package imapx

import (
	"io"
	"net"
	"testing"
	"time"

	"context"
)

// A server that sends the IMAP greeting, accepts one command, then goes silent
// forever must NOT wedge the client: the idle read-timeout has to abort the
// blocked read so the command returns an error instead of hanging. This is the
// exact production failure (account stuck in "running" with zero progress).
func TestConnectIdleReadTimeoutUnwedgesSilentServer(t *testing.T) {
	ln, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("listen: %v", err)
	}
	defer ln.Close()

	go func() {
		c, err := ln.Accept()
		if err != nil {
			return
		}
		defer c.Close()
		_, _ = io.WriteString(c, "* OK IMAP4rev2 ready\r\n")
		// Read the LOGIN command bytes, then never answer.
		buf := make([]byte, 512)
		_, _ = c.Read(buf)
		// Block until the client gives up and closes the connection.
		_, _ = c.Read(buf)
	}()

	old := idleReadTimeout
	idleReadTimeout = 150 * time.Millisecond
	defer func() { idleReadTimeout = old }()

	port := ln.Addr().(*net.TCPAddr).Port
	ep := Endpoint{Host: "127.0.0.1", Port: port, TLSMode: "plain"}

	c, err := Connect(context.Background(), ep)
	if err != nil {
		t.Fatalf("Connect: %v", err)
	}

	done := make(chan error, 1)
	go func() { done <- c.Login("user", "pass").Wait() }()

	select {
	case err := <-done:
		if err == nil {
			t.Fatal("expected an error from Login against a silent server, got nil")
		}
	case <-time.After(3 * time.Second):
		t.Fatal("Login did not return: idle read-timeout was not enforced (connection wedged)")
	}
}