"""
Telegram Listener API blueprint.

Routes under ``/api/telegram/`` that manage the Telegram bot listener service.
"""

from __future__ import annotations

import os
import re
import subprocess
from pathlib import Path

from flask import Blueprint, jsonify, request

from lib.runner import run_pos, run_cmd
from lib.parsers import parse_telegram_commands
from lib.config import load_telegram_env, mask_secrets

telegram_bp = Blueprint("telegram", __name__, url_prefix="/api/telegram")

_SERVICE = "pos-telegram-listener.service"


# ── Helpers ──────────────────────────────────────────────────────────────────

def _systemd_user(*args: str, timeout: int = 15) -> dict:
    """Run a ``systemctl --user`` command."""
    return run_cmd(["systemctl", "--user"] + list(args), timeout=timeout)


# ── Routes ───────────────────────────────────────────────────────────────────

@telegram_bp.route("/status", methods=["GET"])
def telegram_status():
    """Check the systemd user service status for the Telegram listener.

    Returns::

        {"running": bool, "active_state": str, "sub_state": str}
    """
    # Check active state
    res = _systemd_user("is-active", _SERVICE)
    running = res["returncode"] == 0 and res["stdout"].strip() == "active"

    # Get detailed properties
    props: dict = {"active_state": res["stdout"].strip(), "sub_state": ""}
    detail = _systemd_user("show", _SERVICE, "--property=ActiveState,SubState,MainPID")
    if detail["returncode"] == 0:
        for line in detail["stdout"].splitlines():
            if "=" in line:
                k, v = line.split("=", 1)
                props[k.strip().lower()] = v.strip()

    return jsonify({
        "running": running,
        "active_state": props.get("activestate", "unknown"),
        "sub_state": props.get("substate", "unknown"),
        "pid": props.get("mainpid", ""),
    })


@telegram_bp.route("/enable", methods=["POST"])
def telegram_enable():
    """Enable the Telegram listener service."""
    result = run_pos(["communication", "telegram-listener", "--enable"], timeout=30)
    if result.get("error") and result["returncode"] != 0:
        return jsonify({
            "error": result["error"],
            "stderr": result.get("stderr", ""),
        }), 500

    return jsonify({"message": result["stdout"].strip() or "telegram listener enabled"})


@telegram_bp.route("/disable", methods=["POST"])
def telegram_disable():
    """Disable the Telegram listener service."""
    result = run_pos(["communication", "telegram-listener", "--disable"], timeout=30)
    if result.get("error") and result["returncode"] != 0:
        return jsonify({
            "error": result["error"],
            "stderr": result.get("stderr", ""),
        }), 500

    return jsonify({"message": result["stdout"].strip() or "telegram listener disabled"})


@telegram_bp.route("/commands", methods=["GET"])
def telegram_commands():
    """Read the telegram_commands.env and return parsed command map."""
    config_dir = Path(
        __import__("os").environ.get(
            "XDG_CONFIG_HOME",
            __import__("os").path.expanduser("~/.config"),
        )
    ) / "linux_post_install"
    map_file = config_dir / "telegram_commands.env"

    if not map_file.is_file():
        return jsonify({"commands": [], "map_file": str(map_file)})

    text = map_file.read_text(encoding="utf-8", errors="replace")
    commands = parse_telegram_commands(text)
    return jsonify({"commands": commands, "map_file": str(map_file)})


@telegram_bp.route("/commands", methods=["POST"])
def telegram_commands_add():
    """Add a command to the telegram_commands.env map file.

    Expects JSON body: ``{"command": "/status", "description": "...", "script": "..."}``
    """
    body = request.get_json(silent=True) or {}
    command = (body.get("command") or "").strip()
    description = (body.get("description") or "").strip()
    script = (body.get("script") or "").strip()

    if not command:
        return jsonify({"error": "missing command name"}), 400
    if not script:
        return jsonify({"error": "missing bash script"}), 400

    # Validate command starts with /
    if not command.startswith("/"):
        command = "/" + command

    # Validate command name (alphanumeric, hyphens, underscores)
    if not re.match(r"^/[a-zA-Z0-9_-]+$", command):
        return jsonify({"error": f"invalid command name: {command} — use only letters, numbers, hyphens"}), 400

    # Build the map line
    if description:
        line = f"{command}::{description}={script}"
    else:
        line = f"{command}={script}"

    # Write to the map file
    config_dir = Path(
        os.environ.get(
            "XDG_CONFIG_HOME",
            os.path.expanduser("~/.config"),
        )
    ) / "linux_post_install"
    map_file = config_dir / "telegram_commands.env"

    # Check if command already exists
    if map_file.is_file():
        existing = map_file.read_text(encoding="utf-8", errors="replace")
        for existing_line in existing.splitlines():
            existing_line = existing_line.strip()
            if not existing_line or existing_line.startswith("#"):
                continue
            existing_cmd = existing_line.split("=")[0].split("::")[0].strip()
            if existing_cmd == command:
                return jsonify({"error": f"command {command} already exists — delete it first"}), 409

    # Append the new command
    config_dir.mkdir(parents=True, exist_ok=True)
    with open(map_file, "a", encoding="utf-8") as f:
        f.write(line + "\n")

    return jsonify({"ok": True, "command": command, "message": f"Command {command} added"})


@telegram_bp.route("/commands/sync", methods=["POST"])
def telegram_commands_sync():
    """Push mapped commands to the bot's "/" menu (setMyCommands)."""
    result = run_pos(
        ["communication", "telegram-listener", "--sync-commands"],
        timeout=30,
    )
    if result.get("error") and result["returncode"] != 0:
        return jsonify({
            "error": result["error"],
            "stderr": result.get("stderr", ""),
        }), 500

    return jsonify({"message": result["stdout"].strip() or "commands synced"})