#!/usr/bin/env luajit

loadstring = loadstring or load -- for lua 5.2 compat

-- Tracekback (error printout)
local function traceback(message)
   local tp = type(message)
   if tp ~= "string" and tp ~= "number" then return message end
   local debug = _G.debug
   if type(debug) ~= "table" then return message end
   local tb = debug.traceback
   if type(tb) ~= "function" then return message end
   return tb(message)
end

-- help
local help = [==[
Usage: th [options] [script.lua [arguments]]

Options:
  -l name            load library name
  -e statement       execute statement
  -h,--help          print this help
  -a,--async         preload async (libuv) and start async repl (BETA)
  -g,--globals       monitor global variables (print a warning on creation/access)
  -gg,--gglobals     monitor global variables (throw an error on creation/access)
  -x,--gfx           start gfx server and load gfx env
  -i,--interactive   enter the REPL after executing a script ]==]

-- parse arguments
local asyncrepl,run,interactive,progargs,statement,lib,globs,sglobs,lgfx,_
local parg = arg
local nextarg
for _,arg in ipairs(parg) do
   -- nextarg set?
   if nextarg == 'exec' then
      statement = arg
      nextarg = nil
   elseif nextarg == 'lib' then
      lib = arg
      nextarg = nil
   elseif not progargs then
       _,_,lib = arg:find('^%-l(.*)')
       if lib == '' then lib = nil end
   end
   -- load libraries
   if lib then
      local ok, err = xpcall(function() require(lib) end, traceback)
      if not ok then
         print('could not load ' .. lib .. ', skipping')
	 print(err)
      end
   elseif progargs then
      -- program args
      table.insert(progargs,arg)
   elseif not statement then
      -- option?
      local _,_,option = arg:find('^%-%-(.*)')
      local shortopt
      if not option then
         _,_,shortopt = arg:find('^%-(.*)')
      end
      if option or shortopt then
         -- help
         if shortopt == 'h' or option == 'help' then
            print(help)
	    return
         elseif shortopt == 'i' or option == 'interactive' then
            interactive = true
         elseif shortopt == 'e' then
            nextarg = 'exec'
         elseif shortopt == 'a' or option == 'async' then
            asyncrepl = true
            interactive = true
            async = require 'async'
         elseif shortopt == 'g' or option == 'globals' then
            globs = true
         elseif shortopt == 'gg' or option == 'gglobals' then
            sglobs = true
         elseif shortopt == 'x' or option == 'gfx' then
            lgfx = true
         elseif shortopt == 'l' then
            nextarg = 'lib'
         else
            -- unknown
            print('Error: unrecognized flag --' .. (option ~= nil and option or shortopt))
            print(help)
	    return
         end
      else
         -- exec program
         run = arg
         progargs = {}
         for k,v in pairs(parg) do
            if k <= 0 then
               progargs[k] = v
            end
         end
      end
   end
end

-- load repl
local repl = require 'trepl'
local col = require 'trepl.colorize'

-- load startup file
if os.getenv('TREPLSTARTUP') and not (interactive or statement) then
    dofile(os.getenv('TREPLSTARTUP'))
end

-- load gfx env?
if lgfx then
   local ok = pcall(require, 'gfx.js')
   if ok then
      gfx.startserver()
      gfx.clear()
      gfx.show()
      sys.sleep(1)
   else
      print('could not load gfx.js, please install with: luarocks install gfx.js')
   end
end

-- monitor globals
if globs then
   monitor_G()
elseif sglobs then
   monitor_G(true)
end

-- statement
if statement then
   -- exec statement:
   local s = loadstring(statement)
   local ok,res = pcall(s)
   if not ok then
      print(res)
      return
   end
   -- quit by default
   if not interactive then return end
end

-- run program
if run then
   -- set prog args:
   arg = progargs
   -- run
   dofile(run)
   -- quit by default
   if not interactive then return end
end

-- start repl
if asyncrepl then
   -- verbose
   print(
[[
 
  ______             __   ]]..col.Black[[|  Torch7]]..[[ 
 /_  __/__  ________/ /   ]]..col.Black[[|  ]]..col.magenta[[Scientific computing for Lua.]]..[[ 
  / / / _ \/ __/ __/ _ \  ]]..col.Black[[|  Type ? for help]]..[[ 
 /_/  \___/_/  \__/_//_/  ]]..col.Black[[|  ]]..col.blue[[https://github.com/torch]]..[[ 
                          ]]..col.Black[[|  ]]..col.blue[[http://torch.ch]]..[[ 
 
]] .. col.red('WARNING: ') .. col.Black('you are running an experimental asynchronous interpreter for Torch.') .. [[ 
]] .. col.Black('Note 1: It has no support for readline/completion yet.') .. [[ 
]] .. col.Black('Note 2: The event-loop has been started in the background: ') .. col.none('async.go()') .. [[ 
]] .. col.Black('        Statements like ') .. col.none('async.setInterval(1000, function() print("test") end)') .. [[ 
]] .. col.Black('        are run asynchronously to the interpreter. ') .. [[ 
]] .. col.Black('Note 3: See ') .. col.blue('http://github.com/clementfarabet/async') .. col.Black(' for help' ) .. [[ 
 
]]
)

   -- BETA: async repl
   async.repl()
   async.go()

else

   -- verbose
   print(
[[
 
  ______             __   ]]..col.Black[[|  Torch7]]..[[ 
 /_  __/__  ________/ /   ]]..col.Black[[|  ]]..col.magenta[[Scientific computing for Lua.]]..[[ 
  / / / _ \/ __/ __/ _ \  ]]..col.Black[[|  Type ? for help]]..[[ 
 /_/  \___/_/  \__/_//_/  ]]..col.Black[[|  ]]..col.blue[[https://github.com/torch]]..[[ 
                          ]]..col.Black[[|  ]]..col.blue[[http://torch.ch]]..[[ 
]]
)

   -- globs?
   if globs then
      print(
         col.red('WARNING: ') .. col.Black('global monitoring is on.\n') ..
         col.Black('This is typically not a good idea when running a live interpreter.\n')
      )
   end

   -- regular repl
   repl()
end