package ethlog

import (
	"fmt"
	"io/ioutil"
	"math/rand"
	"os"
	"sync"
	"testing"
	"time"
)

type TestLogSystem struct {
	mutex  sync.Mutex
	output string
	level  LogLevel
}

func (ls *TestLogSystem) Println(v ...interface{}) {
	ls.mutex.Lock()
	ls.output += fmt.Sprintln(v...)
	ls.mutex.Unlock()
}

func (ls *TestLogSystem) Printf(format string, v ...interface{}) {
	ls.mutex.Lock()
	ls.output += fmt.Sprintf(format, v...)
	ls.mutex.Unlock()
}

func (ls *TestLogSystem) SetLogLevel(i LogLevel) {
	ls.mutex.Lock()
	ls.level = i
	ls.mutex.Unlock()
}

func (ls *TestLogSystem) GetLogLevel() LogLevel {
	ls.mutex.Lock()
	defer ls.mutex.Unlock()
	return ls.level
}

func (ls *TestLogSystem) CheckOutput(t *testing.T, expected string) {
	ls.mutex.Lock()
	output := ls.output
	ls.mutex.Unlock()
	if output != expected {
		t.Errorf("log output mismatch:\n   got: %q\n  want: %q\n", output, expected)
	}
}

}

func TestLoggerFlush(t *testing.T) {
	Reset()

	logger := NewLogger("TEST")
	testLogSystem := &TestLogSystem{level: WarnLevel}
	AddLogSystem(testLogSystem)
	for i := 0; i < 5; i++ {
		logger.Errorf(".")
	}
	Flush()
	output := testLogSystem.Output
	if output != "[TEST] .[TEST] .[TEST] .[TEST] .[TEST] ." {
		t.Error("Expected complete logger output '[TEST] .[TEST] .[TEST] .[TEST] .[TEST] .', got ", output)
	}
}

func TestLoggerPrintln(t *testing.T) {
	Reset()

	logger := NewLogger("TEST")
	testLogSystem := &TestLogSystem{level: WarnLevel}
	AddLogSystem(testLogSystem)
	logger.Errorln("error")
	logger.Warnln("warn")
	logger.Infoln("info")
	logger.Debugln("debug")
	Flush()

	testLogSystem.CheckOutput(t, "[TEST] error\n[TEST] warn\n")
}

func TestLoggerPrintf(t *testing.T) {
	Reset()

	logger := NewLogger("TEST")
	testLogSystem := &TestLogSystem{level: WarnLevel}
	AddLogSystem(testLogSystem)
	logger.Errorf("error to %v\n", []int{1, 2, 3})
	logger.Warnf("warn")
	logger.Infof("info")
	logger.Debugf("debug")
	Flush()
	testLogSystem.CheckOutput(t, "[TEST] error to [1 2 3]\n[TEST] warn")
}

func TestMultipleLogSystems(t *testing.T) {
	Reset()

	logger := NewLogger("TEST")
	testLogSystem0 := &TestLogSystem{level: ErrorLevel}
	testLogSystem1 := &TestLogSystem{level: WarnLevel}
	AddLogSystem(testLogSystem0)
	AddLogSystem(testLogSystem1)
	logger.Errorln("error")
	logger.Warnln("warn")
	Flush()

	testLogSystem0.CheckOutput(t, "[TEST] error\n")
	testLogSystem1.CheckOutput(t, "[TEST] error\n[TEST] warn\n")
}

func TestFileLogSystem(t *testing.T) {
	Reset()

	logger := NewLogger("TEST")
	filename := "test.log"
	file, _ := os.OpenFile(filename, os.O_RDWR|os.O_CREATE, os.ModePerm)
	testLogSystem := NewStdLogSystem(file, 0, WarnLevel)
	AddLogSystem(testLogSystem)
	logger.Errorf("error to %s\n", filename)
	logger.Warnln("warn")
	Flush()
	contents, _ := ioutil.ReadFile(filename)
	output := string(contents)
	if output != "[TEST] error to test.log\n[TEST] warn\n" {
		t.Error("Expected contents of file 'test.log': '[TEST] error to test.log\\n[TEST] warn\\n', got ", output)
	} else {
		os.Remove(filename)
	}
}

func TestNoLogSystem(t *testing.T) {
	Reset()

	logger := NewLogger("TEST")
	logger.Warnln("warn")
	Flush()
}

func TestConcurrentAddSystem(t *testing.T) {
	rand.Seed(time.Now().Unix())
	Reset()

	logger := NewLogger("TEST")
	stop := make(chan struct{})
	writer := func() {
		select {
		case <-stop:
			return
		default:
			logger.Infoln("foo")
			Flush()
		}
	}

	go writer()
	go writer()

	stopTime := time.Now().Add(100 * time.Millisecond)
	for time.Now().Before(stopTime) {
		time.Sleep(time.Duration(rand.Intn(20)) * time.Millisecond)
		AddLogSystem(&TestLogSystem{level: InfoLevel})
	}
	close(stop)
}