internal/handlers/status.go

@@ -2,22 +2,217 @@ package handlers
 
 import (
 	"net/http"
+	"sort"
+	"time"
+
+	"sneak.berlin/go/dnswatcher/internal/state"
 )
 
+// statusDomainInfo holds status information for a monitored domain.
+type statusDomainInfo struct {
+	Nameservers []string  `json:"nameservers"`
+	LastChecked time.Time `json:"lastChecked"`
+}
+
+// statusHostnameNSInfo holds per-nameserver status for a hostname.
+type statusHostnameNSInfo struct {
+	Records     map[string][]string `json:"records"`
+	Status      string              `json:"status"`
+	LastChecked time.Time           `json:"lastChecked"`
+}
+
+// statusHostnameInfo holds status information for a monitored hostname.
+type statusHostnameInfo struct {
+	Nameservers map[string]*statusHostnameNSInfo `json:"nameservers"`
+	LastChecked time.Time                        `json:"lastChecked"`
+}
+
+// statusPortInfo holds status information for a monitored port.
+type statusPortInfo struct {
+	Open        bool      `json:"open"`
+	Hostnames   []string  `json:"hostnames"`
+	LastChecked time.Time `json:"lastChecked"`
+}
+
+// statusCertificateInfo holds status information for a TLS certificate.
+type statusCertificateInfo struct {
+	CommonName              string    `json:"commonName"`
+	Issuer                  string    `json:"issuer"`
+	NotAfter                time.Time `json:"notAfter"`
+	SubjectAlternativeNames []string  `json:"subjectAlternativeNames"`
+	Status                  string    `json:"status"`
+	LastChecked             time.Time `json:"lastChecked"`
+}
+
+// statusCounts holds summary counts of monitored resources.
+type statusCounts struct {
+	Domains      int `json:"domains"`
+	Hostnames    int `json:"hostnames"`
+	Ports        int `json:"ports"`
+	PortsOpen    int `json:"portsOpen"`
+	Certificates int `json:"certificates"`
+	CertsOK      int `json:"certificatesOk"`
+	CertsError   int `json:"certificatesError"`
+}
+
+// statusResponse is the full /api/v1/status response.
+type statusResponse struct {
+	Status       string                            `json:"status"`
+	LastUpdated  time.Time                         `json:"lastUpdated"`
+	Counts       statusCounts                      `json:"counts"`
+	Domains      map[string]*statusDomainInfo      `json:"domains"`
+	Hostnames    map[string]*statusHostnameInfo    `json:"hostnames"`
+	Ports        map[string]*statusPortInfo        `json:"ports"`
+	Certificates map[string]*statusCertificateInfo `json:"certificates"`
+}
+
 // HandleStatus returns the monitoring status handler.
 func (h *Handlers) HandleStatus() http.HandlerFunc {
-	type response struct {
-		Status string `json:"status"`
-	}
-
 	return func(
 		writer http.ResponseWriter,
 		request *http.Request,
 	) {
+		snap := h.state.GetSnapshot()
+
+		resp := buildStatusResponse(snap)
+
 		h.respondJSON(
 			writer, request,
-			&response{Status: "ok"},
+			resp,
 			http.StatusOK,
 		)
 	}
 }
+
+// buildStatusResponse constructs the full status response from
+// the current monitoring snapshot.
+func buildStatusResponse(
+	snap state.Snapshot,
+) *statusResponse {
+	resp := &statusResponse{
+		Status:       "ok",
+		LastUpdated:  snap.LastUpdated,
+		Domains:      make(map[string]*statusDomainInfo),
+		Hostnames:    make(map[string]*statusHostnameInfo),
+		Ports:        make(map[string]*statusPortInfo),
+		Certificates: make(map[string]*statusCertificateInfo),
+	}
+
+	buildDomains(snap, resp)
+	buildHostnames(snap, resp)
+	buildPorts(snap, resp)
+	buildCertificates(snap, resp)
+	buildCounts(resp)
+
+	return resp
+}
+
+func buildDomains(
+	snap state.Snapshot,
+	resp *statusResponse,
+) {
+	for name, ds := range snap.Domains {
+		ns := make([]string, len(ds.Nameservers))
+		copy(ns, ds.Nameservers)
+		sort.Strings(ns)
+
+		resp.Domains[name] = &statusDomainInfo{
+			Nameservers: ns,
+			LastChecked: ds.LastChecked,
+		}
+	}
+}
+
+func buildHostnames(
+	snap state.Snapshot,
+	resp *statusResponse,
+) {
+	for name, hs := range snap.Hostnames {
+		info := &statusHostnameInfo{
+			Nameservers: make(map[string]*statusHostnameNSInfo),
+			LastChecked: hs.LastChecked,
+		}
+
+		for ns, nsState := range hs.RecordsByNameserver {
+			recs := make(map[string][]string, len(nsState.Records))
+			for rtype, vals := range nsState.Records {
+				copied := make([]string, len(vals))
+				copy(copied, vals)
+				recs[rtype] = copied
+			}
+
+			info.Nameservers[ns] = &statusHostnameNSInfo{
+				Records:     recs,
+				Status:      nsState.Status,
+				LastChecked: nsState.LastChecked,
+			}
+		}
+
+		resp.Hostnames[name] = info
+	}
+}
+
+func buildPorts(
+	snap state.Snapshot,
+	resp *statusResponse,
+) {
+	for key, ps := range snap.Ports {
+		hostnames := make([]string, len(ps.Hostnames))
+		copy(hostnames, ps.Hostnames)
+		sort.Strings(hostnames)
+
+		resp.Ports[key] = &statusPortInfo{
+			Open:        ps.Open,
+			Hostnames:   hostnames,
+			LastChecked: ps.LastChecked,
+		}
+	}
+}
+
+func buildCertificates(
+	snap state.Snapshot,
+	resp *statusResponse,
+) {
+	for key, cs := range snap.Certificates {
+		sans := make([]string, len(cs.SubjectAlternativeNames))
+		copy(sans, cs.SubjectAlternativeNames)
+
+		resp.Certificates[key] = &statusCertificateInfo{
+			CommonName:              cs.CommonName,
+			Issuer:                  cs.Issuer,
+			NotAfter:                cs.NotAfter,
+			SubjectAlternativeNames: sans,
+			Status:                  cs.Status,
+			LastChecked:             cs.LastChecked,
+		}
+	}
+}
+
+func buildCounts(resp *statusResponse) {
+	var portsOpen, certsOK, certsError int
+
+	for _, ps := range resp.Ports {
+		if ps.Open {
+			portsOpen++
+		}
+	}
+
+	for _, cs := range resp.Certificates {
+		switch cs.Status {
+		case "ok":
+			certsOK++
+		case "error":
+			certsError++
+		}
+	}
+
+	resp.Counts = statusCounts{
+		Domains:      len(resp.Domains),
+		Hostnames:    len(resp.Hostnames),
+		Ports:        len(resp.Ports),
+		PortsOpen:    portsOpen,
+		Certificates: len(resp.Certificates),
+		CertsOK:      certsOK,
+		CertsError:   certsError,
+	}
+}