import { defineStore } from "pinia";
import { messageService } from "@/services/message";
import { conversationDb } from "@/utils/db/conversationDB";
import { useMessage } from "@/components/messages/useAlert";

const message = useMessage();

export const useConversationStore = defineStore('conversation', {
    state: () => ({
        conversations: []
    }),
    actions: {
        async addConversation(conversation) {
            await conversationDb.save(conversation);
            this.conversations.unshift(conversation)
        },
        /**
         * 加载当前会话消息列表 
         */
        async loadUserConversations() {
            if (this.conversations.length == 0) {
                try {
                    const covnersationsCache = await conversationDb.getAll();
                    if (covnersationsCache && covnersationsCache.length > 0) {
                        covnersationsCache.sort((a, b) => {
                            return new Date(a.dateTime) - new Date(b.dateTime);
                        })
                    }
                } catch (e) {
                    message.error('读取本地会话缓存失败...');
                    console.log('读取本地会话缓存失败：', e);
                }
            }
            await this.fetchConversationsFromServier()
        },
        /**
         * 从服务器加载新消息
         * @param {*} sessionId 
         * @returns 
         */
        async fetchConversationsFromServier() {
            const newConversations = (await messageService.getConversations()).data;
            if (newConversations.length > 0) {
                // 1. 将当前的本地数据转为 Map，方便通过 ID 快速查找 (O(1) 复杂度)
                const localMap = new Map(this.conversations.map(item => [item.id, item]));
                newConversations.forEach(item => {
                    const existingItem = localMap.get(item.id);
                    if (existingItem) {
                        // --- 局部更新 ---
                        // 使用 Object.assign 将新数据合并到旧对象上，保持响应式引用
                        Object.assign(existingItem, item);
                    } else {
                        // --- 插入新会话 ---
                        this.conversations.unshift(item);
                    }
                    // 同步到本地数据库
                    conversationDb.save(item);
                });

            }
        }
    }
})