-- Name generation unit

markov = {

    -- Set of working letters and digits ('#' and '$' represents starting and ending word boundary respectively)
    letters = {
        'a', 'b', 'c', 'd', 'e',
        'f', 'g', 'h', 'i', 'j',
        'k', 'l', 'm', 'n', 'o',
        'p', 'q', 'r', 's', 't',
        'u', 'v', 'w', 'x', 'y',
        'z', 'A', 'B', 'C', 'D',
        'E', 'F', 'G', 'H', 'I',
        'J', 'K', 'L', 'M', 'N',
        'O', 'P', 'Q', 'R', 'S',
        'T', 'U', 'V', 'W', 'X',
        'Y', 'Z', ' ', '-', '_',
        '#', '$'
    },

    -- The dictionary itself
    dictionary = {},

    -- Creates the dictionary setting all letter transitions to zero
    createdictionary = function(athis)
        local lletter1, lletter2
        for lletter1 = 1, 57 do
            for lletter2 = 1, 57 do
                print('Setting frequency of : ' .. letters[lletter1] .. ' -> ' .. letters[lletter2] .. ' to zero.')
                athis.dictionary[letters[lletter1] .. letters[lletter2]] = 0
            end
        end
    end,

    -- Increases the frequency of a certain letter transition
    increasefrequency = function(athis, aletter1, aletter2)
        print('Increase frequency of : ' .. aletter1 .. ' -> ' .. aletter2)
        athis.dictionary[aletter1 .. aletter2] = athis.dictionary[aletter1 .. aletter2] + 1
    end,

    -- Normalizes all letter frequencies to within 0..100 range
    normalizefrequencies = function(athis, aletter1, aletter2)
        local lmax = 0
        local lmin = 0
        local lletter1, lletter2
        for lletter1 = 1, 57 do
            for lletter2 = 1, 57 do
                if athis.dictionary[letters[lletter1] .. letters[lletter2]] > lmax then
                    lmax = athis.dictionary[letters[lletter1] .. letters[lletter2]]
                elseif athis.dictionary[letters[lletter1] .. letters[lletter2]] > lmin then
                    lmin = athis.dictionary[letters[lletter1] .. letters[lletter2]]
                else
                end
            end
        end
        local lsize = lmax - lmin
        local lratio = lsize / 100
        for lletter1 = 1, 57 do
            for lletter2 = 1, 57 do
                athis.dictionary[letters[lletter1] .. letters[lletter2]] = athis.dictionary[letters[lletter1] .. letters[lletter2]] / lratio
            end
        end
    end,

    -- Adds a word to the dictionary, increasing the letters transitions accordingly
    addword = function(athis, aword)
        local lword = '#' .. aword .. '$'
        print('Adding word to the dictionary : ' .. lword)
        for lchar = 1, strlen(lword) - 1 do
            athis:increasefrequency(string.sub(lword, lchar, 2))
        end
    end,

    -- Gets a row of frequencies from a certain letter aletter towards each other letter frequency
    -- Applies a random factor to their frequencies
    getfrequencies = function(athis, aletter)
        local result = {}
        for lletter = 1, 57 do
            local freq = athis.dictionary[aletter .. letters[lletter]]
            print('Frequency of ' .. aletter .. ' -> ' .. letters[lletter] .. ' is ' .. freq)
            result[letters[lletter]] = freq * math.random() * math.random(25)
        end
    end,

    -- Get the most probably next letter from a certain letter
    getnextletter = function(athis, astartingletter)
        local lfreq = athis:getfrequencies(astartingletter)
        local selletter = '$'
        local selletterfreq = -100
        for lletter = 1, 57 do
            if lfreq[letters[lletter]] > selletterfreq then
                selletter = letters[lletter]
                selletterfreq = lfreq[letters[lletter]]
            end
        end
    end,

    -- Concatenates a letter into a word
    appendletter = function(athis, alump, anextletter)
        if anextletter = '#' then
        elseif anextletter = '$' then
        else
            return alump .. anextletter
        end
    end,

    -- Generates a new word
    generateword = function(athis)
        local lnextletter = athis.letters[math.random(57)]
        while lnextletter = '#' or lnextletter = '$' do
            lnextletter = athis.letters[math.random(57)]
        end
        local lword = ''
        while lnextletter ~= '$' do
            athis:appendletter(lword, lnextletter)
            lnextletter = athis:getnextletter(lnextletter)
        end
        return lword
    end
}