.crft api

--Example format
--[[
furnace={m@minecraft;s@cobblestone;n@none
m:s&m:s&m:s&
m:s&n:n&m:s&
m:s&m:s&m:s&}
]]--

local meta = {
    getAmounts = function( self )
        local am = {}
        for k, v in pairs( self ) do
            am[ v ] = am[ v ] and am[ v ] + 1 or 1
        end
        return am
    end,
    getAmount = function( self, material )
        if type( material ) ~= "string" or type( self ) ~= "table" then
            error( "Expected table, string, got " .. type(self) ..", " .. material, 2 )
        end
        local am = 0
        for k, v in pairs( self ) do
            if v == material then
                am = am + 1
            end
        end
        return am
    end,
}

function makeCraft( tCraft )
    local checklist = {}
    for k, v in pairs( tCraft ) do
        local mod, item = v:match( "(%w+):(%w+)" )
        checklist[ mod ] = checklist[ mod ] and checklist[ mod ] + 1 or 1
        checklist[ item ] = checklist[ item ] and checklist[ item ] + 1 or 0
    end
    local tShortcuts = {}
    for k, v in pairs( checklist ) do
        if v > 1 then
            if not tShortcuts[ k:sub( 1, 1 ) ] then
                tShortcuts[ k:sub( 1, 1 ) ] = k
            elseif not tShortcuts[ k:sub( 1, 2 ) ] then
                tShortcuts[ k:sub( 1, 2 ) ] = k
            end
        end
    end
    local sShort = ""
    for k, v in pairs( tShortcuts ) do
        sShort = sShort .. k .. "@" .. v .. ";"
    end
    local tLines = {"","",""}
    for i = 1, 3 do
        tLines[ 1 ] = tLines[ 1 ] .. ( tCraft[ i ] or "none:none" ) .. "&"
    end
    for i = 5, 7 do
        tLines[ 2 ] = tLines[ 2 ] .. ( tCraft[ i ] or "none:none" ) .. "&"
    end
    for i = 9, 10 do
        tLines[ 3 ] = tLines[ 3 ] .. ( tCraft[ i ] or "none:none" ) .. "&"
    end
    local s = table.concat( tLines, "\n" )
    for short, long in pairs( tShortcuts ) do
        s = s:gsub( long, short )
    end
    if #sShort > 0 then
        s = sShort .. "\n" .. s
    end
    return s
end

local function parse( str )
    local tLines = {}
    for line in str:gmatch( "[^\r\n]+" ) do
        tLines[ #tLines + 1 ] = line
    end
    local tShortcuts = {}
    if tLines[ 1 ]:find( "@" ) then
        --encoding is present
        for s, o in tLines[ 1 ]:gmatch( "([^@]+)@([^;]+);?" ) do
            tShortcuts[ s ] = o
        end
        table.remove( tLines, 1 )
    end
    local tInv = {}
    local row = 0
    for _, str in ipairs( tLines ) do
        local l = 1
        for mod, item in str:gmatch( "(%w+):(%w+)" ) do
            tInv[ (row * 4) + l ] = ( tShortcuts[ mod ] or mod ) .. ":" .. ( tShortcuts[ item ] or item )
            l = l + 1
        end
        row = row + 1
    end
    return setmetatable( tInv, meta )
end

function loadCrafts( sPath )
    if not fs.exists( sPath ) then
        error( "No such file " .. sPath, 2 )
    end
    local tCrafts = {}
    local file = fs.open( sPath, "r" )
    for name, craft in file.readAll():gmatch( "(.-)%={(.-)}" ) do
        tCrafts[ name ] = parse( craft )
    end
    return tCrafts
end

function saveCrafts( sFile, tCrafts )
    local tSaves = {}
    for k, v in pairs( tCrafts ) do
        tSaves[ #tSaves + 1 ] = k .. "={" .. makeCraft( v ) .. "}"
    end
    sSave = table.concat( tSaves, "\n" )
    local file = fs.open( sFile, "w" )
    file.write( sSave )
    file.close()
end