package copper

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/detectorspb"
)

type Scanner struct {
	detectors.DefaultMultiPartCredentialProvider
}

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

var (
	client = 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{"copper"}) + `\b([a-z0-9]{32})\b`)
	idPat  = regexp.MustCompile(`\b([a-z0-9]{4,25}@[a-zA-Z0-9]{2,12}.[a-zA-Z0-9]{2,6})\b`)
)

type UserApiResponse struct {
	Id    int    `json:"id"`
	Email string `json:"email"`
}

// 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{"copper"}
}

// FromData will find and optionally verify Copper 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: detectorspb.DetectorType_Copper,
				Raw:          []byte(resMatch),
				RawV2:        []byte(resMatch + resIdMatch),
			}

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

			results = append(results, s1)

		}

	}

	return results, nil
}

func verifyCopper(ctx context.Context, client *http.Client, email, apiKey string) (bool, error) {
	req, err := http.NewRequestWithContext(
		ctx,
		http.MethodGet,
		"https://api.copper.com/developer_api/v1/users/me",
		http.NoBody,
	)
	if err != nil {
		return false, err
	}
	req.Header.Add("X-PW-AccessToken", apiKey)
	req.Header.Add("X-PW-Application", "developer_api")
	req.Header.Add("X-PW-UserEmail", email)
	req.Header.Add("Content-Type", "application/json")
	res, err := client.Do(req)
	if err != nil {
		return false, err
	}
	defer func() {
		_, _ = io.Copy(io.Discard, res.Body)
		_ = res.Body.Close()
	}()

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

		var respBody UserApiResponse
		if err := json.Unmarshal(respBytes, &respBody); err != nil {
			return false, err
		}

		// strict verification with email in credentials
		if respBody.Email == email {
			return true, nil
		}

		return false, fmt.Errorf("email mismatch in verification response")
	case http.StatusUnauthorized:
		return false, nil
	default:
		return false, fmt.Errorf("unexpected status code :%d", res.StatusCode)
	}
}

func (s Scanner) Type() detectorspb.DetectorType {
	return detectorspb.DetectorType_Copper
}

func (s Scanner) Description() string {
	return "Copper is a CRM platform that helps businesses manage their relationships with customers and leads. Copper API keys can be used to access and modify customer data and interactions."
}
