import type { Prisma } from '../../generated/prisma';
import { addDays, berlinDayOf, dayToDate } from '../common/dates';
import type { SeasonState } from '../season/season-types';
import type { AutopilotInput } from './autopilot.types';

const LATEST_FIRST = [{ date: 'desc' }, { createdAt: 'desc' }] as const;

/** Without an inspection a feeding counts for A6 if it is at most this old. */
const FEEDING_LOOKBACK_DAYS = 60;

/**
 * The day SPAETSOMMER began, for the feedings and treatments of A4/A5. In
 * SPAETSOMMER that is the real start of the segment. The stored state keeps
 * only the start of the current segment, so in HERBST it is the calendar day
 * of TRACHTENDE (`calendarTrachtende`, MM-DD), at the latest the start of
 * HERBST.
 *
 * TODO: store the real start as `lateSummerSince` on ApiaryPhenology (needs
 * a migration) so HERBST no longer depends on the calendar day.
 */
export function lateSummerStart(
  season: SeasonState,
  calendarTrachtende: string,
): string | null {
  if (season.segment === 'SPAETSOMMER') {
    return season.segmentSince;
  }
  if (season.segment !== 'HERBST') {
    return null;
  }
  const calendarDay = `${season.year}-${calendarTrachtende}`;
  return calendarDay < season.segmentSince ? calendarDay : season.segmentSince;
}

/**
 * What the autopilot rules need of one colony, in a fixed sequence of
 * queries (no query per rule, none per record). Resolves to null for a
 * colony that does not exist. The caller holds the colony row lock, so the
 * picture stays consistent while the rules run.
 */
export async function loadAutopilotInputIn(
  tx: Prisma.TransactionClient,
  colonyId: string,
  season: SeasonState,
  calendarTrachtende: string,
  today: string,
): Promise<AutopilotInput | null> {
  const colony = await tx.colony.findUnique({
    where: { id: colonyId },
    select: {
      id: true,
      code: true,
      status: true,
      colonyType: true,
      apiaryId: true,
      createdAt: true,
      feedStatus: true,
      currentQueen: { select: { id: true, hatchYear: true } },
    },
  });
  if (colony === null) {
    return null;
  }
  const inspection = await tx.inspection.findFirst({
    where: { colonyId },
    orderBy: [...LATEST_FIRST],
    select: {
      id: true,
      date: true,
      colonyStrength: true,
      feedStatus: true,
      queenCellsPresent: true,
    },
  });
  const varroa = await tx.varroaMeasurement.findFirst({
    where: { colonyId },
    orderBy: [...LATEST_FIRST],
    select: { id: true, date: true },
  });
  // The latest END day wins, not the latest entry: a backdated or
  // overlapping treatment must not hide one that ends later.
  const treatments = await tx.treatment.findMany({
    where: { colonyId },
    orderBy: [{ date: 'desc' }, { id: 'asc' }],
    select: { id: true, date: true, startDate: true, endDate: true },
  });
  const lastTreatment = treatments
    .map((treatment) => ({
      id: treatment.id,
      startDay: berlinDayOf(treatment.startDate ?? treatment.date),
      endDay: berlinDayOf(treatment.endDate ?? treatment.date),
    }))
    .reduce<{ id: string; startDay: string; endDay: string } | null>(
      (latest, candidate) =>
        latest === null || candidate.endDay > latest.endDay
          ? candidate
          : latest,
      null,
    );
  const varroaSinceLastTreatmentEnd =
    lastTreatment !== null &&
    (await tx.varroaMeasurement.count({
      where: { colonyId, date: { gt: dayToDate(lastTreatment.endDay) } },
    })) > 0;
  // Feedings that answer a low feed status: since the inspection; without
  // one only recent ones, from the colony's creation at the earliest.
  const createdOn = berlinDayOf(colony.createdAt);
  const lookbackFrom = addDays(today, -FEEDING_LOOKBACK_DAYS);
  const feedingsSince =
    inspection === null
      ? dayToDate(createdOn > lookbackFrom ? createdOn : lookbackFrom)
      : inspection.date;
  const feedingsSinceInspection = await tx.feeding.count({
    where: { colonyId, date: { gte: feedingsSince } },
  });
  const lateSummer = lateSummerStart(season, calendarTrachtende);
  const sinceLateSummer =
    lateSummer === null ? null : { gte: dayToDate(lateSummer) };
  const feedingsSinceLateSummer =
    sinceLateSummer === null
      ? 0
      : await tx.feeding.count({ where: { colonyId, date: sinceLateSummer } });
  const treatmentsSinceLateSummer =
    sinceLateSummer === null
      ? 0
      : await tx.treatment.count({
          where: { colonyId, date: sinceLateSummer },
        });
  const winterChecks = await tx.winterCheck.findMany({
    where: { colonyId, winterYear: { gte: season.year - 1 } },
    select: { winterYear: true, season: true },
    orderBy: [{ winterYear: 'asc' }, { season: 'asc' }],
  });
  return {
    colony: {
      id: colony.id,
      code: colony.code,
      status: colony.status,
      colonyType: colony.colonyType,
      apiaryId: colony.apiaryId,
      createdOn: berlinDayOf(colony.createdAt),
      feedStatus: colony.feedStatus,
    },
    lastInspection:
      inspection === null
        ? null
        : { ...inspection, date: berlinDayOf(inspection.date) },
    lastVarroa:
      varroa === null
        ? null
        : { id: varroa.id, date: berlinDayOf(varroa.date) },
    lastTreatment,
    varroaSinceLastTreatmentEnd,
    feedingsSinceInspection,
    feedingsSinceLateSummer,
    treatmentsSinceLateSummer,
    queen: colony.currentQueen,
    winterChecks,
    season,
  };
}