import { requestTranscription } from "#lib/api/media.js";
import { t } from "#lib/i18n/locale.svelte.js";
import type { MessageKey } from "#lib/i18n/messages.js";

const REFUSALS: Record<string, MessageKey> = {
  empty: "media.transcribeEmpty",
  no_premium: "media.transcribeNoPremium",
  pending: "media.transcribePending",
  too_long: "media.transcribeTooLong",
};

export class Transcript {
  readonly #chatId: () => number;
  readonly #messageId: () => number;
  readonly #initial: () => string | null;
  failure = $state<string | null>(null);
  fetched = $state<string | null>(null);
  pending = $state(false);
  shown = $state(false);

  constructor(
    chatId: () => number,
    messageId: () => number,
    initial: () => string | null
  ) {
    this.#chatId = chatId;
    this.#messageId = messageId;
    this.#initial = initial;
  }

  get text(): string | null {
    return this.fetched ?? this.#initial();
  }

  get open(): boolean {
    return this.shown && Boolean(this.text);
  }

  async toggle(): Promise<void> {
    if (this.text) {
      this.shown = !this.shown;
      return;
    }
    if (this.pending) {
      return;
    }
    this.pending = true;
    this.failure = null;
    try {
      const outcome = await requestTranscription(
        this.#chatId(),
        this.#messageId()
      );
      if ("text" in outcome) {
        this.fetched = outcome.text;
        this.shown = true;
      } else {
        this.failure = t(REFUSALS[outcome.error] ?? "media.transcribeFailed");
      }
    } catch {
      this.failure = t("media.transcribeFailed");
    } finally {
      this.pending = false;
    }
  }
}