/**
 * CodeLens 提供器 - 提供 Accept/Reject 按钮
 */

import * as vscode from 'vscode';
import { SnapshotManager } from '../snapshot/snapshotManager';
import { COMMANDS } from '../models/constants';

export class CodeLensProvider implements vscode.CodeLensProvider {
  private _onDidChangeCodeLenses = new vscode.EventEmitter<void>();
  readonly onDidChangeCodeLenses = this._onDidChangeCodeLenses.event;

  constructor(private snapshotManager: SnapshotManager) {}

  /**
   * 刷新 CodeLens
   */
  refresh(): void {
    this._onDidChangeCodeLenses.fire();
  }

  /**
   * 提供 CodeLens
   */
  provideCodeLenses(
    document: vscode.TextDocument,
    token: vscode.CancellationToken
  ): vscode.CodeLens[] {
    const snapshot = this.snapshotManager.getSnapshotByFilePath(document.uri.fsPath);
    if (!snapshot || snapshot.status !== 'active') {
      return [];
    }

    const codeLenses: vscode.CodeLens[] = [];

    // 为每个待处理的块添加 CodeLens
    snapshot.chunks.forEach(chunk => {
      if (chunk.status !== 'pending') return;

      const range = new vscode.Range(
        new vscode.Position(chunk.startLine, 0),
        new vscode.Position(chunk.startLine, 0)
      );

      // Accept 按钮
      codeLenses.push(
        new vscode.CodeLens(range, {
          title: '$(check) Accept',
          command: COMMANDS.ACCEPT_CHUNK,
          arguments: [snapshot.id, chunk.id],
          tooltip: '接受此变更块',
        })
      );

      // Reject 按钮
      codeLenses.push(
        new vscode.CodeLens(range, {
          title: '$(close) Reject',
          command: COMMANDS.REJECT_CHUNK,
          arguments: [snapshot.id, chunk.id],
          tooltip: '拒绝此变更块',
        })
      );
    });

    // 如果有多个块，添加全局操作按钮
    const pendingChunks = snapshot.chunks.filter(c => c.status === 'pending');
    if (pendingChunks.length > 1) {
      const firstChunk = pendingChunks[0];
      const range = new vscode.Range(
        new vscode.Position(firstChunk.startLine, 0),
        new vscode.Position(firstChunk.startLine, 0)
      );

      codeLenses.push(
        new vscode.CodeLens(range, {
          title: '$(check-all) Accept All',
          command: COMMANDS.ACCEPT_ALL,
          arguments: [snapshot.id],
          tooltip: '接受所有变更',
        })
      );

      codeLenses.push(
        new vscode.CodeLens(range, {
          title: '$(trash) Reject All',
          command: COMMANDS.REJECT_ALL,
          arguments: [snapshot.id],
          tooltip: '拒绝所有变更',
        })
      );
    }

    return codeLenses;
  }
}