import {
  CryptoHelper,
  Identity_DECRYPTED,
  Identity_ENCRYPTED,
  NostrHelper,
  StorageService,
} from '@common';

export const addIdentity = async function (
  this: StorageService,
  data: {
    nick: string;
    privkeyString: string;
  }
): Promise<void> {
  this.assureIsInitialized();

  const privkey = NostrHelper.getNostrPrivkeyObject(
    data.privkeyString.toLowerCase()
  ).hex;

  // Check if an identity with the same privkey already exists.
  const existingIdentity = (
    this.getBrowserSessionHandler().browserSessionData?.identities ?? []
  ).find((x) => x.privkey === privkey);
  if (existingIdentity) {
    throw new Error(
      `An identity with the same private key already exists: ${existingIdentity.nick}`
    );
  }

  const browserSessionData = this.getBrowserSessionHandler().browserSessionData;
  if (!browserSessionData) {
    throw new Error('Browser session data is undefined.');
  }

  const decryptedIdentity: Identity_DECRYPTED = {
    id: CryptoHelper.v4(),
    nick: data.nick,
    privkey,
    createdAt: new Date().toISOString(),
  };

  // Add the new identity to the session data.
  browserSessionData.identities.push(decryptedIdentity);
  let isFirstIdentity = false;
  if (browserSessionData.identities.length === 1) {
    isFirstIdentity = true;
    browserSessionData.selectedIdentityId = decryptedIdentity.id;
  }
  this.getBrowserSessionHandler().saveFullData(browserSessionData);

  // Encrypt the new identity and add it to the sync data.
  const encryptedIdentity = await encryptIdentity.call(this, decryptedIdentity);
  const encryptedIdentities = [
    ...(this.getBrowserSyncHandler().browserSyncData?.identities ?? []),
    encryptedIdentity,
  ];

  await this.getBrowserSyncHandler().saveAndSetPartialData_Identities({
    identities: encryptedIdentities,
  });

  if (isFirstIdentity) {
    await this.getBrowserSyncHandler().saveAndSetPartialData_SelectedIdentityId(
      {
        selectedIdentityId: encryptedIdentity.id,
      }
    );
  }
};

export const deleteIdentity = async function (
  this: StorageService,
  identityId: string | undefined
): Promise<void> {
  this.assureIsInitialized();

  if (!identityId) {
    return;
  }

  const browserSessionData = this.getBrowserSessionHandler().browserSessionData;
  const browserSyncData = this.getBrowserSyncHandler().browserSyncData;
  if (!browserSessionData || !browserSyncData) {
    throw new Error('Browser session or sync data is undefined.');
  }

  browserSessionData.identities = browserSessionData.identities.filter(
    (x) => x.id !== identityId
  );
  browserSessionData.permissions = browserSessionData.permissions.filter(
    (x) => x.identityId !== identityId
  );
  browserSessionData.relays = browserSessionData.relays.filter(
    (x) => x.identityId !== identityId
  );
  if (browserSessionData.selectedIdentityId === identityId) {
    // Choose another identity to be selected or null if there is none.
    browserSessionData.selectedIdentityId =
      browserSessionData.identities.length > 0
        ? browserSessionData.identities[0].id
        : null;
  }
  await this.getBrowserSessionHandler().saveFullData(browserSessionData);

  // Handle Sync data.
  const encryptedIdentityId = await this.encrypt(identityId);
  await this.getBrowserSyncHandler().saveAndSetPartialData_Identities({
    identities: browserSyncData.identities.filter(
      (x) => x.id !== encryptedIdentityId
    ),
  });
  await this.getBrowserSyncHandler().saveAndSetPartialData_Permissions({
    permissions: browserSyncData.permissions.filter(
      (x) => x.identityId !== encryptedIdentityId
    ),
  });
  await this.getBrowserSyncHandler().saveAndSetPartialData_Relays({
    relays: browserSyncData.relays.filter(
      (x) => x.identityId !== encryptedIdentityId
    ),
  });
  await this.getBrowserSyncHandler().saveAndSetPartialData_SelectedIdentityId({
    selectedIdentityId:
      browserSessionData.selectedIdentityId === null
        ? null
        : await this.encrypt(browserSessionData.selectedIdentityId),
  });
};

export const switchIdentity = async function (
  this: StorageService,
  identityId: string | null
): Promise<void> {
  this.assureIsInitialized();

  // Check, if the identity really exists.
  const browserSessionData = this.getBrowserSessionHandler().browserSessionData;

  if (!browserSessionData?.identities.find((x) => x.id === identityId)) {
    return;
  }

  browserSessionData.selectedIdentityId = identityId;
  await this.getBrowserSessionHandler().saveFullData(browserSessionData);

  const encryptedIdentityId =
    identityId === null ? null : await this.encrypt(identityId);
  await this.getBrowserSyncHandler().saveAndSetPartialData_SelectedIdentityId({
    selectedIdentityId: encryptedIdentityId,
  });
};

export const encryptIdentity = async function (
  this: StorageService,
  identity: Identity_DECRYPTED
): Promise<Identity_ENCRYPTED> {
  const encryptedIdentity: Identity_ENCRYPTED = {
    id: await this.encrypt(identity.id),
    nick: await this.encrypt(identity.nick),
    createdAt: await this.encrypt(identity.createdAt),
    privkey: await this.encrypt(identity.privkey),
  };

  return encryptedIdentity;
};

/**
 * Locked vault context for decryption during unlock
 * - v1 vaults use password (PBKDF2)
 * - v2 vaults use keyBase64 (pre-derived Argon2id key)
 */
export type LockedVaultContext =
  | { iv: string; password: string; keyBase64?: undefined }
  | { iv: string; keyBase64: string; password?: undefined };

export const decryptIdentities = async function (
  this: StorageService,
  identities: Identity_ENCRYPTED[],
  withLockedVault: LockedVaultContext | undefined = undefined
): Promise<Identity_DECRYPTED[]> {
  const decryptedIdentities: Identity_DECRYPTED[] = [];

  for (const identity of identities) {
    const decryptedIdentity = await decryptIdentity.call(
      this,
      identity,
      withLockedVault
    );
    decryptedIdentities.push(decryptedIdentity);
  }

  return decryptedIdentities;
};

export const decryptIdentity = async function (
  this: StorageService,
  identity: Identity_ENCRYPTED,
  withLockedVault: LockedVaultContext | undefined = undefined
): Promise<Identity_DECRYPTED> {
  if (typeof withLockedVault === 'undefined') {
    const decryptedIdentity: Identity_DECRYPTED = {
      id: await this.decrypt(identity.id, 'string'),
      nick: await this.decrypt(identity.nick, 'string'),
      createdAt: await this.decrypt(identity.createdAt, 'string'),
      privkey: await this.decrypt(identity.privkey, 'string'),
    };

    return decryptedIdentity;
  }

  // v2: Use pre-derived key
  if (withLockedVault.keyBase64) {
    const decryptedIdentity: Identity_DECRYPTED = {
      id: await this.decryptWithLockedVaultV2(
        identity.id,
        'string',
        withLockedVault.iv,
        withLockedVault.keyBase64
      ),
      nick: await this.decryptWithLockedVaultV2(
        identity.nick,
        'string',
        withLockedVault.iv,
        withLockedVault.keyBase64
      ),
      createdAt: await this.decryptWithLockedVaultV2(
        identity.createdAt,
        'string',
        withLockedVault.iv,
        withLockedVault.keyBase64
      ),
      privkey: await this.decryptWithLockedVaultV2(
        identity.privkey,
        'string',
        withLockedVault.iv,
        withLockedVault.keyBase64
      ),
    };
    return decryptedIdentity;
  }

  // v1: Use password (PBKDF2)
  const decryptedIdentity: Identity_DECRYPTED = {
    id: await this.decryptWithLockedVault(
      identity.id,
      'string',
      withLockedVault.iv,
      withLockedVault.password!
    ),
    nick: await this.decryptWithLockedVault(
      identity.nick,
      'string',
      withLockedVault.iv,
      withLockedVault.password!
    ),
    createdAt: await this.decryptWithLockedVault(
      identity.createdAt,
      'string',
      withLockedVault.iv,
      withLockedVault.password!
    ),
    privkey: await this.decryptWithLockedVault(
      identity.privkey,
      'string',
      withLockedVault.iv,
      withLockedVault.password!
    ),
  };

  return decryptedIdentity;
};