snap/server.go

package snap

import (
	"fmt"
	"html/template"
	"io"
	"io/ioutil"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/gorilla/mux"

	"git.thirdmartini.com/pub/fancylog"

	"git.thirdmartini.com/pub/snap/auth"
)

type Server struct {
	address    string
	path       string
	theme      string
	debug      bool
	auth       auth.AuthManager
	router     *mux.Router
	templates  string
	cachedTmpl *template.Template
}

type SnapBaseContent struct {
	Theme   string
	Content interface{}
}

func (s *Server) makeContext(auth *auth.AuthData, w http.ResponseWriter, r *http.Request) *Context {
	c := &Context{
		r:    r,
		w:    w,
		srv:  s,
		auth: auth,
		vars: mux.Vars(r),
	}
	return c
}

func (s *Server) authenticated(auth auth.AuthManager, handle func(c *Context)) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		log.Debug("authenticated request: ", r.RequestURI)

		rec, ok := auth.DoAuth(w, r)

		if !ok {
			http.Error(w, "Not authorized", 401)
		} else {
			c := s.makeContext(rec, w, r)
			handle(c)
		}
	}
}

func (s *Server) wrapper(handle func(c *Context)) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		log.Debug("request: ", r.RequestURI)
		c := s.makeContext(nil, w, r)
		handle(c)

		// discard the rest of the body content
		io.Copy(ioutil.Discard, r.Body)
		defer r.Body.Close()
	}
}

// This is a bit different then the standard template.parseFiles code in that it gives us hiarchial templates
//     header.html
//     mydirectory/service.html ...
func (s *Server) parseTemplates(t *template.Template, filenames ...string) (*template.Template, error) {
	//if err := t.checkCanParse(); err != nil {
	//	return nil, err
	//}

	if len(filenames) == 0 {
		// Not really a problem, but be consistent.
		return nil, fmt.Errorf("html/template: no files named in call to ParseFiles")
	}
	for _, filename := range filenames {
		b, err := ioutil.ReadFile(filename)
		if err != nil {
			return nil, err
		}
		data := string(b)
		name := strings.TrimPrefix(filename, s.templates+"/")
		// log.Println("Template:", name)

		// First template becomes return value if not already defined,
		// and we use that one for subsequent New calls to associate
		// all the templates together. Also, if this file has the same name
		// as t, this file becomes the contents of t, so
		//  t, err := New(name).Funcs(xxx).ParseFiles(name)
		// works. Otherwise we create a new template associated with t.
		var tmpl *template.Template
		if t == nil {
			t = template.New(name)
		}
		if name == t.Name() {
			tmpl = t
		} else {
			tmpl = t.New(name)
		}
		_, err = tmpl.Parse(data)
		if err != nil {
			return nil, err
		}
	}
	return t, nil
}

func (s *Server) loadTemplates() *template.Template {
	tmpl := template.New("")

	err := filepath.Walk(s.templates, func(path string, info os.FileInfo, err error) error {
		if strings.Contains(path, ".html") {
			_, err := s.parseTemplates(tmpl, path)
			if err != nil {
				log.Println(err)
			}
			/*
				_, err = tmpl.ParseFiles(path)
				if err != nil {
					log.Println(err)
				}
			*/
		}
		return err
	})

	if err != nil {
		log.Fatal(err)
	}

	return tmpl
}

func (s *Server) getTemplates() *template.Template {
	if s.debug {
		return s.loadTemplates()
	}

	if s.cachedTmpl == nil {
		s.cachedTmpl = s.loadTemplates()
	}
	return s.cachedTmpl
}

func (s *Server) render(w http.ResponseWriter, tmpl string, content interface{}) {
	err := s.getTemplates().ExecuteTemplate(w, tmpl, content)
	if err != nil {
		log.Warn(err)
	}
}

func (s *Server) reply(w http.ResponseWriter, msg string) {
	w.Write([]byte(msg))
}

func (s *Server) renderError(w http.ResponseWriter, code int, msg string) {
	w.WriteHeader(code)
	w.Write([]byte(msg))
}

func (s *Server) HandleFuncAuthenticated(path string, f func(c *Context)) *mux.Route {
	if s.auth == nil {
		return nil
	}

	return s.router.HandleFunc(path, s.authenticated(s.auth, f))
}

func (s *Server) HandleFuncCustomAuth(auth auth.AuthManager, path string, f func(c *Context)) *mux.Route {
	if auth == nil {
		log.Warn("Nil auth on", path)
		return nil
	}
	return s.router.HandleFunc(path, s.authenticated(auth, f))
}

func (s *Server) HandleFunc(path string, f func(c *Context)) *mux.Route {
	return s.router.HandleFunc(path, s.wrapper(f))
}

func (s *Server) SetDebug(enable bool) {
	s.debug = enable
}

func (s *Server) EnableStatus(path string) {
}

func (s *Server) SetTheme(theme string) {
	s.theme = theme
}

func (s *Server) SetTemplatePath(path string) {
	s.templates = path
}

func (s *Server) Router() *mux.Router {
	return s.router
}

func (s *Server) ServeTLS(keyPath string, certPath string) error {
	srv := &http.Server{
		Handler: s.router,
		Addr:    s.address,
		// Good practice: enforce timeouts for servers you create!
		WriteTimeout: 120 * time.Second,
		ReadTimeout:  120 * time.Second,
	}

	return srv.ListenAndServeTLS(certPath, keyPath)
}

// Serve serve content forever
func (s *Server) Serve() error {
	srv := &http.Server{
		Handler: s.router,
		Addr:    s.address,
		// Good practice: enforce timeouts for servers you create!
		WriteTimeout: 120 * time.Second,
		ReadTimeout:  120 * time.Second,
	}

	return srv.ListenAndServe()
}

func (s *Server) WithStaticFiles(prefix string, path string) *Server {
	s.router.PathPrefix(prefix).Handler(http.StripPrefix(prefix, http.FileServer(http.Dir(path))))
	return s
}

func (s *Server) WithTheme(themeURL string) *Server {
	s.theme = themeURL
	return s
}

func (s *Server) WithDebug(debugURL string) *Server {
	sub := s.router.PathPrefix("/sovereign/debug").Subrouter()
	setupDebugHandler(sub)
	return s
}

func New(address string, path string, auth auth.AuthManager) *Server {
	s := Server{
		router:    mux.NewRouter(),
		auth:      auth,
		address:   address,
		path:      path,
		templates: "templates",
		theme:     "/static/css/default.css",
	}

	//s.router.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir(s.path+"static/"))))
	return &s
}