otiai10/amesh-bot

package commands

import (
    "bytes"
    "context"
    "encoding/json"
    "fmt"
    "math/rand"
    "net/http"
    "net/url"
    "strings"
    "time"

    "github.com/otiai10/amesh-bot/service"
    "github.com/otiai10/goapis/google"
    "github.com/otiai10/largo"
    "github.com/slack-go/slack"
    "github.com/slack-go/slack/slackevents"
)

type CommandCtxKey string

const imageSearchMaxRetry = 3
const imageSearchIntentCtxKey CommandCtxKey = "image_search_intent"

type CustomSearchClient interface {
    CustomSearch(url.Values) (*http.Response, error)
}

// ImageCommand ...
type ImageCommand struct {
    Search CustomSearchClient
}

// Match ...
func (cmd ImageCommand) Match(event slackevents.AppMentionEvent) bool {
    tokens := largo.Tokenize(event.Text)[1:]
    if len(tokens) == 0 {
        return false
    }
    return tokens[0] == "img" || tokens[0] == "image"
}

// Handle ...
// TODO: slack-go/slack を使いましょうね.
func (cmd ImageCommand) Execute(ctx context.Context, client service.ISlackClient, event slackevents.AppMentionEvent) (err error) {

    help := bytes.NewBuffer(nil)
    unsafe := false
    verbose := false
    filter := false // TODO: 今はBoolVarだが、他のfilterにも対応した
    flevel := 60
    fset := largo.NewFlagSet("img", largo.ContinueOnError)
    fset.Description = "画像検索コマンド"
    fset.BoolVar(&verbose, "verbose", false, "検索のverboseログを表示します").Alias("v")
    fset.BoolVar(&unsafe, "unsafe", false, "セーフサーチを無効にした検索をします").Alias("U")
    fset.BoolVar(&filter, "filter", false, "画像をフィルタ処理して表示します (今はモザイクだけ対応)").Alias("F")
    fset.IntVar(&flevel, "level", 60, "画像フィルタの強さ (-levelを使った場合、-filterの指定は省略可)").Alias("L")
    fset.Output = help
    fset.Parse(largo.Tokenize(event.Text)[2:])
    words := fset.Rest()

    msg := inreply(event)
    if fset.HelpRequested() {
        msg.Text = "```" + help.String() + "```"
        _, err := client.PostMessage(ctx, msg)
        return err
    }

    intent := RecoverIntent(ctx)
    if intent.Retry > imageSearchMaxRetry {
        msg.Blocks = append(msg.Blocks, cmd.notfoundMessageBlock(intent))
        _, err = client.PostMessage(ctx, msg)
        return err
    }

    rand.Seed(time.Now().Unix())
    query := strings.Join(words, "+")
    intent.Add("q", query)
    intent.Add("num", "10")
    intent.Add("searchType", "image")
    intent.Unsafe(unsafe)

    res, err := cmd.Search.CustomSearch(intent.Build())
    if err != nil {
        return err
    }
    defer res.Body.Close()

    result := new(google.CustomSearchResponse)
    if err := json.NewDecoder(res.Body).Decode(result); err != nil {
        return err
    }

    if len(result.Items) == 0 {
        fmt.Printf("[DEBUG] RETRY for NOTFOUND: %d", intent.Retry)
        ctx = IncrementRetryIntent(ctx, intent, result.Queries.Request[0])
        return cmd.Execute(ctx, client, event)
    }

    index := rand.Intn(len(result.Items))
    item := result.Items[index]

    link := item.Link
    title := item.Title

    if filter || fset.Lookup("level").Given() {
        if req, ok := ctx.Value("webhook_request").(*http.Request); ok {
            u, _ := url.Parse("https://" + req.Host + "/image")
            u.RawQuery = url.Values{"url": {link}, "level": {fmt.Sprintf("%d", flevel)}}.Encode()
            // AppEngine上のProxyサーバのエンドポイントを向かせる
            // あとの流れは、controllers.Imageを参照
            link = u.String()
        } else {
            fmt.Printf("[DEBUG] failed to retrieve webhook_request context: %v\n", ctx.Err())
        }
    }

    block := slack.NewImageBlock(link, title, "", slack.NewTextBlockObject(
        slack.PlainTextType, item.Title, false, false,
    ))
    msg.Blocks = append(msg.Blocks, block)

    if verbose {
        msg.Blocks = append(msg.Blocks, slack.NewContextBlock("",
            slack.NewTextBlockObject(
                slack.MarkdownType,
                item.Image.ContextLink+"\n"+cmd.formatQueryMetadata(intent),
                false, false,
            ),
        ))
    }

    sent, err := client.PostMessage(ctx, msg)
    if err != nil {
        fmt.Printf("[DEBUG] RETRY for ERROR: %d", intent.Retry)
        ctx = IncrementRetryIntent(ctx, intent, result.Queries.Request[0])
        return cmd.Execute(ctx, client, event)
    }

    // filterリクエストの場合は、自分の投稿に、unfilterなリンクを返す
    if filter || fset.Lookup("level").Given() {
        unfurl := false
        msg := inreply(event)
        if event.ThreadTimeStamp == "" { // imgコマンドが非スレッドの場合
            msg.ThreadTimestamp = sent.Timestamp // 応答済み投稿を起点にスレッド開始
        }
        msg.Text = ":warning: " + item.Link
        msg.UnfurlMedia = &unfurl
        _, err = client.PostMessage(ctx, msg)
    }
    return err
}

// Help ...
func (cmd ImageCommand) Help() string {
    return "画像検索コマンド\n```@amesh img|image {query}```"
}

func (cmd ImageCommand) notfoundMessageBlock(intent *SearchIntent) slack.Block {
    q := intent.Values
    q.Del("cx")
    q.Del("key")
    text := ":neutral_face: 画像が見つかりませんでした: " + cmd.formatQueryMetadata(intent)
    return slack.NewContextBlock("", slack.NewTextBlockObject(slack.MarkdownType, text, false, true))
}

func (cmd ImageCommand) formatQueryMetadata(intent *SearchIntent) string {
    q := intent.Values
    return fmt.Sprintf(
        "q=%s, num=%s, start=%s, safe=%s, retry=%d",
        q.Get("q"), q.Get("num"), q.Get("start"), q.Get("safe"), intent.Retry,
    )
}