import {
  DEFAULT_PAGE_SIZE,
  buildPaginatedResult,
  ok,
  type PaginationInput,
  type ReadonlyDB,
} from "@tailor-platform/erp-kit/core";
import type { DB } from "../generated/kysely-tailordb";

type WorkRuleAssignmentOrderByField = "effectiveStart" | "targetType";

export interface ListWorkRuleAssignmentsInput extends PaginationInput<WorkRuleAssignmentOrderByField> {
  workRuleId?: string;
}

/**
 * Function: listWorkRuleAssignments
 * Description: Returns a paginated list of WorkRuleAssignment generations, history included
 * (closed generations alongside current ones), so the full assignment timeline of a target
 * is reconstructable. May be narrowed to the assignments referencing one WorkRule.
 */
export async function run(db: ReadonlyDB<DB>, input: ListWorkRuleAssignmentsInput) {
  const limit = input.limit ?? DEFAULT_PAGE_SIZE;
  const offset = input.offset ?? 0;
  const orderBy = input.orderBy ?? "id";
  const orderDirection = input.orderDirection ?? "asc";

  let query = db.selectFrom("WorkRuleAssignment").selectAll();

  if (input.workRuleId !== undefined) {
    query = query.where("workRuleId", "=", input.workRuleId);
  }

  const workRuleAssignments = await query
    .orderBy(orderBy, orderDirection)
    .limit(limit + 1)
    .offset(offset)
    .execute();

  return ok(buildPaginatedResult(workRuleAssignments, limit));
}