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import { DB } from "https://deno.land/x/sqlite@v2.3.2/mod.ts";
import { Adapter, AdapterParams, adapters } from './mod.ts';
const CREATE = 'CREATE TABLE IF NOT EXISTS [kv-storage] (area TEXT, key TEXT, value TEXT, PRIMARY KEY (area, key))';const GET = 'SELECT value FROM [kv-storage] WHERE key=:key AND area=:area';const UPSERT = 'INSERT INTO [kv-storage] (area, key, value) VALUES (:area, :key, :value) ON CONFLICT(area, key) DO UPDATE SET value=:value';const DELETE = 'DELETE FROM [kv-storage] WHERE key=:key AND area=:area';const CLEAR = 'DELETE FROM [kv-storage] WHERE area=:area';const KEYS = 'SELECT key FROM [kv-storage] WHERE area=:area';const VALUES = 'SELECT value FROM [kv-storage] WHERE area=:area';const ENTRIES = 'SELECT key, value FROM [kv-storage] WHERE area=:area';
export class SQLiteAdapter implements Adapter {  private filename: string;  private area: string;
  constructor({ area, url }: AdapterParams) {    this.area = area;
    const filename = url.substr('sqlite://'.length);    this.filename = ['', 'memory'].includes(filename ?? '') ? ':memory:' : filename;    const db = new DB(this.filename);    [...db.query(CREATE)];    db.close()  }
  private query(query: string, params?: { key?: string, value?: string }) {    const db = new DB(this.filename);    const ret =  [...db.query(query, { ...params, area: this.area })];    db.close();    return ret;  }
  async get(key: string): Promise<string | undefined> {    return this.query(GET, { key })[0]?.[0];  }
  async set(key: string, value: string) {    this.query(UPSERT, { key, value });  }
  async delete(key: string) {    this.query(DELETE, { key });  }
  async clear() {    this.query(CLEAR);  }
  async *keys() {    for (const [key] of this.query(KEYS)) {      yield key;    }  }
  async *values() {    for (const [value] of this.query(VALUES)) {      yield value;    }  }
  async *entries() {    for (const [key, value] of this.query(ENTRIES)) {      yield [key, value] as [string, string];    }  }
  backingStore() {    return new DB(this.filename);  }}
adapters.set('sqlite:', SQLiteAdapter);