package nostr

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

	"git.minhas.io/asara/gologger"
	"git.minhas.io/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"`
}

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"))

	// 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 {
		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}
		}
	}

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

	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", name, domain)
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	w.Write(j)
	return
}

func NewRelay() *khatru.Relay {
	// relay configuration
	relay = khatru.NewRelay()
	relay.Info.Name = "Devvul Nostr Relay"
	relay.Info.PubKey = "ac7d66c7065e211b27759ffe2b333fde34e307cead79ce7c00f401d8fa6c08d1"
	relay.Info.Description = "nostr relay for devvul users"
	relay.Info.Icon = "https://pfp.nostr.build/ee442b3c54143099fb483b5e3a6e1e41144df5c7457313a30586a082baa1babc.png"
	relay.Info.Version = "0.0.1"
	relay.Info.Contact = "asara@devvul.com"
	relay.Info.Software = "https://git.devvul.com/asara/well-goknown"

	// 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.PreventLargeTags(80),
		policies.RejectEventsWithBase64Media,
		policies.ValidateKind,
	)

	relay.RejectFilter = append(
		relay.RejectFilter,
		policies.RejectKind04Snoopers,
		policies.AntiSyncBots,
		policies.NoComplexFilters,
		policies.NoEmptyFilters,
	)
	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()

	// reject nip-04 messages to users who aren't registered
	if event.Kind == 4 {
		receiver := event.Tags.GetFirst([]string{"p"}).Value()
		var uid int
		err := DB.QueryRow("SELECT id FROM users WHERE pubkey=$1", receiver).Scan(&uid)
		if err != nil {
			l.Debug().Msgf("recipient pubkey %s not found: %s", receiver, err.Error())
			return true, fmt.Sprintf("recipient pubkey %s is not registered to any users", receiver)
		}
	}

	// 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("poster pubkey %s not found: %s", event.PubKey, err.Error())
		return true, fmt.Sprintf("pubkey %s is not registered to any users", event.PubKey)
	}
	return false, ""
}