// BUG-13: cross-pointer reorder blocked (skip/double-act otherwise).
// nextTurn walks turnOrderIds forward from current pointer. Dragging across
// pointer = ambiguous who-acts-next:
//   - upcoming dragged ahead of pointer → walk wraps past → SKIPPED
//   - acted dragged behind pointer → acts again → DOUBLE-ACT
// Full fix needs actedThisRound tracking. Pragmatic now: block both dirs
// during active encounter. Pre-combat: free reorder (no pointer).

'use strict';

const shared = require('@ttrpg/shared');
const {
  makeParticipant,
  startEncounter, nextTurn, reorderParticipants,
} = shared;

function p(id, init) {
  return makeParticipant({ id, name: id, type: 'monster',
    initiative: init, maxHp: 100, currentHp: 100 });
}
function enc(ps) {
  return { name:'t', participants:ps, isStarted:false, isPaused:false,
    round:0, currentTurnParticipantId:null, turnOrderIds:[] };
}
const apply = (e, r) => r && r.patch ? { ...e, ...r.patch } : e;

describe('BUG-13: cross-pointer reorder blocked during active encounter', () => {
  test('dragging not-yet-acted participant ahead of pointer = no-op', () => {
    // [a(10), b(10), c(10)]. a acts -> b current. c not yet acted.
    let e = enc([p('a',10),p('b',10),p('c',10)]);
    e = apply(e, startEncounter(e)); // a (idx0, pointer)
    e = apply(e, nextTurn(e)); // b (idx1, pointer)
    expect(e.currentTurnParticipantId).toBe('b');

    // Drag c (idx2, behind pointer) before b (idx1, pointer). Crosses pointer.
    // Would let c act by initiative-reinsert but nextTurn forward-walk skips.
    // Blocked instead.
    const r = reorderParticipants(e, 'c', 'b');
    expect(r.patch).toBeNull();
    expect(e.turnOrderIds).toEqual(['a','b','c']); // unchanged
  });

  test('dragging already-acted participant behind pointer = no-op', () => {
    // [a(10), b(10), c(10)]. a acts (idx0, ahead of pointer).
    let e = enc([p('a',10),p('b',10),p('c',10)]);
    e = apply(e, startEncounter(e)); // a (pointer idx0)
    e = apply(e, nextTurn(e)); // b (pointer idx1)
    // Drag a (already acted, ahead of pointer) after c (behind pointer).
    // Crosses pointer. Would let a act again. Blocked.
    const r = reorderParticipants(e, 'a', 'c');
    expect(r.patch).toBeNull();
  });

  test('reorder within same side of pointer = allowed', () => {
    // [a(10), b(10), c(10), d(10)]. a current (pointer idx0).
    // b,c,d all behind pointer (upcoming). Reorder among them = safe.
    let e = enc([p('a',10),p('b',10),p('c',10),p('d',10)]);
    e = apply(e, startEncounter(e)); // a (idx0)
    // swap b,c (both idx1,2 — behind pointer). No cross.
    const r = reorderParticipants(e, 'c', 'b');
    expect(r.patch).not.toBeNull();
    expect(r.patch.participants.map(p => p.id)).toEqual(['a','c','b','d']);
  });

  test('pre-combat: free reorder (no pointer)', () => {
    // isStarted=false. No pointer. Reorder allowed freely.
    let e = enc([p('a',10),p('b',10),p('c',10)]);
    const r = reorderParticipants(e, 'c', 'a');
    expect(r.patch).not.toBeNull();
    expect(r.patch.participants.map(p => p.id)).toEqual(['c','a','b']);
  });
});