package main

import (
    "context"
    "fmt"
    "io"
    "time"

    "github.com/projectdiscovery/subfinder/v2/pkg/resolve"
    "github.com/projectdiscovery/subfinder/v2/pkg/runner"
)

func main() {
    opts := &runner.Options{
        Threads:            10,
        Timeout:            60,
        MaxEnumerationTime: 30,
    }

    foundCh := make(chan struct{}, 1)
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()

    opts.ResultCallback = func(result *resolve.HostEntry) {
        fmt.Printf("Found: %s\n", result.Host)
        select {
        case foundCh <- struct{}{}:
            cancel() // Cancel context after first result
        default:
        }
    }

    subfinder, err := runner.NewRunner(opts)
    if err != nil {
        panic(err)
    }

    start := time.Now()
    doneCh := make(chan struct{})
    go func() {
        defer close(doneCh)
        _, _ = subfinder.EnumerateSingleDomainWithCtx(ctx, "facebook.com", []io.Writer{io.Discard})
    }()

    select {
    case <-foundCh:
        fmt.Println("First subdomain found, context cancelled")
    case <-doneCh:
        fmt.Println("Enumeration completed")
    }

    <-doneCh
    fmt.Printf("Total time: %v\n", time.Since(start))
    // Expected: exit immediately after first result
    // Actual: continues until timeout (~60s)
}