import * as secp from "@noble/curves/secp256k1";
import * as utils from "@noble/curves/abstract/utils";
import { v4 as uuid } from "uuid";

import { HexKey, RelaySettings, PinEncrypted, EventPublisher } from "@snort/system";
import { deepClone, sanitizeRelayUrl, unwrap, ExternalStore } from "@snort/shared";

import { DefaultRelays } from "Const";
import { LoginSession, LoginSessionType, createPublisher } from "Login";
import { DefaultPreferences } from "./Preferences";

const AccountStoreKey = "sessions";
const LoggedOut = {
  id: "default",
  type: "public_key",
  preferences: DefaultPreferences,
  readonly: true,
  tags: {
    item: [],
    timestamp: 0,
  },
  follows: {
    item: [],
    timestamp: 0,
  },
  muted: {
    item: [],
    timestamp: 0,
  },
  blocked: {
    item: [],
    timestamp: 0,
  },
  bookmarked: {
    item: [],
    timestamp: 0,
  },
  pinned: {
    item: [],
    timestamp: 0,
  },
  relays: {
    item: Object.fromEntries([...DefaultRelays.entries()].map(a => [unwrap(sanitizeRelayUrl(a[0])), a[1]])),
    timestamp: 0,
  },
  latestNotification: 0,
  readNotifications: 0,
  subscriptions: [],
  appData: {
    item: {
      mutedWords: [],
    },
    timestamp: 0,
  },
  extraChats: [],
} as LoginSession;

export class MultiAccountStore extends ExternalStore<LoginSession> {
  #activeAccount?: HexKey;
  #accounts: Map<string, LoginSession>;
  #publishers = new Map<string, EventPublisher>();

  constructor() {
    super();
    const existing = window.localStorage.getItem(AccountStoreKey);
    if (existing) {
      const logins = JSON.parse(existing);
      this.#accounts = new Map((logins as Array<LoginSession>).map(a => [a.id, a]));
    } else {
      this.#accounts = new Map();
    }
    this.#migrate();
    if (!this.#activeAccount) {
      this.#activeAccount = this.#accounts.keys().next().value;
    }
    // reset readonly on load
    for (const [, v] of this.#accounts) {
      if (v.type === LoginSessionType.PrivateKey && v.readonly) {
        v.readonly = false;
      }
      v.appData ??= {
        item: {
          mutedWords: [],
        },
        timestamp: 0,
      };
      v.extraChats ??= [];
    }
  }

  getSessions() {
    return [...this.#accounts.values()].map(v => ({
      pubkey: unwrap(v.publicKey),
      id: v.id,
    }));
  }

  allSubscriptions() {
    return [...this.#accounts.values()].map(a => a.subscriptions).flat();
  }

  switchAccount(id: string) {
    if (this.#accounts.has(id)) {
      this.#activeAccount = id;
      this.#save();
    }
  }

  getPublisher(id: string) {
    return this.#publishers.get(id);
  }

  setPublisher(id: string, pub: EventPublisher) {
    this.#publishers.set(id, pub);
    this.notifyChange();
  }

  loginWithPubkey(
    key: HexKey,
    type: LoginSessionType,
    relays?: Record<string, RelaySettings>,
    remoteSignerRelays?: Array<string>,
    privateKey?: PinEncrypted,
  ) {
    if (this.#accounts.has(key)) {
      throw new Error("Already logged in with this pubkey");
    }
    const initRelays = this.decideInitRelays(relays);
    const newSession = {
      ...LoggedOut,
      id: uuid(),
      readonly: type === LoginSessionType.PublicKey,
      type,
      publicKey: key,
      relays: {
        item: initRelays,
        timestamp: 1,
      },
      preferences: deepClone(DefaultPreferences),
      remoteSignerRelays,
      privateKeyData: privateKey,
    } as LoginSession;

    const pub = createPublisher(newSession);
    if (pub) {
      this.setPublisher(newSession.id, pub);
    }
    this.#accounts.set(newSession.id, newSession);
    this.#activeAccount = newSession.id;
    this.#save();
    return newSession;
  }

  decideInitRelays(relays: Record<string, RelaySettings> | undefined): Record<string, RelaySettings> {
    if (relays && Object.keys(relays).length > 0) {
      return relays;
    }
    return Object.fromEntries(DefaultRelays.entries());
  }

  loginWithPrivateKey(key: PinEncrypted, entropy?: string, relays?: Record<string, RelaySettings>) {
    const pubKey = utils.bytesToHex(secp.schnorr.getPublicKey(key.value));
    if (this.#accounts.has(pubKey)) {
      throw new Error("Already logged in with this pubkey");
    }
    const initRelays = relays ?? Object.fromEntries(DefaultRelays.entries());
    const newSession = {
      ...LoggedOut,
      id: uuid(),
      type: LoginSessionType.PrivateKey,
      readonly: false,
      privateKeyData: key,
      publicKey: pubKey,
      generatedEntropy: entropy,
      relays: {
        item: initRelays,
        timestamp: 1,
      },
      preferences: deepClone(DefaultPreferences),
    } as LoginSession;

    if ("nostr_os" in window && window.nostr_os) {
      window.nostr_os.saveKey(key.value);
      newSession.type = LoginSessionType.Nip7os;
      newSession.privateKeyData = undefined;
    }
    const pub = EventPublisher.privateKey(key.value);
    this.setPublisher(newSession.id, pub);

    this.#accounts.set(newSession.id, newSession);
    this.#activeAccount = newSession.id;
    this.#save();
    return newSession;
  }

  updateSession(s: LoginSession) {
    if (this.#accounts.has(s.id)) {
      this.#accounts.set(s.id, s);
      console.debug("SET SESSION", s);
      this.#save();
    }
  }

  removeSession(id: string) {
    if (this.#accounts.delete(id)) {
      if (this.#activeAccount === id) {
        this.#activeAccount = undefined;
      }
      this.#save();
    }
  }

  takeSnapshot(): LoginSession {
    const s = this.#activeAccount ? this.#accounts.get(this.#activeAccount) : undefined;
    if (!s) return LoggedOut;

    return { ...s };
  }

  #migrate() {
    let didMigrate = false;

    // replace default tab with notes
    for (const [, v] of this.#accounts) {
      if ((v.preferences.defaultRootTab as string) === "posts") {
        v.preferences.defaultRootTab = "notes";
        didMigrate = true;
      }
    }

    // update session types
    for (const [, v] of this.#accounts) {
      if (!v.type) {
        v.type = v.privateKey ? LoginSessionType.PrivateKey : LoginSessionType.Nip7;
        didMigrate = true;
      }
    }

    // add ids
    for (const [, v] of this.#accounts) {
      if ((v.id?.length ?? 0) === 0) {
        v.id = uuid();
        didMigrate = true;
      }
    }

    // mark readonly
    for (const [, v] of this.#accounts) {
      if (v.type === LoginSessionType.PublicKey && !v.readonly) {
        v.readonly = true;
        didMigrate = true;
      }
      // reset readonly on load
      if (v.type === LoginSessionType.PrivateKey && v.readonly) {
        v.readonly = false;
        didMigrate = true;
      }
    }

    if (didMigrate) {
      console.debug("Finished migration in MultiAccountStore");
      this.#save();
    }
  }

  #save() {
    if (!this.#activeAccount && this.#accounts.size > 0) {
      this.#activeAccount = this.#accounts.keys().next().value;
    }
    const toSave = [];
    for (const v of this.#accounts.values()) {
      if (v.privateKeyData instanceof PinEncrypted) {
        toSave.push({
          ...v,
          privateKeyData: v.privateKeyData.toPayload(),
        });
      } else {
        toSave.push({ ...v });
      }
    }

    window.localStorage.setItem(AccountStoreKey, JSON.stringify(toSave));
    this.notifyChange();
  }
}