package adzuna

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
	detectors.DefaultMultiPartCredentialProvider
}

const adzunaURL = "https://api.adzuna.com"

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{"adzuna"}) + `\b([a-z0-9]{32})\b`)
	idPat  = regexp.MustCompile(detectors.PrefixRegex([]string{"adzuna"}) + `\b([a-z0-9]{8})\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{"adzuna"}
}

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

// FromData will find and optionally verify Adzuna 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_Adzuna,
				Raw:          []byte(resMatch),
				SecretParts: map[string]string{
					"key": resMatch,
					"id":  resIdMatch,
				},
				RawV2: []byte(resMatch + resIdMatch),
			}

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

			results = append(results, s1)
		}
	}

	return results, nil
}

func verifyAdzuna(ctx context.Context, client *http.Client, resMatch, resIdMatch string) (bool, error) {
	// https://developer.adzuna.com/activedocs#!/adzuna/search
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, adzunaURL+fmt.Sprintf("/v1/api/jobs/us/search/1?app_id=%s&app_key=%s", resIdMatch, resMatch), nil)
	if err != nil {
		return false, err
	}

	res, err := client.Do(req)
	if err != nil {
		return false, err
	}
	defer func() { _ = res.Body.Close() }()

	// https://developer.adzuna.com/overview
	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_Adzuna
}

func (s Scanner) Description() string {
	return "Adzuna is a job search engine used to find job listings. Adzuna API keys can be used to access job listing data."
}
