import { create } from 'zustand';
import type { Contact } from '../types';
import * as api from '../api/client';

/** 中间栏的呈现方式：列表（紧凑，答"跟谁在聊"）或卡片（答"在聊什么、进展如何"） */
export type ContactView = 'list' | 'card';

const VIEW_KEY = 'agentmail.contactView';

/**
 * 视图偏好存 localStorage。
 *
 * 这是纯展示偏好，不值得为它建一张表、加一个 API —— 而每次刷新都退回默认视图
 * 会让人反复点同一个按钮。读取时容错：localStorage 在隐私模式下可能抛异常。
 */
function loadView(): ContactView {
  try {
    return localStorage.getItem(VIEW_KEY) === 'card' ? 'card' : 'list';
  } catch {
    return 'list';
  }
}

interface ContactState {
  contacts: Contact[];
  archivedContacts: Contact[];
  showArchived: boolean;
  loading: boolean;
  error: string | null;
  /** 正在等待归档确认的地址 */
  pendingArchive: string | null;
  /** 中间栏呈现方式（持久化到 localStorage） */
  view: ContactView;
  setView: (v: ContactView) => void;

  fetchContacts: () => Promise<void>;
  fetchArchived: () => Promise<void>;
  toggleArchivedView: () => void;
  requestArchive: (address: string) => void;
  cancelArchive: () => void;
  archive: (contact: Contact) => Promise<void>;
  /** SSE session_archived 到达时本地即时移除 */
  removeSessionLocally: (sessionId: string) => void;
}

export const useContactStore = create<ContactState>((set, get) => ({
  contacts: [],
  archivedContacts: [],
  showArchived: false,
  loading: false,
  error: null,
  pendingArchive: null,
  view: loadView(),

  setView: v => {
    set({ view: v });
    try {
      localStorage.setItem(VIEW_KEY, v);
    } catch {
      /* 存不下只是下次回到默认视图，不该让切换本身失败 */
    }
  },

  fetchContacts: async () => {
    set({ loading: true, error: null });
    try {
      const { contacts } = await api.listContacts(false);
      set({ contacts: contacts || [], loading: false });
    } catch (err) {
      set({ error: err instanceof Error ? err.message : String(err), loading: false });
    }
  },

  fetchArchived: async () => {
    try {
      const { contacts } = await api.listContacts(true);
      set({ archivedContacts: contacts || [] });
    } catch (err) {
      set({ error: err instanceof Error ? err.message : String(err) });
    }
  },

  toggleArchivedView: () => {
    const next = !get().showArchived;
    set({ showArchived: next });
    if (next) get().fetchArchived();
  },

  requestArchive: address => set({ pendingArchive: address }),
  cancelArchive: () => set({ pendingArchive: null }),

  archive: async contact => {
    try {
      await api.archiveContact({ session_id: contact.session_id });
      // 本地即时移除，不等 SSE
      set(state => ({
        contacts: state.contacts.filter(c => c.session_id !== contact.session_id),
        pendingArchive: null
      }));
      if (get().showArchived) get().fetchArchived();
    } catch (err) {
      set({
        error: err instanceof Error ? err.message : String(err),
        pendingArchive: null
      });
    }
  },

  removeSessionLocally: sessionId =>
    set(state => ({
      contacts: state.contacts.filter(c => c.session_id !== sessionId)
    }))
}));