updateAEViewer

--Please download it by executing "pastebin get 4nRg9CHU json"
-- in the same directory as this file.
os.loadAPI("json")

--Delay after each loop (seconds)
-- Note: Currently the AE system scanning is very slow. This is an arbitrary number.
updateInterval = 10

--Server auth and connection data
username = "<YOUR USERNAME HERE>"
password = "<YOUR PASSWORD HERE>"
APIUrl = "http://aeviewer-rhbvkleef.rhcloud.com/updateAESystem"

--AE system
ae = peripheral.wrap("left")

--Information monitor
mon = peripheral.wrap("top")

--The state of the AE system since the last check
previousAEState = ""

--Should retry next tick?
re = false

--Available log levels, used for determining the severity of the logging action
LogLevel = {
  deb="debug",
  info="info",
  warn="warning",
  err="error"
}

--Used for clearing a line on a monitor
whitespace = "                                                                                                                   "

--Store current state of AE system in memory
function updateChangeCatalog()
    local state = getCurrentAECatalog()
    if state then
        previousAEState = state
    end
end

function getCurrentAECatalog()
    local itemList = {}
    local items = ae.getAvailableItems()
    for i = 1, #items do
        --There is still something wrong here.
        if(items[i] ~= nil) then
            if(ae.getItemDetail(items[i].fingerprint) ~= nil and ae.getItemDetail(items[i].fingerprint).basic ~= nil) then
                items[i].display_name = textutils.urlEncode(
                    ae.getItemDetail(
                        items[i].fingerprint
                    )
                    .basic()
                    .display_name
                )
            else
                items[i].display_name = "Unknown"
            end
        end
    end
    return items
end

--Compare current state of AE system with
-- the stored state
function checkAEHasChanged()
    if re then
        re = false
        return true
    end
    if not ae.getAvailableItems()[1] then
        log("no items found! Is there power?", LogLevel.warn)
        return false
    end
    return not deepcompare(previousAEState, getCurrentAECatalog(), true);
end

--Sends an update packet to the database server
-- TODO: implement this method
function sendAEUpdatePacket()
    --Send packet
    local handle = http.post(
    APIUrl,
        "aeSystem=" .. textutils.urlEncode(json.encode(previousAEState)) .. "&" ..
        "username=" .. textutils.urlEncode(username) .. "&" ..
        "password=" .. textutils.urlEncode(password)
    )

    --Check for success response
    if not handle then
        log("failed to connect to database", LogLevel.err)
        re = true
    elseif not handle.getResponseCode() == 200 then
        local body = json.decode(handle.readAll())
        if body.status then
            log("received response code " .. handle.getResponseCode() .. " from server with status"..body.status, LogLevel.warn)
        else
            log("received response code " .. handle.getResponseCode() .. " from server", LogLevel.warn)
        end
    else
        log("Successfully sent update!", LogLevel.info)
        mon.setCursorPos(1,1)
        mon.write("Last update packet: " .. gtime() .. whitespace)
    end
end

--Compare two tables/objects
function deepcompare(t1,t2,ignore_mt)
    local ty1 = type(t1)
    local ty2 = type(t2)
    if ty1 ~= ty2 then
        return false
    end
    -- non-table types can be directly compared
    if ty1 ~= 'table' and ty2 ~= 'table' then
        return t1 == t2
    end
    -- as well as tables which have the metamethod __eq
    local mt = getmetatable(t1)
    if not ignore_mt and mt and mt.__eq then
        return t1 == t2
    end
    for k1,v1 in pairs(t1) do
        local v2 = t2[k1]
        if v2 == nil or not deepcompare(v1,v2) then
            return false
        end
    end
    for k2,v2 in pairs(t2) do
        local v1 = t1[k2]
        if v1 == nil or not deepcompare(v1,v2) then
            return false
        end
    end
    return true
end

-- Get the time
function gtime()
    local handle = http.get("http://www.timeapi.org/west/now?format=%20%25l:%25M%20%25p")
    if handle then
        t = string.sub(handle.readAll(), 2, -1)
        if string.sub(t, 1, 1) == " " then
            return string.sub(t, 2, -1)
        else
            return t
        end
    else
        mon.setCursorPos(1,2)
        mon.write("Last critical message: " .. LogLevel.warn .. " [unknown]" .. whitespace)
        mon.setCursorPos(1,3)
        mon.write("Could not request time from internet!" .. whitespace)
        return "NOINTERNET"
    end
end

--Logs the message to the appropriate places
function log(message, logLvl)
    local theTime = gtime()
    if not logLvl then
        logLvl = LogLevel.info
    end
    print("["..theTime.."] "..logLvl..": "..message)
    if logLvl == LogLevel.warn or logLvl == LogLevel.err then
        mon.setCursorPos(1,2)
        mon.write("Last critical message: " .. logLvl .. " [" .. theTime .. "]" .. whitespace)
        mon.setCursorPos(1,3)
        mon.write(message .. whitespace)
    end
    mon.setCursorPos(1,4)
    mon.write("Last debug message: " .. logLvl .. " [" .. theTime .. "]" .. whitespace)
    mon.setCursorPos(1,5)
    mon.write(message .. whitespace)
end

--Initialize display
mon.setCursorPos(1,1)
mon.write("Last update packet:")
mon.setCursorPos(1,2)
mon.write("Last critical message:")
mon.setCursorPos(1,4)
mon.write("Last debug message:")

--Store initial AE state and upload to database
updateChangeCatalog()
sendAEUpdatePacket()
while true do
    os.sleep(updateInterval)
    if checkAEHasChanged() then
        updateChangeCatalog()
        sendAEUpdatePacket()
    else
        --log("AE system has not changed", "info")
    end
end