import { createUserDataSpaceService } from './user-data-space-service.mjs';
import { ensureHealthPageDataForUser } from './health-page-data-bootstrap.mjs';
import { HEALTH_OBSERVATION_DRAFTS_DATASET } from './health-page-data-schema.mjs';

const DATASET_NAME = HEALTH_OBSERVATION_DRAFTS_DATASET.name;

function parseJsonField(value, fallback = {}) {
  if (value == null) return fallback;
  if (typeof value === 'object') return value;
  try {
    return JSON.parse(String(value));
  } catch {
    return fallback;
  }
}

function mapPgDraftRow(row, userId, sourceRef = null) {
  return {
    id: Number(row.id),
    userId: String(userId),
    draftKey: row.draft_key,
    metricSet: row.metric_set,
    extracted: parseJsonField(row.extracted),
    validation: parseJsonField(row.validation),
    status: row.status,
    channel: row.channel,
    sourceRef: sourceRef ?? parseJsonField(row.extracted)?.sourceRef ?? null,
    createdAt: row.created_at ? new Date(row.created_at).getTime() : Date.now(),
    expiresAt: row.expires_at ? new Date(row.expires_at).getTime() : Date.now(),
    committedAt: row.committed_at ? new Date(row.committed_at).getTime() : null,
  };
}

export function createPageDataHealthObservationDraftStore({ resolveWorkspaceRoot, logger = console }) {
  if (typeof resolveWorkspaceRoot !== 'function') {
    throw new Error('createPageDataHealthObservationDraftStore requires resolveWorkspaceRoot');
  }

  async function getUserDataSpace(userId) {
    const workspaceRoot = await resolveWorkspaceRoot(userId);
    if (!workspaceRoot) return null;
    const service = createUserDataSpaceService({ workspaceRoot, userId: String(userId) });
    await ensureHealthPageDataForUser(service, userId);
    return service;
  }

  async function listPending(userId, { limit = 100 } = {}) {
    const service = await getUserDataSpace(userId);
    if (!service) return [];
    try {
      const result = await service.readDatasetRows(DATASET_NAME, {
        limit,
        orderBy: 'created_at',
        orderDir: 'desc',
      });
      const now = Date.now();
      return (result.rows ?? [])
        .map((row) => mapPgDraftRow(row, userId))
        .filter((row) => row.status === 'pending' && row.expiresAt > now);
    } catch (error) {
      if (error?.code === 'dataset_not_found') return [];
      throw error;
    }
  }

  return {
    backend: 'page_data',
    async findByKey(userId, draftKey) {
      const pending = await listPending(userId);
      return pending.find((row) => row.draftKey === draftKey) ?? null;
    },
    async findPendingBySourceRef(userId, sourceRef) {
      if (!sourceRef) return null;
      const pending = await listPending(userId);
      return pending.find((row) => row.sourceRef === sourceRef) ?? null;
    },
    async insert(userId, draft) {
      const service = await getUserDataSpace(userId);
      if (!service) {
        const error = Object.assign(new Error('用户健康草稿空间不可用'), { code: 'health_storage_unavailable' });
        throw error;
      }
      const extracted = { ...draft.extracted, sourceRef: draft.sourceRef ?? null };
      try {
        const { row } = await service.insertDatasetRow(DATASET_NAME, {
          draft_key: draft.draftKey,
          metric_set: draft.metricSet,
          extracted: JSON.stringify(extracted),
          validation: JSON.stringify(draft.validation ?? {}),
          status: 'pending',
          channel: draft.channel ?? 'h5',
          expires_at: new Date(draft.expiresAt ?? Date.now() + 86400000).toISOString(),
        });
        return mapPgDraftRow(row, userId, draft.sourceRef ?? null);
      } catch (error) {
        logger.warn?.('Page Data health draft insert failed:', error);
        throw error;
      }
    },
    async update(userId, draftKey, patch) {
      const service = await getUserDataSpace(userId);
      if (!service) return null;
      const existing = await this.findByKey(userId, draftKey);
      if (!existing?.id) return null;
      const payload = {};
      if (patch.extracted != null) payload.extracted = JSON.stringify(patch.extracted);
      if (patch.validation != null) payload.validation = JSON.stringify(patch.validation);
      if (patch.status != null) payload.status = patch.status;
      if (patch.committedAt != null) payload.committed_at = new Date(patch.committedAt).toISOString();
      const { row } = await service.updateDatasetRow(DATASET_NAME, existing.id, payload);
      return mapPgDraftRow(row, userId, existing.sourceRef);
    },
  };
}