import type { MethodDefinition } from "./types";
import { MODAL_METHOD } from "./modal";
import { FD_METHOD } from "./fd";
import { IMPLICIT_METHOD } from "./implicit";
import type { ProblemSpec } from "../spec/types";

export const METHODS: MethodDefinition[] = [MODAL_METHOD, FD_METHOD, IMPLICIT_METHOD];

export function getMethod(id: string): MethodDefinition {
  const m = METHODS.find((x) => x.id === id);
  if (!m) throw new Error(`unknown method ${id}`);
  return m;
}

/** Reasons a method cannot run on a spec (empty when it can). */
export function methodBlockers(method: MethodDefinition, spec: ProblemSpec): string[] {
  const out: string[] = [];
  if (!method.supports.shape.includes(spec.plate.shape))
    out.push(
      `${method.name} has no solution for the ${spec.plate.shape}; the finite-difference methods embed it in their grid.`,
    );
  if (!method.supports.bc.includes(spec.bc))
    out.push(
      `${method.name} does not support the edge condition "${spec.bc}" (supports: ${method.supports.bc.join(", ")}).`,
    );
  if (!method.supports.excitation.includes(spec.excitation.type))
    out.push(`${method.name} does not support the ${spec.excitation.type} excitation.`);
  return out;
}