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

	Part of AREDN -- Used for creating Amateur Radio Emergency Data Networks
	Copyright (C) 2021 Tim Wilkinson
	Original Perl Copyright (C) 2015 Conrad Lara
	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("nixio")
require("aredn.hardware")
require("aredn.http")
require("aredn.utils")
local html = require("aredn.html")
require("uci")
local aredn_info = require("aredn.info")

-- helpers start

function mesh_ip_to_hostnames(ip)
    if not ip or ip == "" or ip == "none" then
        return ""
    end
    local pattern = "^" .. ip .. "%s+([%w%-]+)"
    for line in io.lines("/etc/hosts")
    do
        local host = line:match(pattern)
        if host then
            return host.gsub("%s+", " / ")
        end
    end
    local hosts = ""
    if nixio.fs.stat("/var/run/hosts_olsr.stable") then
        for line in io.lines("/var/run/hosts_olsr.stable")
        do
            local host = line:match(pattern)
            if host then
                hosts = hosts .. " / " .. host
            end
        end
    end
    return hosts:sub(4, #hosts)
end

function get_default_gw()
    -- a node with a wired default gw will route via this
    local p = io.popen("ip route list table 254")
    if p then
        for line in p:lines()
        do
            local gw = line:match("^default%svia%s([%d%.]+)")
            if gw then
                p:close()
                return gw
            end
        end
        p:close()
    end
    -- table 31 is populated by OLSR
    p = io.popen("ip route list table 31")
    if p then
        for line in p:lines()
        do
            local gw = line:match("^default%svia%s([%d%.]+)")
            if gw then
                p:close()
                return gw
            end
        end
        p:close()
    end
    return "none"
end

function get_memavail()
    local f = io.open("/proc/meminfo", "r")
    if f then
        for line in f:lines()
        do
            local memavail = line:match("^MemAvailable:%s+(%d+)%s+kB")
            if memavail then
                f:close()
                return tonumber(memavail)
            end
        end
        f:close()
    end
    return 0
end

function get_wifi_signal(wifiif)
    local signal = -1000
    local noise = -1000
    for mac, station in pairs(iwinfo.nl80211.assoclist(wifiif))
    do
        if station.signal ~= 0 and station.signal > signal then
            signal = station.signal
        end
        if station.noise ~= 0 and station.noise > noise then
            noise = station.noise
        end
    end
    if signal == -1000 or noise == -1000 then
        return "N/A", "N/A"
    else
        return signal, noise
    end
end

function css_options()
    html.print("<option>Select a theme</option>")
    for file in nixio.fs.glob("/www/*.css")
    do
        if file ~= "/www/style.css" then
            file = file:match("/www/(.*).css")
            html.print("<option value=\"" .. file .. ".css\">" .. file .. "</option>")
        end
    end
end

-- helpers end

local node = aredn_info.get_nvram("node")
if node == "" then
    node = "NOCALL"
end
local tactical = aredn_info.get_nvram("tactical")
local config = aredn_info.get_nvram("config")
if config == "" or nixio.fs.stat("/etc/config.mesh", "type") ~= "dir" then
    config = "not set"
end
local wifi_iface = aredn.hardware.get_iface_name("wifi")
local wifi_nr = wifi_iface:match("wlan(%d+)")
local wifi_disabled = true
local radio = "radio0"
if wifi_nr then
    wifi_disabled = false
    radio = "radio" .. wifi_nr
end

local cursor = uci.cursor()

local wifi_channel
local wifi_chanbw
local wifi_ssid
if not wifi_disabled then
    wifi_channel = tonumber(cursor:get("wireless", radio, "channel"))
    if wifi_channel >= 76 and wifi_channel <= 99 then
        wifi_channel = wifi_channel * 5 + 3000
    end
    wifi_chanbw = cursor:get("wireless", radio, "chanbw")
    wifi_ssid = "N/A"
    cursor:foreach("wireless", "wifi-iface",
        function (section)
            if section.network == "wifi" then
                wifi_ssid = section.ssid
                return false
            end
        end
    )
end

local node_desc = cursor:get("system", "@system[0]", "description")
local lat_lon = "<strong>Location Not Available</strong>"
local lat = cursor:get("aredn", "@location[0]", "lat")
local lon = cursor:get("aredn", "@location[0]", "lon")
if lat and lon then
    lat_lon = string.format("<center><strong>Location: </strong> %s %s</center>", lat, lon)
end

local host_total = 0
local host_nodes = 0
if nixio.fs.stat("/var/run/hosts_olsr.stable") then
    for line in io.lines("/var/run/hosts_olsr.stable")
    do
        if line:match("^10%.") and not line:match("%smid%d+%.") then
            host_total = host_total + 1
            local host = line:match("^10%..+%sdtdlink%.")
            if host then
                host_nodes = host_nodes + 1
            end
        end
    end
end

-- post data

if os.getenv("REQUEST_METHOD") == "POST" then
    require('luci.http')
    require('luci.sys')
    local request = luci.http.Request(luci.sys.getenv(),
      function()
        local v = io.read(1024)
        if not v then
            io.close()
        end
        return v
      end
    )
    local css = request:formvalue("css")
    if css and css:match("%.css$") and nixio.fs.stat("/www/" .. css) then
        nixio.fs.unlink("/tmp/web/style.css")
        nixio.fs.symlink("/www/" .. css, "/tmp/web/style.css")
    end
end

-- generate page

http_header()
html.header(node .. " status", true)
html.print("<body><form method='post' action='/cgi-bin/status' enctype='multipart/form-data'>")
html.print("<center>")

html.alert_banner()
html.msg_banner()

-- page header
html.print("<h1><big>" .. node)
if tactical ~= "" then
    html.print(" / " .. tactical)
end
html.print("</big></h1>")
html.print("<center>" .. lat_lon .. "</center>")
if node_desc then
    html.print("<table id='node_description_display'><tr><td>" .. node_desc .. "</td></tr></table>")
end
html.print("<hr>")

-- nav buttons
html.print("<nobr>")
html.print("<a href='/help.html' target='_blank'>Help</a>")
html.print("&nbsp;&nbsp;")
html.print("<input type=submit name=refresh value=Refresh title='Refresh this page'>")
if config == "mesh" then
    html.print("&nbsp;&nbsp;")
    html.print("<button type=button onClick='window.location=\"mesh\"' title='See what is on the mesh'>Mesh Status</button>")
    if cursor:get("aredn", "@lqm[0]", "enable") == "1" then
        html.print("&nbsp;&nbsp;")
        html.print("<button type=button onClick='window.location=\"lqm\"' title='See the link status to our neighbors'>Neighbor Status</button>")
    end
    if not wifi_disabled then
        html.print("&nbsp;&nbsp;")
        html.print("<button type=button onClick='window.location=\"scan\"' title='See what wireless networks are nearby'>WiFi Scan</button>")
    end
end
html.print("&nbsp;&nbsp")
html.print("<button type=button onClick='window.location=\"setup\"' title='Configure this node'>Setup</button>")
html.print("&nbsp;&nbsp;")
html.print("<select name=\"css\" size=\"1\" onChange=\"form.submit()\" >")
css_options()
html.print("</select>")
html.print("</nobr")

html.print("<input type=hidden name=reload value=reload>")

if config == "not set" then
    html.print("<b><br><br>This node is not yet configured.<br>")
    html.print("Go to the setup page and set your node name and password.<br>")
    html.print("Click Save Changes, <u>even if you didn't make any changes</u>, then the node will reboot.</b>")
    html.print("<br><br>")
    html.print("<div style=\"max-width: 540px\; text-align: left\">")
    html.print("<p>This device can be configured to either permit or prohibit known encrypted traffic on its RF link. It is up to the user to decide which is appropriate based on how it will be used and the license under which it will be operated. These rules vary by country, frequency, and intended use. You are encouraged to read and understand these rules before going further.</p>")
    html.print("<p>This device is pre-configured with no restrictions as to the type of data being passed.</p>")
    html.print("<p>Follow these steps if <span style=\"text-decoration: underline\">you wish to prohibit</span>  known encrypted traffic on the RF link. These instructions will disappear, so copy them for your reference:</p>")
    html.print("<p><ol>")
    html.print("<li>Setup your node name and password as instructed at the top of this page</li>")
    html.print("<li>After you Save Changes allow your node to reboot</li>")
    html.print("<li>Return to the Node Status page and navigate to Setup &gt Administration</li>")
    html.print("<li>Obtain the blockknownencryption package from the AREDN&trade; website OR refresh the Package list (node must be connected to the internet)</li>")
    html.print("<li>Install the blockknownencryption package by uploading it or choosing it from the package drop-down list</li>")
    html.print("<li>Wait until the package installs and then reboot your node</li>")
    html.print("</ol></p>")
    html.print("</div>")
end

-- status display

local col1 = {}
local col2 = {}

-- left column - network interface info

local ip = cursor:get("network", "wifi", "ipaddr")
local cidr = netmask_to_cidr(cursor:get("network", "wifi", "netmask"))
if wifi_disabled then
    col1[#col1 + 1] = "<th align=right><nobr>Primary address</nobr></th><td>" .. ip .. " <small>/ " .. cidr .. "</small><br>"
else
    col1[#col1 + 1] = "<th align=right><nobr>Wifi address</nobr></th><td>" .. ip .. " <small>/ " .. cidr .. "</small><br>"
end

ip = cursor:get("network", "lan", "ipaddr")
mask = cursor:get("network", "lan", "netmask")
local browser_ip
local remote_ip = os.getenv("REMOTE_ADDRESS")
if remote_ip then
    remote_ip = remote_ip.match("::ffff:([%d%.]+)")
end
local hide_local = false
if remote_ip then
    browser_ip = remote_ip
    if not validate_same_subnet(remote_ip, ip, mask) then
        hide_local = true
    end
end

if ip:match("^10%.") or not hide_local then
    cidr = netmask_to_cidr(mask)
    col1[#col1 + 1] = "<th align=right><nobr>LAN address</nobr></th><td>" .. ip .. " <small>/ " .. cidr .. "</small><br>"
end

local wan_iface = aredn.hardware.get_iface_name("wan")
if not hide_local and wan_iface then
    local ip, bcast, mask = aredn.hardware.get_interface_ip4(wan_iface)
    local wprefix = ""
    if wan_iface:match("^wlan%d+$") then
        wprefix = "WiFi "
    end
    if ip then
        cidr = netmask_to_cidr(mask)
        col1[#col1 + 1] = "<th align=right><nobr>" .. wprefix .. "WAN address</nobr></th><td>" .. ip .. " <small>/ " .. cidr .. "</small><br>"
    else
        col1[#col1 + 1] = "<th align=right><nobr>" .. wprefix .. "WAN address</nobr></th><td>none</small><br>"
    end
end

ip = get_default_gw()
if ip:match("^10%.") or not hide_local then
    col1[#col1 + 1] = "<th align=right><nobr>default gateway</nobr></th><td>" .. ip
    if ip:match("^10%.") then
        col1[#col1] = col1[#col1] .. "<br><nobr>" ..  mesh_ip_to_hostnames(ip) .. "</nobr>"
    end
    col1[#col1] = col1[#col1] .. "</td>"
end

if browser_ip then
    col1[#col1 + 1] = "<th align=right><nobr>your address</nobr></th><td>" .. browser_ip .. "<br><nobr>" ..  mesh_ip_to_hostnames(browser_ip) .. "</nobr></td>"
end

if not wifi_disabled then
    col1[#col1 + 1] = "<th align=right><nobr>SSID</nobr></th><td>" .. wifi_ssid .. "</td>"
    col1[#col1 + 1] = "<th align=right><nobr>Channel</nobr></th><td>" .. wifi_channel .. "</td>"
    col1[#col1 + 1] = "<th align=right><nobr>Bandwidth</nobr></th><td>" .. wifi_chanbw .. " MHz</td>"
end

-- right column - system info

if config == "mesh" and not wifi_disabled then
    col2[#col2 + 1] = "<th align=right valign=middle><nobr>Signal/Noise/Ratio</nobr></th><td valign=middle><nobr>"
    local s, n = get_wifi_signal(wifi_iface)
    if s == "N/A" then
        col2[#col2] = col2[#col2] .. "N/A"
    else
        col2[#col2] = col2[#col2] .. "<big><b>" .. s .. " / " .. n .. " / " .. math.abs(s - n) .. " dB</b></big>"
    end
    col2[#col2] = col2[#col2] .. "&nbsp;&nbsp;&nbsp;<button type=button onClick='window.location=\"signal?realtime=1\"' title='Display continuous or archived signal strength on a chart'>Charts</button></nobr></td>"
end

col2[#col2 + 1] = "<th align=right><nobr>firmware version</nobr><br><nobr>model</nobr></th><td>" .. read_all("/etc/mesh-release") .. "<br>" .. (aredn.hardware.get_radio() or { name = "unknown" }).name .. "</td>";

local sysinfo = nixio.sysinfo()
local uptime = string.format("%d:%02d", math.floor(sysinfo.uptime / 3600) % 24, math.floor(sysinfo.uptime / 60) % 60)
if sysinfo.uptime >= 172800 then
    uptime = math.floor(sysinfo.uptime / 86400) .. " days, " .. uptime
elseif sysinfo.uptime >= 86400 then
    uptime = "1 day, " .. uptime
end
col2[#col2 + 1] = "<th align=right><nobr>system time</nobr><br>uptime</th><td>" .. os.date("%a %b %e %Y") .. "&nbsp;" .. os.date("%T %Z") .. "<br>" .. uptime .. "</td>";

local vfs = nixio.fs.statvfs("/overlay")
local fspace = vfs.bfree * vfs.bsize / 1024
if fspace < 100 then
    fspace = "<blink><b>" .. fspace .. " KB</b></blink>"
else
    fspace = fspace .. " KB"
end

local rspace = sysinfo.freeram / 1024
local mavail = get_memavail()
if rspace < mavail then
    rspace = mavail
end

if rspace < 500 then
    rspace = "<blink><b>" .. rspace .. " KB</b></blink>"
else
    rspace = rspace .. " KB"
end

col2[#col2 + 1] = "<th align=right valign=top><nobr>load average</nobr><br><nobr>available space</nobr></th><td>" .. string.format("%.2f, %.2f, %.2f", sysinfo.loads[1], sysinfo.loads[2], sysinfo.loads[3]) .. "<br><nobr>flash = " .. fspace .. "</nobr><br><nobr>memory = " .. rspace .. "</nobr></td>";
col2[#col2 + 1] = "<th align=right valign=top>Host Entries</th><td><nobr>Total = " .. host_total .. "</nobr><br><nobr>Nodes = " .. host_nodes .. "<nobr></td>"

-- now print the tables

html.print("<br><br><table>")
html.print("<tr><td valign=top><table cellpadding=4>")
for i, line in ipairs(col1)
do
    html.print("<tr>" .. line .. "</tr>")
end
html.print("</table></td><td valign=top><table cellpadding=4>")
for i, line in ipairs(col2)
do
    html.print("<tr>" .. line .. "</tr>")
end
html.print("</table></td></tr></table>")

-- end
html.print("</center></form>")

html.footer()
html.print("</body></html>")