import type { ApiClient } from '../api/client';
import type { SessionDetailResponse } from '../api/types';

export type AsyncState = 'idle' | 'loading' | 'success' | 'error';

export interface VerticalSliceState {
  sessionCode: string;
  session: SessionDetailResponse | null;
  joinState: AsyncState;
  startRoundState: AsyncState;
  loadingSession: boolean;
  errorMessage: string | null;
}

export interface VerticalSliceController {
  getState(): VerticalSliceState;
  hydrateLobby(sessionCode: string): Promise<VerticalSliceState>;
  joinLobby(sessionCode: string, nickname: string): Promise<VerticalSliceState>;
  startRound(sessionCode: string, categorySlug: string): Promise<VerticalSliceState>;
}

export function createVerticalSliceController(api: ApiClient): VerticalSliceController {
  const state: VerticalSliceState = {
    sessionCode: '',
    session: null,
    joinState: 'idle',
    startRoundState: 'idle',
    loadingSession: false,
    errorMessage: null
  };

  const normalizeCode = (value: string): string => value.trim().toUpperCase();

  async function hydrateLobby(sessionCode: string): Promise<VerticalSliceState> {
    state.loadingSession = true;
    state.errorMessage = null;
    state.sessionCode = normalizeCode(sessionCode);

    const result = await api.getSession(state.sessionCode);
    state.loadingSession = false;

    if (!result.ok) {
      state.errorMessage = 'Kunne ikke hente lobby-status.';
      return { ...state };
    }

    state.session = result.data;
    return { ...state };
  }

  async function joinLobby(sessionCode: string, nickname: string): Promise<VerticalSliceState> {
    state.joinState = 'loading';
    state.errorMessage = null;

    const join = await api.joinSession({ code: sessionCode, nickname });
    if (!join.ok) {
      state.joinState = 'error';
      state.errorMessage = 'Join fejlede. Tjek kode eller nickname og prøv igen.';
      return { ...state };
    }

    state.joinState = 'success';
    return hydrateLobby(sessionCode);
  }

  async function startRound(sessionCode: string, categorySlug: string): Promise<VerticalSliceState> {
    state.startRoundState = 'loading';
    state.errorMessage = null;

    const start = await api.startRound(sessionCode, { category_slug: categorySlug });
    if (!start.ok) {
      state.startRoundState = 'error';
      state.errorMessage = 'Kunne ikke starte runden. Opdatér lobbyen og prøv igen.';
      return { ...state };
    }

    state.startRoundState = 'success';
    return hydrateLobby(sessionCode);
  }

  return {
    getState: () => ({ ...state }),
    hydrateLobby,
    joinLobby,
    startRound
  };
}