--:Minify:--
local cloptions = {
    a    = false,
    h    = false,
    l    = false,
    help = false,
}
local inpArgs = { ... }
local args    = {}
local name    = syscall.getTask(syscall.getpid()).name

for _, v in pairs(inpArgs) do
    if v:sub(1, 2) == "--" then
        local opt = v:sub(3)
        if cloptions[opt] == nil then
            print(name .. ": unrecognized option '" .. v .. "'.")
            print("try '" .. name .. " --help' for more information.")
            return
        end
        cloptions[opt] = true
    elseif v:sub(1, 1) == "-" then
        for i = 2, #v do
            local opt = v:sub(i, i)
            if cloptions[opt] == nil then
                print(name .. ": invalid option '-" .. opt .. "'.")
                print("try '" .. name .. " --help' for more information.")
                return
            end
            cloptions[opt] = true
        end
    else
        table.insert(args, v)
    end
end

if cloptions.help then
    print("Usage: " .. name .. " [OPTION]... [DIR]")
    print("List all entries in the specified DIRectory, or cwd if not specified.")
    print("")
    print("Options:")
    print("  -a          do not ignore entries starting with .")
    print("  -h          with -l, print sizes in human readable format")
    print("  -l          use a long listing format")
    print("  --help      display this help and exit")
    return
end

local fs  = require("sys.fs")
local dir = args[1] or ""
if dir:sub(1, 1) ~= "/" then
    dir = syscall.getcwd() .. "/" .. dir
end
if dir:sub(-1) ~= "/" then dir = dir .. "/" end

if not fs.isDir(dir) then
    print(name .. ": cannot access '" .. (args[1] or dir) .. "': no such directory")
    return
end

local function permStr(perms, etype)
    local function b(n) return math.floor(perms / (2^n)) % 2 == 1 end
    local t
    if etype == 0x01 then t = "l"
    elseif etype == nil then t = "-"
    else t = "-" end

    local ur = b(5) and "r" or "-"
    local uw = b(4) and "w" or "-"
    local ux = b(9) and (b(6) and "s" or "x") or (b(6) and "S" or "-")
    local gr = b(3) and "r" or "-"
    local gw = b(2) and "w" or "-"
    local gx = b(8) and "x" or "-"
    local wr = b(1) and "r" or "-"
    local ww = b(0) and "w" or "-"
    local wx = b(7) and "x" or "-"

    return t .. ur .. uw .. ux .. gr .. gw .. gx .. wr .. ww .. wx
end

local sizePrefixes = { "K", "M", "G", "T" }
local function humanSize(size)
    local scale = 0
    while size >= 1024 and scale < #sizePrefixes do
        size  = size / 1024
        scale = scale + 1
    end
    if scale == 0 then return tostring(size) end
    if size < 10 then
        return string.format("%.1f%s", size, sizePrefixes[scale])
    end
    return math.floor(size) .. sizePrefixes[scale]
end

local screenSizeStr = syscall.devctl(1, "size")
local sizeX = tonumber(screenSizeStr:match("^(%d+)")) or 80

local list = fs.list(dir)
if not cloptions.a then
    for i = #list, 1, -1 do
        if list[i]:sub(1, 1) == "." then table.remove(list, i) end
    end
end
table.sort(list)

if #list == 0 then return end

if cloptions.l then
    for _, v in ipairs(list) do
        local fullPath = dir .. v
        local stat = syscall.lstat and syscall.lstat(fullPath) or syscall.stat(fullPath)
        local isDir  = fs.isDir(fullPath)
        local isSym  = stat and stat.etype == 0x01

        local typeChar
        if isSym    then typeChar = "l"
        elseif isDir then typeChar = "d"
        else              typeChar = "-" end

        local pstr
        if stat and stat.perms then
            pstr = permStr(stat.perms, stat.etype)
        else
            pstr = typeChar .. "---------"
        end

        local size = (stat and stat.size) or 0
        local sizeStr = cloptions.h and humanSize(size) or tostring(size)

        local mtime = (stat and stat.modified) and math.floor(stat.modified / 1000) or 0

        local owner = (stat and tostring(stat.owner)) or "0"
        local group = (stat and tostring(stat.group)) or "0"

        printInline(pstr .. " " .. owner .. " " .. group .. " ")
        printInline(string.format("%6s", sizeStr) .. " ")
        printInline(tostring(mtime) .. " ")

        if isSym then
            syscall.devctl(1, "sfgc", 6)
            printInline(v)
            syscall.devctl(1, "sfgc", 1)
            local ok, target = pcall(syscall.readlink, fullPath)
            if ok then
                printInline(" -> ")
                local targetExists = pcall(syscall.stat, fullPath)
                syscall.devctl(1, "sfgc", targetExists and 6 or 2)
                printInline(target)
                syscall.devctl(1, "sfgc", 1)
            end
        elseif isDir then
            syscall.devctl(1, "sfgc", 4)
            printInline(v)
            syscall.devctl(1, "sfgc", 1)
        else
            local isExec = stat and stat.perms and (math.floor(stat.perms / (2^9)) % 2 == 1)
            syscall.devctl(1, "sfgc", isExec and 3 or 1)
            printInline(v)
            syscall.devctl(1, "sfgc", 1)
        end
        print("")
    end
    return
end

local colWidth = 0
for _, v in ipairs(list) do
    if #v + 2 > colWidth then colWidth = #v + 2 end
end
local numCols = math.max(1, math.floor(sizeX / colWidth))

for i, v in ipairs(list) do
    local fullPath = dir .. v
    local isDir    = fs.isDir(fullPath)
    local stat     = syscall.lstat and syscall.lstat(fullPath) or syscall.stat(fullPath)
    local isSym    = stat and stat.etype == 0x01

    if isSym then
        syscall.devctl(1, "sfgc", 6)
    elseif isDir then
        syscall.devctl(1, "sfgc", 4)
    else
        local isExec = stat and stat.perms and (math.floor(stat.perms / (2^9)) % 2 == 1)
        syscall.devctl(1, "sfgc", isExec and 3 or 1)
    end

    printInline(v)
    syscall.devctl(1, "sfgc", 1)
    printInline((" "):rep(colWidth - #v))

    if i % numCols == 0 then print("") end
end

if #list % numCols ~= 0 then print("") end