import type { CreateFlowState } from "../../app/(app)/create/types";
import type { FinalReviewChipEditPatch } from "../../app/(app)/create/components/FinalReviewChipEditModal";
import { CUSTOM_RULE_FACET_BY_GROUP } from "./customRuleFacets";

/**
 * `groupKey` cases mirror {@link CUSTOM_RULE_FACETS} / `TemplateFacetGroupKey`
 * (Linear CR-92 — keep exhaustiveness when adding a facet row).
 *
 * Translate a {@link FinalReviewChipEditPatch} into the `Partial<CreateFlowState>`
 * patch that {@link CreateFlowState}'s update merger should write back. Each
 * group key targets its own `*DetailsById` (or `coreValueDetailsByChipId`)
 * record; the patch always merges the new value onto the existing record so
 * other chips' overrides are preserved.
 *
 * Exported as a pure function so it's unit-testable without React.
 */
export function applyFinalReviewChipEditPatch(
  state: CreateFlowState,
  patch: FinalReviewChipEditPatch,
): Partial<CreateFlowState> {
  const facet = CUSTOM_RULE_FACET_BY_GROUP.get(patch.groupKey);
  if (!facet) {
    throw new Error(
      `applyFinalReviewChipEditPatch: unknown facet group ${patch.groupKey}`,
    );
  }
  const stateKey = facet.detailOverridesStateKey;
  const current = state[stateKey];
  const record =
    current && typeof current === "object"
      ? (current as Record<string, unknown>)
      : {};
  return {
    [stateKey]: {
      ...record,
      [patch.overrideKey]: patch.value,
    },
  };
}