package main

import (
	"context"
	"fmt"
	"os"
	"os/signal"
	"time"

	"github.com/urfave/cli/v2"

	"github.com/eosswedenorg/thalos/api"
	"github.com/eosswedenorg/thalos/api/message"
	_ "github.com/eosswedenorg/thalos/api/message/json"
	api_redis "github.com/eosswedenorg/thalos/api/redis"

	"github.com/redis/go-redis/v9"
	log "github.com/sirupsen/logrus"
)

type Tester struct {
	block_num uint32
	timeout   time.Duration
	timer     *time.Ticker
}

func NewTester(timeout time.Duration) *Tester {
	return &Tester{
		block_num: 0,
		timeout:   timeout,
		timer:     time.NewTicker(timeout),
	}
}

func (t *Tester) OnAction(act message.ActionTrace) {
	if t.block_num > 0 {
		var diff int32 = int32(act.BlockNum - t.block_num)
		if diff < 0 || diff > 1 {
			log.WithFields(log.Fields{
				"current_block": t.block_num,
				"block":         act.BlockNum,
				"diff":          diff,
			}).Warn("Invalid")
		}
	}

	t.block_num = act.BlockNum

	t.timer.Reset(t.timeout)
}

var validateCmd = &cli.Command{
	Name:  "validate",
	Usage: "Validate a thalos server by following action traces and makes sure that blocks arrive in order.",
	Flags: []cli.Flag{
		redisUrlFlag,
		redisDbFlag,
		redisPrefixFlag,
		chainIdFlag,
	},
	Action: func(ctx *cli.Context) error {
		tester := NewTester(time.Second * 5)
		status_duration := time.Second * 10

		log.WithFields(log.Fields{
			"url":      ctx.String("redis-url"),
			"prefix":   ctx.String("redis-prefix"),
			"chain_id": ctx.String("chain_id"),
			"database": ctx.Int("redis-db"),
		}).Info("Connecting to redis")

		// Create redis client
		rdb := redis.NewClient(&redis.Options{
			Addr: ctx.String("redis-url"),
			DB:   ctx.Int("redis-db"),
		})

		if err := rdb.Ping(context.Background()).Err(); err != nil {
			return err
		}

		log.Println("Connected to redis")

		log.Info("Starting validation, following the stream")

		sub := api_redis.NewSubscriber(context.Background(), rdb, api_redis.Namespace{
			Prefix:  ctx.String("redis-prefix"),
			ChainID: ctx.String("chain_id"),
		})

		codec, err := message.GetCodec("json")
		if err != nil {
			return err
		}

		client := api.NewClient(sub, codec.Decoder)
		client.OnAction = tester.OnAction

		// Subscribe to all actions
		if err = client.Subscribe(api.ActionChannel{}.Channel()); err != nil {
			return err
		}

		go func() {
			sig := make(chan os.Signal, 1)
			signal.Notify(sig, os.Interrupt)

			for {
				select {
				case <-sig:
					fmt.Println("Got interrupt")
					client.Close()
					return
				case <-tester.timer.C:
					log.WithField("duration", tester.timeout).
						Warn("Did not get any messages during the defined duration")
				case <-time.After(status_duration):
					log.WithFields(log.Fields{
						"current_block": tester.block_num,
					}).Info("Status")
				}
			}
		}()

		// Read stuff.
		client.Run()

		return nil
	},
}