local function GetRedisClient()
    local Host = plugin.ConfigGet('server')
    local Port = plugin.ConfigGet('port')
    local Pass = plugin.ConfigGet('pass')
    local Redis = redis.connect(Host, Port)
    if Redis == nil then
        return nil
    end
    Redis:auth(Pass)
    return Redis
end


-- forgive me father for i have sinned
local function ParsePackXML(XML)
    local _, Start = XML:find("<status>")
    if Start == nil then
        return nil
    end
    local End, _ = XML:find("</status>", Start)
    if End == nil then
        return nil
    end
    return XML:sub(Start+1, End-1)
end

local function GetPackStatus(ID)
    local URL = "http://api.paczkomaty.pl/?do=getpackstatus&packcode=" .. ID
    local Body, Code, Headers = http.request(URL)
    if Code ~= 200 then
        return nil
    end
    return ParsePackXML(Body)
end

local function CheckMate(IRC)
    local Now = os.time()
    local Redis = GetRedisClient()
    if Redis == nil then
        return
    end

    for _, ID in pairs(Redis:smembers("paczkomate:ids")) do
        local LastChecked = tonumber(Redis:hget("paczkomate:objects:" .. ID, "lastchecked"))
        local LastStatus = Redis:hget("paczkomate:objects:" .. ID, "status")
        if Now > LastChecked + 600 then
            Redis:hset("paczkomate:objects:" .. ID, "lastchecked", Now)
            local NewStatus = GetPackStatus(ID)
            if NewStatus ~= LastStatus then
                Redis:hset("paczkomate:objects:" .. ID, "status", NewStatus)
                local Message = string.format("Paczkomate %s status changed (%s -> %s)", ID, LastStatus, NewStatus)
                IRC:Say("#hackerspace-pl-members", Message)
            end
        end
    end
end

plugin.AddCommand('add-paczkomate', 1, function(Username, Channel, ID)
    local Redis = GetRedisClient()
    Redis:transaction(function(t)
        t:sadd('paczkomate:ids', ID)
        t:hset("paczkomate:objects:" .. ID, "lastchecked", 0)
        t:hset("paczkomate:objects:" .. ID, "status", "none")
    end)
    CheckMate(Channel._irc)
end, "Add a InPost tracking number", 10)

local LastGlobalChecked = 0
plugin.AddHook('irc.Message', 'testmate', function(Username, Channel, Message)
    if LastGlobalChecked + 10 < os.time() then
        LastGlobalChecked = os.time()
        pcall(function()
            CheckMate(Channel._irc)
        end)
    end
end)

plugin.AddCommand('list-paczkomate', 0, function(Username, Channel)
    if Channel.Name ~= "#hackerspace-pl-members" then
        Channel:Say("#hackerspace-pl-members only, dear.")
        return
    end
    local Redis = GetRedisClient()
    for _, ID in pairs(Redis:smembers("paczkomate:ids")) do
        local LastStatus = Redis:hget("paczkomate:objects:" .. ID, "status")
        Channel:Say(string.format(" - %s, status: %s", ID, LastStatus))
    end
end)

plugin.AddCommand('check-paczkomate', 0, function(Username, Channel)
    if Channel.Name ~= "#hackerspace-pl-members" then
        Channel:Say("#hackerspace-pl-members only, dear.")
        return
    end
    CheckMate(Channel._irc)
    Channel:Say("Done.")
end)