feat(inventory): add inventory interaction handler utilities

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bot/modules/inventory/inventory.interaction.ts

@@ -0,0 +1,71 @@
+import type { StringSelectMenuInteraction, ButtonInteraction, MessageFlags } from "discord.js";
+import { inventoryService } from "@shared/modules/inventory/inventory.service";
+import { getLootboxResultMessage } from "./inventory.view";
+import type { ItemUsageData } from "@shared/lib/types";
+import { getGuildConfig } from "@shared/lib/config";
+
+export interface InventoryState {
+    ownerId: string;
+    viewerId: string;
+    page: number;
+    selectedItemId: number | null;
+}
+
+/**
+ * Extracts the viewer user ID from an inventory custom ID.
+ * Custom IDs follow the format: inv_{action}_{viewerId}
+ */
+export function parseInventoryCustomId(customId: string): { action: string; viewerId: string } | null {
+    const match = customId.match(/^inv_(\w+?)_(\d+)$/);
+    if (!match) return null;
+    return { action: match[1]!, viewerId: match[2]! };
+}
+
+/**
+ * Checks if a custom ID belongs to the inventory system.
+ */
+export function isInventoryInteraction(customId: string): boolean {
+    return customId.startsWith("inv_");
+}
+
+/**
+ * Handles the "Use" button — executes item effects.
+ * Returns the result messages array from inventoryService.useItem,
+ * plus handles role-based effects that require the guild member.
+ */
+export async function executeItemUse(
+    interaction: ButtonInteraction,
+    userId: string,
+    itemId: number,
+): Promise<{ results: any[]; usageData: ItemUsageData | null; item: any }> {
+    const result = await inventoryService.useItem(userId, itemId);
+
+    // Handle role effects (same logic as /use command)
+    const usageData = result.usageData;
+    if (usageData) {
+        const guildConfig = await getGuildConfig(interaction.guildId!);
+        const colorRoles = guildConfig.colorRoles ?? [];
+
+        for (const effect of usageData.effects) {
+            if (effect.type === "TEMP_ROLE" || effect.type === "COLOR_ROLE") {
+                try {
+                    const member = await interaction.guild?.members.fetch(userId);
+                    if (member) {
+                        if (effect.type === "TEMP_ROLE") {
+                            await member.roles.add(effect.roleId);
+                        } else if (effect.type === "COLOR_ROLE") {
+                            const rolesToRemove = colorRoles.filter((r: string) => member.roles.cache.has(r));
+                            if (rolesToRemove.length > 0) await member.roles.remove(rolesToRemove);
+                            await member.roles.add(effect.roleId);
+                        }
+                    }
+                } catch (e) {
+                    console.error("Failed to assign role in inventory use:", e);
+                    result.results.push("⚠️ Failed to assign role (Check bot permissions)");
+                }
+            }
+        }
+    }
+
+    return result;
+}