add grid state updater utility

consolidates uncap update logic for characters, weapons, and summons into a single generic function with type-based dispatch

src/lib/utils/gridStateUpdater.ts

@@ -0,0 +1,137 @@
+/**
+ * Grid state update utilities
+ * Handles optimistic updates for uncap levels and other grid item properties
+ */
+
+import type { Party } from '$lib/types/api/party'
+import type { GridService } from '$lib/services/grid.service'
+import type { GridItemType, GridCollection } from './gridOperations'
+import { getCollectionKey } from './gridOperations'
+
+export interface UncapUpdateParams {
+	gridItemId: string
+	uncapLevel?: number
+	transcendenceStep?: number
+}
+
+/**
+ * Generic function to update uncap levels for any grid item type
+ * Replaces updateCharacterUncap, updateWeaponUncap, updateSummonUncap
+ *
+ * @param itemType - Type of grid item (character, weapon, or summon)
+ * @param params - Uncap update parameters
+ * @param partyId - Party UUID
+ * @param currentParty - Current party state
+ * @param editKey - Optional edit key for authorization
+ * @param gridService - Grid service instance
+ * @returns Updated party with modified uncap levels
+ *
+ * @example
+ * ```typescript
+ * const updated = await updateGridItemUncap(
+ *   'weapon',
+ *   { gridItemId: 'abc123', uncapLevel: 4, transcendenceStep: 1 },
+ *   party.id,
+ *   party,
+ *   editKey,
+ *   gridService
+ * )
+ * ```
+ */
+export async function updateGridItemUncap(
+	itemType: GridItemType,
+	params: UncapUpdateParams,
+	partyId: string,
+	currentParty: Party,
+	editKey: string | undefined,
+	gridService: GridService
+): Promise<Party> {
+	// Get configuration for this item type
+	const config = getGridItemConfig(itemType)
+
+	// Call appropriate service method
+	const response = await config.updateMethod(
+		gridService,
+		partyId,
+		params.gridItemId,
+		params.uncapLevel,
+		params.transcendenceStep,
+		editKey
+	)
+
+	// Extract updated item from response (handle both camelCase and snake_case)
+	const updatedItem = response[config.responseKey] || response[config.snakeCaseKey]
+	if (!updatedItem) return currentParty
+
+	// Update party state optimistically
+	return mergeUpdatedGridItem(currentParty, config.collectionKey, params.gridItemId, {
+		uncapLevel: updatedItem.uncapLevel ?? updatedItem.uncap_level,
+		transcendenceStep: updatedItem.transcendenceStep ?? updatedItem.transcendence_step
+	})
+}
+
+/**
+ * Configuration map for grid item types
+ */
+function getGridItemConfig(itemType: GridItemType) {
+	const configs = {
+		character: {
+			updateMethod: (gs: GridService, ...args: any[]) => gs.updateCharacterUncap(...args),
+			responseKey: 'gridCharacter',
+			snakeCaseKey: 'grid_character',
+			collectionKey: 'characters' as GridCollection
+		},
+		weapon: {
+			updateMethod: (gs: GridService, ...args: any[]) => gs.updateWeaponUncap(...args),
+			responseKey: 'gridWeapon',
+			snakeCaseKey: 'grid_weapon',
+			collectionKey: 'weapons' as GridCollection
+		},
+		summon: {
+			updateMethod: (gs: GridService, ...args: any[]) => gs.updateSummonUncap(...args),
+			responseKey: 'gridSummon',
+			snakeCaseKey: 'grid_summon',
+			collectionKey: 'summons' as GridCollection
+		}
+	}
+
+	return configs[itemType]
+}
+
+/**
+ * Merges updates into a grid item within party state
+ * Preserves immutability by creating new objects
+ *
+ * @param party - Current party state
+ * @param collection - Collection key (characters, weapons, or summons)
+ * @param itemId - Grid item ID to update
+ * @param updates - Fields to update
+ * @returns New party object with updates applied
+ */
+function mergeUpdatedGridItem(
+	party: Party,
+	collection: GridCollection,
+	itemId: string,
+	updates: any
+): Party {
+	const updatedParty = { ...party }
+	const items = updatedParty[collection]
+
+	if (!items) return party
+
+	const itemIndex = items.findIndex((item: any) => item.id === itemId)
+	if (itemIndex === -1) return party
+
+	const existingItem = items[itemIndex]
+	if (!existingItem) return party
+
+	// Merge updates while preserving essential properties
+	items[itemIndex] = {
+		...existingItem,
+		...updates,
+		id: existingItem.id,
+		position: existingItem.position
+	}
+
+	return updatedParty
+}