import type { Organization } from "fhir/r4";

/**
 * How a practice handles laboratory work, and whether it has imaging on site. The server writes this
 * URL, so the literal must match it. An absent field means "not asked", which is not "no".
 * `laboratory` means the practice performs tests itself; collecting specimens is a separate answer.
 */

export const DIAGNOSTICS_SETTINGS_EXTENSION_URL =
  "https://akashichealthrecords.com/fhir/extensions/diagnostics-settings";

export const DIAGNOSTICS_FIELDS = [
  "ordersExternal",
  "collectsSpecimens",
  "laboratory",
  "acceptsOwnOrders",
  "acceptsOutsideOrders",
  "imaging",
] as const;

export type DiagnosticsField = (typeof DIAGNOSTICS_FIELDS)[number];

export type DiagnosticsDeclaration = Partial<Record<DiagnosticsField, boolean>>;

export const readDiagnosticsDeclaration = (
  organization?: Organization | null,
): DiagnosticsDeclaration => {
  const found = (organization?.extension ?? [])
    .find((e) => e.url === DIAGNOSTICS_SETTINGS_EXTENSION_URL);
  if (!found) return {};

  const declaration: DiagnosticsDeclaration = {};
  for (const field of DIAGNOSTICS_FIELDS) {
    const value = (found.extension ?? []).find((e) => e.url === field)?.valueBoolean;
    if (value !== undefined) declaration[field] = value;
  }
  return declaration;
};

/** The declaration as the Organization extension the server writes, for the copy held in context. */
export const diagnosticsExtension = (declaration: DiagnosticsDeclaration) => ({
  url: DIAGNOSTICS_SETTINGS_EXTENSION_URL,
  extension: DIAGNOSTICS_FIELDS
    .filter((field) => declaration[field] !== undefined)
    .map((field) => ({ url: field, valueBoolean: declaration[field] })),
});

/** Whether the practice has answered at all, which is a different question from what it answered. */
export const hasDeclaredDiagnostics = (declaration: DiagnosticsDeclaration): boolean =>
  DIAGNOSTICS_FIELDS.some((field) => declaration[field] !== undefined);

/**
 * Whether the Lab and imaging setup door is offered. The declaration is answered on that page, so a
 * practice that has not answered is still offered it; one that answered no to all of it is not.
 */
export const offersDiagnosticsSetup = (declaration: DiagnosticsDeclaration): boolean =>
  !hasDeclaredDiagnostics(declaration) || DIAGNOSTICS_FIELDS.some((field) => declaration[field] === true);

/** What the catalogue may offer to add. Neither declared means nothing to add, not everything. */
export const declaredKinds = (
  declaration: DiagnosticsDeclaration,
): ("laboratory" | "imaging")[] => [
  ...(declaration.laboratory === true ? (["laboratory"] as const) : []),
  ...(declaration.imaging === true ? (["imaging"] as const) : []),
];