package network

import (
	"context"
	"encoding/hex"
	"fmt"
	"net"
	"net/url"
	"os"
	"strings"
	"time"

	"github.com/pkg/errors"
	"github.com/projectdiscovery/gologger"
	"github.com/projectdiscovery/nuclei/v2/pkg/output"
	"github.com/projectdiscovery/nuclei/v2/pkg/protocols"
	"github.com/projectdiscovery/nuclei/v2/pkg/protocols/common/replacer"
)

var _ protocols.Request = &Request{}

// ExecuteWithResults executes the protocol requests and returns results instead of writing them.
func (r *Request) ExecuteWithResults(input string, metadata output.InternalEvent, callback protocols.OutputEventCallback) error {
	address, err := getAddress(input)
	if err != nil {
		r.options.Output.Request(r.options.TemplateID, input, "network", err)
		r.options.Progress.DecrementRequests(1)
		return errors.Wrap(err, "could not get address from url")
	}

	for _, kv := range r.addresses {
		replacer := replacer.New(map[string]interface{}{"Hostname": address})
		actualAddress := replacer.Replace(kv.key)
		if kv.value != "" {
			if strings.Contains(address, ":") {
				actualAddress, _, _ = net.SplitHostPort(actualAddress)
			}
			actualAddress = net.JoinHostPort(actualAddress, kv.value)
		}

		err = r.executeAddress(actualAddress, address, input, callback)
		if err != nil {
			gologger.Verbose().Lable("ERR").Msgf("Could not make network request for %s: %s\n", actualAddress, err)
			continue
		}
	}
	return nil
}

// executeAddress executes the request for an address
func (r *Request) executeAddress(actualAddress, address, input string, callback protocols.OutputEventCallback) error {
	if !strings.Contains(actualAddress, ":") {
		err := errors.New("no port provided in network protocol request")
		r.options.Output.Request(r.options.TemplateID, address, "network", err)
		r.options.Progress.DecrementRequests(1)
		return err
	}

	conn, err := r.dialer.Dial(context.Background(), "tcp", actualAddress)
	if err != nil {
		r.options.Output.Request(r.options.TemplateID, address, "network", err)
		r.options.Progress.DecrementRequests(1)
		return errors.Wrap(err, "could not connect to server request")
	}
	defer conn.Close()
	conn.SetReadDeadline(time.Now().Add(5 * time.Second))

	reqBuilder := &strings.Builder{}
	for _, input := range r.Inputs {
		var data []byte

		switch input.Type {
		case "hex":
			data, err = hex.DecodeString(input.Data)
		default:
			data = []byte(input.Data)
		}
		if err != nil {
			r.options.Output.Request(r.options.TemplateID, address, "network", err)
			r.options.Progress.DecrementRequests(1)
			return errors.Wrap(err, "could not write request to server")
		}
		reqBuilder.Grow(len(input.Data))
		reqBuilder.WriteString(input.Data)

		_, err = conn.Write(data)
		if err != nil {
			r.options.Output.Request(r.options.TemplateID, address, "network", err)
			r.options.Progress.DecrementRequests(1)
			return errors.Wrap(err, "could not write request to server")
		}
		r.options.Progress.IncrementRequests()
	}
	if err != nil {
		r.options.Output.Request(r.options.TemplateID, address, "network", err)
		r.options.Progress.DecrementRequests(1)
		return errors.Wrap(err, "could not write request to server")
	}

	if r.options.Options.Debug || r.options.Options.DebugRequests {
		gologger.Info().Str("address", actualAddress).Msgf("[%s] Dumped Network request for %s", r.options.TemplateID, actualAddress)

		fmt.Fprintf(os.Stderr, "%s\n", reqBuilder.String())
	}

	r.options.Output.Request(r.options.TemplateID, actualAddress, "network", err)
	gologger.Verbose().Msgf("Sent TCP request to %s", actualAddress)

	bufferSize := 1024
	if r.ReadSize != 0 {
		bufferSize = r.ReadSize
	}
	buffer := make([]byte, bufferSize)
	n, _ := conn.Read(buffer)
	resp := string(buffer[:n])

	if r.options.Options.Debug || r.options.Options.DebugResponse {
		gologger.Debug().Msgf("[%s] Dumped Network response for %s", r.options.TemplateID, actualAddress)
		fmt.Fprintf(os.Stderr, "%s\n", resp)
	}
	ouputEvent := r.responseToDSLMap(reqBuilder.String(), resp, input, actualAddress)

	event := &output.InternalWrappedEvent{InternalEvent: ouputEvent}
	if r.CompiledOperators != nil {
		result, ok := r.CompiledOperators.Execute(ouputEvent, r.Match, r.Extract)
		if ok && result != nil {
			event.OperatorsResult = result
			event.Results = r.MakeResultEvent(event)
		}
	}
	callback(event)
	return nil
}

// getAddress returns the address of the host to make request to
func getAddress(toTest string) (string, error) {
	if strings.Contains(toTest, "://") {
		parsed, err := url.Parse(toTest)
		if err != nil {
			return "", err
		}
		toTest = parsed.Host
	}
	return toTest, nil
}