import re
from typing import Optional

NON_SOLUTION = re.compile(
    r"(уточнит|приложите скрин|какая ошибка|с какой проблемой"
    r"|нет обратной связи|запрос завершу|открыть его снова"
    r"|откройте новый|обратиться в службу поддержки"
    r"|свяжитесь с технической"
    r"|напишите нам|позвоните нам)", re.I
)


def clean_text(text: str) -> str:
    text = re.sub(r'\[/?q\].*?\[/q\]', '', text, flags=re.DOTALL | re.IGNORECASE)
    text = re.sub(r'https?://\S+', '', text)
    text = re.sub(r'\s+', ' ', text).strip()
    return text


def has_real_solution(messages: list[dict]) -> Optional[str]:
    support_texts = []
    for m in messages:
        if m["role"] == "support":
            cleaned = clean_text(m["text"])
            if cleaned:
                support_texts.append(cleaned)
    if not support_texts:
        return None
    combined = "\n".join(support_texts)
    if len(combined) < 100:
        return None
    last = support_texts[-1]
    if NON_SOLUTION.search(last):
        return None
    if last.strip().endswith("?") and len(last) < 150:
        return None
    return combined


def get_client_dialogue(messages: list[dict]) -> str:
    texts = []
    for m in messages:
        if m["role"] == "client":
            cleaned = clean_text(m["text"])
            if cleaned:
                texts.append(cleaned)
    return "\n".join(texts)


def build_chunk(ticket: dict) -> Optional[dict]:
    msgs = ticket.get("messages") or []
    if not msgs:
        return None
    description = clean_text(ticket.get("description", ""))
    solution = has_real_solution(msgs)
    if not solution:
        return None

    client_msgs = get_client_dialogue(msgs)

    search_parts = []
    if description:
        search_parts.append(description)
    if client_msgs:
        search_parts.append(client_msgs)
    search_text = "\n".join(search_parts).strip()
    if not search_text:
        return None

    full_text = (
        f"Категория: {ticket['category']}\n"
        f"Проблема: {description}\n"
        f"Решение: {solution}"
    )

    return {
        "ticket_id": ticket["ticket_id"],
        "client": ticket["client"],
        "category": ticket["category"],
        "search_text": search_text,
        "full_text": full_text,
        "tenant_id": None,
    }