import {
  type CommonReservedFields,
  type NoReservedFields,
  defaultGqlPermission,
  defaultPermission,
} from "@tailor-platform/erp-kit/core";
import { db, type TailorAnyDBField, type TailorAnyDBType } from "@tailor-platform/sdk";

// Entitlement basis (ADR-005): STATUTORY law-based annual leave, COMPENSATORY compensatory leave, MANUAL discretionary
const GRANT_TYPES = ["STATUTORY", "COMPENSATORY", "MANUAL"] as const;

// Provenance: HIRE front-load, ANNIVERSARY batch, MANUAL administrator action
const GRANT_SOURCES = ["HIRE", "ANNIVERSARY", "MANUAL"] as const;

const builtins = (params: { workerType?: TailorAnyDBType }) => {
  // Cross-module FK: relation only when the foreign type is injected; plain uuid at codegen
  const workerId = db
    .uuid()
    .description(
      "Foreign key to the workforce Worker who owns this grant (entitlement follows the person; ADR-016)",
    );
  return {
    workerId: params.workerType
      ? workerId.relation({
          type: "n-1",
          toward: { type: params.workerType, as: "worker" },
          backward: "leaveGrants",
        })
      : workerId,
    // By-key reference to LeaveType; no FK relation
    leaveTypeKey: db
      .string()
      .description("Key of the LeaveType this grant contributes to (by-key reference, no FK)"),
    grantType: db
      .enum(GRANT_TYPES)
      .description(
        "Entitlement basis: STATUTORY (law-based annual leave), COMPENSATORY (compensatory leave), or MANUAL (discretionary)",
      ),
    grantSource: db
      .enum(GRANT_SOURCES)
      .description(
        "Provenance: HIRE front-load, ANNIVERSARY batch, or MANUAL administrator action",
      ),
    grantedDays: db
      .decimal()
      .description(
        "Originally granted day amount (positive decimal; half-day 0.5 increments valid)",
      ),
    remainingDays: db
      .decimal()
      .description("Still-available day amount; between 0 and grantedDays inclusive"),
    grantedDate: db.date().description("Date this grant becomes valid"),
    expirationDate: db.date().description("Date this grant lapses; strictly after grantedDate"),
    expiredAt: db
      .datetime({ optional: true })
      .description(
        "Timestamp the nightly expiration sweep forfeited the unused remainder; unset while unexpired",
      ),
  };
};

type ReservedFields = keyof ReturnType<typeof builtins> | CommonReservedFields;

export interface CreateLeaveGrantTypeParams<F extends Record<string, TailorAnyDBField>> {
  fields?: NoReservedFields<F, ReservedFields>;
  workerType?: TailorAnyDBType;
}

export function createLeaveGrantType<const F extends Record<string, TailorAnyDBField>>(
  params: CreateLeaveGrantTypeParams<F>,
) {
  return db
    .table("LeaveGrant", {
      ...builtins(params),
      ...((params.fields ?? {}) as F),
      ...db.fields.timestamps(),
    })
    .permission(defaultPermission)
    .gqlPermission(defaultGqlPermission);
}

// Codegen instance with no cross-module types; real FK injected via module.ts
export const leaveGrant = createLeaveGrantType({});