import _ from 'lodash';
import * as Y from 'yjs';
import { openDB, type DBSchema } from 'idb';
import { assert, generateId } from './util';
import { getDocsMap, getVaultMap, type DocMap } from './vault';
import { openDoc } from './persistence';

const DB_NAME = 'synced-docs';
export const LOCAL_DELTA_STORE = 'local-updates';
export const VAULT_STORE = 'vaults';

type LocalDeltaKey = [string, number];
type VaultRecord = { id: string };

interface DocsDatabase extends DBSchema {
  [LOCAL_DELTA_STORE]: {
    key: LocalDeltaKey;
    value: Uint8Array;
  };
  [VAULT_STORE]: {
    key: string;
    value: VaultRecord;
  };
}

export const docsDb = await openDB<DocsDatabase>(DB_NAME, 3, {
  upgrade(db, oldVersion, newVersion) {
    console.log(`Running upgrade from ${oldVersion} to ${newVersion}`);
    if (oldVersion < 2) {
      db.createObjectStore(LOCAL_DELTA_STORE);
    }
    if (oldVersion < 3) {
      db.createObjectStore(VAULT_STORE);
    }
  },
});

async function getOrCreateVaultDoc() {
  const records = await docsDb.getAll(VAULT_STORE);
  if (records.length > 1) {
    throw new Error(`Expected 1 vault record, got ${records.length}`);
  } else if (records.length === 0) {
    const key = generateId();
    const value = { id: key };
    await docsDb.add(VAULT_STORE, value, key);
    records.push(value);
  }

  const id = records[0].id as string;
  if (!id) {
    throw new Error("Vault record didn't have id");
  }
  const vault = await openDoc(id);
  const vaultMap = getVaultMap(vault);
  if (!vaultMap.has('id')) {
    vaultMap.set('id', id);
  }
  if (!vaultMap.has('docs')) {
    vaultMap.set('docs', new Y.Map());
  }

  // Make sure each doc has tags
  const docsMap = vaultMap.get('docs');
  for (const docMap of docsMap.values()) {
    if (!docMap.has('tags')) {
      docMap.set('tags', new Y.Map());
    }
  }

  return vault;
}

export const defaultVault = await getOrCreateVaultDoc();

const docsMap = getDocsMap(defaultVault);
if (docsMap.size === 0) {
  console.log('Running vault migration...');
  for (const oldKey of ['foo', 'bar', 'baz']) {
    const newId = generateId();
    const docInfo = new Y.Map([['title', oldKey]]) as DocMap;
    docsMap.set(newId, docInfo);

    const tx = docsDb.transaction(LOCAL_DELTA_STORE, 'readwrite');
    const recordKeys = (await tx.store.getAllKeys(
      IDBKeyRange.bound([oldKey, -Infinity], [oldKey, Infinity])
    )) as LocalDeltaKey[];
    console.log(
      `Found ${recordKeys.length} records for old document key ${oldKey}`
    );
    for (const oldRecordKey of recordKeys) {
      const record = await tx.store.get(oldRecordKey);
      assert(record, `Couldn't find old record ${oldRecordKey} to convert it`);
      const newRecordKey: LocalDeltaKey = [newId, oldRecordKey[1]];
      await tx.store.put(record, newRecordKey);
    }
    await tx.store.delete(
      IDBKeyRange.bound([oldKey, -Infinity], [oldKey, Infinity])
    );
    tx.commit();
  }
}

(window as any).Y = Y;