import { defineStore } from 'pinia';

interface ScrollStatePayload {
  autoScrollEnabled?: boolean;
  userScrolling?: boolean;
}

interface ChatState {
  messages: Array<any>;
  currentMessageIndex: number;
  streamingMessage: boolean;
  expandedBlocks: Set<string>;
  autoScrollEnabled: boolean;
  userScrolling: boolean;
  thinkingScrollLocks: Map<string, boolean>;
}

const GENERATING_LABELS = [
  '正在构思…',
  '稍候，AI 正在准备',
  '准备工具中',
  '容我三思…',
  '答案马上就来',
  '灵感加载中',
  '思路拼装中',
  '琢磨最佳方案',
  '脑内开会中',
  '整理资料中',
  '润色回复中',
  '调配上下文',
  '搜刮记忆中',
  '快敲完了，别急'
];

function randomGeneratingLabel() {
  if (!GENERATING_LABELS.length) {
    return '';
  }
  const index = Math.floor(Math.random() * GENERATING_LABELS.length);
  return GENERATING_LABELS[index];
}

function createAssistantMessage() {
  return {
    role: 'assistant',
    actions: [],
    streamingThinking: '',
    streamingText: '',
    currentStreamingType: null,
    activeThinkingId: null,
    awaitingFirstContent: false,
    generatingLabel: randomGeneratingLabel()
  };
}

function randomId(prefix: string) {
  return `${prefix}-${Date.now()}-${Math.random().toString(36).slice(2)}`;
}

function cloneSet<T>(source: Set<T>) {
  return new Set<T>(Array.from(source));
}

function cloneMap<K, V>(source: Map<K, V>) {
  return new Map<K, V>(Array.from(source.entries()));
}

function clearAwaitingFirstContent(message: any) {
  if (message && message.awaitingFirstContent) {
    message.awaitingFirstContent = false;
  }
}

export const useChatStore = defineStore('chat', {
  state: (): ChatState => ({
    messages: [],
    currentMessageIndex: -1,
    streamingMessage: false,
    expandedBlocks: new Set<string>(),
    autoScrollEnabled: true,
    userScrolling: false,
    thinkingScrollLocks: new Map<string, boolean>()
  }),
  getters: {
    isScrollLocked: state => state.autoScrollEnabled && !state.userScrolling
  },
  actions: {
    setStreamingMessage(active: boolean) {
      this.streamingMessage = !!active;
    },
    setCurrentMessageIndex(index: number) {
      this.currentMessageIndex = index;
    },
    setMessages(messages: Array<any>) {
      this.messages = messages;
    },
    clearMessages() {
      this.messages = [];
      this.currentMessageIndex = -1;
    },
    toggleBlock(blockId: string) {
      const next = cloneSet(this.expandedBlocks);
      if (next.has(blockId)) {
        next.delete(blockId);
      } else {
        next.add(blockId);
      }
      this.expandedBlocks = next;
    },
    expandBlock(blockId: string) {
      const next = cloneSet(this.expandedBlocks);
      next.add(blockId);
      this.expandedBlocks = next;
    },
    collapseBlock(blockId: string) {
      const next = cloneSet(this.expandedBlocks);
      next.delete(blockId);
      this.expandedBlocks = next;
    },
    clearExpandedBlocks() {
      this.expandedBlocks = new Set<string>();
    },
    setThinkingLock(blockId: string, locked: boolean) {
      const next = cloneMap(this.thinkingScrollLocks);
      if (locked) {
        next.set(blockId, true);
      } else {
        next.delete(blockId);
      }
      this.thinkingScrollLocks = next;
    },
    clearThinkingLocks() {
      this.thinkingScrollLocks = new Map<string, boolean>();
    },
    setScrollState(payload: ScrollStatePayload) {
      if (typeof payload.autoScrollEnabled !== 'undefined') {
        this.autoScrollEnabled = !!payload.autoScrollEnabled;
      }
      if (typeof payload.userScrolling !== 'undefined') {
        this.userScrolling = !!payload.userScrolling;
      }
    },
    enableAutoScroll() {
      this.setScrollState({ autoScrollEnabled: true, userScrolling: false });
    },
    disableAutoScroll() {
      this.setScrollState({ autoScrollEnabled: false, userScrolling: false });
    },
    toggleScrollLockState() {
      const locked = this.isScrollLocked;
      if (locked) {
        this.disableAutoScroll();
        return false;
      }
      this.enableAutoScroll();
      return true;
    },
    ensureAssistantMessage() {
      if (this.currentMessageIndex >= 0) {
        return this.messages[this.currentMessageIndex];
      }
      const message = createAssistantMessage();
      this.messages.push(message);
      this.currentMessageIndex = this.messages.length - 1;
      return message;
    },
    addUserMessage(content: string, images: string[] = []) {
      this.messages.push({
        role: 'user',
        content,
        images
      });
      this.currentMessageIndex = -1;
    },
    startAssistantMessage() {
      const message = createAssistantMessage();
      this.messages.push(message);
      this.currentMessageIndex = this.messages.length - 1;
      this.streamingMessage = true;
      message.awaitingFirstContent = true;
      return message;
    },
    startThinkingAction() {
      const msg = this.ensureAssistantMessage();
      clearAwaitingFirstContent(msg);
      msg.streamingThinking = '';
      msg.currentStreamingType = 'thinking';
      const actionId = randomId('thinking');
      const blockId = actionId;
      const action = {
        id: actionId,
        type: 'thinking',
        content: '',
        streaming: true,
        timestamp: Date.now(),
        blockId
      };
      msg.actions.push(action);
      msg.activeThinkingId = actionId;
      return { action, blockId };
    },
    appendThinkingChunk(content: string) {
      if (this.currentMessageIndex < 0) return null;
      const msg = this.messages[this.currentMessageIndex];
      msg.streamingThinking += content;
      const thinkingAction = this.getActiveThinkingAction(msg);
      if (thinkingAction) {
        thinkingAction.content += content;
        return thinkingAction;
      }
      return null;
    },
    completeThinking(fullContent: string) {
      if (this.currentMessageIndex < 0) return null;
      const msg = this.messages[this.currentMessageIndex];
      const thinkingAction = this.getActiveThinkingAction(msg);
      if (thinkingAction) {
        thinkingAction.streaming = false;
        thinkingAction.content = fullContent;
        msg.streamingThinking = '';
        msg.currentStreamingType = null;
        msg.activeThinkingId = null;
        return thinkingAction.blockId || thinkingAction.id;
      }
      return null;
    },
    startTextAction() {
      const msg = this.ensureAssistantMessage();
      if (!msg) {
        return null;
      }
      clearAwaitingFirstContent(msg);
      msg.streamingText = '';
      msg.currentStreamingType = 'text';
      const action = {
        id: randomId('text'),
        type: 'text',
        content: '',
        streaming: true,
        timestamp: Date.now()
      };
      msg.actions.push(action);
      return action;
    },
    appendTextChunk(content: string) {
      if (this.currentMessageIndex < 0) return null;
      const msg = this.messages[this.currentMessageIndex];
      if (!msg) {
        return null;
      }
      if (typeof msg.streamingText !== 'string') {
        msg.streamingText = '';
      }
      msg.streamingText += content;
      const lastAction = msg.actions[msg.actions.length - 1];
      if (lastAction && lastAction.type === 'text') {
        lastAction.content += content;
        return lastAction;
      }
      return null;
    },
    completeText(fullContent: string) {
      if (this.currentMessageIndex < 0) return;
      const msg = this.messages[this.currentMessageIndex];
      for (let i = msg.actions.length - 1; i >= 0; i--) {
        const action = msg.actions[i];
        if (action.type === 'text' && action.streaming) {
          action.streaming = false;
          if (typeof fullContent === 'string' && fullContent.length) {
            action.content = fullContent;
          }
          break;
        }
      }
      msg.streamingText = '';
      msg.currentStreamingType = null;
    },
    addSystemMessage(content: string) {
      const msg = this.ensureAssistantMessage();
      clearAwaitingFirstContent(msg);
      msg.actions.push({
        id: randomId('system'),
        type: 'system',
        content,
        timestamp: Date.now()
      });
    },
    addAppendPayloadAction(data: any) {
      const msg = this.ensureAssistantMessage();
      clearAwaitingFirstContent(msg);
      msg.actions.push({
        id: `append-payload-${Date.now()}-${Math.random()}`,
        type: 'append_payload',
        append: data,
        timestamp: Date.now()
      });
    },
    addModifyPayloadAction(data: any) {
      const msg = this.ensureAssistantMessage();
      clearAwaitingFirstContent(msg);
      msg.actions.push({
        id: `modify-payload-${Date.now()}-${Math.random()}`,
        type: 'modify_payload',
        modify: data,
        timestamp: Date.now()
      });
    },
    getActiveThinkingAction(msg: any) {
      if (!msg || !Array.isArray(msg.actions)) {
        return null;
      }
      if (msg.activeThinkingId) {
        const found = msg.actions.find(
          (action: any) => action && action.id === msg.activeThinkingId && action.type === 'thinking'
        );
        if (found) {
          return found;
        }
      }
      for (let i = msg.actions.length - 1; i >= 0; i--) {
        const action = msg.actions[i];
        if (action && action.type === 'thinking' && action.streaming !== false) {
          return action;
        }
      }
      return null;
    },
    resetChatState() {
      this.messages = [];
      this.currentMessageIndex = -1;
      this.streamingMessage = false;
      this.clearExpandedBlocks();
      this.clearThinkingLocks();
    }
  }
});