export class ChatClientMock {
  async sendMessage(payload) {
    const taskId = `task-${Date.now()}`;
    await new Promise((resolve) => setTimeout(resolve, 400));
    const text = payload.message.trim();

    if (text.startsWith("/changeset")) {
      const raw = text.slice("/changeset".length).trim();
      const parsed = JSON.parse(raw);
      return { task_id: taskId, status: "done", result_type: "changeset", changeset: parsed.changeset || [] };
    }

    if (text.startsWith("/demo-update ")) {
      const path = text.replace("/demo-update ", "").trim();
      const file = payload.files.find((f) => f.path === path);
      if (!file) {
        return { task_id: taskId, status: "done", result_type: "answer", answer: `Файл ${path} не найден.` };
      }
      const proposed = `${file.content}\n// demo update from mock agent\n`;
      return {
        task_id: taskId,
        status: "done",
        result_type: "changeset",
        changeset: [{ op: "update", path, base_hash: file.content_hash, proposed_content: proposed, reason: "Demo change" }]
      };
    }

    return {
      task_id: taskId,
      status: "done",
      result_type: "answer",
      answer: "Mock-агент активен. Используйте /changeset {json} или /demo-update <path>."
    };
  }
}