export function createInMemoryHealthObservationStore() {
  const rowsByUser = new Map();
  const dedupIndex = new Map();
  let nextId = 1;

  return {
    listUserIds() {
      return [...rowsByUser.keys()];
    },
    async list(userId, { limit = 50 } = {}) {
      const rows = rowsByUser.get(String(userId)) ?? [];
      return rows.filter((row) => row.deletedAt == null).slice(0, limit);
    },
    async findByDedupKey(userId, dedupKey) {
      const id = dedupIndex.get(`${String(userId)}|${dedupKey}`);
      if (!id) return null;
      const rows = rowsByUser.get(String(userId)) ?? [];
      return rows.find((row) => row.id === id) ?? null;
    },
    async insert(userId, observation) {
      if (!observation?.confirmed) {
        const error = Object.assign(new Error('健康观测必须确认后才能保存'), {
          code: 'health_unconfirmed',
        });
        throw error;
      }
      const row = {
        id: nextId++,
        userId: String(userId),
        observedAt: observation.observedAt,
        metricType: observation.metricType,
        valueNum: observation.valueNum ?? null,
        valueText: observation.valueText ?? null,
        unit: observation.unit ?? null,
        context: observation.context ?? null,
        source: observation.source ?? 'manual',
        sourceRef: observation.sourceRef ?? null,
        qualityFlag: observation.qualityFlag ?? 'ok',
        deletedAt: observation.deletedAt ?? null,
        note: observation.note ?? null,
        createdAt: observation.createdAt ?? Date.now(),
      };
      if (observation.dedupKey) {
        dedupIndex.set(`${row.userId}|${observation.dedupKey}`, row.id);
      }
      const list = rowsByUser.get(row.userId) ?? [];
      list.unshift(row);
      rowsByUser.set(row.userId, list);
      return row;
    },
  };
}