local DefaultCapacity = 16
local DummyFunc = function() end

local assert = assert

local PoolMT = {
    __newindex = function()
        error('table pool is read-only')
    end
}

local function TablePool(createOrResetFunc, disposeFunc, capcacity, reserved, ...)
    local pool = {}
    --pool data upvalues
    local poolCreateOrResetFunc = createOrResetFunc or DummyFunc
    local poolDisposeFunc = disposeFunc or DummyFunc
    local poolCapcacity = capcacity or DefaultCapacity
    local poolTable = LuaExt.CreateTable(poolCapcacity, 0)
    local poolCount = 0

    --for usage report
    local poolTryGetCount = 0
    local poolRecycleCount = 0
    local poolCreateCount = 0
    local poolDiscardCount = 0

    if reserved then
        for i = 1, reserved do
            poolTable[i] = poolCreateOrResetFunc(nil, ...)
        end
        poolCount = reserved
        poolCreateCount = reserved
    end

    --for performance, avoid use of table.remove and # operator
    function pool.TryGet(...)
        poolTryGetCount = poolTryGetCount + 1
        if poolCount > 0 then
            local item = poolTable[poolCount]
            poolCount = poolCount - 1
            return poolCreateOrResetFunc(item, ...)
        else
            poolCreateCount = poolCreateCount + 1
            return poolCreateOrResetFunc(nil, ...)
        end
    end
    
    function pool.Recycle(item, ...)
        assert(item, "table pool recycle with nil")
        poolRecycleCount = poolRecycleCount + 1
        poolDisposeFunc(item, ...)
        if poolCount < poolCapcacity then
            poolCount = poolCount + 1
            poolTable[poolCount] = item
        else
            poolDiscardCount = poolDiscardCount + 1
        end
    end

    function pool.Reset(item, ...)
        assert(item, "table pool reset with nil")
        poolDisposeFunc(item, ...)
        return poolCreateOrResetFunc(item, ...)
    end
    
    function pool.GetUsageReport(reset)
        local gc, rc, nc, dc = 
            poolTryGetCount, poolRecycleCount, poolCreateCount, poolDiscardCount
        if reset then
            poolTryGetCount = 0
            poolRecycleCount = 0
            poolCreateCount = 0
            poolDiscardCount = 0
        end
        return poolCount, poolCapcacity, gc, rc, nc, dc
    end

    return setmetatable(pool, PoolMT)
end

return TablePool