package sourcegraph

import (
	"context"
	"fmt"
	"net/http"
	"strings"

	regexp "github.com/wasilibs/go-re2"

	"github.com/trufflesecurity/trufflehog/v3/pkg/common"
	"github.com/trufflesecurity/trufflehog/v3/pkg/detectors"
	"github.com/trufflesecurity/trufflehog/v3/pkg/pb/detector_typepb"
)

type Scanner struct {
	client *http.Client
}

// Ensure the Scanner satisfies the interface at compile time.
var _ detectors.Detector = (*Scanner)(nil)

var (
	defaultClient = common.SaneHttpClient()
	// Make sure that your group is surrounded in boundary characters such as below to reduce false positives.
	keyPat = regexp.MustCompile(`\b(sgp_(?:[a-fA-F0-9]{16}|local)_[a-fA-F0-9]{40}|sgp_[a-fA-F0-9]{40}|[a-fA-F0-9]{40})\b`)
)

// Keywords are used for efficiently pre-filtering chunks.
// Use identifiers in the secret preferably, or the provider name.
func (s Scanner) Keywords() []string {
	return []string{"sgp_"}
}

// FromData will find and optionally verify Sourcegraph secrets in a given set of bytes.
func (s Scanner) FromData(ctx context.Context, verify bool, data []byte) (results []detectors.Result, err error) {
	dataStr := string(data)

	matches := keyPat.FindAllStringSubmatch(dataStr, -1)

	for _, match := range matches {
		resMatch := strings.TrimSpace(match[1])

		s1 := detectors.Result{
			DetectorType: detector_typepb.DetectorType_Sourcegraph,
			Raw:          []byte(resMatch),
			SecretParts:  map[string]string{"key": resMatch},
		}
		s1.ExtraData = map[string]string{
			"rotation_guide": "https://howtorotate.com/docs/tutorials/sourcegraph/",
		}

		if verify {
			client := s.client
			if client == nil {
				client = defaultClient
			}
			payload := strings.NewReader("{\"query\": \"query { currentUser { username } }\"}")

			req, err := http.NewRequestWithContext(ctx, "POST", "https://sourcegraph.com/.api/graphql", payload)
			req.Header.Add("Authorization", "token "+resMatch)
			req.Header.Add("Content-Type", "application/json")

			if err != nil {
				continue
			}
			res, err := client.Do(req)
			if err == nil {
				defer func() { _ = res.Body.Close() }()

				if res.StatusCode >= 200 && res.StatusCode < 300 {
					s1.Verified = true
				} else if res.StatusCode == 401 {
					// The secret is determinately not verified (nothing to do)
				} else {
					err = fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
					s1.SetVerificationError(err, resMatch)
				}
			} else {
				s1.SetVerificationError(err, resMatch)
			}
		}

		results = append(results, s1)
	}

	return results, nil
}

func (s Scanner) Type() detector_typepb.DetectorType {
	return detector_typepb.DetectorType_Sourcegraph
}

func (s Scanner) Description() string {
	return "Sourcegraph is a code search and navigation engine. Sourcegraph tokens can be used to access and interact with Sourcegraph APIs."
}
