package main

import (
	"context"
	"encoding/json"
	"log"
	"net/http"
	"os"
	"time"

	"git.xeserv.us/xena/mercy/internal/common"
	"github.com/nats-io/go-nats"
)

func main() {
	uri := os.Getenv("NATS_URL")
	nc, err := common.NatsConnect(uri)
	if err != nil {
		log.Fatal("Error establishing connection to NATS:", err)
	}

	log.Printf("Connected to NATS at: %s", nc.ConnectedUrl())

	nc.QueueSubscribe("tasks:http", "worker", func(m *nats.Msg) {
		var hc common.HTTPCheckRequest
		err := json.Unmarshal(m.Data, &hc)
		if err != nil {
			log.Printf("tasks:http: error when decoding json: %v", err)
			return
		}

		req, err := http.NewRequest(http.MethodGet, hc.URL, nil)
		if err != nil {
			log.Printf("tasks:http: error when creating request: %v", err)
			return
		}
		ctx, cancel := context.WithTimeout(context.Background(), hc.FailThreshold)
		defer cancel()

		req = req.WithContext(ctx)

		result := common.CheckResult{Preamble: hc.Preamble}
		before := time.Now()

		resp, err := http.DefaultClient.Do(req)
		if err != nil {
			switch err {
			case context.Canceled:
				result.Result = common.Failed
			default:
				log.Printf("tasks:http: error when fetching url %s: %v", hc.URL, err)
				result.ErrData = err.Error()
			}
		}

		if resp.StatusCode/100 == 2 {
			result.Result = common.OK
		}

		if now := time.Now(); before.Add(hc.DegradedThreshold).Before(now) {
			result.Result = common.Degraded
		}

		result.Timestamp = time.Now()
		data, err := json.Marshal(&result)
		if err != nil {
			log.Printf("tasks:http: error encoding json for %#v: %v", result, err)
			return
		}

		err = nc.Publish("results", data)
		if err != nil {
			log.Printf("tasks:http: error publishing results: %v", err)
		}

		log.Printf()
	})

	for {
		select {}
	}
}