import type {
  CatalogPartType,
  HiveCatalog,
  HiveFacts,
  HiveLevelFact,
  HivePart,
  HiveState,
  HiveSystemDto,
} from "./types";

const UNBUILT_FRAME_TYPES = new Set(["NONE", "FOUNDATION", "DIVIDER"]);

/** Catalog of a system as the API returns it (all part types, also inactive). */
export function catalogFromSystem(system: HiveSystemDto): HiveCatalog {
  const rows: CatalogPartType[] = system.partTypes.map((row) => ({
    id: row.id,
    kind: row.kind,
    name: row.name,
    lengthMm: row.lengthMm,
    widthMm: row.widthMm,
    heightMm: row.heightMm,
    frameSlots: row.frameSlots,
    stateSchema: row.stateSchema,
    active: row.active,
  }));
  return { systemId: system.id, partTypes: new Map(rows.map((row) => [row.id, row])) };
}

function allParts(state: HiveState): HivePart[] {
  return state.stack.flatMap((part) => [part, ...(part.inserts ?? [])]);
}

function levelsOf(part: HivePart, catalog: HiveCatalog): HiveLevelFact[] {
  const type = catalog.partTypes.get(part.partTypeId);
  if (!type) return [];
  return type.stateSchema.flatMap((field) => {
    if (field.kind !== "level") return [];
    const raw = part.state[field.key];
    return [
      {
        partId: part.id,
        key: field.key,
        label: field.label,
        unit: field.unit,
        value: typeof raw === "number" ? raw : 0,
        max: field.max,
        ...(field.feedType ? { feedType: field.feedType } : {}),
      },
    ];
  });
}

/** Pure derivation of display facts (spec 5.3), same as the backend. */
export function deriveHiveFacts(state: HiveState, catalog: HiveCatalog): HiveFacts {
  const parts = allParts(state);
  const kindOf = (part: HivePart) => catalog.partTypes.get(part.partTypeId)?.kind;
  const frames = state.stack
    .filter((part) => kindOf(part) === "BOX")
    .flatMap((part) => part.frames ?? []);
  const evaporators = parts.filter((part) => kindOf(part) === "EVAPORATOR");
  const acid = evaporators.reduce((sum, part) => {
    const value = part.state.acidMl;
    return sum + (typeof value === "number" ? value : 0);
  }, 0);
  return {
    boxCount: state.stack.filter((part) => kindOf(part) === "BOX").length,
    broodFrames: frames.filter((f) => f.type === "BROOD").length,
    honeyFrames: frames.filter((f) => f.type === "HONEY").length,
    builtFrames: frames.filter((f) => !UNBUILT_FRAME_TYPES.has(f.type)).length,
    levels: parts.flatMap((part) => levelsOf(part, catalog)),
    hasFloorInsert: parts.some((part) => kindOf(part) === "FLOOR_INSERT"),
    evaporatorAcidMl: evaporators.length > 0 ? acid : null,
  };
}