gosora/routes/api.go

package routes

import (
	"encoding/json"
	"errors"
	"net/http"
	"strconv"
	"strings"

	c "git.tuxpa.in/a/gosora/common"
)

// TODO: Make this a static file somehow? Is it possible for us to put this file somewhere else?
// TODO: Add an API so that plugins can register disallowed areas. E.g. /guilds/join for plugin_guilds
func RobotsTxt(w http.ResponseWriter, r *http.Request) c.RouteError {
    // TODO: Do we have to put * or something at the end of the paths?
    _, _ = w.Write([]byte(`User-agent: *
Disallow: /panel/*
Disallow: /topics/create/
Disallow: /user/edit/*
Disallow: /accounts/*
Disallow: /report/*
`))
    return nil
}

var sitemapPageCap = 40000 // 40k, bump it up to 50k once we gzip this? Does brotli work on sitemaps?

func writeXMLHeader(w http.ResponseWriter, r *http.Request) {
    w.Header().Set("Content-Type", "application/xml")
    w.Write([]byte("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"))
}

// TODO: Keep track of when a sitemap was last modifed and add a lastmod element for it
func SitemapXml(w http.ResponseWriter, r *http.Request) c.RouteError {
    var s string
    if c.Config.SslSchema {
        s = "s"
    }
    sitemapItem := func(path string) {
        w.Write([]byte(`<sitemap>
    <loc>http` + s + `://` + c.Site.URL + "/" + path + `</loc>
</sitemap>
`))
    }
    writeXMLHeader(w, r)
    w.Write([]byte("<sitemapindex xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\n"))
    sitemapItem("sitemaps/topics.xml")
    //sitemapItem("sitemaps/forums.xml")
    //sitemapItem("sitemaps/users.xml")
    w.Write([]byte("</sitemapindex>"))

    return nil
}

type FuzzyRoute struct {
    Path   string
    Handle func(http.ResponseWriter, *http.Request, int) c.RouteError
}

// TODO: Add a sitemap API and clean things up
// TODO: ^-- Make sure that the API is concurrent
// TODO: Add a social group sitemap
var sitemapRoutes = map[string]func(http.ResponseWriter, *http.Request) c.RouteError{
    "forums.xml": SitemapForums,
    "topics.xml": SitemapTopics,
}

// TODO: Use a router capable of parsing this rather than hard-coding the logic in
var fuzzySitemapRoutes = map[string]FuzzyRoute{
    "topics_page_": {"topics_page_(%d).xml", SitemapTopic},
}

func sitemapSwitch(w http.ResponseWriter, r *http.Request) c.RouteError {
    path := r.URL.Path[len("/sitemaps/"):]
    for name, fuzzy := range fuzzySitemapRoutes {
        if strings.HasPrefix(path, name) && strings.HasSuffix(path, ".xml") {
            spath := strings.TrimPrefix(path, name)
            spath = strings.TrimSuffix(spath, ".xml")
            page, err := strconv.Atoi(spath)
            if err != nil {
                // ? What's this? Do we need it? Was it just a quick trace?
                c.DebugLogf("Unable to convert string '%s' to integer in fuzzy route", spath)
                return c.NotFound(w, r, nil)
            }
            return fuzzy.Handle(w, r, page)
        }
    }

    route, ok := sitemapRoutes[path]
    if !ok {
        return c.NotFound(w, r, nil)
    }
    return route(w, r)
}

func SitemapForums(w http.ResponseWriter, r *http.Request) c.RouteError {
    var s string
    if c.Config.SslSchema {
        s = "s"
    }
    sitemapItem := func(path string) {
        w.Write([]byte(`<url>
    <loc>http` + s + `://` + c.Site.URL + path + `</loc>
</url>
`))
    }

    group, err := c.Groups.Get(c.GuestUser.Group)
    if err != nil {
        return c.SilentInternalErrorXML(errors.New("The guest group doesn't exist for some reason"), w, r)
    }

    writeXMLHeader(w, r)
    w.Write([]byte("<urlset xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\n"))

    for _, fid := range group.CanSee {
        // Avoid data races by copying the struct into something we can freely mold without worrying about breaking something somewhere else
        f := c.Forums.DirtyGet(fid).Copy()
        if f.ParentID == 0 && f.Name != "" && f.Active {
            sitemapItem(c.BuildForumURL(c.NameToSlug(f.Name), f.ID))
        }
    }

    w.Write([]byte("</urlset>"))
    return nil
}

// TODO: Add a global ratelimit. 10 50MB files (smaller if compressed better) per minute?
// ? We might have problems with banned users, if they have fewer ViewTopic permissions than guests as they'll be able to see this list. Then again, a banned user could just logout to see it
func SitemapTopics(w http.ResponseWriter, r *http.Request) c.RouteError {
    var s string
    if c.Config.SslSchema {
        s = "s"
    }
    sitemapItem := func(path string) {
        w.Write([]byte(`<sitemap>
    <loc>http` + s + `://` + c.Site.URL + "/" + path + `</loc>
</sitemap>
`))
    }

    group, err := c.Groups.Get(c.GuestUser.Group)
    if err != nil {
        return c.SilentInternalErrorXML(errors.New("The guest group doesn't exist for some reason"), w, r)
    }

    var visibleForums []c.Forum
    for _, fid := range group.CanSee {
        forum := c.Forums.DirtyGet(fid)
        if forum.Name != "" && forum.Active {
            visibleForums = append(visibleForums, forum.Copy())
        }
    }

    topicCount, err := c.TopicCountInForums(visibleForums)
    if err != nil {
        return c.InternalErrorXML(err, w, r)
    }

    pageCount := topicCount / sitemapPageCap
    //log.Print("topicCount", topicCount)
    //log.Print("pageCount", pageCount)
    writeXMLHeader(w, r)
    w.Write([]byte("<sitemapindex xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\n"))
    for i := 0; i <= pageCount; i++ {
        sitemapItem("sitemaps/topics_page_" + strconv.Itoa(i) + ".xml")
    }
    w.Write([]byte("</sitemapindex>"))
    return nil
}

func SitemapTopic(w http.ResponseWriter, r *http.Request, page int) c.RouteError {
    /*var s string
    if c.Config.SslSchema {
        s = "s"
    }
    var sitemapItem = func(path string) {
            w.Write([]byte(`<url>
        <loc>http` + s + `://` + c.Site.URL + "/" + path + `</loc>
    </url>
    `))
        }*/

    group, err := c.Groups.Get(c.GuestUser.Group)
    if err != nil {
        return c.SilentInternalErrorXML(errors.New("The guest group doesn't exist for some reason"), w, r)
    }

    var visibleForums []c.Forum
    for _, fid := range group.CanSee {
        forum := c.Forums.DirtyGet(fid)
        if forum.Name != "" && forum.Active {
            visibleForums = append(visibleForums, forum.Copy())
        }
    }

    argList, qlist := c.ForumListToArgQ(visibleForums)
    topicCount, err := c.ArgQToTopicCount(argList, qlist)
    if err != nil {
        return c.InternalErrorXML(err, w, r)
    }

    pageCount := topicCount / sitemapPageCap
    //log.Print("topicCount", topicCount)
    //log.Print("pageCount", pageCount)
    //log.Print("page",page)
    if page > pageCount {
        page = pageCount
    }

    writeXMLHeader(w, r)
    w.Write([]byte("<urlset xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\n"))

    w.Write([]byte("</urlset>"))
    return nil
}

func SitemapUsers(w http.ResponseWriter, r *http.Request) c.RouteError {
    writeXMLHeader(w, r)
    w.Write([]byte("<sitemapindex xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\n"))
    return nil
}

type JsonMe struct {
    User *c.MeUser
    Site MeSite
}

// We don't want to expose too much information about the site, so we'll make this a small subset of c.site
type MeSite struct {
    MaxReqSize   int
    StaticPrefix string
}

// APIMe returns information about the current logged-in user
// TODO: Find some way to stop intermediaries from doing compression to avoid the BREACH attack
// TODO: Decouple site settings into a different API? I'd like to avoid having too many requests, if possible, maybe we can use a different name for this?
func APIMe(w http.ResponseWriter, r *http.Request, u *c.User) c.RouteError {
    // TODO: Don't make this too JSON dependent so that we can swap in newer more efficient formats
    h := w.Header()
    h.Set("Content-Type", "application/json")
    // We don't want an intermediary accidentally caching this
    // TODO: Use this header anywhere with a user check?
    h.Set("Cache-Control", "private")

    me := JsonMe{u.Me(), MeSite{c.Site.MaxRequestSize, c.StaticFiles.Prefix}}
    jsonBytes, err := json.Marshal(me)
    if err != nil {
        return c.InternalErrorJS(err, w, r)
    }
    w.Write(jsonBytes)

    return nil
}

func OpenSearchXml(w http.ResponseWriter, r *http.Request) c.RouteError {
    w.Header().Set("Content-Type", "application/xml")
    furl := "http"
    if c.Config.SslSchema {
        furl += "s"
    }
    furl += "://" + c.Site.URL
    w.Write([]byte(`<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/" xmlns:moz="http://www.mozilla.org/2006/browser/search/">
    <ShortName>` + c.Site.Name + `</ShortName>
    <InputEncoding>UTF-8</InputEncoding>
    <Url type="text/html" template="` + furl + `/topics/?q={searchTerms}"/>
    <Url type="application/opensearchdescription+xml" rel="self" template="` + furl + `/opensearch.xml"/>
    <moz:SearchForm>` + furl + `</moz:SearchForm>
</OpenSearchDescription>`))
    return nil
}