-- libgen ver. 1.1a
-- lua ver. 5.3 compliant
-- you need 9lua
-- update: 2015/03/04
-- coded by Kenar (Kenji arisawa)
-- some generic stuffs --

str=require("str")
sub = string.sub
gsub = string.gsub
find = string.find
match = string.match
format = string.format
split = str.split

local function dbg(...)
	if DBG then
		print(...)
	end
end

-- for debugging
function chk_G(mod)
	local t={}
	local u
	for k,v in pairs(_G) do t[k]=true end
	u=require(mod)
	for k,v in pairs(_G) do
		if t[k]==nil then print(k,t[k]) end
	end
	return u
end

function printf(fmt,...)
  io.write(format(fmt,...))
end

-- donn't use dprint. we may discard this one in future
function dprint(fmt,...)
  io.write(format(fmt.."\n",...))
end

function fatal(fmt,...)
  io.write(format(fmt.."\n",...))
  os.exit()
end

function basename(path,sep)
    -- usage: d,f = basename(path)
    --   d.."/"..f is equivalent to the path if "/" exist
	local m1,m2
	sep=sep or "/"
	m1,m2=match(path,"^(.-)"..sep.."([^"..sep.."]*)$")
	if m1==nil then
		m1,m2=nil,path
	end
	return m1,m2
end

function readf(file)
	local f,s
	f=io.open(file)
    if f == nil then
      return nil
    end
	s = f:read("a")
    f:close()
    return s
end

function readn(fd,m)
-- simulate Plan 9 readn
  local n = m
  local t,s,r
  t = ""
  repeat
    s,r = p9.read(fd,n)
    if s == nil then
      if r == nil then
        return t,"eof" -- premature eof
      end
      return nil,r -- read error
    end
    n = n - #s
    t = t .. s
  until n == 0
  return t
end

function date(t,time)
  -- t: type of date format, "http", "iso"
  local mon = {[1]="Jan",[2]="Feb",[3]="Mar",[4]="Apr",[5]="May",[6]="Jun",
     [7]="Jul",[8]="Aug",[9]="Sep",[10]="Oct",[11]="Nov",[12]="Dec"}
  local wday={[1]="Sun",[2]="Mon",[3]="Tue",[4]="Wed",[5]="Thu",[6]="Fri",[7]="Sat"}
  if t == nil or t == "%c" then
    return os.date("%c",time)
  end
  local tm = os.date("!*t",time)  -- GMT time
  -- year (four digits), month (1--12), day (1--31), hour (0--23), min (0--59),
  -- sec (0--61), wday (weekday, Sunday is 1), yday (day of the year)
  if t == "http" then
    -- http date defined in rfc2068 used in "getlastmodified"
    return format("%s, %02d %s %d %02d:%02d:%02d GMT",
      wday[tm.wday],tm.day,mon[tm.month],tm.year,tm.hour,tm.min,tm.sec)
  elseif t == "iso" then
    -- ISO 8601 date used in "creationdate property"
    return format("%d-%02d-%02dT%02d:%02d:%02dZ",
      tm.year,tm.month,tm.day,tm.hour,tm.min,tm.sec)
  end
end

--[[	-- under construction
argopt() separate option part and argument part. the usage is:
args,opts,err = argopt(arg,opt)

opt gives flag list.
the format is simply, for example, opt="abc:de:fgh"
where ":" separate flags into three parts,
the first (abc in opt) is flags
the second (de in opt) is flags that are followed by an argument
the third (fgh in opt) is flags that is like second but allows multiple value
  like keywords in sort command
the following syntax is OK
  "abc"
  ":de"
  "abc::fgh"
  "abc:de"

named options are given by, for example:
  command -tabsize:4
or
  command '-tabsize=4'	# '' is required for Plan9 rc
names need not be registered in opt

empty option "-" terminate options part

with command args: -badalice - -e bob carol
a,t,r=argopt(arg,"abc:de:k")
we get for a:
	1	-e
	2	bob
	3	carol
	-1	foo
	0	./foo
and for t:
	1	abc
	2	de
	a	true
	d	alice
	b	true
--]]

-- args,opts,err = argopt(arg,opt)
function argopt(arg,opt)
  local t,t1,t2,t3,o,o1,o2,o3,c,r,x,n
  if opt == nil then
    return arg,nil
  end
  t,t1,t2,t3 = {},{},{},{}
  o = split(opt,":")
  o1,o2,o3 = o[1],o[2],o[3]
  if o2 == nil then
    o2 = ""
  end
  if o3 == nil then
    o3 = ""
  end
  for i=1,#o1 do
    t1[sub(o1,i,i)] = true
  end
  for i=1,#o2 do
    t2[sub(o2,i,i)] = true
  end
  for i=1,#o3 do
    t3[sub(o3,i,i)] = true
  end

  while #arg > 0 and sub(arg[1],1,1) == "-" do
    x = sub(arg[1],2)
	if #x == 0 then
      table.remove(arg,1)
      break
    end
    n = find(x,"([=:])")
    if n then
      t[sub(x,1,n-1)] = sub(x,n+1)
    else
      for i=1,#x do
        c = sub(x,i,i)
        if t1[c] then
          t[c] = true
        elseif t2[c] or t3[c] then
          --t[c] = sub(x,i+1)
  		  local u = sub(x,i+1)
          if u == "" then
            table.remove(arg,1)
            u = arg[1]
          end
          if t2[c] then
            if t[c] then
              r = format("#error: option %s: used more then once",c)
              return nil,nil,r
            end
            t[c] = u
          else -- then t3[c] ~= nil
            if t[c] == nil then
              t[c] = {}
            end
            table.insert(t[c],u)
          end
          if t[c] == nil or sub(u,1,1) == "-" then
            r = format("#error: no arg for %s",c)
            return nil,nil,r
          end
          break
        else
          r = "#error: bad option: "..c
          return nil,nil,r
        end
      end
    end
    table.remove(arg,1)
  end
  return arg,t,r
end



function dumpstr(s)
  if type(s)=="string" then
    local repl={["\n"]="\\n",["\t"]="\\t"}
    return gsub(s,"(%c)",repl)
  end
  return s
end

spectype={}
spectype["string"]=true
spectype["number"]=true
spectype["boolean"]=true

-- under construction
function prtab(t,n,done) -- print table
  if n==nil then
    done={}
    n=""
  end
  if t==nil then
    return
  end
  done[t]=true
  for k,v in pairs(t) do
    if type(v) == "table" then
      if done[v] then
        printf("%s%s\t%s # done\n",n,k,v)
      else
        printf("%s%s\t%s\n",n,k,v)
        prtab(v,n.."\t",done)
      end
    elseif spectype[type(v)] then
      printf("%s%s\t%s: %s\n",n,k,type(v),dumpstr(v))
    else
      printf("%s%s\t%s\n",n,k,v)
    end
  end
end

-- tprint should expand recursively. but currently not.
-- I reserved tabprint for recursive tprint
-- prtab is the trial for tabprint but under construction
local function tprint(...)
	local a
	a = {...}		-- table
	for n,u in ipairs(a) do
		if type(u) == "table" then
			for k,v in pairs(u) do
				print(k,v)
			end
		else
			print(u)
		end
	end
end


return {
  readf=readf,
  printf=printf,
  dprint=dprint,
  basename=basename,
  argopt=argopt,
  date=date,
  chk_G=chk_G,
  prtab=prtab,
  tprint=tprint,
  dbg=dbg,
  dumpstr=dumpstr,
}
--[[
NG code below
We want to call functions by name
return {
  readf,
  printf,
  dprint,
  basename,
  argopt,
  prtab,
  date,
  chk_G
}
--]]