package myfreshworks

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"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
	detectors.DefaultMultiPartCredentialProvider
}

// 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(detectors.PrefixRegex([]string{"freshworks"}) + `\b([a-z0-9A-Z-_]{22})\b`)
	idPat  = regexp.MustCompile(detectors.PrefixRegex([]string{"freshworks"}) + `\b([a-zA-Z0-9-_]{2,20})\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{"freshworks"}
}

// FromData will find and optionally verify Myfreshworks 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)
	idmatches := idPat.FindAllStringSubmatch(dataStr, -1)

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

			s1 := detectors.Result{
				DetectorType: detector_typepb.DetectorType_Myfreshworks,
				Raw:          []byte(resMatch),
				SecretParts:  map[string]string{"key": resMatch},
			}

			if verify {
				client := s.getClient()
				isVerified, verificationErr := verifyMyfreshworks(ctx, client, resMatch, resIdMatch)
				s1.Verified = isVerified
				s1.SetVerificationError(verificationErr, resMatch)
			}

			results = append(results, s1)
		}

	}

	return results, nil
}

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

func verifyMyfreshworks(ctx context.Context, client *http.Client, resMatch, resIdMatch string) (bool, error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, "https://"+resIdMatch+".myfreshworks.com/crm/sales/api/sales_accounts/filters", nil)
	if err != nil {
		return false, err
	}

	req.Header.Add("Authorization", fmt.Sprintf("Token token=%s", resMatch))
	res, err := client.Do(req)
	if err != nil {
		return false, err
	}
	defer func() { _ = res.Body.Close() }()

	if res.StatusCode == http.StatusOK {
		body, err := io.ReadAll(res.Body)
		if err != nil {
			return false, err
		}

		return json.Valid(body), nil
	} else if res.StatusCode != http.StatusUnauthorized && res.StatusCode != http.StatusForbidden {
		return false, fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
	}

	return false, nil
}

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

func (s Scanner) Description() string {
	return "Freshworks is a customer engagement platform offering various services like CRM, IT service management, and more. Freshworks API keys can be used to access and manage these services."
}
