GoBlog/webmention.go

177 lines
4.6 KiB
Go

package main
import (
"database/sql"
"errors"
"fmt"
"net/http"
"net/http/httptest"
"strings"
"time"
)
type webmentionStatus string
const (
webmentionStatusVerified webmentionStatus = "verified"
webmentionStatusApproved webmentionStatus = "approved"
webmentionPath = "/webmention"
)
type mention struct {
ID int
Source string
Target string
Created int64
Title string
Content string
Author string
Status webmentionStatus
}
func initWebmention() error {
// Add hooks
hookFunc := func(p *post) {
if p.Status == statusPublished {
_ = p.sendWebmentions()
}
}
postHooks[postPostHook] = append(postHooks[postPostHook], hookFunc)
postHooks[postUpdateHook] = append(postHooks[postUpdateHook], hookFunc)
postHooks[postDeleteHook] = append(postHooks[postDeleteHook], hookFunc)
// Start verifier
return initWebmentionQueue()
}
func handleWebmention(w http.ResponseWriter, r *http.Request) {
m, err := extractMention(r)
if err != nil {
serveError(w, r, err.Error(), http.StatusBadRequest)
return
}
if !isAllowedHost(httptest.NewRequest(http.MethodGet, m.Target, nil), appConfig.Server.publicHostname) {
serveError(w, r, "target not allowed", http.StatusBadRequest)
return
}
if err = queueMention(m); err != nil {
serveError(w, r, err.Error(), http.StatusInternalServerError)
return
}
w.WriteHeader(http.StatusAccepted)
_, _ = fmt.Fprint(w, "Webmention accepted")
}
func extractMention(r *http.Request) (*mention, error) {
if !strings.Contains(r.Header.Get(contentType), contentTypeWWWForm) {
return nil, errors.New("Unsupported Content-Type")
}
err := r.ParseForm()
if err != nil {
return nil, err
}
source := r.Form.Get("source")
target := unescapedPath(r.Form.Get("target"))
if source == "" || target == "" || !isAbsoluteURL(source) || !isAbsoluteURL(target) {
return nil, errors.New("Invalid request")
}
return &mention{
Source: source,
Target: target,
Created: time.Now().Unix(),
}, nil
}
func webmentionExists(source, target string) bool {
result := 0
row, err := appDbQueryRow("select exists(select 1 from webmentions where source = ? and target = ?)", source, target)
if err != nil {
return false
}
if err = row.Scan(&result); err != nil {
return false
}
return result == 1
}
func createWebmention(source, target string) (err error) {
return queueMention(&mention{
Source: source,
Target: unescapedPath(target),
Created: time.Now().Unix(),
})
}
func deleteWebmention(id int) error {
_, err := appDbExec("delete from webmentions where id = @id", sql.Named("id", id))
return err
}
func approveWebmention(id int) error {
_, err := appDbExec("update webmentions set status = ? where id = ?", webmentionStatusApproved, id)
return err
}
type webmentionsRequestConfig struct {
target string
status webmentionStatus
asc bool
offset, limit int
}
func buildWebmentionsQuery(config *webmentionsRequestConfig) (query string, args []interface{}) {
args = []interface{}{}
filter := ""
if config != nil {
if config.target != "" && config.status != "" {
filter = "where target = @target and status = @status"
args = append(args, sql.Named("target", unescapedPath(config.target)), sql.Named("status", config.status))
} else if config.target != "" {
filter = "where target = @target"
args = append(args, sql.Named("target", config.target))
} else if config.status != "" {
filter = "where status = @status"
args = append(args, sql.Named("status", config.status))
}
}
order := "desc"
if config.asc {
order = "asc"
}
query = "select id, source, target, created, title, content, author, status from webmentions " + filter + " order by created " + order
if config.limit != 0 || config.offset != 0 {
query += " limit @limit offset @offset"
args = append(args, sql.Named("limit", config.limit), sql.Named("offset", config.offset))
}
return query, args
}
func getWebmentions(config *webmentionsRequestConfig) ([]*mention, error) {
mentions := []*mention{}
query, args := buildWebmentionsQuery(config)
rows, err := appDbQuery(query, args...)
if err != nil {
return nil, err
}
for rows.Next() {
m := &mention{}
err = rows.Scan(&m.ID, &m.Source, &m.Target, &m.Created, &m.Title, &m.Content, &m.Author, &m.Status)
if err != nil {
return nil, err
}
mentions = append(mentions, m)
}
return mentions, nil
}
func countWebmentions(config *webmentionsRequestConfig) (count int, err error) {
query, params := buildWebmentionsQuery(config)
query = "select count(*) from (" + query + ")"
row, err := appDbQueryRow(query, params...)
if err != nil {
return
}
err = row.Scan(&count)
return
}