package webhooks

import (
	"fmt"
	"net/url"
	"path"
	"time"

	"github.com/fleetdm/fleet/v4/server/fleet"
)

// VulnMapper used for mapping vulnerabilities and their associated data into the payload that
// will be sent via thrid party webhooks.
type VulnMapper interface {
	GetPayload(*url.URL, []fleet.HostVulnerabilitySummary, string, fleet.CVEMeta) WebhookPayload
}

type hostPayloadPart struct {
	ID                     uint     `json:"id"`
	Hostname               string   `json:"hostname"`
	DisplayName            string   `json:"display_name"`
	URL                    string   `json:"url"`
	SoftwareInstalledPaths []string `json:"software_installed_paths,omitempty"`
}

type WebhookPayload struct {
	CVE              string     `json:"cve"`
	Link             string     `json:"details_link"`
	EPSSProbability  *float64   `json:"epss_probability,omitempty"`   // Premium feature only
	CVSSScore        *float64   `json:"cvss_score,omitempty"`         // Premium feature only
	CISAKnownExploit *bool      `json:"cisa_known_exploit,omitempty"` // Premium feature only
	CVEPublished     *time.Time `json:"cve_published,omitempty"`      // Premium feature only

	Hosts []*hostPayloadPart `json:"hosts_affected"`
}

type Mapper struct{}

func NewMapper() VulnMapper {
	return &Mapper{}
}

func (m *Mapper) getHostPayloadPart(
	hostBaseURL *url.URL,
	hosts []fleet.HostVulnerabilitySummary,
) []*hostPayloadPart {
	shortHosts := make([]*hostPayloadPart, len(hosts))
	for i, h := range hosts {
		hostURL := *hostBaseURL
		hostURL.Path = path.Join(hostURL.Path, "hosts", fmt.Sprint(h.ID))
		hostPayload := hostPayloadPart{
			ID:          h.ID,
			Hostname:    h.Hostname,
			DisplayName: h.DisplayName,
			URL:         hostURL.String(),
		}

		for _, p := range h.SoftwareInstalledPaths {
			if p != "" {
				hostPayload.SoftwareInstalledPaths = append(
					hostPayload.SoftwareInstalledPaths,
					p,
				)
			}
		}
		shortHosts[i] = &hostPayload
	}
	return shortHosts
}

func (m *Mapper) GetPayload(
	hostBaseURL *url.URL,
	hosts []fleet.HostVulnerabilitySummary,
	cve string,
	meta fleet.CVEMeta,
) WebhookPayload {
	return WebhookPayload{
		CVE:   cve,
		Link:  fmt.Sprintf("https://nvd.nist.gov/vuln/detail/%s", cve),
		Hosts: m.getHostPayloadPart(hostBaseURL, hosts),
	}
}