from __future__ import annotations

import logging
import re

logger = logging.getLogger(__name__)


class MattermostGating:
    def __init__(self, account: dict):
        self.chatmode = account.get("chatmode", "oncall")
        self.onchar_prefixes = account.get("onchar_prefixes", [">", "!"])
        self.require_mention = account.get("require_mention", True)

    def should_respond(
        self,
        chat_type: str,
        message_text: str,
        was_mentioned: bool,
    ) -> tuple[bool, str]:
        if chat_type == "direct":
            return True, "dm_always"

        if self.chatmode == "onmessage":
            return True, "onmessage"

        if self.chatmode == "onchar":
            return self._check_onchar(message_text)

        if self.chatmode == "oncall":
            if was_mentioned:
                return True, "mentioned"
            return self._check_onchar_fallback(message_text)

        return False, "unknown_chatmode"

    def _check_onchar(self, text: str) -> tuple[bool, str]:
        stripped = text.strip()
        for prefix in self.onchar_prefixes:
            if stripped.startswith(prefix):
                return True, "onchar_triggered"
        return False, "onchar_not_triggered"

    def _check_onchar_fallback(self, text: str) -> tuple[bool, str]:
        if not self.require_mention:
            return True, "mention_not_required"

        for prefix in self.onchar_prefixes:
            if text.strip().startswith(prefix):
                return True, "onchar_fallback"

        return False, "missing_mention"

    def was_mentioned(self, text: str, bot_user_id: str, bot_username: str | None = None) -> bool:
        mentions = self.extract_mentions(text)
        if bot_user_id in mentions:
            return True
        if bot_username:
            return bot_username in text or f"@{bot_username}" in text
        return False

    def extract_mentions(self, text: str) -> list[str]:
        user_ids = re.findall(r"@([a-z0-9]{26})", text, re.IGNORECASE)
        usernames = re.findall(r"@(\w+)", text)
        return user_ids + usernames

    def strip_onchar_prefix(self, text: str) -> str:
        stripped = text.strip()
        for prefix in self.onchar_prefixes:
            if stripped.startswith(prefix):
                return stripped[len(prefix):].strip()
        return text