/*
 * config_test.go - tests for setting up the config file
 *
 * Copyright 2017 Google Inc.
 * Author: Joe Richey (joerichey@google.com)
 *
 * 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 actions

import (
	"io/ioutil"
	"log"
	"os"
	"testing"
	"time"
)

const testTime = 10 * time.Millisecond

func init() {
	// All our testing uses an alternative config file location, so we don't
	// need root to run the tests
	ConfigFileLocation = "fscrypt_test.conf"
}

// Tests that we can make the config files with and without legacy settings
func TestMakeConfig(t *testing.T) {
	defer os.RemoveAll(ConfigFileLocation)

	err := NewConfigFile(testTime, true)
	if err != nil {
		t.Error(err)
	}
	os.RemoveAll(ConfigFileLocation)

	err = NewConfigFile(testTime, false)
	if err != nil {
		t.Error(err)
	}
}

// Tests that we can find valid hashing costs for various time targets and the
// estimations are somewhat close to the targets.
func TestCostsSearch(t *testing.T) {
	for _, target := range []time.Duration{
		100 * time.Microsecond,
		1 * time.Millisecond,
		10 * time.Millisecond,
		100 * time.Millisecond,
	} {
		costs, err := getHashingCosts(target)
		if err != nil {
			t.Error(err)
		}
		actual, err := timeHashingCosts(costs)
		if err != nil {
			t.Error(err)
		}

		// Timing tests are only reliable for sufficiently long targets.
		if target > time.Millisecond {
			if actual*2 < target {
				t.Errorf("actual=%v is too small (target=%v)", actual, target)
			}
			if target*2 < actual {
				t.Errorf("actual=%v is too big (target=%v)", actual, target)
			}
		}
	}
}

func benchmarkCostsSearch(b *testing.B, target time.Duration) {
	// Disable logging for benchmarks
	log.SetOutput(ioutil.Discard)
	for i := 0; i < b.N; i++ {
		_, err := getHashingCosts(target)
		if err != nil {
			b.Fatal(err)
		}
	}
}

func BenchmarkCostsSearch10ms(b *testing.B) {
	benchmarkCostsSearch(b, 10*time.Millisecond)
}

func BenchmarkCostsSearch100ms(b *testing.B) {
	benchmarkCostsSearch(b, 100*time.Millisecond)
}

func BenchmarkCostsSearch1s(b *testing.B) {
	benchmarkCostsSearch(b, time.Second)
}