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

const builtins = {
  // Polymorphic target (who the rule applies to): a workforce entity referenced by id. targetType
  // is a discriminator; targetId is the referenced id for every type (Worker / Position /
  // JobProfile / EmploymentType catalog / WorkRegime catalog). No single fixed foreign type exists
  // across the union, so this is a discriminator + plain uuid rather than a `.relation()`.
  targetType: db
    .enum(["WORKER", "POSITION", "JOB_PROFILE", "EMPLOYMENT_TYPE", "WORK_REGIME"] as const)
    .description(
      "Whether the target is a Worker, Position, JobProfile, EmploymentType, or WorkRegime",
    ),
  targetId: db
    .uuid()
    .description(
      "Id of the target this rule applies to (cross-module): a Worker, Position, JobProfile, EmploymentType, or WorkRegime, per targetType",
    ),
  // Grant (what's permitted): currently a WorkRule referenced by id. Modeled as a plain field
  // rather than a `.relation()` to match the polymorphic-target shape above. The TIME_ENTRY_CODE
  // grant kind (and its companion timeEntryCodeKey) was dropped in issue #39 — nothing evaluated
  // it; the assignment path (assignWorkRule) only ever consults WORK_RULE grants. `grantType` is
  // kept as an enum and `workRuleId` stays optional to preserve the polymorphic-grant seam for a
  // future generalization (e.g. granting compliance/leave rules); command-layer validation
  // enforces that a WORK_RULE grant resolves a WorkRule. WorkRuleAssignment integration is #41.
  grantType: db
    .enum(["WORK_RULE"] as const)
    .description("What kind of grant this is; currently always WORK_RULE"),
  workRuleId: db
    .uuid({ optional: true })
    .description("Id of the WorkRule granted to the target; set when grantType is WORK_RULE"),
  // Effective-dating per ADR-013
  effectiveStart: db.date().description("Date this eligibility generation becomes effective"),
  effectiveEnd: db
    .date({ optional: true })
    .description(
      "Date this eligibility generation stops being effective; null means current generation",
    ),
  versionOf: db
    .uuid()
    .description(
      "Stable key grouping all generations of the same logical eligibility rule across time",
    ),
};

type ReservedFields = keyof typeof builtins | CommonReservedFields;

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

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

export const eligibilityRule = createEligibilityRuleType({});