Implement AS and prefix detail pages

- Implement handleASDetail() and handlePrefixDetail() HTML handlers
- Create AS detail HTML template with prefix listings
- Create prefix detail HTML template with route information
- Add timeSince template function for human-readable durations
- Update templates.go to include new templates
- Server-side rendered pages as requested (no client-side API calls)

internal/server/handlers.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"net"
 	"net/http"
 	"runtime"
 	"strconv"
@@ -458,16 +459,160 @@ func (s *Server) handlePrefixDetailJSON() http.HandlerFunc {
 
 // handleASDetail returns a handler that serves the AS detail HTML page
 func (s *Server) handleASDetail() http.HandlerFunc {
-	return func(w http.ResponseWriter, _ *http.Request) {
-		// TODO: Implement AS detail HTML page
-		http.Error(w, "Not implemented", http.StatusNotImplemented)
+	return func(w http.ResponseWriter, r *http.Request) {
+		asnStr := chi.URLParam(r, "asn")
+		asn, err := strconv.Atoi(asnStr)
+		if err != nil {
+			http.Error(w, "Invalid ASN", http.StatusBadRequest)
+
+			return
+		}
+
+		asInfo, prefixes, err := s.db.GetASDetails(asn)
+		if err != nil {
+			if errors.Is(err, database.ErrNoRoute) {
+				http.Error(w, "AS not found", http.StatusNotFound)
+			} else {
+				s.logger.Error("Failed to get AS details", "error", err)
+				http.Error(w, "Internal server error", http.StatusInternalServerError)
+			}
+
+			return
+		}
+
+		// Group prefixes by IP version
+		const ipVersionV4 = 4
+		var ipv4Prefixes, ipv6Prefixes []database.LiveRoute
+		for _, p := range prefixes {
+			if p.IPVersion == ipVersionV4 {
+				ipv4Prefixes = append(ipv4Prefixes, p)
+			} else {
+				ipv6Prefixes = append(ipv6Prefixes, p)
+			}
+		}
+
+		// Prepare template data
+		data := struct {
+			ASN          *database.ASN
+			IPv4Prefixes []database.LiveRoute
+			IPv6Prefixes []database.LiveRoute
+			TotalCount   int
+			IPv4Count    int
+			IPv6Count    int
+		}{
+			ASN:          asInfo,
+			IPv4Prefixes: ipv4Prefixes,
+			IPv6Prefixes: ipv6Prefixes,
+			TotalCount:   len(prefixes),
+			IPv4Count:    len(ipv4Prefixes),
+			IPv6Count:    len(ipv6Prefixes),
+		}
+
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		tmpl := templates.ASDetailTemplate()
+		if err := tmpl.Execute(w, data); err != nil {
+			s.logger.Error("Failed to render AS detail template", "error", err)
+			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		}
 	}
 }
 
 // handlePrefixDetail returns a handler that serves the prefix detail HTML page
 func (s *Server) handlePrefixDetail() http.HandlerFunc {
-	return func(w http.ResponseWriter, _ *http.Request) {
-		// TODO: Implement prefix detail HTML page
-		http.Error(w, "Not implemented", http.StatusNotImplemented)
+	return func(w http.ResponseWriter, r *http.Request) {
+		prefix := chi.URLParam(r, "prefix")
+		if prefix == "" {
+			http.Error(w, "Prefix parameter is required", http.StatusBadRequest)
+
+			return
+		}
+
+		routes, err := s.db.GetPrefixDetails(prefix)
+		if err != nil {
+			if errors.Is(err, database.ErrNoRoute) {
+				http.Error(w, "Prefix not found", http.StatusNotFound)
+			} else {
+				s.logger.Error("Failed to get prefix details", "error", err)
+				http.Error(w, "Internal server error", http.StatusInternalServerError)
+			}
+
+			return
+		}
+
+		// Group by origin AS and collect unique AS info
+		type ASNInfo struct {
+			Number      int
+			Handle      string
+			Description string
+			PeerCount   int
+		}
+		originMap := make(map[int]*ASNInfo)
+		for _, route := range routes {
+			if _, exists := originMap[route.OriginASN]; !exists {
+				// Get AS info from database
+				asInfo, _, _ := s.db.GetASDetails(route.OriginASN)
+				handle := ""
+				description := ""
+				if asInfo != nil {
+					handle = asInfo.Handle
+					description = asInfo.Description
+				}
+				originMap[route.OriginASN] = &ASNInfo{
+					Number:      route.OriginASN,
+					Handle:      handle,
+					Description: description,
+					PeerCount:   0,
+				}
+			}
+			originMap[route.OriginASN].PeerCount++
+		}
+
+		// Get the first route to extract some common info
+		var maskLength, ipVersion int
+		if len(routes) > 0 {
+			// Parse CIDR to get mask length and IP version
+			_, ipNet, err := net.ParseCIDR(prefix)
+			if err == nil {
+				ones, _ := ipNet.Mask.Size()
+				maskLength = ones
+				if ipNet.IP.To4() != nil {
+					ipVersion = 4
+				} else {
+					ipVersion = 6
+				}
+			}
+		}
+
+		// Convert origin map to sorted slice
+		var origins []*ASNInfo
+		for _, origin := range originMap {
+			origins = append(origins, origin)
+		}
+
+		// Prepare template data
+		data := struct {
+			Prefix      string
+			MaskLength  int
+			IPVersion   int
+			Routes      []database.LiveRoute
+			Origins     []*ASNInfo
+			PeerCount   int
+			OriginCount int
+		}{
+			Prefix:      prefix,
+			MaskLength:  maskLength,
+			IPVersion:   ipVersion,
+			Routes:      routes,
+			Origins:     origins,
+			PeerCount:   len(routes),
+			OriginCount: len(originMap),
+		}
+
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		tmpl := templates.PrefixDetailTemplate()
+		if err := tmpl.Execute(w, data); err != nil {
+			s.logger.Error("Failed to render prefix detail template", "error", err)
+			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		}
 	}
 }