// Copyright 2017 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// govanityurls serves Go vanity URLs.
package main
import (
"fmt"
"html/template"
"net/http"
"sort"
"strings"
"gopkg.in/yaml.v2"
)
type handler struct {
host string
paths pathConfigSet
}
type pathConfig struct {
path string
repo string
display string
vcs string
}
func newHandler(config []byte) (*handler, error) {
var parsed struct {
Host string `yaml:"host,omitempty"`
Paths map[string]struct {
Repo string `yaml:"repo,omitempty"`
Display string `yaml:"display,omitempty"`
VCS string `yaml:"vcs,omitempty"`
} `yaml:"paths,omitempty"`
}
if err := yaml.Unmarshal(config, &parsed); err != nil {
return nil, err
}
h := &handler{host: parsed.Host}
for path, e := range parsed.Paths {
pc := pathConfig{
path: strings.TrimSuffix(path, "/"),
repo: e.Repo,
display: e.Display,
vcs: e.VCS,
}
switch {
case e.Display != "":
// Already filled in.
case strings.HasPrefix(e.Repo, "https://github.com/"):
pc.display = fmt.Sprintf("%v %v/tree/master{/dir} %v/blob/master{/dir}/{file}#L{line}", e.Repo, e.Repo, e.Repo)
case strings.HasPrefix(e.Repo, "https://bitbucket.org"):
pc.display = fmt.Sprintf("%v %v/src/default{/dir} %v/src/default{/dir}/{file}#{file}-{line}", e.Repo, e.Repo, e.Repo)
}
switch {
case e.VCS != "":
// Already filled in.
if e.VCS != "bzr" && e.VCS != "git" && e.VCS != "hg" && e.VCS != "svn" {
return nil, fmt.Errorf("configuration for %v: unknown VCS %s", path, e.VCS)
}
case strings.HasPrefix(e.Repo, "https://github.com/"):
pc.vcs = "git"
default:
return nil, fmt.Errorf("configuration for %v: cannot infer VCS from %s", path, e.Repo)
}
h.paths = append(h.paths, pc)
}
sort.Sort(h.paths)
return h, nil
}
func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
current := r.URL.Path
pc, subpath := h.paths.find(current)
if pc == nil && current == "/" {
h.serveIndex(w, r)
return
}
if pc == nil {
http.NotFound(w, r)
return
}
if err := vanityTmpl.Execute(w, struct {
Import string
Subpath string
Repo string
Display string
VCS string
}{
Import: h.Host(r) + pc.path,
Subpath: subpath,
Repo: pc.repo,
Display: pc.display,
VCS: pc.vcs,
}); err != nil {
http.Error(w, "cannot render the page", http.StatusInternalServerError)
}
}
func (h *handler) serveIndex(w http.ResponseWriter, r *http.Request) {
host := h.Host(r)
handlers := make([]string, len(h.paths))
for i, h := range h.paths {
handlers[i] = host + h.path
}
if err := indexTmpl.Execute(w, struct {
Host string
Handlers []string
}{
Host: host,
Handlers: handlers,
}); err != nil {
http.Error(w, "cannot render the page", http.StatusInternalServerError)
}
}
func (h *handler) Host(r *http.Request) string {
host := h.host
if host == "" {
host = defaultHost(r)
}
return host
}
var indexTmpl = template.Must(template.New("index").Parse(`
{{.Host}}
{{range .Handlers}}- {{.}}
{{end}}
`))
var vanityTmpl = template.Must(template.New("vanity").Parse(`
Nothing to see here; see the package on godoc.
`))
type pathConfigSet []pathConfig
func (pset pathConfigSet) Len() int {
return len(pset)
}
func (pset pathConfigSet) Less(i, j int) bool {
return pset[i].path < pset[j].path
}
func (pset pathConfigSet) Swap(i, j int) {
pset[i], pset[j] = pset[j], pset[i]
}
func (pset pathConfigSet) find(path string) (pc *pathConfig, subpath string) {
i := sort.Search(len(pset), func(i int) bool {
return pset[i].path >= path
})
if i < len(pset) && pset[i].path == path {
return &pset[i], ""
}
if i > 0 && strings.HasPrefix(path, pset[i-1].path+"/") {
return &pset[i-1], path[len(pset[i-1].path)+1:]
}
return nil, ""
}