package server

import (
	"bytes"
	"crypto/sha256"
	"encoding/hex"
	"io/fs"
	"net/http"
	"strings"
	"time"

	"steward/internal/api"
	"steward/internal/version"
)

func (s *Server) routes() {
	m := s.mux
	p := api.Prefix
	m.HandleFunc("GET /healthz", func(w http.ResponseWriter, r *http.Request) {
		writeJSON(w, http.StatusOK, map[string]any{"ok": true, "version": version.String()})
	})
	// Authentication, users and tokens
	m.HandleFunc("POST "+p+"/auth/login", s.public(s.login))
	m.HandleFunc("POST "+p+"/auth/logout", s.authed(s.logout))
	m.HandleFunc("GET "+p+"/auth/whoami", s.authed(s.whoami))
	m.HandleFunc("POST "+p+"/me/password", s.authed(s.changeOwnPassword))
	m.HandleFunc("GET "+p+"/me/tokens", s.authed(s.listOwnTokens))
	m.HandleFunc("POST "+p+"/me/tokens", s.authed(s.createOwnToken))
	m.HandleFunc("GET "+p+"/tokens", s.authed(s.listAllTokens))
	m.HandleFunc("DELETE "+p+"/tokens/{id}", s.authed(s.revokeToken))
	m.HandleFunc("POST "+p+"/tokens/{id}/rotate", s.authed(s.rotateToken))
	m.HandleFunc("GET "+p+"/users", s.authed(s.listUsers))
	m.HandleFunc("POST "+p+"/users", s.authed(s.createUser))
	m.HandleFunc("PATCH "+p+"/users/{id}", s.authed(s.updateUser))
	m.HandleFunc("DELETE "+p+"/users/{id}", s.authed(s.deleteUser))
	m.HandleFunc("GET "+p+"/users/{id}/tokens", s.authed(s.listUserTokens))
	m.HandleFunc("POST "+p+"/users/{id}/tokens", s.authed(s.createUserToken))
	// Configuration
	m.HandleFunc("GET "+p+"/settings", s.authed(s.getSettings))
	m.HandleFunc("PATCH "+p+"/settings", s.authed(s.updateSettings))
	m.HandleFunc("GET "+p+"/subnets", s.authed(s.listSubnets))
	m.HandleFunc("POST "+p+"/subnets", s.authed(s.createSubnet))
	m.HandleFunc("GET "+p+"/subnets/{ref}", s.authed(s.getSubnet))
	m.HandleFunc("PATCH "+p+"/subnets/{ref}", s.authed(s.updateSubnet))
	m.HandleFunc("DELETE "+p+"/subnets/{ref}", s.authed(s.deleteSubnet))
	m.HandleFunc("GET "+p+"/reservations", s.authed(s.listReservations))
	m.HandleFunc("POST "+p+"/reservations", s.authed(s.createReservation))
	m.HandleFunc("GET "+p+"/reservations/{ref}", s.authed(s.getReservation))
	m.HandleFunc("PATCH "+p+"/reservations/{ref}", s.authed(s.updateReservation))
	m.HandleFunc("DELETE "+p+"/reservations/{ref}", s.authed(s.deleteReservation))
	m.HandleFunc("GET "+p+"/history", s.authed(s.listHistory))
	m.HandleFunc("GET "+p+"/history/{id}", s.authed(s.getHistory))
	m.HandleFunc("POST "+p+"/history/{id}/revert", s.authed(s.revertHistory))
	m.HandleFunc("POST "+p+"/import/kea", s.authed(s.importKea))
	m.HandleFunc("GET "+p+"/catalog", s.authed(s.catalog))
	m.HandleFunc("GET "+p+"/interfaces", s.authed(s.interfaces))
	// Leases and activity
	m.HandleFunc("GET "+p+"/leases", s.authed(s.listLeases))
	m.HandleFunc("GET "+p+"/leases/{ip}", s.authed(s.getLease))
	m.HandleFunc("DELETE "+p+"/leases/{ip}", s.authed(s.deleteLease))
	m.HandleFunc("POST "+p+"/leases/{ip}/reserve", s.authed(s.reserveLease))
	m.HandleFunc("GET "+p+"/events", s.authed(s.listEvents))
	m.HandleFunc("GET "+p+"/events/{id}", s.authed(s.getEvent))
	// Status and audit
	m.HandleFunc("GET "+p+"/status", s.authed(s.status))
	m.HandleFunc("GET "+p+"/audit", s.authed(s.listAudit))
	m.HandleFunc("GET "+p+"/certificate", s.authed(s.certificate))
	m.HandleFunc("POST "+p+"/certificate/check", s.authed(s.certificateCheck))
	m.HandleFunc("POST "+p+"/certificate/renew", s.authed(s.certificateRenew))
	m.HandleFunc(p+"/", func(w http.ResponseWriter, r *http.Request) {
		writeError(w, http.StatusNotFound, "not_found", "no such API endpoint: "+r.Method+" "+r.URL.Path)
	})
	// Web UI
	if s.web != nil {
		files := http.FileServer(http.FS(s.web))
		etags := contentETags(s.web)
		m.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
			if r.Method != http.MethodGet && r.Method != http.MethodHead {
				w.Header().Set("Allow", "GET, HEAD")
				http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
				return
			}
			if r.URL.Path == "/" || r.URL.Path == "/index.html" {
				b, err := fs.ReadFile(s.web, "index.html")
				if err != nil {
					http.NotFound(w, r)
					return
				}
				w.Header().Set("Content-Type", "text/html; charset=utf-8")
				w.Header().Set("Cache-Control", "no-cache")
				w.Header().Set("ETag", etags["index.html"])
				http.ServeContent(w, r, "index.html", time.Time{}, bytes.NewReader(b))
				return
			}
			if strings.HasPrefix(r.URL.Path, "/assets/") {
				w.Header().Set("Cache-Control", "no-cache")
				if tag, ok := etags[strings.TrimPrefix(r.URL.Path, "/")]; ok {
					w.Header().Set("ETag", tag)
				}
				files.ServeHTTP(w, r)
				return
			}
			http.NotFound(w, r)
		})
	}
}

// contentETags gives every embedded file an ETag from its content.
func contentETags(fsys fs.FS) map[string]string {
	tags := map[string]string{}
	fs.WalkDir(fsys, ".", func(path string, d fs.DirEntry, err error) error {
		if err != nil || d.IsDir() {
			return nil
		}
		b, err := fs.ReadFile(fsys, path)
		if err != nil {
			return nil
		}
		sum := sha256.Sum256(b)
		tags[path] = `"` + hex.EncodeToString(sum[:12]) + `"`
		return nil
	})
	return tags
}