package reader

import (
	"bytes"
	"crypto/tls"
	"strings"
	"testing"
	"time"

	"github.com/stretchr/testify/require"
)

func TestConnReadN(t *testing.T) {
	timeout := time.Duration(5) * time.Second

	t.Run("Test with N as -1", func(t *testing.T) {
		reader := strings.NewReader("Hello, World!")
		data, err := ConnReadNWithTimeout(reader, -1, timeout)
		if err != nil {
			t.Errorf("Unexpected error: %v", err)
		}
		if string(data) != "Hello, World!" {
			t.Errorf("Expected 'Hello, World!', got '%s'", string(data))
		}
	})

	t.Run("Test with N as 0", func(t *testing.T) {
		reader := strings.NewReader("Hello, World!")
		data, err := ConnReadNWithTimeout(reader, 0, timeout)
		if err != nil {
			t.Errorf("Unexpected error: %v", err)
		}
		if len(data) != 0 {
			t.Errorf("Expected empty, got '%s'", string(data))
		}
	})

	t.Run("Test with N greater than MaxReadSize", func(t *testing.T) {
		reader := bytes.NewReader(make([]byte, MaxReadSize+1))
		_, err := ConnReadNWithTimeout(reader, MaxReadSize+1, timeout)
		if err != ErrTooLarge {
			t.Errorf("Expected 'ErrTooLarge', got '%v'", err)
		}
	})

	t.Run("Test with N less than MaxReadSize", func(t *testing.T) {
		reader := strings.NewReader("Hello, World!")
		data, err := ConnReadNWithTimeout(reader, 5, timeout)
		if err != nil {
			t.Errorf("Unexpected error: %v", err)
		}
		if string(data) != "Hello" {
			t.Errorf("Expected 'Hello', got '%s'", string(data))
		}
	})
	t.Run("Read From Connection", func(t *testing.T) {
		conn, err := tls.Dial("tcp", "projectdiscovery.io:443", &tls.Config{InsecureSkipVerify: true})
		_ = conn.SetReadDeadline(time.Now().Add(5 * time.Second))
		require.Nil(t, err, "could not connect to projectdiscovery.io over tls")
		defer func() {
			_ = conn.Close()
		}()
		_, err = conn.Write([]byte("GET / HTTP/1.1\r\nHost: projectdiscovery.io\r\nConnection: close\r\n\r\n"))
		require.Nil(t, err, "could not write to connection")
		data, err := ConnReadNWithTimeout(conn, -1, timeout)
		require.Nilf(t, err, "could not read from connection: %s", err)
		require.NotEmpty(t, data, "could not read from connection")
	})

	t.Run("Read From Connection which times out", func(t *testing.T) {
		conn, err := tls.Dial("tcp", "projectdiscovery.io:443", &tls.Config{InsecureSkipVerify: true})
		_ = conn.SetReadDeadline(time.Now().Add(1 * time.Second)) // shorter deadline to force timeout
		require.Nil(t, err, "could not connect to projectdiscovery.io over tls")
		defer func() {
			_ = conn.Close()
		}()
		_, err = conn.Write([]byte("GET / HTTP/1.1\r\nHost: projectdiscovery.io\r\nConnection: close\r\n\r\n"))
		require.Nil(t, err, "could not write to connection")
		data, err := ConnReadNWithTimeout(conn, -1, 1*time.Second) // shorter timeout
		// The function should return data and ignore timeout error if data was received
		require.Nil(t, err, "should ignore timeout error when data is available")
		require.NotEmpty(t, data, "should have received some data before timeout")
	})
}