add domain whois/dns support, refactor codebase

internal/server/handlers.go

@@ -0,0 +1,138 @@
+package server
+
+import (
+	"log/slog"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"ipinfo/internal/common"
+	"ipinfo/internal/db"
+
+	"golang.org/x/net/idna"
+)
+
+const favicon = `<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16"></svg>`
+
+// faviconHandler handles requests for the favicon.
+func faviconHandler(w http.ResponseWriter, _ *http.Request) {
+	w.Header().Set("Content-Type", "image/svg+xml")
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write([]byte(favicon))
+}
+
+// handleDomainLookup handles domain lookup requests.
+func handleDomainLookup(w http.ResponseWriter, _ *http.Request, domain string) {
+	punycodeDomain, err := idna.ToASCII(domain)
+	if err != nil {
+		sendJSONError(w, "Please provide a valid domain name.", http.StatusBadRequest)
+		return
+	}
+
+	if len(punycodeDomain) > 253 {
+		sendJSONError(w, "Please provide a valid domain name.", http.StatusBadRequest)
+		return
+	}
+
+	data, err := common.LookupDomainData(punycodeDomain)
+	if err != nil {
+		slog.Error("failed to look up domain data", "domain", punycodeDomain, "error", err)
+		sendJSONError(w, "Error retrieving data for domain.", http.StatusInternalServerError)
+		return
+	}
+
+	sendJSONResponse(w, data, http.StatusOK)
+}
+
+// handleASNLookup handles ASN lookup requests.
+func handleASNLookup(w http.ResponseWriter, _ *http.Request, path string, geoIP *db.GeoIPManager) {
+	var asnStr string
+	lowerPath := strings.ToLower(path)
+
+	if strings.HasPrefix(lowerPath, "asn/") {
+		asnStr = path[4:]
+	} else if strings.HasPrefix(lowerPath, "as") {
+		asnStr = path[2:]
+	} else {
+		sendJSONError(w, "Invalid ASN query format. Use /asn/<number> or /AS<number>.", http.StatusBadRequest)
+		return
+	}
+
+	asn, err := strconv.ParseUint(asnStr, 10, 32)
+	if err != nil || asn == 0 {
+		sendJSONError(w, "Invalid ASN: must be a positive number.", http.StatusBadRequest)
+		return
+	}
+
+	data, err := common.LookupASNData(geoIP, uint(asn))
+	if err != nil {
+		if strings.Contains(err.Error(), "no prefixes found") {
+			sendJSONError(w, err.Error(), http.StatusNotFound)
+		} else {
+			slog.Error("failed to look up asn data", "asn", asn, "error", err)
+			sendJSONError(w, "Error retrieving data for ASN.", http.StatusInternalServerError)
+		}
+		return
+	}
+
+	sendJSONResponse(w, data, http.StatusOK)
+}
+
+// handleIPLookup handles IP lookup requests.
+func handleIPLookup(w http.ResponseWriter, r *http.Request, path string, geoIP *db.GeoIPManager) {
+	parts := strings.Split(path, "/")
+	var ipAddress, field string
+
+	switch len(parts) {
+	case 0:
+		ipAddress = GetRealIP(r) // No more "common." prefix
+	case 1:
+		if parts[0] == "" {
+			ipAddress = GetRealIP(r) // No more "common." prefix
+		} else if _, ok := fieldMap[parts[0]]; ok {
+			ipAddress = GetRealIP(r) // No more "common." prefix
+			field = parts[0]
+		} else {
+			ipAddress = parts[0]
+		}
+	case 2:
+		ipAddress = parts[0]
+		field = parts[1]
+	default:
+		sendJSONError(w, "Invalid request format.", http.StatusBadRequest)
+		return
+	}
+
+	ip := net.ParseIP(ipAddress)
+	if ip == nil {
+		sendJSONError(w, "Please provide a valid IP address.", http.StatusBadRequest)
+		return
+	}
+
+	if field != "" {
+		if _, ok := fieldMap[field]; !ok {
+			sendJSONError(w, "Please provide a valid field.", http.StatusBadRequest)
+			return
+		}
+	}
+
+	if common.IsBogon(ip) {
+		sendJSONResponse(w, bogonDataStruct{IP: ip.String(), Bogon: true}, http.StatusOK)
+		return
+	}
+
+	data := common.LookupIPData(geoIP, ip)
+	if data == nil {
+		sendJSONError(w, "Could not retrieve data for the specified IP.", http.StatusNotFound)
+		return
+	}
+
+	if field != "" {
+		value := getField(data, field)
+		sendJSONResponse(w, map[string]*string{field: value}, http.StatusOK)
+		return
+	}
+
+	sendJSONResponse(w, data, http.StatusOK)
+}