Standalone file explorer

-- Explorer App by LegoStax
-- Originally designed for an upcoming security suite...

local RUNNING = false
local PATH = "/"
local COPYPATH = ""
local CUTPATH = ""
local w,h = term.getSize()
local WALL = ""
-- for drawing and scroll
local beginFiles = 0
local scrollpos = 1
local greatestpos = 1
local pospossible = 1
local oldItems = nil
local pos = nil
local selectedItem = -1

if term.isColor() or term.isColour() then
    RUNNING = true
end

local function clear(bg)
    bg = bg or colors.black
    term.setBackgroundColor(bg)
    term.clear()
    term.setCursorPos(1,1)
end

local function printPos(msg,x,y,bg,fg)
    if bg then term.setBackgroundColor(bg) end
    if fg then term.setTextColor(fg) end
    term.setCursorPos(x,y)
    term.write(msg)
end

local function printCenter(msg,y,bg,fg)
    local x = (w-msg:len())/2
    printPos(msg,x,y,bg,fg)
    return x
end

local function listFiles(d)
    local dir = nil
    if d then
        dir = shell.resolve(d)
    else
        dir = shell.dir()
    end

    local all = fs.list(dir)
    local files = {}
    local folders = {}
    local hidden = settings.get("list.show_hidden")
    for n, item in pairs(all) do
        if hidden or string.sub(item,1,1) ~= "." then
            local path = fs.combine(dir, item)
            if fs.isDir(path) then
                table.insert(folders, item)
            else
                table.insert(files, item)
            end
        end
    end
    table.sort(folders)
    table.sort(files)
    return folders, files
end

local function calculateItems()
    local folders, files = listFiles(PATH)
    local items = folders
    beginFiles = #folders+1
    for i = 1,#files do
        table.insert(items,files[i])
    end
    -- calculate greatestpos
    for i = 1,#items do
        if items[i]:len() > greatestpos then
            greatestpos = items[i]:len()
        end
    end
    pospossible = #items-(h-3)
    return items
end

local function drawTopBar()
    term.setBackgroundColor(colors.gray)
    term.setCursorPos(1,1)
    term.clearLine()
    printPos("QuickScape",1,1,colors.gray,colors.white)
    printPos(WALL,13,1,colors.gray,colors.red)
    printPos("X",w,1,colors.red,colors.white)
end

local function drawCurrentPath()
    term.setBackgroundColor(colors.lightGray)
    term.setCursorPos(1,2)
    term.clearLine()
    printPos(" <  "..PATH,1,2,colors.lightGray)
end

local function drawItems(items)
    if not items then
        items = oldItems
    end
    oldItems = items

    term.setBackgroundColor(colors.white)
    term.setTextColor(colors.blue)
    term.setCursorPos(5,3)
    for i = scrollpos,#items do
        if i > #items then break end
        if i == beginFiles then term.setTextColor(colors.black) end
        if i == selectedItem then
            term.setBackgroundColor(colors.blue)
            term.setTextColor(colors.white)
        else
            term.setBackgroundColor(colors.white)
            if i < beginFiles then term.setTextColor(colors.blue)
            else term.setTextColor(colors.black) end
        end
        term.write(items[i])
        term.setBackgroundColor(colors.white)
        for i = 1,greatestpos do term.write(" ") end
        local x,y = term.getCursorPos()
        y = y+1
        term.setCursorPos(5,y)
        if y > h then break end
    end
end

local function rightClickMenu(x,y,mode)
    if mode == 1 then -- file +11
        printPos(" Cut       ",x,y,colors.gray,colors.white)
        printPos(" Copy      ",x,y+1)
        printPos(" Delete    ",x,y+2)
        printPos(" Rename    ",x,y+3)
        printPos(" Open With ",x,y+4)
    elseif mode == 2 then -- folder +8
        printPos(" Cut    ",x,y,colors.gray,colors.white)
        printPos(" Copy   ",x,y+1)
        printPos(" Delete ",x,y+2)
        printPos(" Rename ",x,y+3)
    else -- misc +12
        printPos(" Paste      ",x,y,colors.gray,colors.white)
        printPos(" New File   ",x,y+1)
        printPos(" New Folder ",x,y+2)
    end
end

local function animSelected(msg,x,y,bg,fg)
    printPos(msg,x,y,bg,fg)
    sleep(0.1)
end

local function errorBox(e)
    printPos(e,1,1,colors.red,colors.white)

    while true do
        local e = {os.pullEvent()}
        if e[1] == "mouse_click" or e[1] == "key" then break end
    end
end

local function drawScreen()
    clear(colors.white)
    drawTopBar()
    drawCurrentPath()
    drawItems(calculateItems())
    WALL = ""
end

local function closeApp()
    animSelected("X",w,1,colors.white,colors.red)
    RUNNING = false
end

local function logVars(msg)
    local f = fs.open("logs", "a")
    f.write("\n"..msg)
    f.close()
end
-- 8:"New File" 10:"New Folder" 6:"Rename"
local function prompt(msg,data)
    local linepadding = ""
    for i = 1,2+msg:len() do
        linepadding = linepadding .. " "
    end

    local y = math.floor(h/2)
    printCenter(" "..msg.." ",y,colors.lightGray,colors.black)
    printCenter(linepadding,y+1)
    printCenter(linepadding,y+2)
    local x = (w-msg:len())/2
    term.setCursorPos(x,y+1)
    if data then
        for i = 1,data:len() do os.queueEvent("char", string.sub(data,i,i)) end
    end
    local input = read()
    return input
end

local function run(path)
    shell.switchTab(shell.openTab(path))
    --[[clear(colors.black)
    printCenter("Awaiting term_resize", (h-1)/2)
    local e = {os.pullEvent("term_resize")}
    --w,h = e[2],e[3]
    drawScreen()]]--
end

local function rightClickHandler(x,y,mode,item)
    local actualX, actualY = x,y
    if mode == 1 then
        if x > w-10 then
            actualX = w-10
        end
        if y > h-4 then
            actualY = h-4
        end
        rightClickMenu(actualX, actualY, 1)
        while true do
            local e = {os.pullEvent()}
            if e[1] == "mouse_click" and e[2] == 1 then
                if e[3] == w and e[4] == 1 then
                    closeApp()
                    break
                elseif e[3] >= actualX and e[3] <= actualX+11 then
                    if e[4] == actualY then -- cut
                        animSelected(" Cut       ",actualX,actualY,colors.lightGray,colors.black)
                        CUTPATH = shell.resolve(PATH..oldItems[item])
                        COPYPATH = ""
                        break
                    elseif e[4] == actualY+1 then -- copy
                        animSelected(" Copy      ",actualX,actualY+1,colors.lightGray,colors.black)
                        COPYPATH = shell.resolve(PATH..oldItems[item])
                        CUTPATH = ""
                        break
                    elseif e[4] == actualY+2 then -- delete
                        animSelected(" Delete    ",actualX,actualY+2,colors.lightGray,colors.black)
                        fs.delete(PATH..oldItems[item])
                        selectedItem = -1
                        break
                    elseif e[4] == actualY+3 then -- rename
                        animSelected(" Rename    ",actualX,actualY+3,colors.lightGray,colors.black)
                        local newname = PATH..prompt("Rename",oldItems[item])
                        if not newname == oldItems[item] and not fs.exists(newname) then fs.move(oldItems[item],newname) end
                        break
                    elseif e[4] == actualY+4 then -- open with
                        animSelected(" Open With ",actualX,actualY+4,colors.lightGray,colors.black)
                        local newx, newy = nil,nil
                        if actualX > 7 then
                            printPos(" Edit  ",actualX-7,actualY+3,colors.gray,colors.white)
                            printPos(" Paint ",actualX-7,actualY+4,colors.gray,colors.white)
                            newx = actualX-7
                            newy = actualY+3
                        else
                            printPos(" Edit  ",actualX+11,actualY+3,colors.gray,colors.white)
                            printPos(" Paint ",actualX+11,actualY+4,colors.gray,colors.white)
                            newx = actualX+11
                            newy = actualY+3
                        end
                        while true do
                            local e = {os.pullEvent()}
                            if e[1] == "mouse_click" and e[2] == 1 then
                                if e[3] == w and e[4] == 1 then
                                    RUNNING = false
                                    break
                                elseif e[3] >= newx and e[3] <= newx+7 then
                                    if e[4] == newy then --edit
                                        run("edit "..PATH..oldItems[item])
                                        break
                                    elseif e[4] == newy+1 then --paint
                                        run("paint "..PATH..oldItems[item])
                                        break
                                    else break end
                                else break end
                            end
                        end
                        break
                    elseif e[4] > actualY+4 or e[4] < actualY then break end
                else
                    break
                end
            end
        end
    elseif mode == 2 then
        if x > w-7 then
            actualX = w-7
        end
        if y > w-3 then
            actualY = w-3
        end
        rightClickMenu(actualX, actualY, 2)
        while true do
            local e = {os.pullEvent()}
            if e[1] == "mouse_click" and e[2] == 1 then
                if e[3] == w and e[4] == 1 then
                    closeApp()
                    break
                elseif e[3] >= actualX and e[3] <= actualX+8 then
                    if e[4] == actualY then -- cut
                        animSelected(" Cut    ",actualX,actualY,colors.lightGray,colors.black)
                        CUTPATH = shell.resolve(PATH..oldItems[item])
                        COPYPATH = ""
                        break
                    elseif e[4] == actualY+1 then -- copy
                        animSelected(" Copy   ",actualX,actualY+1,colors.lightGray,colors.black)
                        COPYPATH = shell.resolve(PATH..oldItems[item])
                        CUTPATH = ""
                        break
                    elseif e[4] == actualY+2 then -- delete
                        animSelected(" Delete ",actualX,actualY+2,colors.lightGray,colors.black)
                        fs.delete(PATH..oldItems[item])
                        selectedItem = -1
                        break
                    elseif e[4] == actualY+3 then -- rename
                        animSelected(" Rename ",actualX,actualY+3,colors.lightGray,colors.black)
                        local newname = PATH..prompt("Rename",oldItems[item])
                        if not newname == oldItems[item] and not fs.exists(newname) then fs.move(oldItems[item],newname) end
                        break
                    elseif e[4] > actualY+3 or e[4] < actualY then break end
                else
                    break
                end
            end
        end
    else
        if x > w-11 then
            actualX = w-11
        end
        if y > h-2 then
            actualY = h-2
        end
        rightClickMenu(actualX, actualY, 3)
        while true do
            local e = {os.pullEvent()}
            if e[1] == "mouse_click" and e[2] == 1 then
                if e[3] == w and e[4] == 1 then
                    closeApp()
                    break
                elseif e[3] >= actualX and e[3] <= actualX+12 then
                    if e[4] == actualY then -- paste
                        animSelected(" Paste      ",actualX,actualY,colors.lightGray,colors.black)
                        if COPYPATH ~= "" then
                            if not fs.exists(PATH..fs.getName(COPYPATH)) and fs.exists(COPYPATH) then fs.copy(COPYPATH, PATH..fs.getName(COPYPATH))
                            else
                                WALL = "Error"
                                COPYPATH = ""
                            end
                        elseif CUTPATH ~= "" then
                            if not fs.exists(PATH..fs.getName(CUTPATH)) and fs.exists(CUTPATH) then
                                fs.move(CUTPATH, PATH..fs.getName(CUTPATH))
                                CUTPATH = ""
                            else
                                WALL = "Error"
                                CUTPATH = ""
                            end
                        else
                            WALL = "Cut or Copy something first"
                        end
                        break
                    elseif e[4] == actualY+1 then -- new file
                        animSelected(" New File   ",actualX,actualY+1,colors.lightGray,colors.black)
                        local newfile = PATH..prompt("New File")
                        if not fs.exists(newfile) then
                            local f = fs.open(newfile, "w")
                            f.write("")
                            f.close()
                        else
                            WALL = "Item exists"
                        end
                        break
                    elseif e[4] == actualY+2 then -- new folder
                        animSelected(" New Folder ",actualX,actualY+2,colors.lightGray,colors.black)
                        local newfolder = PATH..prompt("New Folder")
                        if not fs.exists(newfolder) then
                            fs.makeDir(PATH..newfolder)
                        else
                            WALL = "Item exists"
                        end
                        break
                    elseif e[4] > actualY+2 or e[4] < actualY then break end
                else
                    break
                end
            end
        end
    end
end

local function evtHandler()
    drawScreen()
    while RUNNING do
        local e = {os.pullEvent()}
        if e[1] == "mouse_click" and e[2] == 1 and e[3] == w and e[4] == 1 then
            closeApp()
        elseif e[1] == "key" and e[2] == keys.q then
            closeApp()
        elseif e[1] == "mouse_scroll" then
            if e[2] == 1 and scrollpos < pospossible then
                scrollpos = scrollpos+1
            elseif e[2] == -1 and scrollpos > 1 then
                scrollpos = scrollpos-1
            end
            --logVars()
            drawItems()
        elseif e[1] == "mouse_click" and e[2] == 1 and e[3] >= 1 and e[3] <= 3 and e[4] == 2 then
            animSelected(" < ",1,2,colors.gray,colors.lightGray)
            if PATH ~= "/" then
                for i = PATH:len()-1,1,-1 do
                    if string.sub(PATH,i,i) == "/" then
                        PATH = string.sub(PATH,1,i)
                        break
                    end
                end
                selectedItem = -1
                scrollpos = 1
                drawScreen()
            else
                printPos(" < ",1,2,colors.lightGray,colors.white)
            end
        elseif e[1] == "mouse_click" then
            if e[4] >= 3 then
                pos = (e[4]-3)+scrollpos
                if pos <= #oldItems then
                    if e[3] >= 5 and e[3] <= oldItems[pos]:len()+4 then
                        if pos == selectedItem then
                            if pos < beginFiles and e[2] == 1 then
                                PATH = PATH..oldItems[pos].."/"
                                selectedItem = -1
                                scrollpos = 1
                                drawScreen()
                            elseif pos >= beginFiles and e[2] == 1 then
                                run(PATH..oldItems[pos])
                            else
                                if pos < beginFiles and e[2] == 2 then -- folder mode
                                    rightClickHandler(e[3],e[4],2,pos)
                                    drawScreen()
                                elseif pos >= beginFiles and e[2] == 2 then -- file mode
                                    rightClickHandler(e[3],e[4],1,pos)
                                    drawScreen()
                                end
                            end
                        else
                            selectedItem = pos
                            drawItems()
                            if pos >= beginFiles and e[2] == 2 then -- file mode
                                rightClickHandler(e[3],e[4],1,pos)
                                drawScreen()
                            elseif pos < beginFiles and e[2] == 2 then -- folder mode
                                rightClickHandler(e[3],e[4],2,pos)
                                drawScreen()
                            end
                        end
                    else
                        selectedItem = -1
                        drawItems()
                        if e[2] == 2 then
                            rightClickHandler(e[3],e[4],3,pos)
                            drawScreen()
                        end
                    end
                else
                    selectedItem = -1
                    drawItems()
                    if e[2] == 2 then
                        rightClickHandler(e[3],e[4],3,pos)
                        drawScreen()
                    end
                end
            end
        elseif e[1] == "term_resize" then
            w,h = term.getSize()
            drawScreen()
        end
    end
end

evtHandler()
clear(colors.black)
coroutine.yield()