#!/usr/bin/env lua

usage = "USAGE: manifold.lua (<manifold.mf> | <script.lua>).. <output.lua>)"

loads = {}

function slice( list, start_point, end_point )
    local list_length = table.getn( list )

    if start_point == nil then
        start_point = 1
    elseif start_point < 0 then
        start_point = list_length + start_point
        if start_point < 1 then
            start_point = 1
        end
    elseif (start_point == nil) or (start_point == 0) then
        start_point = 1
    end

    if end_point == nil then
        end_point = 1
    elseif end_point < 0 then
        end_point = start_point - end_point
        if end_point < 1 then
            end_point = list_length
        end
    elseif (end_point == nil) or (end_point == 0) then
        end_point = list_length
    end

    if start_point > end_point then
        local mid_point = start_point
        start_point = end_point
        end_point = mid_point
    end

    local next_index = start_point

    return function ()
        local index = next_index
        next_index = next_index + 1

        if index <= end_point then
            return list[ index ]    
        end
    end
end

function last( list )
    return list[ table.getn( list ) ]
end

function append( list, item )
    list[ table.getn( list ) + 1 ] = item
    return list
end

function ends_with( data, ending )
    return string.find( data, ending .. "$" )
end

function manifold( results, sources )
    for source in sources do
        if ends_with(source, "[.][mM][fF]") then
            if not manifold( results, io.open( source, "r" ):lines() )then
                return false
            end
        elseif ends_with(source, "[.][lL][uU][Aa]") then
            -- for line in io.open( source, "r" ):lines() do
            --    append( results, line )
            -- end
            append( results, source )
        else
            print( "Unrecognized source: " .. source )
            return false
        end
    end

    return results
end

if table.getn( arg ) == 0 then
    print( usage )
elseif table.getn( arg ) == 1 then
    print( usage )
elseif table.getn( arg )then
    local results = manifold( {}, slice( arg, 1 ) )
    if results then
        local output, err = io.open(last( arg ), "w")

--      if output then
--          for k,v in ipairs( results ) do
--              output:write( v, "\n" )
--          end
--      else
--          print( err )
--          os.exit( 2 )
--      end

        os.execute( 'luac -o ' .. last( arg ) .. ' ' .. table.concat( results, " " ) )
        os.exit( 0 )
    else
        os.exit( 1 )
    end
end