-- this is essentially 
-- https://github.com/jupyter/nbconvert/blob/main/nbconvert/filters/ansi.py
-- converted to lua

local ANSI_COLORS = {
    "ansi-black",
    "ansi-red",
    "ansi-green",
    "ansi-yellow",
    "ansi-blue",
    "ansi-magenta",
    "ansi-cyan",
    "ansi-white",
    "ansi-black-intense",
    "ansi-red-intense",
    "ansi-green-intense",
    "ansi-yellow-intense",
    "ansi-blue-intense",
    "ansi-magenta-intense",
    "ansi-cyan-intense",
    "ansi-white-intense"
}

--[[
local re = require "re"

local codes = {
    -- attributes
    reset = 0,
    bright = 1,
    dim = 2,
    underscore = 4,
    -- blink = 5,
    reverse = 7,
    -- hidden = 8,

    -- foreground
    black = 30,
    red = 31,
    green = 32,
    yellow = 33,
    blue = 34,
    magenta = 35,
    cyan = 36,
    white = 37,

    -- background
    onblack = 40,
    onred = 41,
    ongreen = 42,
    onyellow = 43,
    onblue = 44,
    onmagenta = 45,
    oncyan = 46,
    onwhite = 47,
}

local ANSI = re.compile [[
    '\x1b%[' {.*?} {[@-~]} 
    ]]

--]]

local function LaTeXconverter()
    
end

local function HTMLconverter(fg, bg, bold, underline, inverse)
    if not (fg or bg or bold or underline or inverse) then
        return "",""
    end
    local classes = {}
    local styles  = {}

    if inverse then
        fg, bg = bg, fg
    end

    if type(fg) == "number" then
        table.insert(classes, ANSI_COLORS[fg] .. "-fg")
    elseif fg then
        table.insert(styles, string.format("color: rgb(%d,%d,%d)", fg[1], fg[2], fg[3]))
    elseif inverse then
        table.insert(classes,"ansi-default-inverse-fg")
    end

    if type(bg) == "number" then
        table.insert(classes, ANSI_COLORS[bg] .. "-bg")
    elseif bg then
        table.insert(styles, string.format("background-color: rgb(%d,%d,%d)", bg[1], bg[2], bg[3]))
    elseif inverse then
        table.insert(classes,"ansi-default-inverse-bg")
    end

    if bold then
        table.insert(classes, "ansi-bold")
    end

    if underline then
        table.insert(classes, "ansi-underline")
    end

    local starttag = "<span" 
    if classes then
        starttag = starttag .. ' class="' ..  table.concat(classes, " ") .. '"' 
    end

    if styles then
        starttag = starttag .. ' style="' ..  table.concat(styles, " ") .. '"' 
    end

    return starttag,"</span>" 
end

   
function CodeBlock(e)
    local converter
    if FORMAT:match 'latex' then
        converter = LaTeXconverter
    elseif FORMAT:match 'html' then
        converter = HTMLconverter
    elseif FORMAT:match 'native' then
        converter = HTMLconverter
    else
        return
    end
    if string.find(e.text, "\x1b%[") then
        local bold = false
        local underline = false
        local inverse = false
        local text = e.text
        local out = ""
        local chunk = ""
        local fg = {}
        local bg = {}
        local starttag = ""
        local endtag = ""

        while text do
            local s1, e1, c1, d1 = string.find(text, "\x1b%[(.-)([@-~])")
            if s1 then
                if d1 == "m" then
                    local numbers={}
                    for i in string.gmatch(c1, "[^;]") do
                        table.insert(numbers, tonumber(i))
                    end
                end
                chunk, text = text:sub(1, s1-1), text:sub(e1+1)
            else
                chunk, text = text, ""
            end

            if chunk then
                if bold and type(fg)=="number" and fg<8 then
                    starttag, endtag = converter(fg+8, bg, bold, underline, inverse)
                else
                    starttag, endtag = converter(fg, bg, bold, underline, inverse)
                end    
                out = out .. starttag .. chunk .. endtag
            end
        end

    end
end