package hetzner

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"regexp"
	"strconv"
	"strings"
	"time"

	"git.stinnesbeck.com/go/log"
	"github.com/hetznercloud/hcloud-go/hcloud"
)

type VersionInfo struct {
	Source  string `json:"source"`
	Version string `json:"version"`
}

func connect() *hcloud.Client {
	return hcloud.NewClient(hcloud.WithToken(os.Getenv("HETZNER_CLOUD_API_TOKEN")))
}

func GetNewSuffix(servers []*hcloud.Server) (int, error) {
	// cop out if there are no servers yet
	if len(servers) == 0 {
		return 1, nil
	}

	// variable to hold highest number
	var highestNumber int

	// loop through all servers
	for i := range servers {
		serverNameSlice := strings.Split(servers[i].Name, "-")
		suffix, err := strconv.Atoi(serverNameSlice[len(serverNameSlice)-1])
		if err != nil {
			return 0, err
		}

		// compare our current number agains the highest yet
		if suffix > highestNumber {
			highestNumber = suffix
		}
	}
	// return one number higher than highest number
	return highestNumber + 1, nil
}

// ListJynxServers lists all servers managed by Jynx hosted on Hetzner Cloud
func ListJynxServers(prefix string) ([]*hcloud.Server, error) {
	// connect to the hcloud API
	client := connect()

	// get all servers
	servers, err := client.Server.All(context.Background())
	if err != nil {
		return nil, err
	}

	// create object that holds all servers managed by Jynx
	var jynxServers []*hcloud.Server

	// loop through servers and filter out managed servers
	for _, server := range servers {
		if strings.HasPrefix(server.Name, prefix) {
			jynxServers = append(jynxServers, server)
		}
	}

	// return managed servers
	return jynxServers, nil
}

func CheckServerDeletions(servers []*hcloud.Server) error {
	interval := os.Getenv("SCALER_POLL_INTERVAL")
	if interval == "" {
		interval = "5"
	}

	pollIntervalSeconds, err := strconv.Atoi(interval)
	if err != nil {
		return err
	}

	if pollIntervalSeconds < 60 {
		pollIntervalSeconds = 60
	}

	if pollIntervalSeconds > 3600 {
		pollIntervalSeconds %= 3600
	}

	for i, server := range servers {
		safeInterval := time.Duration(3600-pollIntervalSeconds) * time.Second
		optimalDeleteTime := server.Created.Add(safeInterval).Local()
		log.PrintDebug(server.Name, "optimal delete time:", optimalDeleteTime)
		if time.Now().Local().Before(optimalDeleteTime) {
			continue
		}

		// check if HETZNER_SERVER_MIN was provided as an environment variable
		if minServersString := os.Getenv("HETZNER_SERVER_MIN"); minServersString != "" {
			minServers, err := strconv.Atoi(minServersString)
			if err != nil {
				return err
			}

			// if the amount of servers is less than the minimal amount required
			// leave this server running
			if i < minServers {
				log.PrintDebug("not deleting server", server.Name, "because HETZNER_SERVER_MIN is", minServers)
				continue
			}
		}

		// optimal delete time has passed, delete the server
		if err := DeleteServer(server); err != nil {
			return err
		}
	}

	return nil
}

func DeleteServer(server *hcloud.Server) error {
	client := connect()
	log.PrintInfo("Deleting", server.Name)
	_, response, err := client.Server.DeleteWithResult(context.Background(), server)
	if err != nil {
		return err
	}

	if response.StatusCode != 200 {
		return fmt.Errorf("api returned errorcode %d", response.StatusCode)
	}

	return nil
}
func CreateServers(servers []string) error {
	// connect to hcloud API
	client := connect()

	// read in some environment variables
	agentSecret := os.Getenv("WOODPECKER_AGENT_SECRET")
	r := regexp.MustCompile(`http[s]*:\/\/(.*)`)
	woodpeckerHostname := os.Getenv("WOODPECKER_HOSTNAME")
	hasPort := regexp.MustCompile(`^.*(:\d+)`)
	withoutPort := regexp.MustCompile(`^https?:\/\/(.*):`)
	woodpeckerHost := r.FindStringSubmatch(woodpeckerHostname)[1]
	if hasPort.MatchString(woodpeckerHost) {
		woodpeckerHost = withoutPort.FindStringSubmatch(woodpeckerHost)[1]
	}

	// default port for stats
	statsPort := "9000"

	// check if port was set
	if port := os.Getenv("WOODPECKER_STATS_PORT"); port != "" {
		statsPort = port
	}
	woodpeckerHost += ":" + statsPort

	// get woodpecker server version
	// prepare request
	req, err := http.NewRequest(http.MethodGet, woodpeckerHostname+"/version", nil)
	if err != nil {
		return err
	}

	c := http.DefaultClient
	response, err := c.Do(req)
	if err != nil {
		return err
	}

	b, err := io.ReadAll(response.Body)
	if err != nil {
		return err
	}

	var version VersionInfo

	err = json.Unmarshal(b, &version)

	if err != nil {
		return err
	}

	// loop through each server
	for _, server := range servers {
		// create unique AgentCMD for cloud init
		AgentCMD := fmt.Sprintf("docker run -d -v /var/run/docker.sock:/var/run/docker.sock -e WOODPECKER_GRPC_SECURE=false -e WOODPECKER_SERVER=%s -e WOODPECKER_AGENT_SECRET=%s -e WOODPECKER_MAX_PROCS=%d -e WOODPECKER_HOSTNAME=%s woodpeckerci/woodpecker-agent:v"+version.Version, woodpeckerHost, agentSecret, 1, server)

		userdata := fmt.Sprintf("#cloud-config\nruncmd:\n  - %s", AgentCMD)
		labels := make(map[string]string)
		labels["created_by"] = "jynx"
		labels["created"] = fmt.Sprintf("%d", time.Now().Unix())

		var sshkeys []*hcloud.SSHKey
		sshKeyNames := strings.Split(os.Getenv("HETZNER_SSH_KEY_NAMES"), ",")

		sshkeys, err := getSSHKeys(sshKeyNames...)
		if err != nil {
			return nil
		}

		// get location and server type from environment
		serverImage := os.Getenv("HETZNER_SERVER_IMAGE")
		serverLocation := os.Getenv("HETZNER_SERVER_LOCATION")
		serverType := os.Getenv("HETZNER_SERVER_TYPE")

		// set default values for servers if none were provided
		switch "" {
		case serverImage:
			serverImage = "docker-ce"
		case serverLocation:
			serverLocation = "fsn1"
		case serverType:
			serverType = "cax11"
		}

		serverOpts := hcloud.ServerCreateOpts{
			Image:            &hcloud.Image{Name: serverImage},
			Labels:           labels,
			Location:         &hcloud.Location{Name: serverLocation},
			Name:             server,
			PublicNet:        &hcloud.ServerCreatePublicNet{EnableIPv4: true},
			SSHKeys:          sshkeys,
			ServerType:       &hcloud.ServerType{Name: serverType},
			StartAfterCreate: hcloud.Ptr(true),
			UserData:         userdata,
		}
		_, _, err = client.Server.Create(context.Background(), serverOpts)
		if err != nil {
			return err
		}
	}

	return nil
}