package logger

import (
	"bytes"
	"context"
	"strings"
	"testing"
)

func TestTextFormat(t *testing.T) {
	buf := &bytes.Buffer{}
	l := New(
		WithOutputFile(""),
		WithFormat(TEXT),
		WithTimeFormat("2006-01-02"),
	)

	l.mu.Lock()
	l.writer = buf
	l.mu.Unlock()

	l.Info("hello %s", "world")

	output := buf.String()
	if !strings.Contains(output, "hello world") {
		t.Errorf("expected 'hello world' in output, got: %s", output)
	}
}

func TestJSONFormat(t *testing.T) {
	buf := &bytes.Buffer{}
	l := New(
		WithOutputFile(""),
		WithFormat(JSON),
	)

	l.mu.Lock()
	l.writer = buf
	l.mu.Unlock()

	l.Info("test message")

	output := buf.String()
	if !strings.Contains(output, `"message":"test message"`) {
		t.Errorf("expected JSON message in output, got: %s", output)
	}
	if !strings.Contains(output, `"level":"INFO"`) {
		t.Errorf("expected level INFO in output, got: %s", output)
	}
}

func TestWithFields(t *testing.T) {
	buf := &bytes.Buffer{}
	l := New(
		WithOutputFile(""),
		WithFormat(TEXT),
	)

	l.mu.Lock()
	l.writer = buf
	l.mu.Unlock()

	l.InfoField("user logged in",
		"user_id", 123,
		"action", "login",
	)

	output := buf.String()
	if !strings.Contains(output, "user_id=123") {
		t.Errorf("expected user_id=123 in output, got: %s", output)
	}
	if !strings.Contains(output, "action=login") {
		t.Errorf("expected action=login in output, got: %s", output)
	}
}

func TestContextTraceID(t *testing.T) {
	buf := &bytes.Buffer{}
	l := New(
		WithOutputFile(""),
		WithFormat(JSON),
	)

	l.mu.Lock()
	l.writer = buf
	l.mu.Unlock()

	ctx := context.WithValue(context.Background(), "trace_id", "req-123")
	l.InfoCtx(ctx, "request processed")

	output := buf.String()
	if !strings.Contains(output, `"trace_id":"req-123"`) {
		t.Errorf("expected trace_id in output, got: %s", output)
	}
}

func TestCustomFieldKey(t *testing.T) {
	buf := &bytes.Buffer{}
	l := New(
		WithOutputFile(""),
		WithFormat(JSON),
		WithFieldKey("request_id"),
	)

	l.mu.Lock()
	l.writer = buf
	l.mu.Unlock()

	ctx := context.WithValue(context.Background(), "request_id", "req-456")
	l.InfoCtx(ctx, "request processed")

	output := buf.String()
	if !strings.Contains(output, `"request_id":"req-456"`) {
		t.Errorf("expected request_id in output, got: %s", output)
	}
}

func TestCaller(t *testing.T) {
	buf := &bytes.Buffer{}
	l := New(
		WithOutputFile(""),
		WithFormat(TEXT),
		WithCaller(true),
	)

	l.mu.Lock()
	l.writer = buf
	l.mu.Unlock()

	l.Info("test caller")

	output := buf.String()
	if !strings.Contains(output, "logger_test.go:") {
		t.Errorf("expected caller info in output, got: %s", output)
	}
}

func TestLevelFiltering(t *testing.T) {
	buf := &bytes.Buffer{}
	l := New(
		WithOutputFile(""),
		WithLevel(ERROR),
	)

	l.mu.Lock()
	l.writer = buf
	l.mu.Unlock()

	l.Debug("debug message")
	l.Info("info message")
	l.Error("error message")

	output := buf.String()
	if strings.Contains(output, "debug message") {
		t.Errorf("debug message should be filtered out, got: %s", output)
	}
	if strings.Contains(output, "info message") {
		t.Errorf("info message should be filtered out, got: %s", output)
	}
	if !strings.Contains(output, "error message") {
		t.Errorf("error message should be present, got: %s", output)
	}
}

func TestGlobalLogger(t *testing.T) {
	buf := &bytes.Buffer{}
	original := defaultLogger
	defer func() { defaultLogger = original }()

	defaultLogger = New(
		WithOutputFile(""),
		WithFormat(TEXT),
	)

	defaultLogger.mu.Lock()
	defaultLogger.writer = buf
	defaultLogger.mu.Unlock()

	Info("global logger test")

	output := buf.String()
	if !strings.Contains(output, "global logger test") {
		t.Errorf("expected global logger output, got: %s", output)
	}
}

// Benchmarks

func benchmarkLogger(format Format, caller bool) *Logger {
	buf := &bytes.Buffer{}
	l := New(
		WithOutputFile(""),
		WithFormat(format),
		WithCaller(caller),
	)
	l.mu.Lock()
	l.writer = buf
	l.mu.Unlock()
	return l
}

func BenchmarkInfoText(b *testing.B) {
	l := benchmarkLogger(TEXT, false)
	msg := "hello world"
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.Info("hello world")
		_ = msg
	}
}

func BenchmarkInfoTextWithArgs(b *testing.B) {
	l := benchmarkLogger(TEXT, false)
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.Info("user %s logged in from %s", "john", "192.168.1.1")
	}
}

func BenchmarkInfoJSON(b *testing.B) {
	l := benchmarkLogger(JSON, false)
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.Info("hello world")
	}
}

func BenchmarkInfoField(b *testing.B) {
	l := benchmarkLogger(TEXT, false)
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.InfoField("user logged in",
			"user_id", 123,
			"action", "login",
			"ip", "192.168.1.1",
		)
	}
}

func BenchmarkInfoFieldJSON(b *testing.B) {
	l := benchmarkLogger(JSON, false)
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.InfoField("user logged in",
			"user_id", 123,
			"action", "login",
			"ip", "192.168.1.1",
		)
	}
}

func BenchmarkInfoWithCaller(b *testing.B) {
	l := benchmarkLogger(TEXT, true)
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.Info("hello world")
	}
}

func BenchmarkInfoCtx(b *testing.B) {
	l := benchmarkLogger(JSON, false)
	ctx := context.WithValue(context.Background(), "trace_id", "req-123456789")
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.InfoCtx(ctx, "request processed")
	}
}

func BenchmarkInfoFiltered(b *testing.B) {
	l := New(
		WithOutputFile(""),
		WithLevel(ERROR),
	)
	l.mu.Lock()
	l.writer = &bytes.Buffer{}
	l.mu.Unlock()
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.Info("this should be filtered")
	}
}

func BenchmarkManyFields(b *testing.B) {
	l := benchmarkLogger(JSON, false)
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		l.InfoField("event",
			"field1", "value1",
			"field2", "value2",
			"field3", "value3",
			"field4", "value4",
			"field5", "value5",
			"field6", "value6",
			"field7", "value7",
			"field8", "value8",
		)
	}
}

func BenchmarkGlobalInfo(b *testing.B) {
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		Info("hello world")
	}
}

func BenchmarkGlobalInfoField(b *testing.B) {
	b.ResetTimer()
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		InfoField("event",
			"key1", "value1",
			"key2", "value2",
		)
	}
}