local component = require("component")
local computer = require("computer")
local fs = require("filesystem")
local event = require("event")

-- get GPU
local gpu = component.proxy(component.list("gpu", true)())

if gpu == nil then
    return -1
end


local resolution = {}
resolution.w, resolution.h = gpu.maxResolution()
local bg_color = 0xa2cffe
local touch_listeners = {} -- {x start,y start,x end,y end,function to call, with args}
local windows = {} -- {WINDOW_NAME,X,Y,WIDTH,HEIGHT}
-- local 

gpu.setResolution(resolution.w, resolution.h)

local function add_touch_listener(xs,ys,xe,ye,call,args)
    table.insert(touch_listeners, {xs,ys,xe,ye,call,args})
    return #touch_listeners
end


local function draw_nav()
    gpu.setBackground(0xffffff)
    gpu.setForeground(0xffffff)

    gpu.fill(1, 1, resolution.w, 1, " ")

    gpu.setForeground(0x000000)
    gpu.setBackground(0xffffff)

    gpu.set(2,1, "@")
    local totalmem = computer.totalMemory()
    local freemem = computer.freeMemory()
    gpu.set(6,1, tostring(totalmem-freemem) .. " b / " .. tostring(totalmem) .. " b")

    gpu.setBackground(bg_color)
end

local function draw_bg()
    gpu.setBackground(bg_color)
    gpu.fill(1, 2, resolution.w, resolution.h, " ")
end

local function draw_windows()
    for i = 1, #windows do
        gpu.setBackground(0x000000)
        gpu.setForeground(0xffffff)
        gpu.fill(
            windows[i][2],
            windows[i][3]-1,
            windows[i][2]+windows[i][4],
            windows[i][3]-1,
            " "
        )
        gpu.set(windows[i][2], windows[i][3]-1, "X | " .. windows[i][1])
        gpu.setBackground(0xaaaaaa)
        gpu.fill(
            windows[i][2],
            windows[i][3],
            windows[i][2]+windows[i][4],
            windows[i][3]+windows[i][5],
            " "
        )
    end
end

local function keyin()
    return event.pull("key_down")
end


local function open_exec_menu(args)
    gpu.setBackground(0xdadada)
    gpu.fill(1,3,resolution.w, 1, " ")
    gpu.setBackground(bg_color)
    local grab = true
    local buffer = ""
    local curr_loc_x = 1
    while grab do
        local _,_,next_key = keyin()
        if next_key == 13 then
            local result = table.pack(pcall(fs.dofile, buffer))
            if not result[1] then
                print(result[2] .. "\n")
            end
            buffer = ""
            curr_loc_x = 1
            grab = false
        elseif next_key == 8 then
            if #buffer ~= 0 then
                buffer = buffer:sub(1, -2)
                gpu.set(curr_loc_x-1, 2, " ")
                curr_loc_x = curr_loc_x - 1
            end
        else
            buffer = buffer .. string.char(next_key)
            gpu.set(curr_loc_x, 2, string.char(next_key))
            curr_loc_x = curr_loc_x + 1
        end
    end
    gpu.setBackground(bg_color)
    gpu.fill(1,2,resolution.w, 3, " ")
end


draw_bg()
draw_nav()


add_touch_listener(2, 1, 2, 1, open_exec_menu, {})

while true do
    local event,uuid,x,y = computer.pullSignal(0.3)
    if event == "touch" then
        for i = 1, #touch_listeners do
            if touch_listeners[i][1] <= x and x <= touch_listeners[i][3] then
                if touch_listeners[i][2] <= y and y <= touch_listeners[i][4] then
                    touch_listeners[i][5](touch_listeners[i][6])
                end
            end
        end
    end

    draw_nav()
    draw_windows()
end