local acc, name, data = ...

local list_topic_id = 13152151

local function get_list_from_top()
    local t = acc.discussion().get_topic(list_topic_id)
    if not t then return end

    local list, index = {}, {}
    for c in acc.discussion().comments(t) do
        if not c.deleted and type(c.removed) ~= "number" then
            local id = c.user.id
            if id and not index[id] then
                table.insert(list, id)
                index[id] = true
            end
        end
    end
    return list
end

local function vocabulary_size(usr)
    local hres = acc.http_get_data("/vocabularies/size", { user_id = usr.id() })
    if not hres.error then
        local v_list = hres.data.vocab_size and hres.data.vocab_size.languages or {}
        local lgstr  = usr.get("learning_language_string")
        for i = 1, #v_list do
            local vl = v_list[i]
            if vl.language_string == lgstr then
                return type(vl.count) == "number" and vl.count or nil
            end
        end
    end
end

if not data then
    acc.output().printf("Getting the list from post %d...", list_topic_id)
    local list = get_list_from_top()
    if not list then
        acc.output().print("Error!")
        return {}
    end
    data = {}
    data.ulist = list
    data.pos   = 1
    data.keep  = true
    data.vlist = {}
    data.users = 0
end

local size = #data.ulist
while data.pos <= size do
    local usr = acc.user(data.ulist[data.pos])
    if usr then
        local from, to = usr.get("fromLanguage"), usr.get("learningLanguage")
        acc.output().printf("[%3d/%3d] %-20s | %s -> %s", data.pos, size, usr.get("username"), from, to)
        if from == "en" then -- from English only
            -- Getting vocab data
            local uvocab = vocabulary_size(usr)
            if not uvocab then acc.output().print("Failed to get vocabulary size") end
            --
            local v = data.vlist[to]
            if not v then
                data.vlist[to] = { count = uvocab, language_string = usr.get("learning_language_string") }
            elseif v.count < uvocab then
                v.count = uvocab
            end
            data.users = data.users + 1
        end
    end
    data.pos = data.pos + 1
    if (data.pos - 1) % 100 == 0 then
        break
    end
end

if data.pos <= size then
    acc.output().print("Went to bed")
    data.timeout = 2 * 60
    return data
end

local print_list = {}
for lg, d in pairs(data.vlist) do
    table.insert(print_list, { lang = lg, language_string = d.language_string, count = d.count })
end
table.sort(print_list, function(a, b) return a.count > b.count end)

acc.output().print("--------------------")
for i = 1, #print_list do
    local v = print_list[i]
    acc.output().printf("%s(%s): %d", v.language_string, v.lang, v.count)
end
acc.output().printf("The list size: %d", #print_list)
acc.output().printf("Number of users: %d", data.users)

return {}