local fs=require("filesystem")
local shell=require("shell")
local tty=require("tty")
local unicode=require("unicode")
local tx=require("transforms")
local text=require("text")

local dirsArg,ops=shell.parse(...)

if ops.help then
print([[Usage: ls [OPTION]... [FILE]...
  -a, --all                  do not ignore entries starting with .
      --full-time            with -l, print time in full iso format
  -h, --human-readable       with -l and/or -s, print human readable sizes
      --si                   likewise, but use powers of 1000 not 1024
  -l                         use a long listing format
  -r, --reverse              reverse order while sorting
  -R, --recursive            list subdirectories recursively
  -S                         sort by file size
  -t                         sort by modification time, newest first
  -X                         sort alphabetically by entry extension
  -1                         list one file per line
  -p                         append / indicator to directories
  -M                         display Microsoft-style file and directory
                             count after listing
      --no-color             Do not colorize the output (default colorized)
      --help                 display this help and exit
For more info run: man ls]])
return 0
end

if#dirsArg==0 then
table.insert(dirsArg,".")
end

local ec=0
local fOut=tty.isAvailable()and io.output().tty
local function perr(msg)io.stderr:write(msg,"\n")ec=2 end
local set_color=function()end
local function colorize()return end
if fOut and not ops["no-color"]then
local LSC=tx.foreach(text.split(os.getenv("LS_COLORS")or"",{":"},true),function(e)
local parts=text.split(e,{"="},true)
return parts[2],parts[1]
end)
colorize=function(info)
return
info.isLink and LSC.ln or
info.isDir and LSC.di or
LSC['*'..info.ext]or
LSC.fi
end
set_color=function(c)
io.write(string.char(0x1b),"[",c or"","m")
end
end
local msft={reports=0,proxies={}}
function msft.report(files,dirs,used,proxy)
local free=proxy.spaceTotal()-proxy.spaceUsed()
set_color()
local pattern="%5i File(s) %s bytes\n%5i Dir(s)  %11s bytes free\n"
io.write(string.format(pattern,files,tostring(used),dirs,tostring(free)))
end
function msft.tail(names)
local fsproxy=fs.get(names.path)
if not fsproxy then
return
end
local totalSize,totalFiles,totalDirs=0,0,0
for i=1,#names do
local info=names[i]
if info.isDir then
totalDirs=totalDirs+1
else
totalFiles=totalFiles+1
end
totalSize=totalSize+info.size
end
msft.report(totalFiles,totalDirs,totalSize,fsproxy)
local ps=msft.proxies
ps[fsproxy]=ps[fsproxy]or{files=0,dirs=0,used=0}
local p=ps[fsproxy]
p.files=p.files+totalFiles
p.dirs=p.dirs+totalDirs
p.used=p.used+totalSize
msft.reports=msft.reports+1
end
function msft.final()
if msft.reports<2 then return end
local groups={}
for proxy,report in pairs(msft.proxies)do
table.insert(groups,{proxy=proxy,report=report})
end
set_color()
print("Total Files Listed:")
for _,pair in ipairs(groups)do
local proxy,report=pair.proxy,pair.report
if#groups>1 then
print("As pertaining to: "..proxy.address)
end
msft.report(report.files,report.dirs,report.used,proxy)
end
end

if not ops.M then
msft.tail=function()end
msft.final=function()end
end

local function nod(n)
return n and(tostring(n):gsub("(%.[0-9]+)0+$","%1"))or"0"
end

local function formatSize(size)
if not ops.h and not ops['human-readable']and not ops.si then
return tostring(size)
end
local sizes={"","K","M","G"}
local unit=1
local power=ops.si and 1000 or 1024
while size>power and unit<#sizes do
unit=unit+1
size=size/power
end
return nod(math.floor(size*10)/10)..sizes[unit]
end

local function pad(txt)
txt=tostring(txt)
return#txt>=2 and txt or"0"..txt
end

local function formatDate(epochms)

local month_names={"January","February","March","April","May","June","July","August","September","October","November","December"}
if epochms==0 then return""end
local d=os.date("*t",epochms)
local day,hour,min,sec=nod(d.day),pad(nod(d.hour)),pad(nod(d.min)),pad(nod(d.sec))
if ops["full-time"]then
return string.format("%s-%s-%s %s:%s:%s ",d.year,pad(nod(d.month)),pad(day),hour,min,sec)
else
return string.format("%s %2s %2s:%2s ",month_names[d.month]:sub(1,3),day,hour,pad(min))
end
end

local function filter(names)
if ops.a then
return names
end
local set={path=names.path}
for _,info in ipairs(names)do
if fs.name(info.name):sub(1,1)~="."then
set[#set+1]=info
end
end
return set
end

local function sort(names)
local once=false
local function ni(v)
for i=1,#names do
local info=names[i]
if info.key==v.key then
return i
end
end
end
local function sorter(key)
once=true
table.sort(names,function(a,b)
local ast=names[ni(a)]
local bst=names[ni(b)]
return ast[key]>bst[key]
end)
end
if ops.t then sorter("time")end
if ops.X then sorter("ext")end
if ops.S then sorter("size")end
local rev=ops.r or ops.reverse
if not once then sorter("sort_name")rev=not rev end
if rev then
for i=1,#names/2 do
names[i],names[#names-i+1]=names[#names-i+1],names[i]
end
end
return names
end

local function dig(names,dirs,dir)
if ops.R then
local di=1
for i=1,#names do
local info=names[i]
if info.isDir then
local path=dir..(dir:sub(-1)=="/"and""or"/")
table.insert(dirs,di,path..info.name)
di=di+1
end
end
end
return names
end

local first_display=true
local function display(names)
local mt={}
local lines=setmetatable({},mt)
if ops.l then
lines.n=#names
local max_size_width=1
local max_date_width=0
for i=1,lines.n do
local info=names[i]
max_size_width=math.max(max_size_width,formatSize(info.size):len())
max_date_width=math.max(max_date_width,formatDate(info.time):len())
end
mt.__index=function(_,index)
local info=names[index]
local file_type=info.isLink and'l'or info.isDir and'd'or'f'
local link_target=info.isLink and string.format(" -> %s",info.link:gsub("/+$","")..(info.isDir and"/"or""))or""
local write_mode=info.fs.isReadOnly()and'-'or'w'
local size=formatSize(info.size)
local modDate=formatDate(info.time)
local format="%s-r%s %"..tostring(max_size_width).."s %"..tostring(max_date_width).."s"
local meta=string.format(format,file_type,write_mode,size,modDate)
local item=info.name..link_target
return{{name=meta},{color=colorize(info),name=item}}
end
elseif ops["1"]or not fOut then
lines.n=#names
mt.__index=function(_,index)
local info=names[index]
return{{color=colorize(info),name=info.name}}
end
else
local num_columns,items_per_column,width=0,0,tty.getViewport()-1
local function real(x,y)
local index=y+((x-1)*items_per_column)
return index<=#names and index or nil
end
local function max_name(column_index)
local max=0
for r=1,items_per_column do
local ri=real(column_index,r)
if not ri then break end
local info=names[ri]
max=math.max(max,unicode.wlen(info.name))
end
return max
end
local function measure()
local total=0
for column_index=1,num_columns do
total=total+max_name(column_index)+(column_index>1 and 2 or 0)
end
return total
end
while items_per_column<#names do
items_per_column=items_per_column+1
num_columns=math.ceil(#names/items_per_column)
if measure()<width then
break
end
end
lines.n=items_per_column
mt.__index=function(_,line_index)
return setmetatable({},{
__len=function()return num_columns end,
__index=function(_,column_index)
local ri=real(column_index,line_index)
if not ri then return end
local info=names[ri]
local name=info.name
return{color=colorize(info),name=name..string.rep(' ',max_name(column_index)-unicode.wlen(name)+(column_index<num_columns and 2 or 0))}
end,
})
end
end
for line_index=1,lines.n do
local line=lines[line_index]
for element_index=1,#line do
local e=line[element_index]
if not e then break end
first_display=false
set_color(e.color)
io.write(e.name)
end
set_color()
print()
end
msft.tail(names)
end
local header=function()end
if#dirsArg>1 or ops.R then
header=function(path)
if not first_display then print()end
set_color()
io.write(path,":\n")
end
end

local function stat(path,name)
local info={}
info.key=name
info.path=name:sub(1,1)=="/"and""or path
info.full_path=fs.concat(info.path,name)
info.isDir=fs.isDirectory(info.full_path)
info.name=name:gsub("/+$","")..(ops.p and info.isDir and"/"or"")
info.sort_name=info.name:gsub("^%.","")
info.isLink,info.link=fs.isLink(info.full_path)
info.size=info.isLink and 0 or fs.size(info.full_path)
info.time=fs.lastModified(info.full_path)/1000
info.fs=fs.get(info.full_path)
info.ext=info.name:match("(%.[^.]+)$")or""
return info
end

local function displayDirList(dirs)
while#dirs>0 do
local dir=table.remove(dirs,1)
header(dir)
local path=shell.resolve(dir)
local list,reason=fs.list(path)
if not list then
perr(reason)
else
local names={path=path}
for name in list do
names[#names+1]=stat(path,name)
end
display(dig(sort(filter(names)),dirs,dir))
end
end
end
local dir_set,file_set={},{path=shell.getWorkingDirectory()}
for _,dir in ipairs(dirsArg)do
local path=shell.resolve(dir)
local real,why=fs.realPath(path)
local access_msg="cannot access "..tostring(path)..": "
if not real then
perr(access_msg..why)
elseif not fs.exists(path)then
perr(access_msg.."No such file or directory")
elseif fs.isDirectory(path)then
table.insert(dir_set,dir)
else
table.insert(file_set,stat(dir,dir))
end
end

io.output():setvbuf("line")

local ok,msg=pcall(function()
if#file_set>0 then display(sort(file_set))end
displayDirList(dir_set)
msft.final()
end)

io.output():flush()
io.output():setvbuf("no")

assert(ok,msg)

return ec