package cmd

import (
	"crypto/rand"
	"encoding/hex"
	"fmt"

	"git.maurice.fr/thomas/mailout/pkg/crypto"
	"git.maurice.fr/thomas/mailout/pkg/database"
	"git.maurice.fr/thomas/mailout/pkg/models"
	"git.maurice.fr/thomas/mailout/pkg/providers/ovh"
	"git.maurice.fr/thomas/mailout/pkg/utils"
	"github.com/google/uuid"
	"github.com/pterm/pterm"
	"github.com/sirupsen/logrus"
	"github.com/spf13/cobra"
)

var (
	flagDKIMKeyActive bool
	flagSelector      string
	flagKeyBits       int
)

var DKIMKeyCmd = &cobra.Command{
	Use:   "dkimkey",
	Short: "manages DKIM keys",
}

var DKIMKeyAddCmd = &cobra.Command{
	Use:   "add [domain]",
	Short: "adds a DKIM signing key",
	Args:  cobra.ExactArgs(1),
	Run: func(cmd *cobra.Command, args []string) {
		db, err := database.NewDB(cfg)
		if err != nil {
			logrus.WithError(err).Fatal("could not connect to the database")
		}

		priv, pub, err := crypto.GenerateKeyPair(flagKeyBits)
		if err != nil {
			panic(err)
		}

		selector := flagSelector
		if selector == "" {
			b := make([]byte, 8)
			_, err := rand.Read(b)
			if err != nil {
				logrus.Fatal("entropy generator is kill")
			}

			selector = hex.EncodeToString(b)
		}

		dkimkey := models.DKIMKey{
			DomainName: args[0],
			PublicKey:  pub,
			PrivateKey: priv,
			Active:     flagUserActive,
			Selector:   selector,
			Record:     fmt.Sprintf("%s._domainkey.%s. IN TXT \"v=DKIM1; k=rsa; p=%s\"", selector, args[0], pub),
		}
		err = db.Save(&dkimkey).Error

		if err != nil {
			logrus.WithError(err).Fatal("could not create DKIM key")
		}

		logrus.Infof("created DKIM key %s", dkimkey.ID)
	},
}

var DKIMKeyListCmd = &cobra.Command{
	Use:   "list",
	Short: "list DKIM keys",
	Run: func(cmd *cobra.Command, args []string) {
		db, err := database.NewDB(cfg)
		if err != nil {
			logrus.WithError(err).Fatal("could not connect to the database")
		}

		qRes := make([]models.DKIMKey, 0)

		err = db.Find(&qRes).Error
		if err != nil {
			logrus.WithError(err).Fatal("could not list keys")
		}

		tData := pterm.TableData{
			{"id", "selector", "domain", "active", "created_at", "updated_at"},
		}
		for _, k := range qRes {
			tData = append(tData, []string{k.ID.String(), k.Selector, k.DomainName, fmt.Sprintf("%v", k.Active), k.CreatedAt.String(), k.UpdatedAt.String()})
		}

		pterm.DefaultTable.WithHasHeader().WithData(tData).Render()
	},
}

var DKIMKeyRecordCmd = &cobra.Command{
	Use:   "record",
	Short: "gives the dns record for a key",
	Run: func(cmd *cobra.Command, args []string) {
		db, err := database.NewDB(cfg)
		if err != nil {
			logrus.WithError(err).Fatal("could not connect to the database")
		}

		qRes := make([]models.DKIMKey, 0)

		id, err := uuid.Parse(args[0])
		if err != nil {
			logrus.WithError(err).Fatal("invalid UUID")
		}

		err = db.Where(models.DKIMKey{ID: id}).Find(&qRes).Error
		if err != nil {
			logrus.WithError(err).Fatal("could not search keys")
		}
		if len(qRes) == 0 {
			logrus.WithError(err).Fatal("No such key")
		}

		fmt.Println(qRes[0].Record)
	},
}

var DKIMKeyDeleteCmd = &cobra.Command{
	Use:   "delete",
	Short: "delete DKIM keys",
	Args:  cobra.ExactArgs(1),
	Run: func(cmd *cobra.Command, args []string) {
		db, err := database.NewDB(cfg)
		if err != nil {
			logrus.WithError(err).Fatal("could not connect to the database")
		}

		id, err := uuid.Parse(args[0])
		if err != nil {
			logrus.WithError(err).Fatal("invalid UUID")
		}
		err = db.Where(&models.DKIMKey{ID: id}).Delete(&models.DKIMKey{}).Error
		if err != nil {
			logrus.WithError(err).Fatal("could not delete DKIM key")
		}

		logrus.Infof("deleted DKIM key %s if it existed", args[0])
	},
}

var DKIMKeyActivateCmd = &cobra.Command{
	Use:   "activate",
	Short: "activates a DKIM key",
	Args:  cobra.ExactArgs(1),
	Run: func(cmd *cobra.Command, args []string) {
		db, err := database.NewDB(cfg)
		if err != nil {
			logrus.WithError(err).Fatal("could not connect to the database")
		}

		id, err := uuid.Parse(args[0])
		if err != nil {
			logrus.WithError(err).Fatal("invalid UUID")
		}

		err = db.Model(&models.DKIMKey{}).Where(&models.DKIMKey{ID: id}).Update("active", true).Error
		if err != nil {
			logrus.WithError(err).Fatal("could not activate DKIM key")
		}

		logrus.Infof("activated DKIM key %s", args[0])
	},
}

var DKIMKeyDeactivateCmd = &cobra.Command{
	Use:   "deactivate",
	Short: "deactivates a DKIM key",
	Args:  cobra.ExactArgs(1),
	Run: func(cmd *cobra.Command, args []string) {
		db, err := database.NewDB(cfg)
		if err != nil {
			logrus.WithError(err).Fatal("could not connect to the database")
		}

		id, err := uuid.Parse(args[0])
		if err != nil {
			logrus.WithError(err).Fatal("invalid UUID")
		}

		err = db.Model(&models.DKIMKey{}).Where(&models.DKIMKey{ID: id}).Update("active", false).Error
		if err != nil {
			logrus.WithError(err).Fatal("could not deactivate DKIM key")
		}

		logrus.Infof("deactivated DKIM key %s", args[0])
	},
}

var DKIMKeyPublishCmd = &cobra.Command{
	Use:   "publish",
	Short: "publishes a DKIM key onto a DNS provider",
	Args:  cobra.ExactArgs(1),
	Run: func(cmd *cobra.Command, args []string) {
		db, err := database.NewDB(cfg)
		if err != nil {
			logrus.WithError(err).Fatal("could not connect to the database")
		}

		qRes := make([]models.DKIMKey, 0)

		id, err := uuid.Parse(args[0])
		if err != nil {
			logrus.WithError(err).Fatal("invalid UUID")
		}

		err = db.Where(models.DKIMKey{ID: id}).Find(&qRes).Error
		if err != nil {
			logrus.WithError(err).Fatal("could not get key")
		}
		if len(qRes) == 0 {
			logrus.WithError(err).Fatal("No such key")
		}

		dkimkey := qRes[0]
		logger := logrus.WithFields(logrus.Fields{
			"dkimkey":  dkimkey.ID,
			"selector": dkimkey.Selector,
		})

		ovhClient, err := ovh.NewOVHProvider(cfg)
		if err != nil {
			logger.WithError(err).Fatal("could not get OVH DNS provider")
		}

		zone, err := utils.GetZone(dkimkey.DomainName)
		if err != nil {
			logger.WithError(err).Fatal("could not determine zone")
		}
		subdomain, err := utils.GetSubdomain(dkimkey.DomainName)
		if err != nil {
			logger.WithError(err).Fatal("could not determine subdomain")
		}

		if subdomain == "" {
			subdomain = zone
		}

		logger = logger.WithFields(logrus.Fields{
			"zone":      zone,
			"subdomain": subdomain,
		})

		dkimSub := fmt.Sprintf("%s._domainkey.%s", dkimkey.Selector, subdomain)
		result := make([]int, 0)

		err = ovhClient.Client.Get(fmt.Sprintf("/domain/zone/%s/record?fieldType=TXT&subDomain=%s", zone, dkimSub), &result)

		if err != nil {
			logger.WithError(err).Fatal("could not lookup records")
		}

		type createParams struct {
			FieldType string `json:"fieldType"`
			SubDomain string `json:"subDomain"`
			Target    string `json:"target"`
			TTL       int    `json:"ttl"`
		}

		type updateParams struct {
			SubDomain string `json:"subDomain"`
			Target    string `json:"target"`
			TTL       int    `json:"ttl"`
		}

		if len(result) == 0 {
			logger.Info("no DKIM records found, creating a new one")

			c := createParams{
				FieldType: "TXT",
				SubDomain: fmt.Sprintf("%s._domainkey.%s", dkimkey.Selector, subdomain),
				Target:    fmt.Sprintf("\"v=DKIM1; k=rsa; p=%s\"", dkimkey.PublicKey),
				TTL:       60,
			}

			err = ovhClient.Client.Post(fmt.Sprintf("/domain/zone/%s/record", zone), &c, nil)
			if err != nil {
				logger.WithError(err).Fatal("could not create new record")
			}
			logger.Info("created new DKIM record")

			err = ovhClient.Client.Post(fmt.Sprintf("/domain/zone/%s/refresh", zone), nil, nil)
			if err != nil {
				logger.WithError(err).Fatal("could not refresh the zone")
			}
			logger.Info("refreshed zone")
		} else if len(result) == 1 {
			logger.Info("found one record, updating it")

			u := updateParams{
				SubDomain: fmt.Sprintf("%s._domainkey.%s", dkimkey.Selector, subdomain),
				Target:    fmt.Sprintf("\"v=DKIM1; k=foo; p=%s\"", dkimkey.PublicKey),
				TTL:       60,
			}

			err = ovhClient.Client.Put(fmt.Sprintf("/domain/zone/%s/record/%d", zone, result[0]), &u, nil)
			if err != nil {
				logger.WithError(err).Fatal("could not update record")
			}
			logger.Info("updated existing record")

			err = ovhClient.Client.Post(fmt.Sprintf("/domain/zone/%s/refresh", zone), nil, nil)
			if err != nil {
				logger.WithError(err).Fatal("could not refresh the zone")
			}
			logger.Info("refreshed zone")
		}
	},
}

var DKIMKeyUnpublishCmd = &cobra.Command{
	Use:   "unpublish",
	Short: "removes a DKIM key onto a DNS provider",
	Args:  cobra.ExactArgs(1),
	Run: func(cmd *cobra.Command, args []string) {
		db, err := database.NewDB(cfg)
		if err != nil {
			logrus.WithError(err).Fatal("could not connect to the database")
		}

		qRes := make([]models.DKIMKey, 0)

		id, err := uuid.Parse(args[0])
		if err != nil {
			logrus.WithError(err).Fatal("invalid UUID")
		}

		err = db.Where(models.DKIMKey{ID: id}).Find(&qRes).Error
		if err != nil {
			logrus.WithError(err).Fatal("could not get key")
		}
		if len(qRes) == 0 {
			logrus.WithError(err).Fatal("No such key")
		}

		dkimkey := qRes[0]
		logger := logrus.WithFields(logrus.Fields{
			"dkimkey":  dkimkey.ID,
			"selector": dkimkey.Selector,
		})

		ovhClient, err := ovh.NewOVHProvider(cfg)
		if err != nil {
			logger.WithError(err).Fatal("could not get OVH DNS provider")
		}

		zone, err := utils.GetZone(dkimkey.DomainName)
		if err != nil {
			logger.WithError(err).Fatal("could not determine zone")
		}
		subdomain, err := utils.GetSubdomain(dkimkey.DomainName)
		if err != nil {
			logger.WithError(err).Fatal("could not determine subdomain")
		}

		if subdomain == "" {
			subdomain = zone
		}

		logger = logger.WithFields(logrus.Fields{
			"zone":      zone,
			"subdomain": subdomain,
		})

		dkimSub := fmt.Sprintf("%s._domainkey.%s", dkimkey.Selector, subdomain)
		result := make([]int, 0)

		err = ovhClient.Client.Get(fmt.Sprintf("/domain/zone/%s/record?fieldType=TXT&subDomain=%s", zone, dkimSub), &result)

		if err != nil {
			logger.WithError(err).Fatal("could not lookup records")
		}

		if len(result) == 0 {
			logger.Info("no DKIM records found, no need to do anything")
		} else if len(result) == 1 {
			logger.Info("found one record, deleting it")

			err = ovhClient.Client.Delete(fmt.Sprintf("/domain/zone/%s/record/%d", zone, result[0]), nil)
			if err != nil {
				logger.WithError(err).Fatal("could not delete record")
			}
			logger.Info("deleted existing record")

			err = ovhClient.Client.Post(fmt.Sprintf("/domain/zone/%s/refresh", zone), nil, nil)
			if err != nil {
				logger.WithError(err).Fatal("could not refresh the zone")
			}
			logger.Info("refreshed zone")
		}
	},
}

func InitDKIMKeyCmd() {
	DKIMKeyCmd.AddCommand(DKIMKeyAddCmd)
	DKIMKeyCmd.AddCommand(DKIMKeyListCmd)
	DKIMKeyCmd.AddCommand(DKIMKeyDeleteCmd)
	DKIMKeyCmd.AddCommand(DKIMKeyActivateCmd)
	DKIMKeyCmd.AddCommand(DKIMKeyDeactivateCmd)
	DKIMKeyCmd.AddCommand(DKIMKeyRecordCmd)
	DKIMKeyCmd.AddCommand(DKIMKeyPublishCmd)
	DKIMKeyCmd.AddCommand(DKIMKeyUnpublishCmd)

	DKIMKeyAddCmd.PersistentFlags().BoolVarP(&flagDKIMKeyActive, "active", "a", true, "whether or not the created key is active")
	DKIMKeyAddCmd.PersistentFlags().StringVarP(&flagSelector, "selector", "s", "", "force a selector for the key")
	DKIMKeyAddCmd.PersistentFlags().IntVarP(&flagKeyBits, "key-bits", "k", 2048, "force a size for the key")
}