import type {
  CircuitSectionRenumberAssignment,
} from "../../domain/models/circuit-section-renumber-project-command.model.js";
import type { CircuitTreeSectionDto } from "../types.js";

export function buildCircuitSectionRenumberAssignments(
  sections: CircuitTreeSectionDto[],
  sectionId: string
): CircuitSectionRenumberAssignment[] {
  const targetSection = sections.find(
    (section) => section.id === sectionId
  );
  if (!targetSection) {
    throw new Error("Der Bereich wurde nicht gefunden.");
  }

  const identifiersOutsideSection = new Set(
    sections
      .filter((section) => section.id !== sectionId)
      .flatMap((section) =>
        section.circuits.map(
          (circuit) => circuit.equipmentIdentifier
        )
      )
  );
  const orderedCircuits = [...targetSection.circuits].sort(
    (left, right) =>
      left.sortOrder - right.sortOrder || left.id.localeCompare(right.id)
  );
  const assignments: CircuitSectionRenumberAssignment[] = [];
  let suffix = 1;
  for (const circuit of orderedCircuits) {
    let targetEquipmentIdentifier = `${targetSection.prefix}${suffix}`;
    while (
      identifiersOutsideSection.has(targetEquipmentIdentifier)
    ) {
      suffix += 1;
      targetEquipmentIdentifier = `${targetSection.prefix}${suffix}`;
    }
    assignments.push({
      circuitId: circuit.id,
      expectedEquipmentIdentifier: circuit.equipmentIdentifier,
      targetEquipmentIdentifier,
    });
    suffix += 1;
  }

  if (
    assignments.every(
      (assignment) =>
        assignment.expectedEquipmentIdentifier ===
        assignment.targetEquipmentIdentifier
    )
  ) {
    return [];
  }
  return assignments;
}