/**
 * Tauri adapter for {@link ConversationGateway} (LS7 human transcript viewer).
 *
 * This is the only frontend place that knows the `read_conversation_page`
 * command name and its argument shape; features consume the gateway port
 * through DI.
 *
 * **Wire contract (verified against LS6 — `crates/app-tauri/src/commands.rs`
 * + `dto.rs`):** the command takes a *single* `request` argument deserialized
 * into `ReadConversationPageRequestDto` (`#[serde(rename_all = "camelCase")]`)
 * with flat fields `projectId`, `conversationId`, `anchor` (optional turn id),
 * `direction` (`"forward"`/`"backward"`, default backward) and `limit`
 * (optional, `0`/omit ⇒ default 50, clamped to `[1, 200]`). It returns a
 * `TurnPageDto` (`turns` / `hasMore` / `nextAnchor`). Note: there is **no**
 * nested `cursor` object on the wire — the backend builds the domain
 * `PageCursor` itself from the flat `anchor`/`direction` fields.
 */

import { invoke } from "@tauri-apps/api/core";

import type { TurnPage } from "@/domain";
import type { ConversationGateway, ConversationPageRequest } from "@/ports";
import { normalizeTurnPage } from "./conversationNormalization";

export class TauriConversationGateway implements ConversationGateway {
  async readPage(
    projectId: string,
    conversationId: string,
    request?: ConversationPageRequest,
  ): Promise<TurnPage> {
    const page = await invoke<unknown>("read_conversation_page", {
      request: {
        projectId,
        conversationId,
        anchor: request?.anchor,
        direction: request?.direction ?? "backward",
        limit: request?.limit,
      },
    });
    return normalizeTurnPage(page);
  }
}