add grid operations utility

- getCollectionKey: map grid type to party collection
- getGridMethodName: map operation + type to service method
- executeGridOperation: consolidate move/swap operations
- removeGridItem: generic grid item removal
- updateGridItem: generic grid item updates

src/lib/utils/gridOperations.ts

@@ -0,0 +1,207 @@
+/**
+ * Grid operation utilities
+ * Consolidates duplicated grid CRUD logic
+ */
+
+import type { Party } from '$lib/types/api/party'
+import type { GridService } from '$lib/services/grid.service'
+import type { PartyService } from '$lib/services/party.service'
+
+export type GridItemType = 'character' | 'weapon' | 'summon'
+export type GridCollection = 'characters' | 'weapons' | 'summons'
+
+/**
+ * Maps grid item type to collection key in Party object
+ *
+ * @param type - Grid item type (character, weapon, or summon)
+ * @returns Collection key name
+ *
+ * @example
+ * ```typescript
+ * const key = getCollectionKey('weapon') // Returns: 'weapons'
+ * const items = party[key] // Access party.weapons
+ * ```
+ */
+export function getCollectionKey(type: GridItemType): GridCollection {
+	const map: Record<GridItemType, GridCollection> = {
+		character: 'characters',
+		weapon: 'weapons',
+		summon: 'summons'
+	}
+	return map[type]
+}
+
+/**
+ * Maps operation and grid type to service method name
+ *
+ * @param operation - CRUD operation type
+ * @param type - Grid item type
+ * @returns Method name on GridService
+ *
+ * @example
+ * ```typescript
+ * const methodName = getGridMethodName('add', 'weapon') // Returns: 'addWeapon'
+ * const methodName = getGridMethodName('remove', 'character') // Returns: 'removeCharacter'
+ * ```
+ */
+export function getGridMethodName(
+	operation: 'add' | 'move' | 'remove' | 'update',
+	type: GridItemType
+): string {
+	const typeCapitalized = type.charAt(0).toUpperCase() + type.slice(1)
+	return `${operation}${typeCapitalized}`
+}
+
+/**
+ * Execute grid move/swap operation
+ * Consolidates handleSwap and handleMove logic
+ *
+ * @param operationType - Type of operation (move or swap)
+ * @param source - Source item information
+ * @param target - Target position information
+ * @param context - Party context (ID, shortcode, edit key)
+ * @param gridService - Grid service instance
+ * @param partyService - Party service instance
+ * @returns Updated party data
+ *
+ * @example
+ * ```typescript
+ * const updated = await executeGridOperation(
+ *   'swap',
+ *   { type: 'weapon', itemId: 'abc123', position: 0 },
+ *   { type: 'weapon', position: 1, itemId: 'def456' },
+ *   { partyId: party.id, shortcode: party.shortcode, editKey },
+ *   gridService,
+ *   partyService
+ * )
+ * ```
+ */
+export async function executeGridOperation(
+	operationType: 'move' | 'swap',
+	source: { type: GridItemType; itemId: string; position: number },
+	target: { type: GridItemType; position: number; itemId?: string },
+	context: { partyId: string; shortcode: string; editKey?: string },
+	gridService: GridService,
+	partyService: PartyService
+): Promise<Party> {
+	// Validation
+	if (operationType === 'swap' && !target.itemId) {
+		throw new Error('Swap operation requires target item')
+	}
+	if (operationType === 'move' && target.itemId) {
+		throw new Error('Move operation requires empty target')
+	}
+
+	// Call appropriate grid service method
+	const methodName = getGridMethodName('move', source.type)
+	const method = (gridService as any)[methodName]
+
+	if (!method) {
+		throw new Error(`Unknown grid method: ${methodName}`)
+	}
+
+	await method.call(
+		gridService,
+		context.partyId,
+		source.itemId,
+		target.position,
+		context.editKey,
+		{ shortcode: context.shortcode }
+	)
+
+	// Clear cache and refresh party
+	partyService.clearPartyCache(context.shortcode)
+	return await partyService.getByShortcode(context.shortcode)
+}
+
+/**
+ * Generic grid item remover
+ * Replaces three similar remove{Type} methods in clientGridService
+ *
+ * @param type - Grid item type to remove
+ * @param partyId - Party UUID
+ * @param gridItemId - Grid item UUID to remove
+ * @param party - Current party state
+ * @param shortcode - Party shortcode for cache clearing
+ * @param editKey - Optional edit key for authorization
+ * @param gridService - Grid service instance
+ * @returns Updated party with item removed
+ *
+ * @example
+ * ```typescript
+ * const updated = await removeGridItem(
+ *   'weapon',
+ *   party.id,
+ *   gridWeaponId,
+ *   party,
+ *   party.shortcode,
+ *   editKey,
+ *   gridService
+ * )
+ * ```
+ */
+export async function removeGridItem(
+	type: GridItemType,
+	partyId: string,
+	gridItemId: string,
+	party: Party,
+	shortcode: string,
+	editKey: string | undefined,
+	gridService: GridService
+): Promise<Party> {
+	// Call appropriate remove method
+	const methodName = getGridMethodName('remove', type)
+	const method = (gridService as any)[methodName]
+
+	await method.call(gridService, partyId, gridItemId, editKey, { shortcode })
+
+	// Update local state by removing item
+	const collection = getCollectionKey(type)
+	const updatedParty = { ...party }
+
+	if (updatedParty[collection]) {
+		updatedParty[collection] = updatedParty[collection].filter(
+			(item: any) => item.id !== gridItemId
+		)
+	}
+
+	return updatedParty
+}
+
+/**
+ * Generic grid item updater
+ * Replaces three similar update{Type} methods
+ *
+ * @param type - Grid item type to update
+ * @param partyId - Party UUID
+ * @param gridItemId - Grid item UUID to update
+ * @param updates - Object containing fields to update
+ * @param editKey - Optional edit key for authorization
+ * @param gridService - Grid service instance
+ * @returns Updated grid item data
+ *
+ * @example
+ * ```typescript
+ * const updated = await updateGridItem(
+ *   'weapon',
+ *   party.id,
+ *   gridWeaponId,
+ *   { ax1: 10, ax2: 5 },
+ *   editKey,
+ *   gridService
+ * )
+ * ```
+ */
+export async function updateGridItem(
+	type: GridItemType,
+	partyId: string,
+	gridItemId: string,
+	updates: any,
+	editKey: string | undefined,
+	gridService: GridService
+): Promise<any> {
+	const methodName = getGridMethodName('update', type)
+	const method = (gridService as any)[methodName]
+
+	return await method.call(gridService, partyId, gridItemId, updates, editKey)
+}