package nostr

import (
	"context"
	"encoding/json"
	"fmt"
	"net"
	"net/http"
	"strings"

	"git.devvul.com/asara/gologger"
	"git.devvul.com/asara/well-goknown/config"
	"github.com/fiatjaf/eventstore/postgresql"
	"github.com/fiatjaf/khatru"
	"github.com/fiatjaf/khatru/policies"
	"github.com/jmoiron/sqlx"
	"github.com/nbd-wtf/go-nostr"
)

var (
	DB      *sqlx.DB
	RelayDb postgresql.PostgresBackend
	relay   *khatru.Relay
)

type nostrUser struct {
	Pubkey string  `db:"pubkey"`
	Relays *string `db:"relays,omitempty"`
}

type nostrWellKnown struct {
	Names  map[string]string   `json:"names"`
	Relays map[string][]string `json:"relays,omitempty"`
	NIP46  map[string][]string `json:"nip46,omitempty"`
}

func GetNostrAddr(w http.ResponseWriter, r *http.Request) {
	l := gologger.Get(config.GetConfig().LogLevel).With().Str("context", "nostr").Logger()

	// get query string for username
	r.ParseForm()
	name := strings.ToLower(r.FormValue("name"))
	if name == "_" {
		name = ""
	}

	// normalize domain
	domain, _, err := net.SplitHostPort(r.Host)
	if err != nil {
		domain = r.Host
	}

	// get owner id for nip05 request
	var uid int
	err = DB.QueryRow("SELECT owner_id FROM nip05s WHERE name=$1 AND domain=$2", name, domain).Scan(&uid)
	if err != nil {
		l.Error().Msgf("user (%s@%s) doesn't exist: %s", name, domain, err.Error())
		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		return
	}

	// get the pubkey and relays associated with the nip05
	user := nostrUser{}
	err = DB.QueryRow("SELECT pubkey, relays FROM users WHERE id=$1", uid).Scan(&user.Pubkey, &user.Relays)
	if err != nil {
		l.Error().Msgf("unable to get user info for uid %v: %s", uid, err.Error())
		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		return
	}

	// get all names associated with the pubkey
	names := []string{}
	err = DB.Select(&names, "SELECT nip05s.name FROM nip05s JOIN users ON nip05s.owner_id = users.id WHERE nip05s.owner_id = $1", uid)
	if err != nil {
		l.Error().Msgf("unable to get nip05 names for uid %v: %s", uid, err.Error())
		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		return
	}

	// map of names
	n := make(map[string]string)
	for _, name := range names {
		if name == "" {
			n["_"] = user.Pubkey
		} else {
			n[name] = user.Pubkey
		}
	}

	// map of relays
	s := make(map[string][]string)
	if user.Relays != nil {
		if strings.Contains(*user.Relays, ",") {
			s[user.Pubkey] = strings.Split(*user.Relays, ",")
		} else {
			s[user.Pubkey] = []string{*user.Relays}
		}
	}

	// map of nip46
	t := make(map[string][]string)
	t[user.Pubkey] = []string{"wss://relay.devvul.com"}

	ret := nostrWellKnown{
		Names:  n,
		Relays: s,
		NIP46:  t,
	}

	j, err := json.Marshal(ret)
	if err != nil {
		l.Error().Msg(err.Error())
		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
		return
	}

	l.Debug().Msgf("returning nip05 for %s@%s: %s", name, domain, user.Pubkey)
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	w.Write(j)
	return
}

func NewRelay(version string) *khatru.Relay {
	// relay configuration
	relay = khatru.NewRelay()
	relay.Info.Name = config.GetConfig().RelayName
	relay.Info.PubKey = config.GetConfig().RelayPubkey
	relay.Info.Description = config.GetConfig().RelayDescription
	relay.Info.Icon = config.GetConfig().RelayIcon
	relay.Info.Contact = config.GetConfig().RelayContact
	relay.Info.Version = version
	relay.Info.Software = "https://git.devvul.com/asara/well-goknown"
	// contact lists
	relay.Info.SupportedNIPs = append(relay.Info.SupportedNIPs, 2)
	// dms
	relay.Info.SupportedNIPs = append(relay.Info.SupportedNIPs, 4)

	relay.OnConnect = append(relay.OnConnect, func(ctx context.Context) {
		khatru.RequestAuth(ctx)
	})

	// storage
	relay.StoreEvent = append(relay.StoreEvent, RelayDb.SaveEvent)
	relay.QueryEvents = append(relay.QueryEvents, RelayDb.QueryEvents)
	relay.CountEvents = append(relay.CountEvents, RelayDb.CountEvents)
	relay.DeleteEvent = append(relay.DeleteEvent, RelayDb.DeleteEvent)

	// apply policies
	//policies.ApplySaneDefaults(relay)

	relay.RejectEvent = append(
		relay.RejectEvent,
		RejectUnregisteredNpubs,
		policies.RejectEventsWithBase64Media,
		policies.ValidateKind,
	)

	relay.RejectFilter = append(
		relay.RejectFilter,
		policies.RejectKind04Snoopers,
	)
	return relay
}

func RejectUnregisteredNpubs(ctx context.Context, event *nostr.Event) (reject bool, msg string) {
	l := gologger.Get(config.GetConfig().LogLevel).With().Str("context", "nostr-reject-unregistered").Logger()

	// always allow auth messages
	if event.Kind == 22242 {
		return false, ""
	}

	// reject nip-04 messages to users who aren't registered
	if event.Kind == 4 {
		receiver := event.Tags.GetFirst([]string{"p"}).Value()
		var rid int
		err := DB.QueryRow("SELECT id FROM users WHERE pubkey=$1", receiver).Scan(&rid)
		if err != nil {
			rid = -1
		}

		var sid int
		err = DB.QueryRow("SELECT id FROM users WHERE pubkey=$1", event.PubKey).Scan(&sid)
		if err != nil {
			sid = -1
		}

		if rid != -1 || sid != -1 {
			l.Debug().Msgf("pubkeys %s or %s not found to be registered", receiver, event.PubKey)
			return true, fmt.Sprintf("nobody in this nip04 message is registered to the relay")
		}
		return false, ""
	}

	// check if user is registered
	var uid int
	err := DB.QueryRow("SELECT id FROM users WHERE pubkey=$1", event.PubKey).Scan(&uid)
	if err != nil {
		l.Debug().Msgf("kind: %v, pubkey: %s, error: %s", event.Kind, event.PubKey, err.Error())
		return true, fmt.Sprintf("restricted: pubkey %s is not registered to any users", event.PubKey)
	}
	return false, ""
}