EasyDev

local increase = 5

local function tConcat(t1,t2)
    for i=1,#t2 do
        t1[#t1+1] = t2[i]
    end
    return t1
end

local tArgs = { ... }
if #tArgs >= 1 then
    if math.floor(tonumber(tArgs[1])) > 0 then --error checking
            increase = math.floor(tonumber(tArgs[1]))
    end
end

local tFilesUsed = {} --preventing repetition

local tKeywords = {
    ["and"] = true,
    ["break"] = true,
    ["do"] = true,
    ["else"] = true,
    ["elseif"] = true,
    ["end"] = true,
    ["false"] = true,
    ["for"] = true,
    ["function"] = true,
    ["if"] = true,
    ["in"] = true,
    ["local"] = true,
    ["nil"] = true,
    ["not"] = true,
    ["or"] = true,
    ["repeat"] = true,
    ["return"] = true,
    ["then"] = true,
    ["true"] = true,
    ["until"] = true,
    ["while"] = true
}

local w,h = term.getSize()
local X, Y = 1, 2

local tLines = {}

-- Colours
local highlightColour, keywordColour, commentColour, textColour, bgColour
if term.isColour() then
    bgColour = colours.black
    textColour = colours.white
    highlightColour = colours.yellow
    keywordColour = colours.blue
    commentColour = colours.green
    stringColour = colours.red
else
    bgColour = colours.black
    textColour = colours.white
    highlightColour = colours.white
    keywordColour = colours.white
    commentColour = colours.white
    stringColour = colours.white
end

local function tryWrite( sLine, regex, colour )
    local match = string.match( sLine, regex )
    if match then
        if type(colour) == "number" then
            term.setTextColour( colour )
        else
            term.setTextColour( colour(match) )
        end
        term.write( match )
        term.setTextColour( textColour )
        return string.sub( sLine, string.len(match) + 1 )
    end
    return nil
end

local function writeHighlighted( sLine )
    while string.len(sLine) > 0 do
        sLine =
            tryWrite( sLine, "^%-%-%[%[.-%]%]", commentColour ) or
            tryWrite( sLine, "^%-%-.*", commentColour ) or
            tryWrite( sLine, "^\".-[^\\]\"", stringColour ) or
            tryWrite( sLine, "^\'.-[^\\]\'", stringColour ) or
            tryWrite( sLine, "^%[%[.-%]%]", stringColour ) or
            tryWrite( sLine, "^[%w_]+", function( match )
                if tKeywords[ match ] then
                    return keywordColour
                end
                return textColour
            end ) or
            tryWrite( sLine, "^[^%w_]", textColour )
    end
end
local function redrawLine() --this is taken from edit, since I tried to do this myself but bios.lua kept throwing a fit
    local sLine = tLines[Y]
    --print(Y, ';')
    term.setCursorPos( 1, math.min(h, Y) )
    term.clearLine()
    writeHighlighted( sLine )
end

while true do
    term.clear()
    term.setCursorPos(1, 1)
    if term.isColor() then
        term.setTextColor(colors.yellow)
    end

    tFiles = tConcat(fs.find('/rom/apis/*'), fs.find('/rom/programs/*'))

    if #tFilesUsed == #tFiles then
        tFilesUsed = {}
    end

    local i = 0
    repeat
        i = math.random(#tFiles)
    until tFilesUsed[i] == nil

    local f = fs.open(tFiles[i], 'r')
    --local f2 = fs.open(fs.combine('/rom/programs', tFiles[i]), 'r')

    --if f2 then f = f2 end
    if f then --protecting against specific apis, such as turtle or advanced that is not in use
        tLines = {}
        Y = 1
        X = 1
        table.insert(tLines, 'Creating ' .. tFiles[i])
        redrawLine()
        Y = 2
        table.insert(tLines, ' ')
        redrawLine()
        local str = f.readAll()
        f.close()
        if term.isColor() then
            term.setTextColor(colors.white)
        end

        local pos = 1
        local continue = true

        local currentStr = ''
        local currentPos = 0
        local linePos = 0
        while str:sub(pos, pos + increase - 1) ~= '' and continue do
            local sEvent, nKey = os.pullEvent()
            if sEvent == 'key' then
                if nKey == 1 then --esc
                    term.clear()
                    term.setCursorPos(1, 1)
                    if term.isColor() then
                        term.setTextColor(colors.white)
                    end
                    return --exit
                elseif nKey == 14 or nKey == 211 then --backspace or delete
                    --pretend this does something, i haven't figured out what to do
                elseif nKey == 28 then --enter
                    continue = false --next file
                else
                    for i = 1, increase do
                        local c = str:sub(pos, pos)
                        currentPos = currentPos + 1
                        linePos = linePos + 1

                        X = (currentPos % w - 1) + 1
                        --Y = Y + math.floor(linePos / w)

                        if c == '\n' or #tLines == 0 or math.floor(linePos / w) == 1 then
                            table.insert(tLines, '')
                            currentStr = ''
                            currentPos = 0
                            linePos = 0
                            Y = Y + 1
                            X = 1

                            if Y >= h then print(' ') end
                        else
                            currentStr = currentStr .. c
                            tLines[#tLines] = currentStr
                            --print('fef')
                            redrawLine()
                            --print('feef')
                        end
                        pos = pos + 1

                        --write(c)
                    end
                end
            end
        end
    end
    tFilesUsed[i] = tFiles[i] --adding it to the table
end