package main

import (
	"fmt"
	"time"

	"git.uploadfilter24.eu/covidnetes/woodpecker-autoscaler/internal/config"
	"git.uploadfilter24.eu/covidnetes/woodpecker-autoscaler/internal/health"
	"git.uploadfilter24.eu/covidnetes/woodpecker-autoscaler/internal/hetzner"
	"git.uploadfilter24.eu/covidnetes/woodpecker-autoscaler/internal/logging"
	"git.uploadfilter24.eu/covidnetes/woodpecker-autoscaler/internal/woodpecker"
	"github.com/hetznercloud/hcloud-go/hcloud"
	log "github.com/sirupsen/logrus"
)

func SpawnNewAgent(cfg *config.Config) {
	agent, err := woodpecker.CreateWoodpeckerAgent(cfg)
	if err != nil {
		log.WithFields(log.Fields{
			"Caller": "SpawnNewAgent",
		}).Fatal(fmt.Sprintf("Error creating new agent: %s", err.Error()))
	}
	server, err := hetzner.CreateNewAgent(cfg, agent)
	if err != nil {
		log.WithFields(log.Fields{
			"Caller": "SpawnNewAgent",
		}).Fatal(fmt.Sprintf("Error spawning new agent: %s", err.Error()))
	}
	for {
		server, err = hetzner.RefreshNodeInfo(cfg, server.ID)
		if err != nil {
			log.WithFields(log.Fields{
				"Caller": "SpawnNewAgent",
			}).Fatal(fmt.Sprintf("Failed to start Agent: %s", err.Error()))
		}
		if server.Status == hcloud.ServerStatusRunning {
			log.WithFields(log.Fields{
				"Caller": "SpawnNewAgent",
			}).Infof("%s started!", server.Name)
			break
		}
		log.WithFields(log.Fields{
			"Caller": "SpawnNewAgent",
		}).Infof("%s is in status %s", server.Name, server.Status)
		time.Sleep(30 * time.Second)
	}
}

func CheckJobs(cfg *config.Config, ownedNodes []hcloud.Server, pendingTasks int) {
	log.WithFields(log.Fields{
		"Caller": "CheckJobs",
	}).Info("Checking if agents can be removed")
	runningTasks, err := woodpecker.CheckRunning(cfg)
	if err != nil {
		log.WithFields(log.Fields{
			"Caller": "CheckJobs",
		}).Fatal(fmt.Sprintf("Error checking woodpecker queue: %s", err.Error()))
	}
	if (runningTasks <= len(ownedNodes) && runningTasks != 0) || pendingTasks > 0 {
		log.WithFields(log.Fields{
			"Caller": "CheckJobs",
		}).Info("Still found running tasks. No agent to be removed")
	} else {
		if len(ownedNodes) == 0 {
			log.WithFields(log.Fields{
				"Caller": "CheckJobs",
			}).Info("Nothing running and not owning any nodes")
		} else {
			log.WithFields(log.Fields{
				"Caller": "CheckJobs",
			}).Info("No tasks running. Will remove agents")
			Decom(cfg, ownedNodes)
		}
	}
}

func Decom(cfg *config.Config, ownedNodes []hcloud.Server) {
	for _, server := range ownedNodes {
		if cfg.CostOptimizedMode {
			runtime, err := hetzner.CheckRuntime(cfg, &server)
			if err != nil {
				log.WithFields(log.Fields{
					"Caller": "Decom",
				}).Warnf("Error while checking runtime of node %s: %s", server.Name, err.Error())
			}
			log.WithFields(log.Fields{
				"Caller": "Decom",
			}).Debugf("Node %s is running for %f", server.Name, runtime.Minutes())
			// Check if next check if sooner than the 60 Minute mark of the next hetzner check
			// https://docs.hetzner.com/cloud/billing/faq/#how-do-you-bill-your-servers
			if (runtime + time.Duration(cfg.CheckInterval)*time.Minute) < 60 {
				log.WithFields(log.Fields{
					"Caller": "Decom",
				}).Infof("Skipping node termination of %s (running for %f Minutes) in Cost Optimized Mode", server.Name, runtime.Minutes())
				continue
			}
		}
		agentId, err := hetzner.DecomNode(cfg, &server)
		if err != nil {
			log.WithFields(log.Fields{
				"Caller": "Decom",
			}).Warnf("Error while deleting node %s: %s", server.Name, err.Error())
		}
		err = woodpecker.DecomAgent(cfg, agentId)
		if err != nil {
			log.WithFields(log.Fields{
				"Caller": "Decom",
			}).Warnf("Could not delete node %s in woodpecker: %s", server.Name, err.Error())
		}
		log.WithFields(log.Fields{
			"Caller": "Decom",
		}).Infof("Deleted node %s", server.Name)
	}
}

func main() {

	cfg, err := config.GenConfig()
	logging.ConfigureLogger(cfg)

	if err != nil {
		log.WithFields(log.Fields{
			"Caller": "Main",
		}).Fatal(fmt.Sprintf("Error generating Config: %s", err.Error()))
	}

	go func() {
		log.WithFields(log.Fields{
			"Caller": "Main",
		}).Info("Starting Health Endpoint")
		health.StartHealthEndpoint()
	}()

	log.WithFields(log.Fields{
		"Caller": "Main",
	}).Info("Entering main event loop")

	for {
		pendingTasks, err := woodpecker.CheckPending(cfg)
		if err != nil {
			log.WithFields(log.Fields{
				"Caller": "Main",
			}).Fatal(fmt.Sprintf("Error checking woodpecker queue: %s", err.Error()))
		}
		ownedNodes, err := hetzner.ListAgents(cfg)
		if err != nil {
			log.WithFields(log.Fields{
				"Caller": "Main",
			}).Fatal(fmt.Sprintf("Error collecting owned hetzner nodes: %s", err.Error()))
		}
		log.WithFields(log.Fields{
			"Caller": "Main",
		}).Infof("Currently owning %d Agents", len(ownedNodes))
		if pendingTasks > len(ownedNodes) {
			SpawnNewAgent(cfg)
		} else {
			CheckJobs(cfg, ownedNodes, pendingTasks)
		}
		log.WithFields(log.Fields{
			"Caller": "Main",
		}).Infof("Recheck in %d", cfg.CheckInterval)
		time.Sleep(time.Duration(cfg.CheckInterval) * time.Minute)
	}
}