local socket = require"socket"

local http = require"socket.http"

local url = require"socket.url"

local ltn12 = require"ltn12"

local token_class =  '[^%c%s%(%)%<%>%@%,%;%:%\\%"%/%[%]%?%=%{%}]'

local function unquote(t, quoted) 

    local n = string.match(t, "%$(%d+)$")

    if n then n = tonumber(n) end

    if quoted[n] then return quoted[n]

    else return t end

end

local function parse_set_cookie(c, quoted, cookie_table)

    c = c .. ";$last=last;"

    local _, __, n, v, i = string.find(c, "(" .. token_class .. 

        "+)%s*=%s*(.-)%s*;%s*()")

    local cookie = {

        name = n, 

        value = unquote(v, quoted), 

        attributes = {}

    }

    while 1 do

        _, __, n, v, i = string.find(c, "(" .. token_class .. 

            "+)%s*=?%s*(.-)%s*;%s*()", i)

        if not n or n == "$last" then break end

        cookie.attributes[#cookie.attributes+1] = {

            name = n, 

            value = unquote(v, quoted)

        }

    end

    cookie_table[#cookie_table+1] = cookie

end

local function split_set_cookie(s, cookie_table)

    cookie_table = cookie_table or {}

    -- remove quoted strings from cookie list

    local quoted = {}

    s = string.gsub(s, '"(.-)"', function(q)

        quoted[#quoted+1] = q

        return "$" .. #quoted

    end)

    -- add sentinel

    s = s .. ",$last="

    -- split into individual cookies

    i = 1

    while 1 do

        local _, __, cookie, next_token

        _, __, cookie, i, next_token = string.find(s, "(.-)%s*%,%s*()(" .. 

            token_class .. "+)%s*=", i)

        if not next_token then break end

        parse_set_cookie(cookie, quoted, cookie_table)

        if next_token == "$last" then break end

    end

    return cookie_table

end

local function quote(s)

    if string.find(s, "[ %,%;]") then return '"' .. s .. '"'

    else return s end

end

local _empty = {}

local function build_cookies(cookies) 

    s = ""

    for i,v in ipairs(cookies or _empty) do

        if v.name then

            s = s .. v.name

            if v.value and v.value ~= "" then 

                s = s .. '=' .. quote(v.value)

            end

        end

        if v.name and #(v.attributes or _empty) > 0 then s = s .. "; "  end

        for j,u in ipairs(v.attributes or _empty) do

            if u.name then

                s = s .. u.name

                if u.value and u.value ~= "" then

                    s = s .. '=' .. quote(u.value)

                end

            end

            if j < #v.attributes then s = s .. "; "  end

        end

        if i < #cookies then s = s .. ", " end

    end

    return s 

end