// Test helper: in-memory mock storage. Records all writes (addDoc/updateDoc).
// Captures encounter patches + log entries so tests assert persistence.
function createMockStorage() {
  const docs = new Map();        // path -> data
  const calls = [];              // ordered {fn, path, data}

  return {
    calls,
    docs,
    async getDoc(path) { return docs.has(path) ? { ...docs.get(path) } : null; },
    async setDoc(path, data) {
      calls.push({ fn: 'setDoc', path, data });
      docs.set(path, { ...data });
    },
    async addDoc(path, data) {
      calls.push({ fn: 'addDoc', path, data });
    },
    async updateDoc(path, patch) {
      calls.push({ fn: 'updateDoc', path, data: patch });
      if (!docs.has(path)) docs.set(path, {});
      docs.set(path, { ...docs.get(path), ...patch });
    },
    async deleteDoc(path) {
      calls.push({ fn: 'deleteDoc', path });
      docs.delete(path);
    },
    async getCollection() { return []; },
    async batchWrite(ops) {
      for (const op of ops) {
        if (op.type === 'delete') await this.deleteDoc(op.path);
        else await this.updateDoc(op.path, op.data);
      }
    },
    async undo() {},
    // filters
    updatesFor(prefix) { return calls.filter(c => c.fn === 'updateDoc' && c.path.startsWith(prefix)); },
    logs() { return calls.filter(c => c.fn === 'addDoc').map(c => c.data); },
  };
}

// Standard ctx for tests. encPath + logPath + displayPath preset.
// Returns { storage, ctx } so tests destructure both in one call:
//   const { storage, ctx } = mockCtx();
function mockCtx(storage) {
  storage = storage || createMockStorage();
  const ctx = {
    storage,
    encPath: 'encounters/e1',
    logPath: 'logs',
    displayPath: 'activeDisplay/status',
  };
  return { storage, ctx };
}

// Standard 2-participant ready encounter.
function readyEnc(opts = {}) {
  return {
    id: 'e1',
    name: opts.name || 'TestEnc',
    round: 0,
    isStarted: false,
    isPaused: false,
    currentTurnParticipantId: null,
    turnOrderIds: [],
    participants: opts.participants || [
      { id: 'p1', name: 'Bob', type: 'character', initiative: 10, maxHp: 10, currentHp: 10, isActive: true, conditions: [], deathSaves: 0, deathFails: 0, isStable: false, isDying: false },
      { id: 'p2', name: 'Mob', type: 'monster', initiative: 5, maxHp: 10, currentHp: 10, isActive: true, conditions: [], deathSaves: 0, deathFails: 0, isStable: false, isDying: false },
    ],
  };
}

module.exports = { createMockStorage, mockCtx, readyEnc };