/**
 * Quick Slots Tests — Phase 4.6
 *
 * Tests: slot assignment, active selection, key switching.
 */

import { describe, it, expect } from 'vitest';
import { QuickSlots, SLOT_COUNT } from '../src/player/quickslots';

describe('QuickSlots — creation', () => {
  it('starts with all slots empty', () => {
    const qs = new QuickSlots();
    for (let i = 0; i < SLOT_COUNT; i++) {
      expect(qs.getSlot(i)).toBeNull();
    }
  });

  it('starts with slot 0 active', () => {
    const qs = new QuickSlots();
    expect(qs.activeIndex).toBe(0);
  });

  it('has 4 slots', () => {
    expect(SLOT_COUNT).toBe(4);
    const qs = new QuickSlots();
    expect(qs.getAll()).toHaveLength(4);
  });
});

describe('QuickSlots — assignment', () => {
  it('assigns item to slot', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    expect(qs.getSlot(0)).toBe('Na');
  });

  it('replaces existing item in slot', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    qs.assign(0, 'Fe');
    expect(qs.getSlot(0)).toBe('Fe');
  });

  it('clears slot with null', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    qs.assign(0, null);
    expect(qs.getSlot(0)).toBeNull();
  });

  it('ignores invalid index', () => {
    const qs = new QuickSlots();
    qs.assign(-1, 'Na');
    qs.assign(4, 'Na');
    // No crash, no change
    expect(qs.getAll()).toEqual([null, null, null, null]);
  });
});

describe('QuickSlots — active slot', () => {
  it('returns active slot item', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    expect(qs.getActive()).toBe('Na');
  });

  it('returns null for empty active slot', () => {
    const qs = new QuickSlots();
    expect(qs.getActive()).toBeNull();
  });

  it('switches active slot', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    qs.assign(1, 'Fe');
    qs.assign(2, 'Cu');

    qs.setActive(1);
    expect(qs.activeIndex).toBe(1);
    expect(qs.getActive()).toBe('Fe');

    qs.setActive(2);
    expect(qs.getActive()).toBe('Cu');
  });

  it('clamps active index to valid range', () => {
    const qs = new QuickSlots();
    qs.setActive(-1);
    expect(qs.activeIndex).toBe(0);

    qs.setActive(10);
    expect(qs.activeIndex).toBe(3);
  });
});

describe('QuickSlots — getAll', () => {
  it('returns snapshot of all slots', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    qs.assign(2, 'Fe');
    expect(qs.getAll()).toEqual(['Na', null, 'Fe', null]);
  });
});

describe('QuickSlots — auto-assign', () => {
  it('assigns to first empty slot', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    const index = qs.autoAssign('Fe');
    expect(index).toBe(1);
    expect(qs.getSlot(1)).toBe('Fe');
  });

  it('returns -1 when all slots full', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    qs.assign(1, 'Fe');
    qs.assign(2, 'Cu');
    qs.assign(3, 'S');
    const index = qs.autoAssign('H');
    expect(index).toBe(-1);
  });

  it('does not duplicate item already in a slot', () => {
    const qs = new QuickSlots();
    qs.assign(0, 'Na');
    const index = qs.autoAssign('Na');
    expect(index).toBe(-1); // already assigned
    expect(qs.getAll().filter(s => s === 'Na')).toHaveLength(1);
  });
});