import { browser } from "$app/environment";
import { validateSignature } from "./keystore";

export const canaries: Canary[] = [];
export interface CanaryInterface {
  name: string,
  description: string,
  signer: string,
  url: string,
  keyIdentifier: string,
  contentType: string,
  upstream?: string
}
export interface Canary extends CanaryInterface { }
type _PreCanaryInterfaceEntries = {
  [T in keyof CanaryInterface]: [T, CanaryInterface[T]]
}
type CanaryInterfaceEntry = _PreCanaryInterfaceEntries[keyof _PreCanaryInterfaceEntries]
export class Canary {
  public constructor(
    canary: CanaryInterface
  ) {
    const entries = Object.entries(canary) as CanaryInterfaceEntry[];
    for (const a of entries) {
      // @ts-ignore we know the value will match in type
      this[a[0]] = a[1];
    }
    canaries.push(this);
  }
  public forceContentType = false;
  public async getRawText() {
    if (!browser) throw new Error('This should only be done in a browser.')
    const res = await fetch(this.url)
    if (res.ok) {
      if (!this.forceContentType) this.contentType = res.headers.get('Content-Type') || this.contentType
      const text = await res.text()
      return text
    } else {
      throw new Error(`Fetching canary failed with code ${res.status} (${res.statusText}):
${await res.text().catch(e => `Unknown (Unable to get text, ${JSON.stringify(e)})`)}`)
    }
  }
  public async getValidatedText(rawText: string | Promise<string> = this.getRawText()) {
    return await validateSignature(await rawText, this.keyIdentifier)
  }
  /** Returns downloadable data url if signature passes, otherwise returns null */
  public async getUrl(rawText: string | Promise<string> = this.getRawText()) {
    const t = await rawText;
    let stripped: string;
    try {
      stripped = await this.getValidatedText(t);
    } catch (error) {
      console.warn('Failed to validate signature: ', error);
      return null;
    }
    return {
      stripped: URL.createObjectURL(new Blob([stripped], {
        type: this.contentType,
      })),
      signed: URL.createObjectURL(new Blob([t], {
        type: this.contentType,
      })),
    }
  }
}
new Canary(
  {
    name: 'estrogen.zone',
    description: 'Services hosted around estrogen.zone and yuridick.gay',
    signer: 'memdmp',
    url: '/canaries/memdmp:estrogen.zone',
    keyIdentifier: 'memdmp',
    contentType: 'text/plain; charset=utf-8'
  }
);

new Canary(
  {
    name: 'kyun.host',
    description: 'The VPS provider "kyun.host"',
    signer: 'napatha',
    url: '/canaries/napatha:kyun.host',
    keyIdentifier: 'napatha',
    contentType: 'text/plain; charset=utf-8',
    upstream: 'https://files.kyun.host/canary.txt'
  }
);