local text=require("text")

local rules={}
local vt100={rules=rules}
local full




rules[{"%[","[%d;]*","m"}]=function(window,_,number_text)


local colors={0x0,0xff0000,0x00ff00,0xffff00,0x0000ff,0xff00ff,0x00B6ff,0xffffff}
local fg,bg=window.gpu.setForeground,window.gpu.setBackground
if window.flip then
fg,bg=bg,fg
end
number_text=" _ "..number_text:gsub("^;$",""):gsub(";"," _ ").." _ "
local parts=text.internal.tokenize(number_text)
local last_was_break
for _,part in ipairs(parts)do
local num=tonumber(part[1].txt)
last_was_break,num=not num,num or last_was_break and 0

local flip=num==7
if flip then
if not window.flip then
local rgb,pal=bg(window.gpu.getForeground())
fg(pal or rgb,not not pal)
fg,bg=bg,fg
end
elseif num==5 then
window.blink=true
elseif num==0 then
bg(colors[1])
fg(colors[8])
elseif num then
num=num-29
local set=fg
if num>10 then
num=num-10
set=bg
end
local color=colors[num]
if color then
set(color)
end
end
window.flip=flip
end
end

local function save_attributes(window,seven,s)
if seven=="7"or s=="s"then
window.saved=
{
window.x,
window.y,
{window.gpu.getBackground()},
{window.gpu.getForeground()},
window.flip,
window.blink
}
else
local data=window.saved or{1,1,{0x0},{0xffffff},window.flip,window.blink}
window.x=data[1]
window.y=data[2]
window.gpu.setBackground(table.unpack(data[3]))
window.gpu.setForeground(table.unpack(data[4]))
window.flip=data[5]
window.blink=data[6]
end
end



rules[{"[78]"}]=save_attributes



rules[{"%[","[su]"}]=save_attributes


function vt100.parse(window)
if window.output_buffer:sub(1,1)~="\27"then
return""
end
local any_valid

for rule,action in pairs(rules)do
local last_index=1
local captures={}
for _,pattern in ipairs(rule)do
if last_index>=#window.output_buffer then
any_valid=true
break
end
local si,ei,capture=window.output_buffer:find("^("..pattern..")",last_index+1)
if not si then
break
end
captures[#captures+1]=capture
last_index=ei
end

if#captures==#rule then
action(window,table.unpack(captures))
window.output_buffer=window.output_buffer:sub(last_index+1)
return""
end
end

if not full then

full=true
dofile("/lib/core/full_vt.lua")
return vt100.parse(window)
end

if not any_valid then

window.output_buffer=window.output_buffer:sub(2)
return"\27"
end


end

return vt100