import * as plugins from './smartclickhouse.plugins.js';
import { SmartClickHouseDb } from './smartclickhouse.classes.smartclickhouse.js';

export type TClickhouseColumnDataType =
  | 'String'
  | "DateTime64(3, 'Europe/Berlin')"
  | 'Float64'
  | 'Array(String)'
  | 'Array(Float64)';
export interface IColumnInfo {
  database: string;
  table: string;
  name: string;
  type: TClickhouseColumnDataType;
  position: string;
  default_kind: string;
  default_expression: string;
  data_compressed_bytes: string;
  data_uncompressed_bytes: string;
  marks_bytes: string;
  comment: string;
  is_in_partition_key: 0 | 1;
  is_in_sorting_key: 0 | 1;
  is_in_primary_key: 0 | 1;
  is_in_sampling_key: 0 | 1;
  compression_codec: string;
  character_octet_length: null;
  numeric_precision: null;
  numeric_precision_radix: null;
  numeric_scale: null;
  datetime_precision: '3';
}

export interface ITimeDataTableOptions {
  tableName: string;
  retainDataForDays: number;
}

export class TimeDataTable {
  public static async getTable(smartClickHouseDbRefArg: SmartClickHouseDb, tableNameArg: string) {
    const newTable = new TimeDataTable(smartClickHouseDbRefArg, {
      tableName: tableNameArg,
      retainDataForDays: 30,
    });

    await newTable.setup();

    return newTable;
  }

  // INSTANCE
  public healingDeferred: plugins.smartpromise.Deferred<any>;
  public smartClickHouseDbRef: SmartClickHouseDb;
  public options: ITimeDataTableOptions;

  constructor(smartClickHouseDbRefArg: SmartClickHouseDb, optionsArg: ITimeDataTableOptions) {
    this.smartClickHouseDbRef = smartClickHouseDbRefArg;
    this.options = optionsArg;
  }

  public async setup() {
    // create table in clickhouse
    await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
        CREATE TABLE IF NOT EXISTS ${this.smartClickHouseDbRef.options.database}.${this.options.tableName} (
          timestamp DateTime64(3, 'Europe/Berlin'),
          message String
        ) ENGINE=MergeTree() ORDER BY timestamp`);

    // lets adjust the TTL
    await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
        ALTER TABLE ${this.smartClickHouseDbRef.options.database}.${this.options.tableName} MODIFY TTL toDateTime(timestamp) + INTERVAL ${this.options.retainDataForDays} DAY
      `);

    await this.updateColumns();
    console.log(`=======================`);
    console.log(
      `table with name "${this.options.tableName}" in database ${this.smartClickHouseDbRef.options.database} has the following columns:`
    );
    for (const column of this.columns) {
      console.log(`>> ${column.name}: ${column.type}`);
    }
    console.log('^^^^^^^^^^^^^^\n');
  }

  public columns: IColumnInfo[] = [];

  /**
   * updates the columns
   */
  public async updateColumns() {
    this.columns = await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
      SELECT * FROM system.columns
      WHERE database LIKE '${this.smartClickHouseDbRef.options.database}'
      AND table LIKE '${this.options.tableName}' FORMAT JSONEachRow
    `);
    return this.columns;
  }

  /**
   * stores a json and tries to map it to the nested syntax
   */
  public async addData(dataArg: any) {
    if (this.healingDeferred) {
      return;
    }

    // the storageJson
    let storageJson: { [key: string]: any } = {};

    // helper stuff

    const getClickhouseTypeForValue = (valueArg: any): TClickhouseColumnDataType => {
      const typeConversion: { [key: string]: TClickhouseColumnDataType } = {
        string: 'String',
        number: 'Float64',
        undefined: null,
        null: null,
      };
      if (valueArg instanceof Array) {
        const arrayType = typeConversion[typeof valueArg[0] as string];
        if (!arrayType) {
          return null;
        } else {
          return `Array(${arrayType})` as TClickhouseColumnDataType;
        }
      }
      return typeConversion[typeof valueArg as string];
    };
    const checkPath = async (
      pathArg: string,
      typeArg: TClickhouseColumnDataType,
      prechecked = false
    ) => {
      let columnFound = false;
      for (const column of this.columns) {
        if (pathArg === column.name) {
          columnFound = true;
          break;
        }
      }
      if (!columnFound) {
        if (!prechecked) {
          await this.updateColumns();
          await checkPath(pathArg, typeArg, true);
          return;
        }
        const alterString = `ALTER TABLE ${this.smartClickHouseDbRef.options.database}.${this.options.tableName} ADD COLUMN ${pathArg} ${typeArg} FIRST`;
        try {
          await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
          ${alterString}
        `);
        } catch (err) {
          console.log(alterString);
          for (const column of this.columns) {
            console.log(column.name);
          }
        }
        await this.updateColumns();
      }
    };

    // key checking
    const flatDataArg = plugins.smartobject.toFlatObject(dataArg);
    for (const key of Object.keys(flatDataArg)) {
      const value = flatDataArg[key];
      if (key === 'timestamp' && typeof value !== 'number') {
        throw new Error('timestamp must be of type number');
      } else if (key === 'timestamp') {
        storageJson.timestamp = flatDataArg[key];
        continue;
      }
      // lets deal with the rest
      const clickhouseType = getClickhouseTypeForValue(value);
      if (!clickhouseType) {
        continue;
      }
      await checkPath(key, clickhouseType);
      storageJson[key] = value;
    }

    const result = await this.smartClickHouseDbRef.clickhouseHttpClient
      .insertPromise(this.smartClickHouseDbRef.options.database, this.options.tableName, [
        storageJson,
      ])
      .catch(async () => {
        if (this.healingDeferred) {
          return;
        }
        this.healingDeferred = plugins.smartpromise.defer();
        console.log(`Ran into an error. Trying to set up things properly again.`);
        await this.smartClickHouseDbRef.pingDatabaseUntilAvailable();
        await this.smartClickHouseDbRef.createDatabase();
        await this.setup();
        this.columns = [];
        this.healingDeferred.resolve();
        this.healingDeferred = null;
      });
    return result;
  }

  /**
   * deletes the entire table
   */
  public async delete() {
    await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
      DROP TABLE IF EXISTS ${this.smartClickHouseDbRef.options.database}.${this.options.tableName}
    `);
    this.columns = [];
  }

  /**
   * deletes entries older than a specified number of days
   * @param days number of days
   */
  public async deleteOldEntries(days: number) {
    await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
      ALTER TABLE ${this.smartClickHouseDbRef.options.database}.${this.options.tableName}
      DELETE WHERE timestamp < now() - INTERVAL ${days} DAY
    `);
  }

  public async getLastEntries(count: number) {
    const result = await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
      SELECT * FROM ${this.smartClickHouseDbRef.options.database}.${this.options.tableName}
      ORDER BY timestamp DESC
      LIMIT ${count} FORMAT JSONEachRow
    `);
    return result;
  }

  public async getEntriesNewerThan(unixTimestamp: number) {
    const result = await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
      SELECT * FROM ${this.smartClickHouseDbRef.options.database}.${this.options.tableName}
      WHERE timestamp > toDateTime(${unixTimestamp / 1000}) FORMAT JSONEachRow
    `);
    return result;
  }

  public async getEntriesBetween(unixTimestampStart: number, unixTimestampEnd: number) {
    const result = await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
      SELECT * FROM ${this.smartClickHouseDbRef.options.database}.${this.options.tableName}
      WHERE timestamp > toDateTime(${unixTimestampStart / 1000})
      AND timestamp < toDateTime(${unixTimestampEnd / 1000}) FORMAT JSONEachRow
    `);
    return result;
  }

  /**
   * streams all new entries using an observable
   */
  public streamNewEntries(): plugins.smartrx.rxjs.Observable<any> {
    return new plugins.smartrx.rxjs.Observable((observer) => {
      const pollInterval = 1000; // Poll every 1 second
      let lastTimestamp: number;

      const fetchLastEntryTimestamp = async () => {
        const lastEntry = await this.smartClickHouseDbRef.clickhouseHttpClient.queryPromise(`
        SELECT max(timestamp) as lastTimestamp FROM ${this.smartClickHouseDbRef.options.database}.${this.options.tableName} FORMAT JSONEachRow
      `);
        lastTimestamp = lastEntry.length
          ? new Date(lastEntry[0].lastTimestamp).getTime()
          : Date.now();
      };

      const fetchNewEntries = async () => {
        const newEntries = await this.getEntriesNewerThan(lastTimestamp);
        if (newEntries.length > 0) {
          for (const entry of newEntries) {
            observer.next(entry);
          }
          lastTimestamp = new Date(newEntries[newEntries.length - 1].timestamp).getTime();
        }
      };

      const startPolling = async () => {
        await fetchLastEntryTimestamp();
        const intervalId = setInterval(fetchNewEntries, pollInterval);

        // Cleanup on unsubscribe
        return () => clearInterval(intervalId);
      };

      startPolling().catch((err) => observer.error(err));
    });
  }
}