import { AuthorityNotice, ComplianceSettings } from '../../generated/prisma';
import { DbClient } from '../prisma/db-client';
import {
  buildHerdSnapshot,
  herdDeviation,
  HerdDeviation,
  HerdSnapshot,
  loadHerdApiaryRows,
} from './herd-snapshot';

export const COMPLIANCE_SETTINGS_ID = 'singleton';

export interface HerdStatus {
  settings: ComplianceSettings;
  baseline: AuthorityNotice | null;
  current: HerdSnapshot;
  /** null without a baseline: there is nothing to deviate from. */
  deviation: HerdDeviation | null;
}

/** The settings row, created with its defaults when it does not exist yet. */
export async function complianceSettingsIn(
  db: DbClient,
): Promise<ComplianceSettings> {
  const existing = await db.complianceSettings.findUnique({
    where: { id: COMPLIANCE_SETTINGS_ID },
  });
  if (existing) {
    return existing;
  }
  return db.complianceSettings.upsert({
    where: { id: COMPLIANCE_SETTINGS_ID },
    update: {},
    create: { id: COMPLIANCE_SETTINGS_ID },
  });
}

/**
 * The baseline is the newest SENT registration or herd change (by sentOn);
 * TSK reports go to another recipient and do not count.
 */
export function findBaselineIn(db: DbClient): Promise<AuthorityNotice | null> {
  return db.authorityNotice.findFirst({
    where: { status: 'SENT', kind: { in: ['REGISTRATION', 'HERD_CHANGE'] } },
    orderBy: [{ sentOn: 'desc' }, { createdAt: 'desc' }, { id: 'desc' }],
  });
}

export async function herdStatusIn(
  db: DbClient,
  now: Date,
): Promise<HerdStatus> {
  const settings = await complianceSettingsIn(db);
  const baseline = await findBaselineIn(db);
  const current = buildHerdSnapshot(await loadHerdApiaryRows(db), now);
  return {
    settings,
    baseline,
    current,
    deviation: baseline
      ? herdDeviation(
          {
            snapshot: baseline.snapshot as unknown as HerdSnapshot,
            totalColonies: baseline.totalColonies,
          },
          current,
          settings,
        )
      : null,
  };
}