-- Webserver
local configFile="config.lua"
local httpSending=false
local sentBytes=0
function sendPage(conn, nameOfFile, replaceMap)
  collectgarbage()
  print("Sending " .. nameOfFile .. " " .. sentBytes .. "B already; " .. node.heap() .. "B in heap")
  conn:on("sent", function(conn) 
    if (sentBytes == 0) then
        conn:close() 
        print("Page sent")
        collectgarbage()
        httpSending=false
    else
        collectgarbage()
        sendPage(conn, nameOfFile, replaceMap)
    end
  end)

  if file.open(nameOfFile, "r") then
    local buf=""
    if (sentBytes <= 0) then
        buf=buf .. "HTTP/1.1 200 OK\r\n"
        buf=buf .. "Content-Type: text/html\r\n"
        buf=buf .. "Connection: close\r\n"
        buf=buf .. "Date: Thu, 29 Dec 2016 20:18:20 GMT\r\n"
        buf=buf .. "\r\n\r\n"
    end
    -- amount of sent bytes is always zero at the beginning (so no problem)
    file.seek("set", sentBytes)
    
    local line = file.readline()
    
    while (line ~= nil) do
        -- all placeholder begin with a $, so search for it in the current line
        if (line:find("$") ~= nil) then
            -- Replace the placeholder with the dynamic content
            if (replaceMap ~= nil) then
                for key,value in pairs(replaceMap) 
                do 
                    line = string.gsub(line, key, value)
                end
            end
        end

        
        -- increase the amount of sent bytes
        sentBytes=sentBytes+string.len(line)
        
        buf = buf .. line
        
        -- Sent after 500 bytes data
        if ( (string.len(buf) >= 500) or (node.heap() < 2000) ) then
            line=nil
            conn:send(buf)
            print("Sent part of " .. sentBytes .. "B")
            -- end the function, this part is sent
            return 
        else
            -- fetch the next line
            line = file.readline()
        end
    end
    --reset amount of sent bytes, as we reached the end
    sentBytes=0
    -- send the rest
    if (string.len(buf) > 0) then
        conn:send(buf)
        print("Sent rest")
    end
  end
end

function fillDynamicMap()    
    replaceMap = {}
    ssid, _ = wifi.sta.getconfig()
    if (ssid == nil) then return replaceMap end
    if (sntpserverhostname == nil) then sntpserverhostname="ptbtime1.ptb.de" end
    if (timezoneoffset == nil) then timezoneoffset=1 end
    -- Set the default color, if nothing is set
    if (color == nil) then color=string.char(0,0,250) end
    if (color1 == nil) then color1=color end
    if (color2 == nil) then color2=color end
    if (color3 == nil) then color3=color end
    if (color4 == nil) then color4=color end
    if (colorBg == nil) then colorBg=string.char(0,0,0) end
    local hexColor = "#" .. string.format("%02x",string.byte(color,2)) .. string.format("%02x",string.byte(color,1)) .. string.format("%02x",string.byte(color,3))
    local hexColor1 = "#" .. string.format("%02x",string.byte(color1,2)) .. string.format("%02x",string.byte(color1,1)) .. string.format("%02x",string.byte(color1,3))
    local hexColor2 = "#" .. string.format("%02x",string.byte(color2,2)) .. string.format("%02x",string.byte(color2,1)) .. string.format("%02x",string.byte(color2,3))
    local hexColor3 = "#" .. string.format("%02x",string.byte(color3,2)) .. string.format("%02x",string.byte(color3,1)) .. string.format("%02x",string.byte(color3,3))
    local hexColor4 = "#" .. string.format("%02x",string.byte(color4,2)) .. string.format("%02x",string.byte(color4,1)) .. string.format("%02x",string.byte(color4,3))
    local hexColorBg = "#" .. string.format("%02x",string.byte(colorBg,2)) .. string.format("%02x",string.byte(colorBg,1)) .. string.format("%02x",string.byte(colorBg,3))

    replaceMap["$SSID"]=ssid
    replaceMap["$SNTPSERVER"]=sntpserverhostname
    replaceMap["$TIMEOFFSET"]=timezoneoffset
    replaceMap["$THREEQUATER"]=(threequater and "checked" or "")
    replaceMap["$ADDITIONAL_LINE"]=""
    replaceMap["$HEXCOLORFG"]=hexColor
    replaceMap["$HEXCOLOR1"]=hexColor1
    replaceMap["$HEXCOLOR2"]=hexColor2
    replaceMap["$HEXCOLOR3"]=hexColor3
    replaceMap["$HEXCOLOR4"]=hexColor4
    replaceMap["$HEXCOLORBG"]=hexColorBg
    replaceMap["$INV46"]=((inv46 ~= nil and inv46 == "on") and "checked" or "")
    replaceMap["$AUTODIM"]=((dim ~= nil and dim == "on") and "checked" or "")
    return replaceMap   
end

function readHex(source, variable)
	local hexColor=string.sub(source, 4)
	local red = tonumber(string.sub(hexColor, 1, 2), 16)
	local green = tonumber(string.sub(hexColor, 3, 4), 16)
	local blue = tonumber(string.sub(hexColor, 5, 6), 16)
	file.write(variable.."=string.char(" .. green .. "," .. red .. "," .. blue .. ")\n")
end

function startWebServer()
 srv=net.createServer(net.TCP)
 srv:listen(80,function(conn)
  conn:on("receive", function(conn,payload)
   if (httpSending) then
     print("HTTP sending... be patient!")
     return
   end
   if (payload:find("GET /") ~= nil) then
    httpSending=true
   if (color == nil) then
        color=string.char(0,128,0)
    end
    ws2812.write(string.char(0,0,0):rep(56) .. color:rep(2) .. string.char(0,0,0):rep(4) .. color:rep(2) .. string.char(0,0,0):rep(48))
    if (sendPage ~= nil) then
       print("Sending webpage.html (" .. tostring(node.heap()) .. "B free) ...")
       -- Load the sendPagewebcontent
       replaceMap=fillDynamicMap()
       sendPage(conn, "webpage.html", replaceMap)
    end
   else if (payload:find("POST /") ~=nil) then
    --code for handling the POST-request (updating settings)
     _, postdatastart = payload:find("\r\n\r\n")
     --Next lines catches POST-requests without POST-data....
     if postdatastart==nil then postdatastart = 1 end
     local postRequestData=string.sub(payload,postdatastart+1)
     local _POST = {}
     for i, j in string.gmatch(postRequestData, "(%w+)=([^&]+)&*") do
       _POST[i] = j
     end

     --- Do the magic!
     if (_POST.action ~= nil and _POST.action == "Reboot") then
        node.restart()
        return
     end

    if ((_POST.ssid~=nil) and (_POST.sntpserver~=nil) and (_POST.timezoneoffset~=nil)) then
        print("New config!")
        if (_POST.password==nil) then
            _, password, _, _ = wifi.sta.getconfig()
            print("Restoring password : " .. password)
            _POST.password = password
            password = nil
        end
        -- Safe configuration:
        file.remove(configFile .. ".new")
        sec, _ = rtctime.get()
        file.open(configFile.. ".new", "w+")
          file.write("-- Config\n" .. "station_cfg={}\nstation_cfg.ssid=\"" .. _POST.ssid .. "\"\nstation_cfg.pwd=\"" .. _POST.password .. "\"\nstation_cfg.save=false\nwifi.sta.config(station_cfg)\n")
          file.write("sntpserverhostname=\"" .. _POST.sntpserver .. "\"\n" .. "timezoneoffset=\"" .. _POST.timezoneoffset .. "\"\n".. "inv46=\"" .. tostring(_POST.inv46) .. "\"\n" .. "dim=\"" .. tostring(_POST.dim) .. "\"\n")
        
        if ( _POST.fcolor ~= nil) then
            -- color=string.char(_POST.green, _POST.red, _POST.blue)  
            print ("Got fcolor: " .. _POST.fcolor)
	    readHex(_POST.fcolor, "color")
        end
        if ( _POST.mcolor1  ~= nil) then
	    readHex(_POST.mcolor1, "color1")
        end
        if ( _POST.mcolor2  ~= nil) then
	    readHex(_POST.mcolor2, "color2")
        end
        if ( _POST.mcolor3  ~= nil) then
	    readHex(_POST.mcolor3, "color3")
        end
        if ( _POST.mcolor4  ~= nil) then
	    readHex(_POST.mcolor4, "color4")
        end
        if ( _POST.bcolor  ~= nil) then
            local hexColor=string.sub(_POST.bcolor, 4)
	    readHex(_POST.bcolor, "colorBg")
        end
        if (getTime ~= nil) then
            time = getTime(sec, timezoneoffset)
            file.write("print(\"Config from " .. time.year .. "-" .. time.month .. "-" .. time.day .. " " .. time.hour .. ":" .. time.minute .. ":" .. time.second .. "\")\n")
        end
	if (_POST.web ~= nil) then
            file.write("web=true\n")
            -- fill the current values
            web=true
        else
            file.write("web=nil\n") -- use webserver instead of mqtt or telnet
            -- fill the current values
            web=nil
        end
        if (_POST.threequater ~= nil) then
            file.write("threequater=true\n")
            -- fill the current values
            threequater=true
        else
            file.write("threequater=nil\n") -- unset threequater
            -- fill the current values
            threequater=nil
        end
        file.close()
        collectgarbage()
        sec=nil
        file.remove(configFile)
        print("Rename config")
        if (file.rename(configFile .. ".new", configFile)) then
            print("Successfully")
	    local mytimer = tmr.create()
	    mytimer:register(50, tmr.ALARM_SINGLE, function (t)
                replaceMap=fillDynamicMap()
                replaceMap["$ADDITIONAL_LINE"]="<h2><font color=\"green\">New configuration saved</font></h2>"
                print("Send success to client")
                sendPage(conn, "webpage.html", replaceMap)
		t:unregister()
            end)
	    mytimer:start()
        else
	    local mytimer = tmr.create()
	    mytimer:register(50, tmr.ALARM_SINGLE, function (t)
                replaceMap=fillDynamicMap()
                replaceMap["$ADDITIONAL_LINE"]="<h2><font color=\"red\">ERROR</font></h2>"
                sendPage(conn, "webpage.html", replaceMap)
		t:unregister()
            end)
	    mytimer:start()
        end
  else
      replaceMap=fillDynamicMap()
      replaceMap["$ADDITIONAL_LINE"]="<h2><font color=\"orange\">Not all parameters set</font></h2>"
      sendPage(conn, "webpage.html", replaceMap)
  end
    else
     print("Hello via telnet")
     --here is code, if the connection is not from a webbrowser, i.e. telnet or nc
     global_c=conn
     function s_output(str)
      if(global_c~=nil)
        then global_c:send(str)
      end
     end    
     node.output(s_output, 0)
     global_c:on("receive",function(c,l)
       node.input(l)
     end)
     global_c:on("disconnection",function(c)
       node.output(nil)
       global_c=nil
     end)
     print("Welcome to Word Clock") 
    end
   end
   end)
  conn:on("disconnection", function(c)
          print("Goodbye")
          node.output(nil)        -- un-register the redirect output function, output goes to serial
          collectgarbage()
          --reset amount of sent bytes, as we reached the end
          sentBytes=0
       end)
 end)

end


-- start the webserver module 
collectgarbage()
wifi.setmode(wifi.SOFTAP)
cfg={}
cfg.ssid="wordclock"
cfg.pwd="wordclock"
wifi.ap.config(cfg)

-- Write the buffer to the LEDs
local color=string.char(0,128,0)
local white=string.char(0,0,0)
local ledBuf= white:rep(6) .. color .. white:rep(7) .. color:rep(3) .. white:rep(44) .. color:rep(3) .. white:rep(50)
ws2812.write(ledBuf)
color=nil
white=nil
ledBuf=nil

print("Waiting in access point >wordclock< for Clients")
print("Please visit 192.168.4.1")
startWebServer()
collectgarbage()