// Copyright 2024 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Package lru defines the IssuanceChainCache type, which implements IssuanceChainCache interface with Get and Set operations.
package lru

import (
	"context"
	"time"

	"github.com/hashicorp/golang-lru/v2/expirable"
)

type CacheOption struct {
	Size int
	TTL  time.Duration
}

type IssuanceChainCache struct {
	opt   CacheOption
	cache *expirable.LRU[string, []byte]
}

func NewIssuanceChainCache(opt CacheOption) *IssuanceChainCache {
	cache := expirable.NewLRU[string, []byte](int(opt.Size), nil, opt.TTL)
	return &IssuanceChainCache{
		opt:   opt,
		cache: cache,
	}
}

func (c *IssuanceChainCache) Get(_ context.Context, key []byte) ([]byte, error) {
	chain, _ := c.cache.Get(string(key))
	return chain, nil
}

func (c *IssuanceChainCache) Set(_ context.Context, key []byte, chain []byte) error {
	c.cache.Add(string(key), chain)
	return nil
}