/**
 * 状态栏管理器 — 常驻显示
 *
 * 始终在左侧状态栏显示 AI Diff 状态:
 * - 有 pending 变更: $(diff) AI Diff: N文件 M编辑 (黄色) — 点击打开文件列表
 * - Diff 活跃: 右侧额外显示 Accept/Reject 按钮
 * - 无变更: $(diff) AI Diff (暗色) — 点击打开文件列表
 */

import * as vscode from 'vscode';
import { ChangeSetManager } from '../snapshot/snapshotManager';
import { DiffViewer, DiffSession } from './diffViewer';
import { COMMANDS } from '../models/constants';

export class StatusBarManager {
  /** ★ 常驻摘要按钮 */
  private summaryItem: vscode.StatusBarItem;
  /** Diff 模式 Accept 按钮（接受当前文件所有变更） */
  private acceptBtn: vscode.StatusBarItem;
  /** Diff 模式 Reject 按钮（拒绝当前文件所有变更） */
  private rejectBtn: vscode.StatusBarItem;
  /** ★ 上一次编辑按钮 */
  private prevEditBtn: vscode.StatusBarItem;
  /** ★ 下一次编辑按钮 */
  private nextEditBtn: vscode.StatusBarItem;

  constructor(
    private changeSetManager: ChangeSetManager,
    private diffViewer: DiffViewer
  ) {
    // ★ 常驻摘要 — 始终显示
    this.summaryItem = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Left, 100);
    this.summaryItem.command = COMMANDS.SHOW_DIFF_PANEL;
    this.summaryItem.text = '$(diff) AI Diff';
    this.summaryItem.tooltip = 'AI Diff — 点击查看变更列表';
    this.summaryItem.show();

    // Accept 按钮（接受当前文件所有变更）
    this.acceptBtn = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Right, 100);
    this.acceptBtn.command = 'aiDiffPreview.acceptAllFromDiff';

    // Reject 按钮（拒绝当前文件所有变更）
    this.rejectBtn = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Right, 99);
    this.rejectBtn.command = 'aiDiffPreview.rejectCurrentDiff';

    // ★ 上一次编辑按钮
    this.prevEditBtn = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Right, 98);
    this.prevEditBtn.command = 'aiDiffPreview.prevEdit';
    this.prevEditBtn.tooltip = '上一次编辑 (Alt+Left)';

    // ★ 下一次编辑按钮
    this.nextEditBtn = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Right, 97);
    this.nextEditBtn.command = 'aiDiffPreview.nextEdit';
    this.nextEditBtn.tooltip = '下一次编辑 (Alt+Right)';
  }

  enterDiffMode(session: DiffSession): void {
    this.acceptBtn.text = '$(check) Accept';
    this.acceptBtn.backgroundColor = new vscode.ThemeColor('statusBarItem.warningBackground');
    this.acceptBtn.tooltip = '接受此文件所有变更';
    this.acceptBtn.show();

    this.rejectBtn.text = '$(close) Reject';
    this.rejectBtn.backgroundColor = new vscode.ThemeColor('statusBarItem.errorBackground');
    this.rejectBtn.tooltip = '拒绝此文件所有变更';
    this.rejectBtn.show();

    // ★ 根据 session 状态显示编辑导航按钮
    if (session.editIndex !== undefined && session.totalEdits !== undefined) {
      // 逐次编辑模式：显示 Prev/Next 和计数
      this.prevEditBtn.text = `$(arrow-left) ${session.editIndex + 1}/${session.totalEdits}`;
      this.prevEditBtn.command = 'aiDiffPreview.prevEdit';
      this.prevEditBtn.tooltip = `上一次编辑 (Alt+Left) — 当前第 ${session.editIndex + 1}/${session.totalEdits} 次`;
      this.prevEditBtn.show();

      this.nextEditBtn.text = '$(arrow-right)';
      this.nextEditBtn.command = 'aiDiffPreview.nextEdit';
      this.nextEditBtn.tooltip = '下一次编辑 (Alt+Right)';
      this.nextEditBtn.show();
    } else {
      // 聚合视图模式：显示"逐次查看"入口
      this.prevEditBtn.text = '$(list-ordered) 逐次查看';
      this.prevEditBtn.command = 'aiDiffPreview.showEditAtIndex';
      this.prevEditBtn.tooltip = '切换到逐次编辑查看模式';
      this.prevEditBtn.show();
      this.nextEditBtn.hide();
    }
  }

  exitDiffMode(): void {
    this.acceptBtn.hide();
    this.rejectBtn.hide();
    this.prevEditBtn.hide();
    this.nextEditBtn.hide();
  }

  /** ★ 常驻刷新 */
  refresh(): void {
    const session = this.diffViewer.getActiveSession();
    if (session) {
      this.enterDiffMode(session);
    } else {
      this.exitDiffMode();
    }

    const set = this.changeSetManager.getCurrentSet();
    if (!set) {
      // ★ 无变更集也常驻显示
      this.summaryItem.text = '$(diff) AI Diff';
      this.summaryItem.tooltip = 'AI Diff — 等待变更';
      this.summaryItem.backgroundColor = undefined;
      this.summaryItem.show();
      return;
    }

    const pendingFiles = set.changes.filter(c => c.status === 'pending');
    const totalEdits = pendingFiles.reduce(
      (sum, c) => sum + c.edits.filter(e => e.status === 'pending').length, 0
    );

    if (pendingFiles.length === 0 && set.changes.length > 0) {
      this.summaryItem.text = '$(diff) AI Diff: 已完成';
      this.summaryItem.tooltip = '所有变更已处理';
      this.summaryItem.backgroundColor = undefined;
    } else if (pendingFiles.length > 0) {
      this.summaryItem.text = `$(diff) AI Diff: ${pendingFiles.length}文件 ${totalEdits}编辑`;
      this.summaryItem.tooltip = `点击查看变更列表\n${pendingFiles.map(c => `• ${c.filePath} (${c.edits.length}次)`).join('\n')}`;
      this.summaryItem.backgroundColor = new vscode.ThemeColor('statusBarItem.warningBackground');
    }

    this.summaryItem.show();
  }

  dispose(): void {
    this.summaryItem.dispose();
    this.acceptBtn.dispose();
    this.rejectBtn.dispose();
    this.prevEditBtn.dispose();
    this.nextEditBtn.dispose();
  }
}