customAssetHelper.lua

--[[
customAssetHelper.lua
v0.1.0
system for defining custom SMBX2 assets types similar with similar folder structures to costumes.
written by rixithechao, partially derived from the basegame costume framework
--]]

local lunajson = require("ext/lunajson")

local assetHelper = {}



-- ASSET SET METHODS
local function loadLunaFile(path, prefix)
    local luafile = nil;
    local func, err = loadfile(path)
    if(func)then
        luafile = func()
        if(type(luafile) ~= "table")then
            error(prefix.." Lua file \""..path.."\" did not return the table (got "..type(luafile)..")", 2)
        end
    else
        if(not err:find("such file"))then
            error(err,2)
        end
    end

    if(not luafile) then error(prefix.." Lua file failed to load correctly: \""..path.."\"",2) end

    return luafile;
end

local function tryLunaEvent(self, evName, ...)
    local currentLuna = self.currentLuna

    if  currentLuna ~= nil  and  currentLuna[evName] ~= nil  and  type(currentLuna[evName]) == "function"  then
        if  type(arg) == "table"  then
            currentLuna[evName](...)
        else
            currentLuna[evName]()
        end
    end
end

local function cleanup(self, ...)

    -- Clean up previous lua
    self:tryLunaEvent("onCleanup", ...)
    if(self.currentLuna ~= nil) then
        clearEvents(self.currentLuna)
    end

    self.currentLuna = nil
end




-- METHODS

--[[ registerAssetType args
    folder      string                         the folder the assets are stored in
    prefix      string                         the prefix for the global constants
    jsonfunc    function (jsonData,k,v,path)   a function for processing and adding to the imported json data
    images      list of strings                image filenames to check for
    singleluna  bool                           if true, functionality for managing a current luna.lua file will be included
]]
function assetHelper.importAssets(args)
    local assets = {}
    local lookup = {}

    -- Loop through alll subfolders
    for  k,v in ipairs(Misc.listDirectories(Misc.episodePath().."/"..args.folder))  do

        -- Ignore default (why do I have this check again)
        if  v ~= "default"  then


            -- CREATE THE PREFIX_NAME CONSTANT
            _G[args.prefix:upper().."_"..v:upper()] = k


            -- GET THE PATHS
            local absPath = Misc.episodePath()..args.folder.."\\"..v
            local path = args.folder.."/"..v


            -- IMPORT LUA
            local lunaTbl = nil
            local lunaFile = Misc.resolveFile(path.."\\luna.lua")
            if  lunaFile ~= nil  then
                lunaTbl = loadLunaFile(lunaFile, args.prefix)
            end


            -- IMPORT CONFIG JSON
            local jsonData = {}
            if  Misc.resolveFile(path.."\\config.json") ~= nil  then
                local f = io.open(absPath.."\\config.json", "r")
                local content = f:read("*all")
                f:close()
                jsonData = lunajson.decode(content)
            end


            -- IMPORT SPECIFIC IMAGES
            if  args.images ~= nil  then
                jsonData.img = {}

                for  k,v in ipairs(args.images)  do
                    local resolvePath = path.."/"..v..".png"
                    if  Misc.resolveFile(resolvePath)  then
                        jsonData.img[v] = Graphics.loadImageResolved(resolvePath)
                    end
                end
            end


            -- PROCESS JSON DATA, LOAD EXTRA FILES, ETC
            if  args.jsonfunc ~= nil  then
                args.jsonfunc(jsonData, k,v,path)
            end


            -- FINAL ASSET TABLE
            local thisAsset = table.join({
                key = v,
                path = path,
                absPath = absPath,
                luna = lunaTbl
            }, jsonData)


            -- INDEX THE ASSET
            assets[k] = thisAsset
            lookup[v] = k
        end
    end

    assets._lookup = lookup

    -- Luna.lua management functionality
    if  args.singleluna  then
        assets.tryLunaEvent = tryLunaEvent
        assets.cleanup = cleanup
    end


    -- Return
    return assets
end




return assetHelper