local lorem = {}

local WORDS_IN_SENTENCE      = {min = 5, max = 15}
local SENTENCES_IN_PARAGRAPH = {min = 2, max = 7 }
local PARAGRAPHS_IN_TEXT     = {min = 2, max = 7 }

local function random_int(min, max)
    return math.random(min, max)
end

local BASE_PHRASE = [[
Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Suspendisse rutrum accumsan elit vel auctor.
Praesent sit amet aliquam turpis.
Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae.
Maecenas non erat ut elit sodales commodo.
Nam gravida ipsum quis nulla tempus, quis pulvinar augue tristique.
Nulla massa odio, imperdiet non ultricies tincidunt, viverra sed lorem.
Nulla elementum sapien ut commodo aliquet.
Pellentesque iaculis turpis tellus, eget laoreet augue condimentum vel.
Quisque at risus rhoncus, facilisis tellus nec, tristique dolor.
Maecenas cursus magna eget imperdiet laoreet.
]]

local function get_words(phrase)
    local list = {}
    for word in phrase:gmatch('%a+') do
        table.insert(list, word:lower())
    end
    return list
end

lorem.__index = lorem
lorem._dict = get_words(BASE_PHRASE)

function lorem:generator(phrase)
    if type(phrase) ~= 'string' then
        error('First argument of lorem.generator should be a string', 2)
    end
    local g = {_dict = {}}
    for word in phrase:gmatch('%a+') do
        table.insert(g._dict, word:lower())
    end
    if #(g._dict) == 0 then
        error('String argument of lorem.generator should contain words', 2)
    end
    setmetatable(g, self)
    return g
end

function lorem:word()
    return self._dict[random_int(1, #(self._dict))]
end

function lorem:sentence()
    local n = random_int(WORDS_IN_SENTENCE.min, WORDS_IN_SENTENCE.max)
    local words = {}
    for i = 1, n do
        words[i] = self:word()
    end
    local s = table.concat(words, ' ')
    s = s .. "."
    s = s:sub(1, 1):upper() .. s:sub(2)
    return s
end

function lorem:paragraph()
    local n = random_int(SENTENCES_IN_PARAGRAPH.min, SENTENCES_IN_PARAGRAPH.max)
    local sentences = {}
    for i = 1, n do
        sentences[i] = self:sentence()
    end
    return table.concat(sentences, ' ')
end

function lorem:text()
    local n = random_int(PARAGRAPHS_IN_TEXT.min, PARAGRAPHS_IN_TEXT.max)
    local paragraphs = {}
    for i = 1, n do
        paragraphs[i] = self:paragraph()
    end
    return table.concat(paragraphs, '\n')
end

return lorem