"""Arma 3 ban manager — bidirectional sync between DB bans and BattlEye ban file."""
from __future__ import annotations

import logging
import os
from pathlib import Path

from pydantic import BaseModel

from core.utils.file_utils import get_server_dir

logger = logging.getLogger(__name__)

_BANS_FILE = "battleye/bans.txt"


class Arma3BanData(BaseModel):
    """Ban data schema for Arma 3."""
    guid: str = ""
    ip: str = ""


class Arma3BanManager:
    """
    Implements BanManager protocol for Arma3 BattlEye.

    Also provides richer file-based operations for the ban endpoints.
    """

    def __init__(self, server_id: int | None = None) -> None:
        self._server_id = server_id

    def _bans_path(self) -> Path:
        if self._server_id is None:
            raise ValueError("server_id required for file-based ban operations")
        server_dir = get_server_dir(self._server_id)
        return server_dir / _BANS_FILE

    # ── BanManager protocol methods ──

    def get_ban_file_path(self, server_dir: Path) -> Path:
        return server_dir / _BANS_FILE

    def sync_bans_to_file(self, bans: list[dict], ban_file: Path) -> None:
        """Write bans from DB to BattlEye ban file format."""
        lines = []
        for ban in bans:
            identifier = ban.get("player_uid") or ban.get("guid") or ban.get("ip", "")
            ban_type = ban.get("ban_type", "GUID")
            reason = ban.get("reason", "")
            duration = ban.get("duration_minutes", 0)
            reason_clean = reason.replace("\n", " ").replace("\r", "").strip()
            if identifier:
                lines.append(f"{ban_type} {identifier} {duration} {reason_clean}".strip())

        ban_file.parent.mkdir(parents=True, exist_ok=True)
        tmp_path = str(ban_file) + ".tmp"
        try:
            with open(tmp_path, "w", encoding="utf-8") as f:
                f.write("\n".join(lines) + "\n" if lines else "")
            os.replace(tmp_path, str(ban_file))
        except OSError as exc:
            self._safe_delete(tmp_path)
            raise

    def read_bans_from_file(self, ban_file: Path) -> list[dict]:
        """Read bans from BattlEye ban file into standard format."""
        if not ban_file.exists():
            return []

        bans = []
        for line_num, line in enumerate(ban_file.read_text(encoding="utf-8", errors="replace").splitlines(), 1):
            line = line.strip()
            if not line or line.startswith("//") or line.startswith("#"):
                continue

            parsed = self._parse_ban_line(line, line_num)
            if parsed:
                bans.append(parsed)

        return bans

    def get_ban_data_schema(self) -> type[BaseModel] | None:
        return Arma3BanData

    # ── Richer file-based operations (used by ban endpoints) ──

    def get_bans(self) -> list[dict]:
        """Read all bans from bans.txt. Returns list of dicts."""
        bans_path = self._bans_path()
        if not bans_path.exists():
            return []

        bans = []
        try:
            with open(bans_path, "r", encoding="utf-8", errors="replace") as f:
                for line_num, line in enumerate(f, 1):
                    line = line.strip()
                    if not line or line.startswith("#"):
                        continue
                    parsed = self._parse_ban_line(line, line_num)
                    if parsed:
                        bans.append(parsed)
        except OSError as exc:
            logger.error("Cannot read bans.txt: %s", exc)

        return bans

    def add_ban(self, identifier: str, ban_type: str, reason: str, duration_minutes: int) -> None:
        """Append a ban entry to bans.txt."""
        reason_clean = reason.replace("\n", " ").replace("\r", "").strip()
        line = f"{ban_type} {identifier} {duration_minutes} {reason_clean}\n"

        bans_path = self._bans_path()
        bans_path.parent.mkdir(parents=True, exist_ok=True)

        try:
            with open(bans_path, "a", encoding="utf-8") as f:
                f.write(line)
        except OSError as exc:
            logger.error("Cannot write bans.txt: %s", exc)

    def remove_ban(self, identifier: str) -> bool:
        """Remove all ban entries matching the given identifier. Returns True if removed."""
        bans_path = self._bans_path()
        if not bans_path.exists():
            return False

        try:
            with open(bans_path, "r", encoding="utf-8", errors="replace") as f:
                lines = f.readlines()
        except OSError as exc:
            logger.error("Cannot read bans.txt: %s", exc)
            return False

        new_lines = []
        removed = 0
        for line in lines:
            stripped = line.strip()
            if stripped and not stripped.startswith("#"):
                parts = stripped.split(None, 3)
                if len(parts) >= 2 and parts[1] == identifier:
                    removed += 1
                    continue
            new_lines.append(line)

        if removed == 0:
            return False

        tmp_path = str(bans_path) + ".tmp"
        try:
            with open(tmp_path, "w", encoding="utf-8") as f:
                f.writelines(new_lines)
            os.replace(tmp_path, str(bans_path))
        except OSError as exc:
            self._safe_delete(tmp_path)
            logger.error("Cannot update bans.txt: %s", exc)
            return False

        return True

    # ── Internal ──

    def _parse_ban_line(self, line: str, line_num: int) -> dict | None:
        """Parse one ban line: TYPE IDENTIFIER DURATION REASON"""
        parts = line.split(None, 3)
        if len(parts) < 2:
            return None

        ban_type = parts[0].upper()
        if ban_type not in ("GUID", "IP"):
            return None

        identifier = parts[1]
        duration = 0
        reason = ""

        if len(parts) >= 3:
            try:
                duration = int(parts[2])
            except ValueError:
                duration = 0

        if len(parts) >= 4:
            reason = parts[3]

        return {
            "type": ban_type,
            "identifier": identifier,
            "duration_minutes": duration,
            "reason": reason,
            "is_permanent": duration == 0,
        }

    @staticmethod
    def _safe_delete(path: str) -> None:
        try:
            os.unlink(path)
        except OSError as exc:
            logger.debug("Arma3BanManager: could not delete %s: %s", path, exc)