closure.lua

local userArch = 
{
    [1] = {
        id = 1,
        [1] = { index = 1, level = 1, pos = { x = 100, y = 100 }, finishedTime = 0
        }
    },
    [2] = {
        id = 2,
        [1] = { index = 1, level = 3, pos = { x = 150, y = 150 }, finishedTime = 18948788493
        },
        [2] = { index = 2, level = 3, pos = { x = 200, y = 200 }, finishedTime = 0
        },
        [3] = { index = 3, level = 4, pos = { x = 150, y = 150 }, finishedTime = 18948788493
        },
        [4] = { index = 4, level = 4, pos = { x = 200, y = 200 }, finishedTime = 18948788493
        },
        [5] = { index = 5, level = 3, pos = { x = 300, y = 300 }, finishedTime = 18948788493
        }
    }
}

local t = {
    id = 2,
    [1] = { index = 1, level = 3, pos = { x = 150, y = 150 }, finishedTime = 18948788493
    },
    [2] = { index = 2, level = 3, pos = { x = 200, y = 200 }, finishedTime = 0
    },
    [3] = { index = 3, level = 4, pos = { x = 150, y = 150 }, finishedTime = 18948788493
    },
    [4] = { index = 4, level = 4, pos = { x = 200, y = 200 }, finishedTime = 18948788493
    },
    [5] = { index = 5, level = 3, pos = { x = 300, y = 300 }, finishedTime = 18948788493
    }
}

local function addIsBuilding(userArch)
    local t = userArch

    local function addIsBuildingForIndex()
        t.isBuilding = os.time() < t.finishedTime
        if t.isBuilding then
            t.leftTime = t.finishedTime - os.time()
        else
            t.leftTime = 0
        end
    end
            
    local function addIsBuildingForId()
        for k, v in pairs(t) do
            t = v
            if k ~= "id" then
                addIsBuildingForIndex()
            end
        end
    end

    if userArch.index ~= nil then
        return addIsBuildingForIndex()
    end
    
    if userArch.id ~= nil then
        return addIsBuildingForId()
    end
    
    for k, v in pairs(userArch) do
        t = v
        return addIsBuildingForId()
    end
end

addIsBuilding(userArch)

print(userArch[1][1].isBuilding, userArch[1][1].leftTime)

addIsBuilding(t)

print(t[1].isBuilding, t[1].leftTime)
print(t[2].isBuilding, t[2].leftTime)