import i18next from "i18next";
import { isJsonObject, JsonObject } from "../Core/Json";
import loadJson from "../Core/loadJson";
import loadWithXhr from "../Core/loadWithXhr";
import TerriaError from "../Core/TerriaError";
import Terria from "./Terria";

export const DEFAULT_MAX_SHARE_SIZE = 200 * 1024; // 200 KB

interface ShareDataServiceOptions {
  terria: Terria;
  url?: string;
}

/**
 * Interface to the terriajs-server service for creating short share links.
 * @param {*} options
 *
 * @alias ShareDataService
 * @constructor
 */
export default class ShareDataService {
  readonly terria: Terria;
  url: string | undefined;
  private _serverConfig: any;

  constructor(options: ShareDataServiceOptions) {
    this.terria = options.terria;
    this.url = options.url;
  }

  init(serverConfig: any): void {
    this.url = this.url ?? this.terria.configParameters.shareUrl ?? "share";
    this._serverConfig = serverConfig;
  }

  get isUsable(): boolean {
    return (
      (this.url !== undefined &&
        typeof this._serverConfig === "object" &&
        typeof this._serverConfig.newShareUrlPrefix === "string") ||
      this.url !== "share"
    );
  }

  // get the raw string from serverConfig.shareMaxRequestSize
  get shareMaxRequestSize(): string | undefined {
    return this._serverConfig.shareMaxRequestSize;
  }

  // get the parsed value in bytes from the server
  get shareMaxRequestSizeBytes(): number | undefined {
    return this._serverConfig.shareMaxRequestSizeBytes;
  }

  /**
   * Allocates a share token using Terria Server, storing the provided data there.
   * @param shareData JSON to store.
   * @return A promise for the token (which can later be resolved at /share/TOKEN).
   */
  async getShareToken(shareData: any): Promise<string> {
    if (!this.isUsable) {
      throw TerriaError.from("`ShareDataService` is not usable");
    }

    try {
      const result = await loadWithXhr({
        url: this.url!,
        method: "POST",
        data: JSON.stringify(shareData),
        headers: { "Content-Type": "application/json" },
        responseType: "json"
      });
      const json = typeof result === "string" ? JSON.parse(result) : result;
      return json.id;
    } catch (error) {
      throw TerriaError.from(error, {
        title: i18next.t("models.shareData.generateErrorTitle"),
        message: i18next.t("models.shareData.generateErrorMessage"),
        importance: 1
      });
    }
  }

  async resolveData(token: string): Promise<JsonObject> {
    if (!this.isUsable) {
      throw TerriaError.from("`ShareDataService` is not usable");
    }

    try {
      const shareJson = await loadJson(this.url + "/" + token);

      if (!isJsonObject(shareJson, false)) {
        throw TerriaError.from(
          `Invalid server response for share ${
            this.url + "/" + token
          }\n\`${JSON.stringify(shareJson)}\``
        );
      }

      return shareJson;
    } catch (error) {
      throw TerriaError.from(error, {
        title: i18next.t("models.shareData.expandErrorTitle"),
        message: i18next.t("models.shareData.expandErrorMessage", {
          appName: this.terria.appName
        }),
        importance: 1
      });
    }
  }
}