gosora/routes.go

/*
*
*    Gosora Route Handlers
*    Copyright Azareal 2016 - 2020
*
 */
package main

import (
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"errors"
	"io"
	"log"
	"net/http"
	"strconv"
	"strings"
	"sync"
	"time"
	"unicode"

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

// A blank list to fill out that parameter in Page for routes which don't use it
var tList []interface{}
var successJSONBytes = []byte(`{"success":1}`)

// TODO: Refactor this
// TODO: Use the phrase system
var phraseLoginAlerts = []byte(`{"msgs":[{"msg":"Login to see your alerts","path":"/accounts/login"}],"count":0}`)
var alertStrPool = sync.Pool{}

// TODO: Refactor this endpoint
// TODO: Move this into the routes package
func routeAPI(w http.ResponseWriter, r *http.Request, user *c.User) c.RouteError {
    // TODO: Don't make this too JSON dependent so that we can swap in newer more efficient formats
    w.Header().Set("Content-Type", "application/json")
    err := r.ParseForm()
    if err != nil {
        return c.PreErrorJS("Bad Form", w, r)
    }

    action := r.FormValue("a")
    if action == "" {
        action = "get"
    }
    if action != "get" && action != "set" {
        return c.PreErrorJS("Invalid Action", w, r)
    }

    switch r.FormValue("m") {
    // TODO: Split this into it's own function
    case "dismiss-alert":
        id, err := strconv.Atoi(r.FormValue("id"))
        if err != nil {
            return c.PreErrorJS("Invalid id", w, r)
        }
        res, err := stmts.deleteActivityStreamMatch.Exec(user.ID, id)
        if err != nil {
            return c.InternalError(err, w, r)
        }
        count, err := res.RowsAffected()
        if err != nil {
            return c.InternalError(err, w, r)
        }
        // Don't want to throw an internal error due to a socket closing
        if c.EnableWebsockets && count > 0 {
            c.DismissAlert(user.ID, id)
        }
        w.Write(successJSONBytes)
    // TODO: Split this into it's own function
    case "alerts": // A feed of events tailored for a specific user
        if !user.Loggedin {
            h := w.Header()
            if gzw, ok := w.(c.GzipResponseWriter); ok {
                w = gzw.ResponseWriter
                h.Del("Content-Encoding")
            }
            etag := "\"1583653869-n\""
            //etag = c.StartEtag
            h.Set("ETag", etag)
            if match := r.Header.Get("If-None-Match"); match != "" {
                if strings.Contains(match, etag) {
                    w.WriteHeader(http.StatusNotModified)
                    return nil
                }
            }
            w.Write(phraseLoginAlerts)
            return nil
        }

        var count int
        err = stmts.getActivityCountByWatcher.QueryRow(user.ID).Scan(&count)
        if err == ErrNoRows {
            return c.PreErrorJS("Unable to get the activity count", w, r)
        } else if err != nil {
            return c.InternalErrorJS(err, w, r)
        }

        if count == 0 {
            if gzw, ok := w.(c.GzipResponseWriter); ok {
                w = gzw.ResponseWriter
                w.Header().Del("Content-Encoding")
            }
            _, _ = io.WriteString(w, `{}`)
            return nil
        }

        rCreatedAt, _ := strconv.ParseInt(r.FormValue("t"), 10, 64)
        rCount, _ := strconv.Atoi(r.FormValue("c"))
        //log.Print("rCreatedAt:", rCreatedAt)
        //log.Print("rCount:", rCount)
        var actors []int
        var alerts []*c.Alert
        var createdAt time.Time
        var topCreatedAt int64

        if count != 0 {
            rows, err := stmts.getActivityFeedByWatcher.Query(user.ID, 12)
            if err != nil {
                return c.InternalErrorJS(err, w, r)
            }
            defer rows.Close()

            for rows.Next() {
                al := &c.Alert{}
                err = rows.Scan(&al.ASID, &al.ActorID, &al.TargetUserID, &al.Event, &al.ElementType, &al.ElementID, &createdAt)
                if err != nil {
                    return c.InternalErrorJS(err, w, r)
                }

                uCreatedAt := createdAt.Unix()
                //log.Print("uCreatedAt", uCreatedAt)
                //if rCreatedAt == 0 || rCreatedAt < uCreatedAt {
                alerts = append(alerts, al)
                actors = append(actors, al.ActorID)
                //}
                if uCreatedAt > topCreatedAt {
                    topCreatedAt = uCreatedAt
                }
            }
            if err = rows.Err(); err != nil {
                return c.InternalErrorJS(err, w, r)
            }
        }

        if len(alerts) == 0 || (rCreatedAt != 0 && rCreatedAt >= topCreatedAt && count == rCount) {
            if gzw, ok := w.(c.GzipResponseWriter); ok {
                w = gzw.ResponseWriter
                w.Header().Del("Content-Encoding")
            }
            _, _ = io.WriteString(w, `{}`)
            return nil
        }

        // Might not want to error here, if the account was deleted properly, we might want to figure out how we should handle deletions in general
        list, err := c.Users.BulkGetMap(actors)
        if err != nil {
            log.Print("actors:", actors)
            return c.InternalErrorJS(err, w, r)
        }

        var sb *strings.Builder
        ii := alertStrPool.Get()
        if ii == nil {
            sb = &strings.Builder{}
        } else {
            sb = ii.(*strings.Builder)
            sb.Reset()
        }
        sb.Grow(c.AlertsGrowHint + (len(alerts) * (c.AlertsGrowHint2 + 1)) - 1)
        sb.WriteString(`{"msgs":[`)

        var ok bool
        for i, alert := range alerts {
            if i != 0 {
                sb.WriteRune(',')
            }
            alert.Actor, ok = list[alert.ActorID]
            if !ok {
                return c.InternalErrorJS(errors.New("No such actor"), w, r)
            }
            err := c.BuildAlertSb(sb, alert, user)
            if err != nil {
                return c.LocalErrorJS(err.Error(), w, r)
            }
        }
        sb.WriteString(`],"count":`)
        sb.WriteString(strconv.Itoa(count))
        sb.WriteString(`,"tc":`)
        //rCreatedAt
        sb.WriteString(strconv.Itoa(int(topCreatedAt)))
        sb.WriteRune('}')

        _, _ = io.WriteString(w, sb.String())
        alertStrPool.Put(sb)
    default:
        return c.PreErrorJS("Invalid Module", w, r)
    }
    return nil
}

// TODO: Remove this line after we move routeAPIPhrases to the routes package
var cacheControlMaxAge = "max-age=" + strconv.Itoa(int(c.Day))

// TODO: Be careful with exposing the panel phrases here, maybe move them into a different namespace? We also need to educate the admin that phrases aren't necessarily secret
// TODO: Move to the routes package
var phraseWhitelist = []string{
    "topic",
    "status",
    "alerts",
    "paginator",
    "analytics",

    "panel", // We're going to handle this specially below as this is a security boundary
}

func routeAPIPhrases(w http.ResponseWriter, r *http.Request, user *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")

    err := r.ParseForm()
    if err != nil {
        return c.PreErrorJS("Bad Form", w, r)
    }
    query := r.FormValue("q")
    if query == "" {
        return c.PreErrorJS("No query provided", w, r)
    }

    var negations, positives []string
    for _, queryBit := range strings.Split(query, ",") {
        queryBit = strings.TrimSpace(queryBit)
        if queryBit[0] == '!' && len(queryBit) > 1 {
            queryBit = strings.TrimPrefix(queryBit, "!")
            for _, ch := range queryBit {
                if !unicode.IsLetter(ch) && ch != '-' && ch != '_' {
                    return c.PreErrorJS("No symbols allowed, only - and _", w, r)
                }
            }
            negations = append(negations, queryBit)
        } else {
            for _, ch := range queryBit {
                if !unicode.IsLetter(ch) && ch != '-' && ch != '_' {
                    return c.PreErrorJS("No symbols allowed, only - and _", w, r)
                }
            }
            positives = append(positives, queryBit)
        }
    }
    if len(positives) == 0 {
        return c.PreErrorJS("You haven't requested any phrases", w, r)
    }
    h.Set("Cache-Control", cacheControlMaxAge) //Cache-Control: max-age=31536000

    var etag string
    _, ok := w.(c.GzipResponseWriter)
    if ok {
        etag = "\"" + strconv.FormatInt(phrases.GetCurrentLangPack().ModTime.Unix(), 10) + "-ng\""
    } else {
        etag = "\"" + strconv.FormatInt(phrases.GetCurrentLangPack().ModTime.Unix(), 10) + "-n\""
    }

    var plist map[string]string
    var notModified, private bool
    posLoop := func(positive string) c.RouteError {
        // ! Constrain it to a subset of phrases for now
        for _, item := range phraseWhitelist {
            if strings.HasPrefix(positive, item) {
                // TODO: Break this down into smaller security boundaries based on control panel sections?
                // TODO: Do we have to be so strict with panel phrases?
                if strings.HasPrefix(positive, "panel") {
                    private = true
                    ok = user.IsSuperMod
                } else {
                    ok = true
                    if notModified {
                        return nil
                    }
                    w.Header().Set("ETag", etag)
                    match := r.Header.Get("If-None-Match")
                    if match != "" && strings.Contains(match, etag) {
                        notModified = true
                        return nil
                    }
                }
                break
            }
        }
        if !ok {
            return c.PreErrorJS("Outside of phrase prefix whitelist", w, r)
        }
        return nil
    }

    // A little optimisation to avoid copying entries from one map to the other, if we don't have to mutate it
    if len(positives) > 1 {
        plist = make(map[string]string)
        for _, positive := range positives {
            rerr := posLoop(positive)
            if rerr != nil {
                return rerr
            }
            pPhrases, ok := phrases.GetTmplPhrasesByPrefix(positive)
            if !ok {
                return c.PreErrorJS("No such prefix", w, r)
            }
            for name, phrase := range pPhrases {
                plist[name] = phrase
            }
        }
    } else {
        rerr := posLoop(positives[0])
        if rerr != nil {
            return rerr
        }
        pPhrases, ok := phrases.GetTmplPhrasesByPrefix(positives[0])
        if !ok {
            return c.PreErrorJS("No such prefix", w, r)
        }
        plist = pPhrases
    }

    if private {
        w.Header().Set("Cache-Control", "private")
    } else if notModified {
        w.WriteHeader(http.StatusNotModified)
        return nil
    }

    for _, negation := range negations {
        for name, _ := range plist {
            if strings.HasPrefix(name, negation) {
                delete(plist, name)
            }
        }
    }

    // TODO: Cache the output of this, especially for things like topic, so we don't have to waste more time than we need on this
    jsonBytes, err := json.Marshal(plist)
    if err != nil {
        return c.InternalError(err, w, r)
    }
    w.Write(jsonBytes)
    return nil
}

// A dedicated function so we can shake things up every now and then to make the token harder to parse
// TODO: Are we sure we want to do this by ID, just in case we reuse this and have multiple antispams on the page?
func routeJSAntispam(w http.ResponseWriter, r *http.Request, user *c.User) c.RouteError {
    h := sha256.New()
    h.Write([]byte(c.JSTokenBox.Load().(string)))
    h.Write([]byte(user.GetIP()))
    jsToken := hex.EncodeToString(h.Sum(nil))

    innerCode := "`document.getElementByld('golden-watch').value='" + jsToken + "';`"
    io.WriteString(w, `let hihi=`+innerCode+`;hihi=hihi.replace('ld','Id');eval(hihi);`)

    return nil
}