// Shop integration tests: GET /api/shop, POST /api/shop/buy, POST /api/shop/sell.
const { describe, it, before, after } = require('node:test');
const assert = require('node:assert/strict');
const { setup, teardown, cleanup } = require('../helpers');

/**
 * Register a user and log them in, returning the session cookie string.
 */
async function registerAndLogin(baseUrl, username, password) {
  // Register
  await fetch(`${baseUrl}/api/auth/register`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ username, password }),
  });

  // Login — extract the session cookie from Set-Cookie
  const res = await fetch(`${baseUrl}/api/auth/login`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ username, password }),
  });
  assert.equal(res.status, 200);
  const json = await res.json();
  assert.equal(json.ok, true);

  // Extract session cookie
  const setCookie = res.headers.get('set-cookie');
  assert.ok(setCookie, 'Login should set a session cookie');
  const cookie = setCookie.split(';')[0]; // "connect.sid=..."
  return cookie;
}

function authHeaders(cookie) {
  return { Cookie: cookie };
}

describe('shop', () => {
  let baseUrl, userSeq = 0;

  before(async () => {
    baseUrl = await setup();
  });

  after(async () => {
    await teardown(); cleanup();
  });

  /**
   * Register, login, create a character, optionally tweak DB fields, return cookie + characterId.
   */
  async function setupHero(overrides = {}, characterClass = 'warrior') {
    userSeq += 1;
    const username = `shopu${userSeq}`;
    const cookie = await registerAndLogin(baseUrl, username, 'password123');

    // Create character
    const charRes = await fetch(`${baseUrl}/api/character`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ name: `ShopHero${userSeq}`, class: characterClass }),
    });
    assert.equal(charRes.status, 201);
    const charJson = await charRes.json();
    const characterId = charJson.data.character.id;

    // Apply overrides via DB
    const db = require('../../src/db').getDb();
    const cols = Object.keys(overrides);
    if (cols.length) {
      db.prepare(`UPDATE characters SET ${cols.map((c) => `${c} = ?`).join(', ')} WHERE id = ?`)
        .run(...Object.values(overrides), characterId);
    }

    return { cookie, characterId };
  }

  /** Grant an item to a character's inventory. Stacks with existing rows. */
  function grantItem(characterId, itemId, quantity = 1) {
    const db = require('../../src/db').getDb();
    const NOW = 1_700_000_000_000;
    const existing = db.prepare(
      'SELECT id, quantity FROM inventory WHERE character_id = ? AND item_id = ?'
    ).get(characterId, itemId);
    if (existing) {
      db.prepare('UPDATE inventory SET quantity = quantity + ? WHERE id = ?').run(quantity, existing.id);
    } else {
      db.prepare('INSERT INTO inventory (character_id, item_id, quantity, equipped_slot, acquired_at) VALUES (?, ?, ?, NULL, ?)')
        .run(characterId, itemId, quantity, NOW);
    }
  }

  // ─── GET /api/shop ────────────────────────────────────────────────────

  it('returns shop stock with purchasable items and sellable materials', async () => {
    const { cookie } = await setupHero({ gold: 500 });

    const res = await fetch(`${baseUrl}/api/shop`, { headers: authHeaders(cookie) });
    const body = await res.json();

    assert.equal(res.status, 200);
    assert.equal(body.ok, true);
    assert.ok(Array.isArray(body.data.stock));
    // Should have items with buy_price > 0 (purchasable)
    const purchasable = body.data.stock.filter((i) => i.buyPrice > 0);
    assert.ok(purchasable.length > 0, 'should have purchasable items');
    // Should have materials (buy_price = 0)
    const materials = body.data.stock.filter((i) => i.buyPrice === 0);
    assert.ok(materials.length > 0, 'should have materials for selling');
    // Character gold should be present
    assert.equal(body.data.character.gold, 500);
  });

  it('filters stock by character level (levelOk flag)', async () => {
    const { cookie } = await setupHero({ gold: 500, level: 1 });

    const res = await fetch(`${baseUrl}/api/shop`, { headers: authHeaders(cookie) });
    const body = await res.json();

    assert.equal(res.status, 200);
    // A level-1 hero should see common items (min_level 1) as levelOk=true
    const commonItems = body.data.stock.filter((i) => i.levelReq === 1 && i.buyPrice > 0);
    assert.ok(commonItems.length > 0);
    for (const item of commonItems) {
      assert.equal(item.levelOk, true);
    }
    // Should NOT see high-level items
    const highLevelItems = body.data.stock.filter((i) => i.levelReq >= 10);
    assert.equal(highLevelItems.length, 0, 'should not show level-10+ items to level-1 hero');
  });

  it('includes sellPrice for materials', async () => {
    const { cookie } = await setupHero({ gold: 100, level: 5 });

    const res = await fetch(`${baseUrl}/api/shop`, { headers: authHeaders(cookie) });
    const body = await res.json();

    const materials = body.data.stock.filter((i) => i.buyPrice === 0);
    assert.ok(materials.length > 0);
    for (const mat of materials) {
      assert.ok(typeof mat.sellPrice === 'number', `material ${mat.name} should have sellPrice`);
      assert.ok(mat.sellPrice >= 1, `material ${mat.name} sellPrice should be >= 1`);
    }
  });

  // ─── POST /api/shop/buy ───────────────────────────────────────────────

  it('buys an item and deducts gold', async () => {
    const { cookie } = await setupHero({ gold: 100 });

    // Buy Rusty Sword (item 1, buy_price 20)
    const res = await fetch(`${baseUrl}/api/shop/buy`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 1, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    assert.equal(body.ok, true);
    // Gold should decrease by 20
    assert.equal(body.data.character.gold, 80);
    // Rusty Sword should be in inventory
    const rustySword = body.data.items.find((i) => i.itemId === 1);
    assert.ok(rustySword, 'Rusty Sword should be in inventory');
    assert.equal(rustySword.quantity, 1);
  });

  it('buys multiple quantity and stacks into existing item', async () => {
    const { cookie } = await setupHero({ gold: 200 });

    // Buy 2 Minor Healing Potions (item 14, stackable, buy_price 15).
    // Starter kit already has 2 potions → total 4 after this buy.
    const res1 = await fetch(`${baseUrl}/api/shop/buy`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 14, quantity: 2 }),
    });
    const body1 = await res1.json();
    assert.equal(body1.ok, true);
    assert.equal(body1.data.character.gold, 170); // 200 - 2*15
    const potion1 = body1.data.items.find((i) => i.itemId === 14);
    assert.equal(potion1.quantity, 4); // 2 starter + 2 bought

    // Buy 3 more of the same → total 7.
    const res2 = await fetch(`${baseUrl}/api/shop/buy`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 14, quantity: 3 }),
    });
    const body2 = await res2.json();
    assert.equal(body2.ok, true);
    assert.equal(body2.data.character.gold, 125); // 170 - 3*15
    const potion2 = body2.data.items.find((i) => i.itemId === 14);
    assert.equal(potion2.quantity, 7); // 4 + 3 stacked
  });

  it('rejects buy with insufficient gold', async () => {
    const { cookie } = await setupHero({ gold: 10 });

    // Try to buy Rusty Sword (cost 20) with only 10 gold
    const res = await fetch(`${baseUrl}/api/shop/buy`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 1, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 422);
    assert.equal(body.ok, false);
    assert.equal(body.error.code, 'INSUFFICIENT_GOLD');
    // Error responses don't include data — gold unchanged is implicit
  });

  it('rejects buy for level-gated item', async () => {
    const { cookie } = await setupHero({ gold: 1000, level: 1 });

    // Try to buy Iron Blade (item 4, min_level 5)
    const res = await fetch(`${baseUrl}/api/shop/buy`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 4, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 422);
    assert.equal(body.ok, false);
    assert.equal(body.error.code, 'LEVEL_TOO_LOW');
  });

  it('rejects buy for non-purchasable material', async () => {
    const { cookie } = await setupHero({ gold: 100 });

    // Try to buy Rat Tail (item 17, material with buy_price 0)
    const res = await fetch(`${baseUrl}/api/shop/buy`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 17, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 400);
    assert.equal(body.ok, false);
    assert.equal(body.error.code, 'VALIDATION_ERROR');
  });

  it('concurrent double-buy: only one succeeds when gold covers exactly one', async () => {
    const { cookie, characterId } = await setupHero({ gold: 20 });

    // Rusty Sword costs 20 gold — exactly enough for one.
    // Send two buy requests concurrently.
    const [resA, resB] = await Promise.all([
      fetch(`${baseUrl}/api/shop/buy`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
        body: JSON.stringify({ itemId: 1, quantity: 1 }),
      }),
      fetch(`${baseUrl}/api/shop/buy`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
        body: JSON.stringify({ itemId: 1, quantity: 1 }),
      }),
    ]);

    const bodyA = await resA.json();
    const bodyB = await resB.json();

    // Exactly one should succeed, the other should fail with INSUFFICIENT_GOLD.
    const success = [bodyA, bodyB].filter((b) => b.ok === true);
    const failures = [bodyA, bodyB].filter((b) => b.ok === false);
    assert.equal(success.length, 1, 'exactly one buy should succeed');
    assert.equal(failures.length, 1, 'exactly one buy should fail');
    assert.equal(failures[0].error.code, 'INSUFFICIENT_GOLD');

    // Gold should be 0 after one successful buy.
    const winner = success[0];
    assert.equal(winner.data.character.gold, 0);
  });

  // ─── POST /api/shop/sell ──────────────────────────────────────────────

  it('sells a material and increases gold', async () => {
    const { cookie, characterId } = await setupHero({ gold: 50 });

    // Grant Rat Tail (item 17, material, common, min_level 1, buy_price 0)
    grantItem(characterId, 17, 1);

    const beforeGold = db_prepareSelect('SELECT gold FROM characters WHERE id = ?', characterId).gold;
    assert.equal(beforeGold, 50);

    // Sell the Rat Tail
    const res = await fetch(`${baseUrl}/api/shop/sell`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 17, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    assert.equal(body.ok, true);
    // Gold should increase
    assert.ok(body.data.character.gold > 50, `gold should increase (was 50, now ${body.data.character.gold})`);
    // Rat Tail should be removed from inventory
    const ratTail = body.data.items.find((i) => i.itemId === 17);
    assert.equal(ratTail, undefined, 'Rat Tail should be removed from inventory');
  });

  it('sells materials with rarity default pricing', async () => {
    const { cookie, characterId } = await setupHero({ gold: 100, level: 5 });

    // Grant Spider Silk (item 19, material, uncommon, min_level 5, buy_price 0)
    grantItem(characterId, 19, 1);

    const res = await fetch(`${baseUrl}/api/shop/sell`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 19, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    assert.equal(body.ok, true);
    // Uncommon material sell: floor(4 * level / min_level) = floor(4 * 5 / 5) = 4
    assert.equal(body.data.character.gold, 104); // 100 + 4
  });

  it('sells uncommon material using rarity default', async () => {
    const { cookie, characterId } = await setupHero({ gold: 100, level: 10 });

    // Grant Imp Horn (item 20, material, uncommon, min_level 10, buy_price 0)
    grantItem(characterId, 20, 1);

    const res = await fetch(`${baseUrl}/api/shop/sell`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 20, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 200);
    assert.equal(body.ok, true);
    // Uncommon material sell: floor(4 * 10 / 10) = 4
    assert.equal(body.data.character.gold, 104); // 100 + 4
  });

  it('rejects selling a non-material item', async () => {
    const { cookie, characterId } = await setupHero({ gold: 100 });

    // Grant Rusty Sword (item 1, weapon — not a material)
    grantItem(characterId, 1, 1);

    const res = await fetch(`${baseUrl}/api/shop/sell`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 1, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 400);
    assert.equal(body.ok, false);
    assert.equal(body.error.code, 'VALIDATION_ERROR');
  });

  it('rejects selling an item not in inventory', async () => {
    const { cookie } = await setupHero({ gold: 100 });

    // Try to sell Rat Tail without granting it first
    const res = await fetch(`${baseUrl}/api/shop/sell`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 17, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 404);
    assert.equal(body.ok, false);
    assert.equal(body.error.code, 'NOT_FOUND');
  });

  // ─── Sell equipped item rejection ─────────────────────────────────────

  it('rejects selling an equipped item', async () => {
    // Use a ranger (starter weapon is Hunters Shortbow, item 3).
    // Grant a Leather Jerkin (item 8, armor) and equip it, then try to sell.
    const { cookie, characterId } = await setupHero({ gold: 100 }, 'ranger');

    grantItem(characterId, 8, 1); // Leather Jerkin (armor)
    const db = require('../../src/db').getDb();
    db.prepare('UPDATE inventory SET equipped_slot = ? WHERE character_id = ? AND item_id = ?').run('armor', characterId, 8);

    // Try to sell the equipped Leather Jerkin — not allowed.
    const res = await fetch(`${baseUrl}/api/shop/sell`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 8, quantity: 1 }),
    });
    const body = await res.json();

    assert.equal(res.status, 400);
    assert.equal(body.ok, false);
    assert.equal(body.error.code, 'VALIDATION_ERROR');
    assert.ok(body.error.message.includes('Unequip'), 'should mention unequipping');
  });

  // ─── Round-trip ───────────────────────────────────────────────────────

  it('buy and sell round-trip: buy then sell loses gold (spread)', async () => {
    const { cookie, characterId } = await setupHero({ gold: 500 });

    // Buy Minor Healing Potion (item 14, buy_price 15, consumable)
    const buyRes = await fetch(`${baseUrl}/api/shop/buy`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 14, quantity: 1 }),
    });
    const buyBody = await buyRes.json();
    assert.equal(buyRes.status, 200);
    assert.equal(buyBody.ok, true);
    const buyGold = buyBody.data.character.gold; // 500 - 15 = 485
    assert.equal(buyGold, 485);

    // Sell Rat Tail (item 17, material, common, min_level 1) — must grant it first
    grantItem(characterId, 17, 1);

    const sellRes = await fetch(`${baseUrl}/api/shop/sell`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', ...authHeaders(cookie) },
      body: JSON.stringify({ itemId: 17, quantity: 1 }),
    });
    const sellBody = await sellRes.json();
    assert.equal(sellRes.status, 200);
    assert.equal(sellBody.ok, true);
    const sellGold = sellBody.data.character.gold;

    // Rat Tail (common, min_level 1) sell: floor(2 * level / 1) = floor(2 * 1 / 1) = 2
    // Final gold = 485 + 2 = 487
    assert.equal(sellGold, 487);
    assert.ok(sellGold < 500, 'round-trip should lose gold due to spread');
    // Rat Tail should be gone from inventory
    const db = require('../../src/db').getDb();
    const invAfter = db.prepare('SELECT * FROM inventory WHERE character_id = ? AND item_id = 17')
      .get(characterId);
    assert.equal(invAfter, undefined, 'Rat Tail should be removed after sell');
  });
});

function db_prepareSelect(sql, ...params) {
  return require('../../src/db').getDb().prepare(sql).get(...params);
}