/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import type { SlashCommand } from './types.js';
import { CommandKind } from './types.js';
import { t } from '../../i18n/index.js';
import {
  uiTelemetryService,
  SessionEndReason,
  SessionStartSource,
  ToolNames,
  SkillTool,
} from '@qwen-code/qwen-code-core';

export const clearCommand: SlashCommand = {
  name: 'clear',
  altNames: ['reset', 'new'],
  get description() {
    return t('Clear conversation history and free up context');
  },
  kind: CommandKind.BUILT_IN,
  action: async (context, _args) => {
    const { config } = context.services;

    if (config) {
      // Fire SessionEnd event before clearing (current session ends)
      try {
        await config
          .getHookSystem()
          ?.fireSessionEndEvent(SessionEndReason.Clear);
      } catch (err) {
        config.getDebugLogger().warn(`SessionEnd hook failed: ${err}`);
      }

      const newSessionId = config.startNewSession();

      // Reset UI telemetry metrics for the new session
      uiTelemetryService.reset();

      // Clear loaded-skills tracking so /context doesn't show stale data
      const skillTool = config
        .getToolRegistry()
        ?.getAllTools()
        .find((tool) => tool.name === ToolNames.SKILL);
      if (skillTool instanceof SkillTool) {
        skillTool.clearLoadedSkills();
      }

      if (newSessionId && context.session.startNewSession) {
        context.session.startNewSession(newSessionId);
      }

      const geminiClient = config.getGeminiClient();
      if (geminiClient) {
        context.ui.setDebugMessage(
          t('Starting a new session, resetting chat, and clearing terminal.'),
        );
        // If resetChat fails, the exception will propagate and halt the command,
        // which is the correct behavior to signal a failure to the user.
        await geminiClient.resetChat();
      } else {
        context.ui.setDebugMessage(t('Starting a new session and clearing.'));
      }

      // Fire SessionStart event after clearing (new session starts)
      try {
        await config
          .getHookSystem()
          ?.fireSessionStartEvent(
            SessionStartSource.Clear,
            config.getModel() ?? '',
          );
      } catch (err) {
        config.getDebugLogger().warn(`SessionStart hook failed: ${err}`);
      }
    } else {
      context.ui.setDebugMessage(t('Starting a new session and clearing.'));
    }

    context.ui.clear();
  },
};