import { BattleExporter, VsHistoryDetail } from "../types.ts";
import { datetime, path } from "../deps.ts";
import { NSOAPP_VERSION, S3SI_VERSION } from "../constant.ts";

const FILENAME_FORMAT = "yyyyMMddHHmmss";

type FileExporterType = {
  type: "VS" | "COOP";
  nsoVersion: string;
  s3siVersion: string;
  exportTime: string;
  data: VsHistoryDetail;
};

/**
 * Exporter to file.
 *
 * This is useful for debugging. It will write each battle detail to a file.
 * Timestamp is used as filename. Example: 2021-01-01T00:00:00.000Z.json
 */
export class FileExporter implements BattleExporter<VsHistoryDetail> {
  name = "file";
  constructor(private exportPath: string) {
  }
  async exportBattle(detail: VsHistoryDetail) {
    await Deno.mkdir(this.exportPath, { recursive: true });

    const playedTime = new Date(detail.playedTime);
    const filename = `${datetime.format(playedTime, FILENAME_FORMAT)}.json`;
    const filepath = path.join(this.exportPath, filename);

    const body: FileExporterType = {
      type: "VS",
      nsoVersion: NSOAPP_VERSION,
      s3siVersion: S3SI_VERSION,
      exportTime: new Date().toISOString(),
      data: detail,
    };

    await Deno.writeTextFile(filepath, JSON.stringify(body));
  }
  async getLatestBattleTime() {
    const dirs: Deno.DirEntry[] = [];
    for await (const i of Deno.readDir(this.exportPath)) dirs.push(i);

    const files = dirs.filter((i) => i.isFile).map((i) => i.name);
    const timestamps = files.map((i) => i.replace(/\.json$/, "")).map((i) =>
      datetime.parse(i, FILENAME_FORMAT)
    );

    return timestamps.reduce((a, b) => (a > b ? a : b), new Date(0));
  }
}