// Copyright © 2022 siddharth ravikumar <s@ricketyspace.net>
// SPDX-License-Identifier: ISC

package cache

import (
	"bytes"
	"fmt"
	"testing"
	"time"
)

func TestNewCache(t *testing.T) {
	c := NewCache()
	if c == nil {
		t.Errorf("cache is nil")
		return
	}
	if c.store == nil {
		t.Errorf("cache.store is nil")
		return
	}
	// Try manually adding an item.
	c.store["foo"] = item{
		value:   []byte("bar"),
		expires: time.Now().Add(time.Second * 10),
	}
	if bytes.Compare(c.store["foo"].value, []byte("bar")) != 0 {
		t.Errorf("cache.store['foo'] is not bar")
		return
	}
}

func TestCacheSet(t *testing.T) {
	c := NewCache()
	if c == nil {
		t.Errorf("cache is nil")
		return
	}
	exp := time.Now().Add(time.Second * 10)
	c.Set("foo", []byte("bar"), exp)
	if bytes.Compare(c.store["foo"].value, []byte("bar")) != 0 {
		t.Errorf("cache.store['foo'] is not bar")
		return
	}
	if c.store["foo"].expires.Unix() != exp.Unix() {
		t.Errorf("cache.store['foo'].expires no set correctly")
		return
	}
}

func TestCacheGet(t *testing.T) {
	c := NewCache()
	if c == nil {
		t.Errorf("cache is nil")
		return
	}

	// Test 1
	exp := time.Now().Add(time.Second * 10)
	c.Set("foo", []byte("bar"), exp)
	if bytes.Compare(c.Get("foo"), []byte("bar")) != 0 {
		t.Errorf("cache.Get(foo) is not bar")
		return
	}

	// Test 2
	exp = time.Now().Add(time.Second * -10)
	c.Set("sna", []byte("fu"), exp)
	if bytes.Compare(c.Get("sna"), []byte{}) != 0 {
		t.Errorf("cache.Get(sna) is not empty: %s", c.Get("sna"))
		return
	}
}

func TestConcurrentSets(t *testing.T) {
	// Expiration time for all keys.
	exp := time.Now().Add(time.Second * 120)

	// Generate some keys.
	keys := make([]string, 0)
	maxKeys := 1000
	for i := 0; i < maxKeys; i++ {
		keys = append(keys, fmt.Sprintf("key-%d", i))
	}

	// Go routing for adding keys to cache.
	addToCache := func(c *Cache, keys []string, donec chan int) {
		for i := 0; i < len(keys); i++ {
			c.Set(keys[i], []byte(fmt.Sprintf("val-%d", i)), exp)
		}
		donec <- 1
	}

	// Init. cache.
	c := NewCache()
	if c == nil {
		t.Errorf("cache is nil")
		return
	}
	donec := make(chan int)

	// Add keys to cache concurrently.
	go addToCache(c, keys, donec)
	go addToCache(c, keys, donec)
	go addToCache(c, keys, donec)
	completed := 0
	for completed < 3 {
		<-donec
		completed += 1
	}

	if len(c.store) != maxKeys {
		t.Errorf("number of keys in store != %d: %v", maxKeys, c.store)
	}
}