to a help page
		qsset["api"]="help"
	end
else
	qsset[arg[1]]=arg[2]
end

info['pages']={}

for page, comps in pairs(qsset) do
	-- ---------------- /mesh page
	if not setContains(info['pages'],page) then
		info['pages'][page]={}
	end

	if page=="api" then
		info['pages'][page]=nil
		info['api_help']="AREDN API. This API's primary function is to drive the Web UI."
	elseif page=="common" then
		for i,comp in pairs(comps:split(',')) do
			if comp=="sysinfo" then
				info['pages'][page][comp]=getSysinfo()
			elseif comp=="alerts" then
				info['pages'][page][comp]=getAlerts()
			end
		end
	elseif page=="status" then
		for i,comp in pairs(comps:split(',')) do
			if comp=="meshrf" then
				info['pages'][page][comp]=getStatusMeshRF()
			elseif comp=="ip" then
				info['pages'][page][comp]=getStatusIp()
			elseif comp=="sysinfo" then
				info['pages'][page][comp]=getSysinfo()
			elseif comp=="memory" then
				info['pages'][page][comp]=getFreeMemory()
			elseif comp=="storage" then
				info['pages'][page][comp]=aredn_info.getFSFree()
			elseif comp=="olsr" then
				info['pages'][page][comp]=aredn_info.getOLSRInfo()
			elseif comp=="location" then
				info['pages'][page][comp]=getLocationInfo()
			elseif comp=="freqlist" then
				info['pages'][page][comp]=getFreqList()
			elseif comp=="alerts" then
				info['pages'][page][comp]=getAlerts()
			end
		end
	elseif page=="traceroute" then
		for i,tonode in pairs(comps:split(',')) do
			-- Validate that input as ip or hostname inside the mesh
			if tonode:match("^[%d%.]+$") or tonode:match("^[%d%a%-%.%_]+$") then
				info['pages'][page][tonode]=nettools.getTraceroute(tonode)
			else
				info['pages'][page][tonode]="Invalid input!"
			end
		end
	elseif page=="ping" then
		for i,tonode in pairs(comps:split(',')) do
			-- Validate that input as ip or hostname inside the mesh
			if tonode:match("^[%d%.]+$") or tonode:match("^[%d%a%-%.%_]+$") then
				info['pages'][page][tonode]=nettools.getPing(tonode)
			else
				info['pages'][page][tonode]="Invalid input!"
			end
		end
	elseif page=="iperf3" then
		local protocol = "tcp"
		for i,tonode in pairs(comps:split(',')) do
			-- Validate that input as ip or hostname inside the mesh
			if tonode == "tcp" or tonode == "udp" then
				protocol = tonode
			elseif tonode:match("^[%d%.]+$") or tonode:match("^[%d%a%-%.%_]+$") then
				info['pages'][page][tonode]=nettools.getIperf3(tonode, protocol)
			else
				info['pages'][page][tonode]="Invalid input!"
			end
		end
	elseif page=="mesh" then
		for i,comp in pairs(comps:split(',')) do
			if comp=="sysinfo" then
				info['pages'][page][comp]=getSysinfo()
			elseif comp=="allhosts" then
				info['pages'][page][comp]=aredn_info.all_hosts()
			elseif comp=="localhosts" then
				info['pages'][page][comp]=aredn_info.getLocalHosts()
			elseif comp=="remotenodes" then
				info['pages'][page][comp]=getRemoteNodes()
			elseif comp=="currentneighbors" then
				info['pages'][page][comp]=aredn_olsr.getCurrentNeighbors(true)
			elseif comp=="services" then
				info['pages'][page][comp]=aredn_info.all_services()
			elseif comp=="previousneighbors" then
				info['pages'][page][comp]={}
			elseif comp=="topology" then
				info['pages'][page][comp]=fetch_json("http://127.0.0.1:9090/topology")
			end
		end
	elseif page=="services" then
		for i,comp in pairs(comps:split(',')) do
			if comp=="sysinfo" then
				info['pages'][page][comp]=getSysinfo()
			elseif comp=="bynode" then
				info['pages'][page][comp]=getServicesByNode()
			elseif comp=="byservice" then
				info['pages'][page][comp]=getServicesByService()
			end
		end
	elseif page=="chart" then
		for i,comp in pairs(comps:split(',')) do
			if comp=="realtime" then
				info['pages'][page][comp]=getSignal(true)
			elseif comp=="archive" then
				info['pages'][page][comp]=getSignal(false)
			end
		end
	elseif page=="scan" then
		for i,comp in pairs(comps:split(',')) do
				if comp=="scanlist" then
					info['pages'][page][comp]=getScanList()
				end
		end
	end
end

-- Output the HTTP header for JSON
-- json_header()
json_header()

-- Output the info table as json
print(json.stringify(info,true))