lsa

--[[ lsa: List Advanced
    Allows the display of hidden files and file sizes
    By Nitrogen Fingers
]]--

local tArgs = {...}
local paths = {}
local files = {}
local errors = {}
local _long, _all = false, false
local w, h = term.getSize()
local _,cy = term.getCursorPos()
local _maxlen, _maxsize, _maxdrive = 0,0,0

--Performs a screen-specific print that will throw an event if the bottom of the screen is reached.
--Doesn't do any wrapping, so make sure the string is the right size
local function lprint(str, col)
    if term.isColour() and col then term.setTextColour(col)
    else term.setTextColour(colours.white) end
    if cy == 1 then
        os.pullEvent("key")
        _,cy = term.getCursorPos()
    end
    local _,_yold = term.getCursorPos()
    print(str)
    local _,_ynew = term.getCursorPos()
    cy = cy - 1 + (_ynew - _yold)
end

--Gets the combined size of a given directory
local function calculateDirectorySize(_fullpath)
    local _size = 0
    local _list = fs.list(_fullpath)
    for i=1,#_list do
        local _newPath = _fullpath.."/".._list[i]
        if fs.isDir(_newPath) then
            _size = _size + calculateDirectorySize(_newPath)
        else
            _size = _size + fs.getSize(_newPath)
        end
    end
    return _size
end

--Figures out the spacing for the columns in a long print
--There's a memory inefficiency here; we're doing a recursive call twice.
--But really, meh.
local function calculateColumnWidths(_list, _path)
    for i=1,#_list do
        local _fullpath = shell.resolve(_path).."/".._list[i]
        if fs.isDir(_fullpath) and _long then
            _maxsize = math.max(_maxsize, #tostring(calculateDirectorySize(_fullpath)))
        elseif _long then
            _maxsize = math.max(_maxsize, #tostring(fs.getSize(_fullpath)))
        end
        if _list[i]:sub(1,1) ~= "." or _all then
            _maxlen = math.max(_maxlen, #_list[i])
            _maxdrive = math.max(_maxdrive, #fs.getDrive(_fullpath))
        end
    end
end

local function printUsageInfo()
    lprint("Usage: ls [option]... [path]...")
    lprint("Lists all files in the specified directories. Files are sorted by type and alpabetically")
    lprint("-l      use long listing format")
    lprint("-a      do not ignore entries starting with \'.\'")
    lprint("-h      display usage info")
end

local function printListing(_list, _path)
    local _files = {}
    for i=#_list,1,-1 do
        local _fullPath = shell.resolve(_path).."/".._list[i]

        if not _all and _list[i]:sub(1,1) == "." then
            table.remove(_list, i)
        elseif not fs.isDir(_fullPath) then
            table.insert(_files, table.remove(_list, i))
        end
    end
    table.sort(_files)
    table.sort(_list)

    local _c = ""
    if _long then
        for i=1,#_list do
            local _fullPath = shell.resolve(_path).."/".._list[i]
            local _size = tostring(calculateDirectorySize(_fullPath))
            term.setTextColour(colours.white)
            local _read = "d"
            if fs.isReadOnly(_fullPath) then _read = _read.."-" else _read = _read.."w" end
            local _drive = fs.getDrive(_fullPath)
            term.write(_read.." "..string.rep(" ", _maxsize - #_size).._size.." ".._drive..
                    string.rep(" ", _maxdrive - #_drive + 1))
            if term.isColour() then term.setTextColour(colours.green) end
            term.write(_list[i])
            lprint("")
        end
        for i=1,#_files do
            local _fullPath = shell.resolve(_path).."/".._files[i]
            local _size = tostring(fs.getSize(_fullPath))
            local _read = "f"
            local _drive = fs.getDrive(_fullPath)
            if fs.isReadOnly(_fullPath) then _read = _read.."-" else _read = _read.."w" end
            lprint(_read.." "..string.rep(" ", _maxsize - #_size).._size.." ".._drive..
                    string.rep(" ", _maxdrive - #_drive + 1).._files[i], colours.white)
        end
    else
        for i=1,#_list do
            if #_c + _maxlen + 1 > w then
                lprint(_c, colours.green)
                _c = ""
            end
            _c = _c.._list[i]..string.rep(" ", _maxlen - #_list[i] + 1)
        end
        if _c ~= "" then
            lprint(_c, colours.green)
            _c = ""
        end
        for i=1,#_files do
            if #_c + _maxlen + 1 > w then
                lprint(_c, colours.white)
                _c = ""
            end
            _c = _c.._files[i]..string.rep(" ", _maxlen - #_files[i] + 1)
        end
        if _c ~= "" then lprint(_c, colours.white) end
    end
end

for i=1,#tArgs do
    if tArgs[i]:sub(1,1) == "-" then
        if #paths > 0 or #files > 0 then
            table.insert(errors, "Option "..tArgs[i].." found after path")
        end

        for j=2,#tArgs[i] do
            local _comm = tArgs[i]:sub(j,j)
            if _comm == "l" then
                _long = true
            elseif _comm == "a" then
                _all = true
            elseif _comm == "h" then
                printUsageInfo()
                return
            else
                table.insert(errors, "Unrecognized option \'"..tArgs[i].."\'. Use -h for help.")
            end
        end
    else
        if not fs.exists(shell.resolve(tArgs[i])) then
            table.insert(errors, "No such file or directory: "..tArgs[i])
        elseif fs.isDir(shell.resolve(tArgs[i])) then
            table.insert(paths, tArgs[i])
            calculateColumnWidths(fs.list(shell.resolve(tArgs[i])), tArgs[i])
        else
            table.insert(files, tArgs[i])
            _maxlen = math.max(_maxlen, #tArgs[i])
            _maxsize = math.max(_maxsize, #tostring(fs.getSize(shell.resolve(tArgs[i]))))
            _maxdrive = math.max(_maxdrive, #fs.getDrive(shell.resolve(tArgs[i])))
        end
    end
end

if #paths == 0 and #files == 0 then
    table.insert(paths, ".")
    calculateColumnWidths(fs.list(shell.resolve(".")), ".")
end
for _,err in pairs(errors) do lprint(err, colours.red) end
if #errors > 0 then
    return
end


if #files > 0 then
    printListing(files, ".")
    if #paths > 0 then lprint("") end
end

for i=1,#paths do
    if #paths > 1 or #files > 1 then lprint(paths[i]..":") end
    printListing(fs.list(shell.resolve(paths[i])), paths[i])
    if i ~= #paths then lprint("") end
end