#!/usr/bin/env bash
# SPDX-License-Identifier: GPL-3.0-or-later
# Copyright (c) 2025 LUXIM d.o.o., Slovenia
# Author: Matjaž Mozetič
#
# Name: backtunnel-share-gui
# Summary: KDE/GUI wrapper to start a BackTunnel share with dialogs and logging.
# Description:
#   GUI front-end that prompts for remote, duration, ports, and invite options using kdialog,
#   then launches backtunnel-share in a terminal (Konsole/xterm) to create the reverse-SSH share.
#   Prefills fields from BackTunnel profiles.ini when available (read-only, best-effort).
#   All output is logged to /tmp/backtunnel-share-gui.<uid>.log for troubleshooting.
#
# Usage:
#   backtunnel-share-gui <folder>
#
# Examples:
#   backtunnel-share-gui ~/projects
#
# Dependencies:
#   - bash
#   - kdialog (for GUI prompts)
#   - konsole or xterm (preferred terminals; falls back to background run if missing)
#   - awk (for simple INI parsing), tee
#   - backtunnel-share (invoked to perform the actual sharing)
#
# Exit codes:
#   0  command launched (terminal or background)
#   1  invalid usage or no folder selected
#
# Notes:
#   - Profiles are used only to prefill fields; @profile is not used directly by this GUI.
#   - If no terminal emulator is available, runs in background and shows a message with the log path.

# GUI wrapper for BackTunnel "Share" action (Dolphin service menu)
# Prompts for parameters via kdialog and launches backtunnel-share in a terminal.

set -euo pipefail

LOG="/tmp/backtunnel-share-gui.$UID.log"
exec > >(tee -a "$LOG") 2>&1
export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:${PATH:-}"

FOLDER="${1:-}"
if [[ -z "$FOLDER" ]]; then
  kdialog --error "No folder selected." || true
  echo "No folder argument passed from service menu." >>"$LOG"
  exit 1
fi

# Defaults
REMOTE_DEFAULT="user@vps.example.com"
DURATION_DEFAULT="2h"
TPORT_DEFAULT="2222"
LPORT_DEFAULT="22"
INVITE_MOUNT_DEFAULT="$HOME/remote-rssh"

# Profiles (search order: user -> system -> packaged fallback)
PROFILES_USER="${XDG_CONFIG_HOME:-$HOME/.config}/backtunnel/profiles.ini"
PROFILES_SYS="/etc/backtunnel/profiles.ini"
PROFILES_PKG="/usr/share/backtunnel/profiles.ini"
if   [[ -f "$PROFILES_USER" ]]; then PROFILES_FILE="$PROFILES_USER"
elif [[ -f "$PROFILES_SYS"  ]]; then PROFILES_FILE="$PROFILES_SYS"
else                                 PROFILES_FILE="$PROFILES_PKG"
fi

# If profiles exist, offer a profile picker and prefill dialogs
if [[ -f "$PROFILES_FILE" ]]; then
  mapfile -t profs < <(awk '/^\[/{gsub(/^\[|\]$/,"",$1); if ($1!="default") print $1}' "$PROFILES_FILE")
  if (( ${#profs[@]} )); then
    choice="$(kdialog --combobox "Choose profile (or Cancel for manual)" "${profs[@]}")" || choice=""
    if [[ -n "$choice" ]]; then
      getval() { awk -v s="[""$choice""]" -v k="$1" '
        $0==s{ok=1; next} /^\[/{ok=0}
        ok && $0 ~ /^[[:alnum:]_.-]+[[:space:]]*=/ {
          line=$0; sub(/[[:space:]]*=[[:space:]]*/, "=", line)
          split(line,a,"="); if(a[1]==k){val=substr(line,index(line,"=")+1); gsub(/^[[:space:]]+|[[:space:]]+$/,"",val); print val; exit}
        }' "$PROFILES_FILE" 2>/dev/null; }
      u="$(getval user)"; h="$(getval host)"
      if [[ -n "$u" && -n "$h" ]]; then
        REMOTE_DEFAULT="$u@$h"
      fi
      v="$(getval tunnel_port)";     [[ -n "$v" ]] && TPORT_DEFAULT="$v"
      v="$(getval local_ssh_port)";  [[ -n "$v" ]] && LPORT_DEFAULT="$v"
      v="$(getval invite_mount)";    [[ -n "$v" ]] && INVITE_MOUNT_DEFAULT="$v"
      # optional: default duration from [default]
      vd="$(awk -v s="[default]" -v k="duration" '
        $0==s{ok=1; next} /^\[/{ok=0}
        ok && $0 ~ /^[[:alnum:]_.-]+[[:space:]]*=/ {
          line=$0; sub(/[[:space:]]*=[[:space:]]*/, "=", line)
          split(line,a,"="); if(a[1]==k){val=substr(line,index(line,"=")+1); gsub(/^[[:space:]]+|[[:space:]]+$/,"",val); print val; exit}
        }' "$PROFILES_FILE" 2>/dev/null)"
      [[ -n "$vd" ]] && DURATION_DEFAULT="$vd"
    fi
  fi
fi

# Dialogs (Cancel returns 1; treat as benign exit)
REMOTE="$(kdialog --inputbox "Remote (user@host or user:host):" "$REMOTE_DEFAULT")" || exit 0
DUR="$(kdialog --combobox "Share duration" 30m 2h 6h 1d 2d --editable "$DURATION_DEFAULT")" || exit 0
TPORT="$(kdialog --inputbox "Tunnel port on remote:" "$TPORT_DEFAULT")" || exit 0
LPORT="$(kdialog --inputbox "Local SSH port to expose:" "$LPORT_DEFAULT")" || exit 0

INV=""   # set to "-i" if chosen
if kdialog --yesno "Print invite line for chat?"; then
  INV="-i"
fi

QR=""    # set to "--qr" if chosen
if kdialog --yesno "Show QR code for the invite?"; then
  QR="--qr"
fi

MP="$(kdialog --inputbox "Suggested mount point in invite:" "$INVITE_MOUNT_DEFAULT")" || exit 0

# Build command safely as an array; append optional flags conditionally (SC2206-safe)
cmd=( backtunnel-share "$FOLDER" with "$REMOTE" for "$DUR" -p "$TPORT" -l "$LPORT" --invite-mount "$MP" )
if [[ -n "$INV" ]]; then cmd+=("$INV"); fi
if [[ -n "$QR"  ]]; then cmd+=("$QR");  fi

if command -v konsole >/dev/null 2>&1; then
  exec konsole --noclose -e "${cmd[@]}"
elif command -v xterm >/dev/null 2>&1; then
  exec xterm -hold -e "${cmd[@]}"
else
  nohup "${cmd[@]}" >>"$LOG" 2>&1 &
  kdialog --msgbox "Sharing started in background.\nSee log: $LOG"
  exit 0
fi