#!/bin/bash

# Enhanced remote-admin connection script
# Checks for free remote-admin PC via SMB share and launches RDP connection

AMPEL_MOUNT="/tmp/remote-ampel"
SHARE="//cluster-ho/Ampel"
SMB_CRED="$HOME/.smbcredentials"
RDP_CRED="$HOME/.remote-admin"
FSTAB_ENTRY="$SHARE $AMPEL_MOUNT cifs credentials=$SMB_CRED,user,noauto,workgroup=ZFD,dir_mode=0777,file_mode=0777,_netdev 0 0"

# Logging function
log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1"
}

ask_permission() {
    read -p "$1 (y/n): " answer
    [[ "$answer" =~ ^[Yy]$ ]]
}

# Trap for cleanup
cleanup() {
    umount "$AMPEL_MOUNT" 2>/dev/null
    log "Unmounted $AMPEL_MOUNT."
}
trap cleanup EXIT

# Check for credentials
if [ ! -f "$RDP_CRED" ]; then
    log "$RDP_CRED not found! Please create it!"
    exit 1
fi
if [ ! -f "$SMB_CRED" ]; then
    log "$SMB_CRED not found! Please create it!"
    exit 2
fi

# Source RDP credentials
source "$RDP_CRED"

# Detect FreeRDP
FREERDP_BIN=$(command -v xfreerdp || command -v wfreerdp)
if [ -z "$FREERDP_BIN" ]; then
    log "No FreeRDP client found (xfreerdp or wfreerdp). Please install one."
    exit 3
fi

# Check fstab entry
if ! grep -qs "$AMPEL_MOUNT" /etc/fstab; then
    log "Fstab entry for $AMPEL_MOUNT not found."
    if ask_permission "Shall I add the entry automatically?"; then
        sudo bash -c "echo '$FSTAB_ENTRY' >> /etc/fstab"
        log "Fstab entry added."
    fi
fi

# Check mount.cifs permissions
if [ ! -u /usr/sbin/mount.cifs ]; then
    log "mount.cifs is missing setuid bit."
    if ask_permission "Shall I set it automatically?"; then
        sudo chmod u+s /usr/sbin/mount.cifs
        log "Setuid bit set on /usr/sbin/mount.cifs."
    fi
fi

# Mount the share
mkdir -p "$AMPEL_MOUNT"
if grep -qs "$AMPEL_MOUNT" /proc/mounts; then
    log "$AMPEL_MOUNT already mounted."
else
    log "Mounting $AMPEL_MOUNT..."
    if ! mount "$AMPEL_MOUNT"; then
        log "Mount failed. Check share configuration."
        exit 4
    fi
    log "Mount successful."
fi

# Search for free remote admin PC
sleep 1
for i in "$AMPEL_MOUNT"/*; do
    [[ "$i" == *FREE* ]] || continue
    RDP=$(basename "$i" | cut -f1,2 -d'-')
    log "$RDP is free. Starting RDP session..."
    "$FREERDP_BIN" /u:"$USERNAME" /p:"$PASSWORD" /v:"$RDP.zfd.forumzfd.de" /dynamic-resolution
    log "Connection closed. Bye."
    exit 0
done

log "No Remote-Admin is free. Try again later."
exit 0