package server

import (
	"encoding/json"
	"local/s2sa/s2sa/server/router"
	"local/s2sa/s2sa/token"
	"net/http"
	"path"
	"strings"
)

const clientsNS = "clients"
const accessorsNS = "accessors"
const wildcard = "{}"
const serverNS = "server"

func (s *Server) Routes() error {
	appendWildcards := func(s string, cnt int) string {
		s = strings.Trim(s, "/")
		return path.Join(s, strings.Repeat("/"+wildcard, cnt))
	}
	paths := []struct {
		base      string
		wildcards int
		method    http.HandlerFunc
	}{
		{
			base:      "admin/register",
			wildcards: 1,
			method:    s.adminRegister,
		},
		{
			base:      "register",
			wildcards: 1,
			method:    s.authenticate(s.registerClient),
		},
		{
			base:      "generate",
			wildcards: 2,
			method:    s.authenticate(s.generateToken),
		},
		{
			base:      "retrieve",
			wildcards: 3,
			method:    s.authenticate(s.retrieveToken),
		},
		{
			base:      "revoke",
			wildcards: 2,
			method:    s.authenticate(s.revokeToken),
		},
		{
			base:      "lookup",
			wildcards: 2,
			method:    s.authenticate(s.lookupToken),
		},
		{
			base:      "policies",
			wildcards: 0,
			method:    s.authenticate(s.getPolicies),
		},
	}
	for _, path := range paths {
		if err := s.Add(appendWildcards(path.base, path.wildcards), path.method); err != nil {
			return err
		}
	}
	return nil
}

func (s *Server) authenticate(foo http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		recipient, accessorToken, ok := r.BasicAuth()
		if !ok {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}
		accessor := strings.Split(accessorToken, ":")[0]
		tokenValue := strings.Split(accessorToken, ":")[1]

		token, err := s.authdb.Get(recipient, accessor)
		if err != nil {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}

		if token.Token != tokenValue {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}
		if token.To != recipient {
			w.WriteHeader(http.StatusUnauthorized)
			return
		}

		foo(w, r)
	}
}

func (s *Server) adminRegister(w http.ResponseWriter, r *http.Request) {
	var name string
	if err := router.Params(r, &name); err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	token, err := s.authdb.New(serverNS, name)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	respondWithToken(token, w, r)
}

func (s *Server) registerClient(w http.ResponseWriter, r *http.Request) {
	var name string
	if err := router.Params(r, &name); err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	if err := s.db.Register(name); err != nil {
		w.WriteHeader(http.StatusInternalServerError)
	}
}

func (s *Server) generateToken(w http.ResponseWriter, r *http.Request) {
	var name, to string
	if err := router.Params(r, &name, &to); err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	token, err := s.db.New(name, to)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	respondWithToken(token, w, r)
}

func (s *Server) retrieveToken(w http.ResponseWriter, r *http.Request) {
	var creator, recipient, accessor string
	if err := router.Params(r, &creator, &recipient, &accessor); err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	token, err := s.db.Get(recipient, accessor)
	if err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	respondWithToken(token, w, r)
}

func respondWithToken(token token.Basic, w http.ResponseWriter, r *http.Request) {
	if err := json.NewEncoder(w).Encode(token); err != nil {
		w.WriteHeader(http.StatusInternalServerError)
	}
}

func (s *Server) revokeToken(w http.ResponseWriter, r *http.Request) {
	var name, accessor string
	if err := router.Params(r, &name, &accessor); err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	if err := s.db.Revoke(name, accessor); err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		return
	}
}

func (s *Server) lookupToken(w http.ResponseWriter, r *http.Request) {
	var creator, recipient string
	if err := router.Params(r, &creator, &recipient); err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	token, err := s.db.Lookup(creator, recipient)
	if err != nil {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	respondWithToken(token, w, r)
}

func (s *Server) getPolicies(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusInternalServerError)
}