os = require "os"
socket = require "socket"

function shortname()
    local long = socket.dns.gethostname()
    return string.gmatch(long, '[^.]+')()
end

function get_queue(mbox)
    --TODO: try to get tail
    return mbox.FILTER_QUEUE:is_newer(84)
end

function _notifirc1(subj, from, body)
    --notify about message using (pre-configured) notifirc
    local fd = assert(io.popen('notifirc -f - "message preview:"', "w"))
    local fmt = "> %s\n> %s\n> BODY: %s"
    fd:write(fmt:format(subj, from, body))
    fd:close()
end

function notifirc_all(seq)
    for _, mesg in ipairs(seq) do
        mbox, uid = table.unpack(mesg)
        subj = mbox[uid]:fetch_field('Subject')
        from = mbox[uid]:fetch_field('From')
        body = mbox[uid]:fetch_body()
        _notifirc1(subj, from, body)
    end
end

function _partinf_compare(a, b)
    if not type(a) == type(b) then
        return false
    end
    if type(a) == 'number' then
        return a == b
    elseif type(a) == 'string' then
        return a:lower() == b:lower()
    end
end

function has_part_like(query, structure)
    if structure == nil then
        return false
    end
    for partid, partinf in pairs(structure) do
        local part_answer = true
        -- check all query parts
        for qkey, qvalue in pairs(query) do
            value = partinf[qkey]
            if not _partinf_compare(value, qvalue) then
                part_answer = false
                break
            end
        end
        if part_answer then
            return true
        end
    end
    return false
end

function filter_part_like(query, seq)
    result = Set {}
    for _, mesg in ipairs(seq) do
        mbox, uid = table.unpack(mesg)
        structure = mbox[uid]:fetch_structure()
        if has_part_like(query, structure) then
            table.insert(result, mesg)
        end
    end
    return result
end