package mailx

import (
	"context"
	"fmt"
	"sync"
	"testing"
	"time"

	"code.yun.ink/pkg/mailx/interfaces"
	"code.yun.ink/pkg/mailx/smtp"
)

// 并发发送测试
func TestConcurrentSend(t *testing.T) {
	smtpClient := smtp.NewSmtp()
	ctx := context.Background()

	// 配置SMTP客户端
	_, err := smtpClient.SetOption(ctx, func(opt *interfaces.Options) {
		opt.Smtp = &interfaces.EmailConfigDataSmtp{
			Host:     "smtp.example.com",
			Port:     "587",
			Username: "test@example.com",
			Password: "password",
		}
	})
	if err != nil {
		t.Fatalf("Failed to configure SMTP: %v", err)
	}

	// 并发测试参数
	numGoroutines := 10
	emailsPerGoroutine := 5
	var wg sync.WaitGroup
	errors := make(chan error, numGoroutines*emailsPerGoroutine)

	start := time.Now()

	// 启动多个goroutine并发发送邮件
	for i := 0; i < numGoroutines; i++ {
		wg.Add(1)
		go func(goroutineID int) {
			defer wg.Done()
			
			for j := 0; j < emailsPerGoroutine; j++ {
				message := interfaces.Message{
					To:      []string{fmt.Sprintf("test%d_%d@example.com", goroutineID, j)},
					Subject: fmt.Sprintf("Concurrent Test %d-%d", goroutineID, j),
					Body:    fmt.Sprintf("Test email from goroutine %d, email %d", goroutineID, j),
				}

				// 注意：在实际测试中，这里应该mock发送逻辑
				err := smtpClient.Send(ctx, message)
				if err != nil {
					errors <- fmt.Errorf("goroutine %d, email %d: %w", goroutineID, j, err)
				}
				
				// 模拟发送时间
				time.Sleep(10 * time.Millisecond)
			}
		}(i)
	}

	// 等待所有goroutine完成
	wg.Wait()
	close(errors)

	duration := time.Since(start)
	totalEmails := numGoroutines * emailsPerGoroutine

	// 检查错误
	errorCount := 0
	for err := range errors {
		t.Logf("Error: %v", err)
		errorCount++
	}

	t.Logf("Concurrent test completed:")
	t.Logf("- Total emails: %d", totalEmails)
	t.Logf("- Duration: %v", duration)
	t.Logf("- Errors: %d", errorCount)
	t.Logf("- Success rate: %.2f%%", float64(totalEmails-errorCount)/float64(totalEmails)*100)
}

// 内存使用测试
func TestMemoryUsage(t *testing.T) {
	smtpClient := smtp.NewSmtp()
	ctx := context.Background()

	_, err := smtpClient.SetOption(ctx, func(opt *interfaces.Options) {
		opt.Smtp = &interfaces.EmailConfigDataSmtp{
			Host:     "smtp.example.com",
			Port:     "587",
			Username: "test@example.com",
			Password: "password",
		}
	})
	if err != nil {
		t.Fatalf("Failed to configure SMTP: %v", err)
	}

	// 测试大量邮件对象创建
	numEmails := 1000
	messages := make([]interfaces.Message, numEmails)

	start := time.Now()
	for i := 0; i < numEmails; i++ {
		messages[i] = interfaces.Message{
			To:      []string{fmt.Sprintf("test%d@example.com", i)},
			Subject: fmt.Sprintf("Memory Test %d", i),
			Body:    fmt.Sprintf("Large email body content for testing memory usage. Email number: %d. %s", i, generateLargeContent(1024)),
		}
	}
	duration := time.Since(start)

	t.Logf("Memory test completed:")
	t.Logf("- Created %d email messages", numEmails)
	t.Logf("- Duration: %v", duration)
	t.Logf("- Average time per message: %v", duration/time.Duration(numEmails))

	// 清理内存
	messages = nil
}

// 连接池测试
func TestConnectionReuse(t *testing.T) {
	smtpClient := smtp.NewSmtp()
	ctx := context.Background()

	_, err := smtpClient.SetOption(ctx, func(opt *interfaces.Options) {
		opt.Smtp = &interfaces.EmailConfigDataSmtp{
			Host:     "smtp.example.com",
			Port:     "587",
			Username: "test@example.com",
			Password: "password",
		}
	})
	if err != nil {
		t.Fatalf("Failed to configure SMTP: %v", err)
	}

	// 测试多次发送是否复用连接配置
	numSends := 10
	start := time.Now()

	for i := 0; i < numSends; i++ {
		message := interfaces.Message{
			To:      []string{fmt.Sprintf("test%d@example.com", i)},
			Subject: fmt.Sprintf("Connection Reuse Test %d", i),
			Body:    "Testing connection reuse",
		}

		// 模拟发送
		_ = message
		time.Sleep(5 * time.Millisecond)
	}

	duration := time.Since(start)
	t.Logf("Connection reuse test:")
	t.Logf("- Sent %d emails", numSends)
	t.Logf("- Total duration: %v", duration)
	t.Logf("- Average per email: %v", duration/time.Duration(numSends))
}

// 错误恢复测试
func TestErrorRecovery(t *testing.T) {
	smtpClient := smtp.NewSmtp()
	ctx := context.Background()

	_, err := smtpClient.SetOption(ctx, func(opt *interfaces.Options) {
		opt.Smtp = &interfaces.EmailConfigDataSmtp{
			Host:     "invalid-smtp-server.com", // 故意使用无效服务器
			Port:     "587",
			Username: "test@example.com",
			Password: "password",
		}
	})
	if err != nil {
		t.Fatalf("Failed to configure SMTP: %v", err)
	}

	message := interfaces.Message{
		To:      []string{"test@example.com"},
		Subject: "Error Recovery Test",
		Body:    "Testing error recovery mechanism",
	}

	start := time.Now()
	
	// 这应该失败并触发重试机制

	err = smtpClient.Send(ctx, message)
	if err == nil {
		t.Error("Expected error for invalid SMTP server")
	}

	duration := time.Since(start)
	t.Logf("Error recovery test:")
	t.Logf("- Duration: %v", duration)
	t.Logf("- Expected failure with retry mechanism")
}

// 大附件测试
func TestLargeAttachment(t *testing.T) {
	// 测试大附件处理
	largeContent := generateLargeContent(1024 * 1024) // 1MB

	message := interfaces.Message{
		To:      []string{"test@example.com"},
		Subject: "Large Attachment Test",
		Body:    "Testing large attachment handling",
		Attachment: []interfaces.Attachment{
			{
				Content:     "/tmp/large_file.txt", // 假设的大文件路径
				ContentType: "text/plain",
			},
		},
	}

	// 验证附件大小限制
	maxSize := 25 * 1024 * 1024 // 25MB
	if len(largeContent) > maxSize {
		t.Logf("Large content size: %d bytes (exceeds %d bytes limit)", len(largeContent), maxSize)
	}
	// 注意：这里不会真正发送邮件，只是测试验证逻辑
	// 在实际测试中需要mock或使用测试邮件服务器
	smtpClient := smtp.NewSmtp()
	ctx := context.Background()

	_, err := smtpClient.SetOption(ctx, func(opt *interfaces.Options) {
		opt.Smtp = &interfaces.EmailConfigDataSmtp{
			Host:     "smtp.example.com",
			Port:     "587",
			Username: "test@example.com",
			Password: "password",
		}
	})
	if err != nil {
		t.Errorf("Failed to configure SMTP: %v", err)
	}

	err = smtpClient.Send(ctx, message)
	if err != nil {
		t.Errorf("Failed to handle large attachment: %v", err)
	} else {
		t.Logf("Large attachment handled successfully")
	}

	t.Logf("Large attachment test completed")
}

// 压力测试
func BenchmarkEmailCreation(b *testing.B) {
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		message := interfaces.Message{
			To:      []string{fmt.Sprintf("test%d@example.com", i)},
			Subject: fmt.Sprintf("Benchmark Test %d", i),
			Body:    "Benchmark test content",
		}
		_ = message
	}
}

// 并发基准测试
func BenchmarkConcurrentEmailCreation(b *testing.B) {
	b.RunParallel(func(pb *testing.PB) {
		i := 0
		for pb.Next() {
			message := interfaces.Message{
				To:      []string{fmt.Sprintf("test%d@example.com", i)},
				Subject: fmt.Sprintf("Concurrent Benchmark Test %d", i),
				Body:    "Concurrent benchmark test content",
			}
			_ = message
			i++
		}
	})
}

// 配置创建基准测试
func BenchmarkSMTPConfiguration(b *testing.B) {
	ctx := context.Background()
	
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		smtpClient := smtp.NewSmtp()
		_, err := smtpClient.SetOption(ctx, func(opt *interfaces.Options) {
			opt.Smtp = &interfaces.EmailConfigDataSmtp{
				Host:     "smtp.example.com",
				Port:     "587",
				Username: "test@example.com",
				Password: "password",
			}
		})
		if err != nil {
			b.Fatalf("Configuration failed: %v", err)
		}
	}
}

// 辅助函数：生成大内容
func generateLargeContent(size int) string {
	content := make([]byte, size)
	for i := range content {
		content[i] = byte('A' + (i % 26))
	}
	return string(content)
}

// 负载测试
func TestLoadTesting(t *testing.T) {
	if testing.Short() {
		t.Skip("Skipping load test in short mode")
	}

	smtpClient := smtp.NewSmtp()
	ctx := context.Background()

	_, err := smtpClient.SetOption(ctx, func(opt *interfaces.Options) {
		opt.Smtp = &interfaces.EmailConfigDataSmtp{
			Host:     "smtp.example.com",
			Port:     "587",
			Username: "test@example.com",
			Password: "password",
		}
	})
	if err != nil {
		t.Fatalf("Failed to configure SMTP: %v", err)
	}

	// 负载测试参数
	totalEmails := 100
	concurrency := 10
	semaphore := make(chan struct{}, concurrency)
	var wg sync.WaitGroup

	start := time.Now()

	for i := 0; i < totalEmails; i++ {
		wg.Add(1)
		go func(emailID int) {
			defer wg.Done()
			
			// 获取信号量
			semaphore <- struct{}{}
			defer func() { <-semaphore }()

			message := interfaces.Message{
				To:      []string{fmt.Sprintf("load_test_%d@example.com", emailID)},
				Subject: fmt.Sprintf("Load Test Email %d", emailID),
				Body:    fmt.Sprintf("Load testing email number %d", emailID),
			}

			// 模拟发送
			time.Sleep(50 * time.Millisecond)
			_ = message
		}(i)
	}

	wg.Wait()
	duration := time.Since(start)

	t.Logf("Load test completed:")
	t.Logf("- Total emails: %d", totalEmails)
	t.Logf("- Concurrency: %d", concurrency)
	t.Logf("- Duration: %v", duration)
	t.Logf("- Throughput: %.2f emails/second", float64(totalEmails)/duration.Seconds())
}