package klaviyo

import (
	"context"
	"encoding/json"
	"fmt"
	regexp "github.com/wasilibs/go-re2"
	"net/http"
	"strings"

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

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(pk_[[:alnum:]]{34})\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{"pk_"}
}

type response struct {
	Errors []struct {
		Id     string `json:"id"`
		Status int    `json:"status"`
		Code   string `json:"code"`
		Title  string `json:"title"`
		Detail string `json:"detail"`
		Source struct {
			Pointer string `json:"pointer"`
		} `json:"source"`
	} `json:"errors"`
}

// FromData will find and optionally verify Klaviyo 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 {
		if len(match) != 2 {
			continue
		}
		resMatch := strings.TrimSpace(match[1])

		s1 := detectors.Result{
			DetectorType: detectorspb.DetectorType_Klaviyo,
			Raw:          []byte(resMatch),
		}

		if verify {
			client := s.client
			if client == nil {
				client = defaultClient
			}
			req, err := http.NewRequestWithContext(ctx, "GET", "https://a.klaviyo.com/api/profiles", nil)
			if err != nil {
				continue
			}
			req.Header.Set("Revision", "2023-02-22")
			req.Header.Set("Authorization", "Klaviyo-API-Key "+resMatch)
			res, err := client.Do(req)
			if err == nil {
				defer res.Body.Close()
				if res.StatusCode >= 200 && res.StatusCode < 300 {
					s1.Verified = true
				} else if res.StatusCode == 403 {
					var apiResp response
					// Klaviyo responds with 403 when the API-key does not have permissions to hit /api/profiles.
					// Ensure that the 403 is from Klaviyo: https://developers.klaviyo.com/en/docs/rate_limits_and_error_handling
					if err = json.NewDecoder(res.Body).Decode(&apiResp); err == nil {
						// valid JSON response
						if len(apiResp.Errors) > 0 {
							// Thus, the key is verified, but it is up to the user to determine what scopes the key has.
							s1.Verified = true
						} else {
							s1.SetVerificationError(fmt.Errorf("errors expected"), resMatch)
						}
					} else {
						s1.SetVerificationError(fmt.Errorf("unexpected API JSON response"), resMatch)
					}
				} 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() detectorspb.DetectorType {
	return detectorspb.DetectorType_Klaviyo
}
