web.go

package youtube

import (
	"context"
	"encoding/xml"
	"errors"
	"fmt"
	"html/template"
	"io"
	"io/ioutil"
	"net/http"
	"net/url"
	"strconv"
	"time"

	"github.com/jinzhu/gorm"
	"github.com/jonas747/discordgo"
	"github.com/jonas747/retryableredis"
	"github.com/jonas747/yagpdb/common"
	"github.com/jonas747/yagpdb/web"
	"github.com/mediocregopher/radix/v3"
	"goji.io"
	"goji.io/pat"
)

type CtxKey int

const (
	CurrentConfig CtxKey = iota
)

type Form struct {
	YoutubeChannelID   string
	YoutubeChannelUser string
	DiscordChannel     int64 `valid:"channel,false"`
	ID                 uint
	MentionEveryone    bool
}

func (p *Plugin) InitWeb() {
	web.LoadHTMLTemplate("../../youtube/assets/youtube.html", "templates/plugins/youtube.html")
	web.AddSidebarItem(web.SidebarCategoryFeeds, &web.SidebarItem{
		Name: "Youtube",
		URL:  "youtube",
		Icon: "fab fa-youtube",
	})

	ytMux := goji.SubMux()
	web.CPMux.Handle(pat.New("/youtube/*"), ytMux)
	web.CPMux.Handle(pat.New("/youtube"), ytMux)

	// Alll handlers here require guild channels present
	ytMux.Use(web.RequireGuildChannelsMiddleware)
	ytMux.Use(web.RequireBotMemberMW)
	ytMux.Use(web.RequirePermMW(discordgo.PermissionMentionEveryone))

	mainGetHandler := web.ControllerHandler(p.HandleYoutube, "cp_youtube")

	ytMux.Handle(pat.Get("/"), mainGetHandler)
	ytMux.Handle(pat.Get(""), mainGetHandler)

	addHandler := web.ControllerPostHandler(p.HandleNew, mainGetHandler, Form{}, "Added a new youtube feed")

	ytMux.Handle(pat.Post(""), addHandler)
	ytMux.Handle(pat.Post("/"), addHandler)
	ytMux.Handle(pat.Post("/:item/update"), web.ControllerPostHandler(BaseEditHandler(p.HandleEdit), mainGetHandler, Form{}, "Updated a youtube feed"))
	ytMux.Handle(pat.Post("/:item/delete"), web.ControllerPostHandler(BaseEditHandler(p.HandleRemove), mainGetHandler, nil, "Removed a youtube feed"))
	ytMux.Handle(pat.Get("/:item/delete"), web.ControllerPostHandler(BaseEditHandler(p.HandleRemove), mainGetHandler, nil, "Removed a youtube feed"))

	// The handler from pubsubhub
	web.RootMux.Handle(pat.New("/yt_new_upload/"+confWebsubVerifytoken.GetString()), http.HandlerFunc(p.HandleFeedUpdate))
}

func (p *Plugin) HandleYoutube(w http.ResponseWriter, r *http.Request) (web.TemplateData, error) {
	ctx := r.Context()
	ag, templateData := web.GetBaseCPContextData(ctx)

	var subs []*ChannelSubscription
	err := common.GORM.Where("guild_id = ?", ag.ID).Order("id desc").Find(&subs).Error
	if err != nil && err != gorm.ErrRecordNotFound {
		return templateData, err
	}

	templateData["Subs"] = subs
	templateData["VisibleURL"] = "/manage/" + discordgo.StrID(ag.ID) + "/youtube"

	return templateData, nil
}

func (p *Plugin) HandleNew(w http.ResponseWriter, r *http.Request) (web.TemplateData, error) {
	ctx := r.Context()
	activeGuild, templateData := web.GetBaseCPContextData(ctx)

	// limit it to max 25 feeds
	var count int
	common.GORM.Model(&ChannelSubscription{}).Where("guild_id = ?", activeGuild.ID).Count(&count)

	if count >= MaxFeedsForContext(ctx) {
		return templateData.AddAlerts(web.ErrorAlert(fmt.Sprintf("Max %d youtube feeds allowed (%d for premium servers)", GuildMaxFeeds, GuildMaxFeedsPremium))), nil
	}

	data := ctx.Value(common.ContextKeyParsedForm).(*Form)

	if data.YoutubeChannelID == "" && data.YoutubeChannelUser == "" {
		return templateData.AddAlerts(web.ErrorAlert("Neither channelid or username specified.")), errors.New("ChannelID and username not specified")
	}

	_, err := p.AddFeed(activeGuild.ID, data.DiscordChannel, data.YoutubeChannelID, data.YoutubeChannelUser, data.MentionEveryone)
	if err != nil {
		if err == ErrNoChannel {
			return templateData.AddAlerts(web.ErrorAlert("No channel by that id/username found")), errors.New("Channel not found")
		}
		return templateData, err
	}

	return templateData, nil
}

type ContextKey int

const (
	ContextKeySub ContextKey = iota
)

func BaseEditHandler(inner web.ControllerHandlerFunc) web.ControllerHandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) (web.TemplateData, error) {
		ctx := r.Context()
		activeGuild, templateData := web.GetBaseCPContextData(ctx)

		id := pat.Param(r, "item")

		// Get the actual watch item from the config
		var sub ChannelSubscription
		err := common.GORM.Model(&ChannelSubscription{}).Where("id = ?", id).First(&sub).Error
		if err != nil {
			return templateData.AddAlerts(web.ErrorAlert("Failed retrieving that feed item")), err
		}

		if sub.GuildID != discordgo.StrID(activeGuild.ID) {
			return templateData.AddAlerts(web.ErrorAlert("This appears to belong somewhere else...")), nil
		}

		ctx = context.WithValue(ctx, ContextKeySub, &sub)

		return inner(w, r.WithContext(ctx))
	}
}

func (p *Plugin) HandleEdit(w http.ResponseWriter, r *http.Request) (templateData web.TemplateData, err error) {
	ctx := r.Context()
	_, templateData = web.GetBaseCPContextData(ctx)

	sub := ctx.Value(ContextKeySub).(*ChannelSubscription)
	data := ctx.Value(common.ContextKeyParsedForm).(*Form)

	sub.MentionEveryone = data.MentionEveryone
	sub.ChannelID = discordgo.StrID(data.DiscordChannel)

	err = common.GORM.Save(sub).Error
	return
}

func (p *Plugin) HandleRemove(w http.ResponseWriter, r *http.Request) (templateData web.TemplateData, err error) {
	ctx := r.Context()
	_, templateData = web.GetBaseCPContextData(ctx)

	sub := ctx.Value(ContextKeySub).(*ChannelSubscription)
	err = common.GORM.Delete(sub).Error
	if err != nil {
		return
	}

	p.MaybeRemoveChannelWatch(sub.YoutubeChannelID)
	return
}

func (p *Plugin) HandleFeedUpdate(w http.ResponseWriter, r *http.Request) {
	query := r.URL.Query()
	ctx := r.Context()
	switch query.Get("hub.mode") {
	case "subscribe":
		if query.Get("hub.verify_token") != confWebsubVerifytoken.GetString() {
			return // We don't want no intruders here
		}

		web.CtxLogger(ctx).Info("Responding to challenge: ", query.Get("hub.challenge"))
		p.ValidateSubscription(w, r, query)
		return
	case "unsubscribe":
		if query.Get("hub.verify_token") != confWebsubVerifytoken.GetString() {
			return // We don't want no intruders here
		}

		w.Write([]byte(query.Get("hub.challenge")))

		topicURI, err := url.ParseRequestURI(query.Get("hub.topic"))
		if err != nil {
			web.CtxLogger(ctx).WithError(err).Error("Failed parsing websub topic URI")
			return
		}

		common.RedisPool.Do(retryableredis.Cmd(nil, "ZREM", RedisKeyWebSubChannels, topicURI.Query().Get("channel_id")))
		return
	}

	// Handle new/udpated video
	defer r.Body.Close()
	bodyReader := io.LimitReader(r.Body, 0xffff1)

	result, err := ioutil.ReadAll(bodyReader)
	if err != nil {
		web.CtxLogger(ctx).WithError(err).Error("Failed reading body")
		return
	}

	var parsed XMLFeed

	err = xml.Unmarshal(result, &parsed)
	if err != nil {
		web.CtxLogger(ctx).WithError(err).Error("Failed parsing feed body: ", string(result))
		return
	}

	err = common.BlockingLockRedisKey(RedisChannelsLockKey, 0, 5)
	if err != nil {
		web.CtxLogger(ctx).WithError(err).Error("Failed locking channels lock")
		return
	}
	defer common.UnlockRedisKey(RedisChannelsLockKey)

	var mn radix.MaybeNil
	common.RedisPool.Do(retryableredis.Cmd(&mn, "ZSCORE", "youtube_subbed_channels", parsed.ChannelID))
	if mn.Nil {
		return
	}

	// Reset the score to be instantly scanned
	common.RedisPool.Do(retryableredis.Cmd(nil, "ZADD", "youtube_subbed_channels", "0", parsed.ChannelID))
}

func (p *Plugin) ValidateSubscription(w http.ResponseWriter, r *http.Request, query url.Values) {
	w.Write([]byte(query.Get("hub.challenge")))

	lease := query.Get("hub.lease_seconds")
	if lease != "" {
		parsed, err := strconv.ParseInt(lease, 10, 64)
		if err != nil {
			web.CtxLogger(r.Context()).WithError(err).Error("Failed parsing websub lease time")
			return
		}

		expires := time.Now().Unix() + parsed

		topicURI, err := url.ParseRequestURI(query.Get("hub.topic"))
		if err != nil {
			web.CtxLogger(r.Context()).WithError(err).Error("Failed parsing websub topic URI")
			return
		}

		common.RedisPool.Do(retryableredis.FlatCmd(nil, "ZADD", RedisKeyWebSubChannels, expires, topicURI.Query().Get("channel_id")))
	}
}

var _ web.PluginWithServerHomeWidget = (*Plugin)(nil)

func (p *Plugin) LoadServerHomeWidget(w http.ResponseWriter, r *http.Request) (web.TemplateData, error) {
	ag, templateData := web.GetBaseCPContextData(r.Context())

	templateData["WidgetTitle"] = "Youtube feeds"
	templateData["SettingsPath"] = "/youtube"

	var numFeeds int64
	result := common.GORM.Model(&ChannelSubscription{}).Where("guild_id = ?", ag.ID).Count(&numFeeds)
	if numFeeds > 0 {
		templateData["WidgetEnabled"] = true
	} else {
		templateData["WidgetDisabled"] = true
	}

	const format = `<p>Active Youtube feeds: <code>%d</code></p>`
	templateData["WidgetBody"] = template.HTML(fmt.Sprintf(format, numFeeds))

	return templateData, result.Error
}