package agora

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/detectorspb"
)

type Scanner struct {
	detectors.DefaultMultiPartCredentialProvider
	client *http.Client
}

const agoraURL = "https://api.agora.io"

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

	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{"agora"}) + `\b([a-z0-9]{32})\b`)
	secretPat = regexp.MustCompile(detectors.PrefixRegex([]string{"agora"}) + `\b([a-z0-9]{32})\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{"agora"}
}

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

// FromData will find and optionally verify Agora 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)
	secretMatches := secretPat.FindAllStringSubmatch(dataStr, -1)

	for _, match := range matches {
		if len(match) != 2 {
			continue
		}

		resMatch := strings.TrimSpace(match[1])

		for _, secret := range secretMatches {
			if len(secret) != 2 {
				continue
			}
			resSecret := strings.TrimSpace(secret[1])

			s1 := detectors.Result{
				DetectorType: detectorspb.DetectorType_Agora,
				Raw:          []byte(resMatch),
				RawV2:        []byte(resMatch + resSecret),
			}

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

			results = append(results, s1)
		}
	}

	return results, nil
}

func verifyAgora(ctx context.Context, client *http.Client, resMatch, resSecret string) (bool, error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, agoraURL+"/dev/v1/projects", nil)
	if err != nil {
		return false, err
	}
	req.SetBasicAuth(resSecret, resMatch)
	res, err := client.Do(req)

	if err != nil {
		return false, err
	}
	defer res.Body.Close()

	// https://docs.agora.io/en/voice-calling/reference/agora-console-rest-api#get-all-projects
	switch res.StatusCode {
	case http.StatusOK, http.StatusCreated:
		return true, nil
	case http.StatusUnauthorized, http.StatusForbidden:
		return false, nil
	default:
		return false, fmt.Errorf("unexpected HTTP response status %d", res.StatusCode)
	}
}

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