import { loadAirportsGeoJson } from '@/lib/airports';
import { haversineKm } from '@/lib/geo';
import { getGameDb } from '@/lib/db/client';
import * as schema from '@/lib/db/schema';
import { catalogEntries, FUEL_PRICE_PER_L, PLANE_TYPES, SELL_FRACTION, type CatalogEntry } from './catalog';
import { fuelAtWeighted, progressAt, positionAt } from '@/lib/sim/movement';

// Read-only game-state snapshot for client polling (GET /api/state).

export interface PlaneState {
  id: string;
  model: string;
  status: 'available' | 'flying';
  fuel: number;
  maxFuel: number;
  locationIcao: string;
  locationName: string;
  // Current flight destination (v0.12.0) — set by fly, null when grounded. The
  // origin of the current leg is always locationIcao while flying.
  destIcao: string | null;
  destName: string | null;
  // Sim-clock departure time of the current flight (v0.8.0) — null when grounded,
  // set by fly while flying so clients can compute progress/ETA from the clock.
  departureSimTime: number | null;
  lat: number;
  lon: number;
  // Upcoming legs NOT yet started (v0.25.0, ISS-043) — ordered ICAOs; the active
  // leg is destIcao. The engine auto-chains queue[0] on landing when fuel covers it.
  queue: string[];
}

// Parse the planes.queue JSON column into an ICAO list (v0.25.0). Guards against
// null/empty/malformed values so a corrupt cell can never break a snapshot or tick.
export function parseIcaoQueue(raw: string | null): string[] {
  if (!raw) return [];
  try {
    const v: unknown = JSON.parse(raw);
    return Array.isArray(v) ? v.filter((x): x is string => typeof x === 'string') : [];
  } catch {
    return [];
  }
}

export interface PackageState {
  id: string;
  originIcao: string;
  originName: string;
  destIcao: string;
  destName: string;
  reward: number;
  cargoType: string;
  cargoCount: number;
  deadlineSimTime: number;
  status: 'open' | 'loaded' | 'delivered' | 'expired' | 'abandoned';
  planeId: string | null;
  createdSimTime: number;
}

export interface StateSnapshot {
  account: { cash: number; reputation: number };
  simState: { clockMs: number; timeScale: number; paused: boolean };
  planes: PlaneState[];
  packages: PackageState[];
  // Market reference data (v0.10.0) — static per build, sent with every snapshot so
  // the client can compute buy/sell/refuel previews without a separate endpoint.
  catalog: CatalogEntry[];
  fuelPricePerL: number;
  sellFraction: number;
}

export async function getStateSnapshot(): Promise<StateSnapshot> {
  const { db } = await getGameDb();
  // NOTE: use plain select(), not the relational db.query.* API — in drizzle-orm
  // 0.45.x the sql-js driver drops the result mapper for relational queries and
  // returns raw rows keyed by SQL column names (snake_case, no type decoding).
  const [accountRows, simRows, planeRows, packageRows] = await Promise.all([
    db.select().from(schema.account),
    db.select().from(schema.simState),
    db.select().from(schema.planes),
    db.select().from(schema.packages),
  ]);
  const accountRow = accountRows[0];
  const simRow = simRows[0];
  if (!accountRow || !simRow) throw new Error('game state missing account/sim_state row');

  const fc = await loadAirportsGeoJson();
  const nameByIcao = new Map(fc.features.map((f) => [f.properties.icao, f.properties.name]));
  const nameOf = (icao: string) => nameByIcao.get(icao) ?? icao;
  const coordsByIcao = new Map(fc.features.map((f) => [f.properties.icao, f.properties]));

  // Analytic movement (v0.7.0): a flying plane's stored lat/lon/fuel are its
  // departure values — live position and fuel are pure functions of the clock.
  const livePlane = (p: schema.PlaneRow) => {
    if (p.status !== 'flying' || p.departureSimTime == null || !p.destIcao) return null;
    const type = PLANE_TYPES[p.model];
    const from = coordsByIcao.get(p.locationIcao);
    const to = coordsByIcao.get(p.destIcao);
    if (!type || !from || !to) return null;
    const distanceKm = haversineKm(from.lat, from.lon, to.lat, to.lon);
    const progress = progressAt(p.departureSimTime, distanceKm, type.speedKmh, simRow.clockMs);
    const pos = positionAt(from.lat, from.lon, to.lat, to.lon, progress);
    return { ...pos, fuel: fuelAtWeighted(p.fuel, type.burnPerKm, type.emptyWeightKg, type.maxFuel, distanceKm, progress) };
  };

  return {
    account: { cash: accountRow.cash, reputation: accountRow.reputation },
    simState: { clockMs: simRow.clockMs, timeScale: simRow.timeScale, paused: simRow.paused },
    catalog: catalogEntries(),
    fuelPricePerL: FUEL_PRICE_PER_L,
    sellFraction: SELL_FRACTION,
    planes: planeRows.map((p) => {
      const live = livePlane(p);
      return {
        id: p.id,
        model: p.model,
        status: p.status,
        fuel: live?.fuel ?? p.fuel,
        maxFuel: p.maxFuel,
        locationIcao: p.locationIcao,
        locationName: nameOf(p.locationIcao),
        destIcao: p.destIcao,
        destName: p.destIcao ? nameOf(p.destIcao) : null,
        departureSimTime: p.departureSimTime,
        lat: live?.lat ?? p.lat,
        lon: live?.lon ?? p.lon,
        queue: parseIcaoQueue(p.queue),
      };
    }),
    packages: packageRows.map((p) => ({
      id: p.id,
      originIcao: p.originIcao,
      originName: nameOf(p.originIcao),
      destIcao: p.destIcao,
      destName: nameOf(p.destIcao),
      reward: p.reward,
      cargoType: p.cargoType,
      cargoCount: p.cargoCount,
      deadlineSimTime: p.deadlineSimTime,
      status: p.status,
      planeId: p.planeId,
      createdSimTime: p.createdSimTime,
    })),
  };
}