mlblive/cmd/subscribe.go

/*
Copyright © 2024 filifa

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package cmd

import (
	"encoding/json"
	"fmt"
	"log"
	"strconv"
	"time"

	"github.com/spf13/cobra"
	"scm.dairydemon.net/filifa/mlblive/cmd/internal/statsapi"
)

var gamePk int

func updateFeed(feedResp []byte, gamePk, ts, updateId string) ([]byte, error) {
	diffPatchResp, err := statsapi.RequestDiffPatch(gamePk, ts, updateId)
	if err != nil {
		return statsapi.RequestFeed(gamePk)
	}

	patches, err := diffPatchResp.ExtractPatches()
	if err != nil {
		return statsapi.RequestFeed(gamePk)
	}

	for _, patch := range patches {
		feedResp, err = patch.Apply(feedResp)
		if err != nil {
			return statsapi.RequestFeed(gamePk)
		}
	}

	return feedResp, err
}

func subscribe(cmd *cobra.Command, args []string) {
	pkStr := strconv.Itoa(gamePk)
	ws, err := statsapi.NewGamedayWebsocket(pkStr)
	if err != nil {
		log.Fatal(err)
	}
	defer ws.Close()

	ch := make(chan error)
	go ws.KeepAlive(10*time.Second, ch)

	feedResp, err := statsapi.RequestFeed(pkStr)
	if err != nil {
		log.Fatal(err)
	}

	var feed statsapi.Feed
	for {
		fmt.Println(string(feedResp))

		err = json.Unmarshal(feedResp, &feed)
		if err != nil {
			log.Fatal(err)
		}
		ts := feed.MetaData.TimeStamp

		var p statsapi.Push
		err = ws.ReadJSON(&p)
		if err != nil {
			log.Fatal(err)
		}

		feedResp, err = updateFeed(feedResp, pkStr, ts, p.UpdateId)
		if err != nil {
			log.Fatal(err)
		}
	}
}

// subscribeCmd represents the subscribe command
var subscribeCmd = &cobra.Command{
	Use:   "subscribe -g [gamePk]",
	Short: "Output live game data",
	Long: `Output live game data.

Establish a websocket connection with ws.statsapi.mlb.com and output JSON with
live updates of a game.`,
	Run: subscribe,
}

func init() {
	rootCmd.AddCommand(subscribeCmd)

	// Here you will define your flags and configuration settings.

	// Cobra supports Persistent Flags which will work for this command
	// and all subcommands, e.g.:
	// subscribeCmd.PersistentFlags().String("foo", "", "A help for foo")

	// Cobra supports local flags which will only run when this command
	// is called directly, e.g.:
	subscribeCmd.Flags().IntVarP(&gamePk, "gamePk", "g", 0, "game PK")
	subscribeCmd.MarkFlagRequired("gamePk")
}