import { useCallback, useMemo, useState } from 'react';
import {
  advanceCapture,
  buildSovereigntyReport,
  computeOffRamp,
  createInitialState,
  persistToVault,
  selectOutlaws,
  setPhase,
  transitionAfterShowdown,
  type LoginMethod,
  type PlayerJourneyState,
} from '@bigtech-sucks/core';

export function useGameState() {
  const [state, setState] = useState<PlayerJourneyState>(() => createInitialState());

  const report = useMemo(
    () => buildSovereigntyReport(state.selectedOutlaws, state.loginMethod),
    [state.selectedOutlaws, state.loginMethod],
  );

  const offRamp = useMemo(
    () => (state.selectedOutlaws.length ? computeOffRamp(state.selectedOutlaws) : null),
    [state.selectedOutlaws],
  );

  const vaultExport = useMemo(() => persistToVault(state), [state]);

  const login = useCallback((method: LoginMethod) => {
    setState((s) => ({ ...s, loginMethod: method }));
  }, []);

  const goToPhase = useCallback((phase: PlayerJourneyState['phase']) => {
    setState((s) => setPhase(s, phase));
  }, []);

  const drawLine = useCallback((ids: string[]) => {
    setState((s) => selectOutlaws(s, ids));
  }, []);

  const startShowdown = useCallback((outlawId: string) => {
    setState((s) => setPhase({ ...s, activeOutlawId: outlawId }, 'showdown'));
  }, []);

  const showdownStep = useCallback(
    (step: 'round_up' | 'validate' | 'cut') => {
      setState((s) => {
        if (!s.activeOutlawId) return s;
        const advanced = advanceCapture(s, s.activeOutlawId, step);
        if (step === 'cut') {
          return transitionAfterShowdown(advanced);
        }
        return advanced;
      });
    },
    [],
  );

  const submitWaitlist = useCallback(async (email: string, channel: string) => {
    const payload = {
      email,
      channel,
      settlerSince: state.settlerSince,
    };

    const res = await fetch('/api/waitlist', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload),
    });

    if (!res.ok) throw new Error('Waitlist submission failed');

    setState((s) => ({ ...s, waitlistEmail: email, waitlistChannel: channel }));
    return payload;
  }, [state.settlerSince]);

  return {
    state,
    report,
    offRamp,
    vaultExport,
    login,
    goToPhase,
    drawLine,
    startShowdown,
    showdownStep,
    submitWaitlist,
  };
}