// Copyright (C) 2019 Marius Schellenberger

package cache

import (
	"git.giftfish.de/ston1th/gowiki/pkg/core"
	"sync"
	"time"
)

type CachedPage struct {
	Page      *core.Page
	CacheTime time.Time
}

type Cache struct {
	sync.RWMutex
	Cache map[string]*CachedPage
}

func NewCache() *Cache {
	return &Cache{Cache: make(map[string]*CachedPage)}
}

func (c *Cache) Add(title string, p *core.Page) {
	now := time.Now()
	c.Lock()
	defer c.Unlock()
	cp, ok := c.Cache[title]
	if ok && now.After(cp.CacheTime) {
		cp.Page = p
		cp.CacheTime = now
		c.Cache[title] = cp
		return
	}
	c.Cache[title] = &CachedPage{p, now}
}

func (c *Cache) Get(title string) (p *core.Page) {
	c.RLock()
	defer c.RUnlock()
	if cp, ok := c.Cache[title]; ok {
		p = new(core.Page)
		*p = *cp.Page
		return
	}
	return nil
}

func (c *Cache) Delete(title string) {
	c.Lock()
	delete(c.Cache, title)
	c.Unlock()
}