package postman

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
}

const verifyURL = "https://api.getpostman.com/collections"

// 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(PMAK-[a-zA-Z-0-9]{59})\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{"PMAK-"}
}

// FromData will find and optionally verify Postman 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_Postman,
			Raw:          []byte(resMatch),
		}

		if verify {
			client := s.getClient()
			isVerified, verificationErr := verifyPostman(ctx, client, resMatch)
			s1.Verified = isVerified
			s1.SetVerificationError(verificationErr, resMatch)
			s1.AnalysisInfo = map[string]string{
				"key": resMatch,
			}
		}

		results = append(results, s1)
	}

	return results, nil
}

func (s Scanner) getClient() *http.Client {
	if s.client != nil {
		return s.client
	}
	return defaultClient
}

func verifyPostman(ctx context.Context, client *http.Client, token string) (bool, error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, verifyURL, nil)
	if err != nil {
		return false, err
	}
	req.Header.Add("x-api-key", token)
	res, err := client.Do(req)
	if err != nil {
		return false, err
	}
	defer res.Body.Close()

	switch res.StatusCode {
	case http.StatusOK:
		return true, nil
	case http.StatusUnauthorized:
		return false, nil
	default:
		return false, fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
	}
}

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

func (s Scanner) Description() string {
	return "Postman is a collaboration platform for API development. Postman API keys can be used to access and modify collections, environments, and other resources."
}
