#!/bin/sh

# "smb" or "nfs"
STORAGE_TYPE="nfs"

# ip or hostname
S_HOST="nfs.lan"

# /path/to/backup
S_PATH="/mnt/media1/backup"

SMB_USER="guest"
SMB_PASS="guest"

LOCAL_KEEP=10
HOST_KEEP=30

HNAME=$(uci get system.@system[0].hostname)
DATE=$(date +%Y-%m-%d_%H-%M)

S_MOUNT="/tmp/share"

C_LIST="
/etc/config/
/etc/xray/
/etc/unbound/
/root/.ssh/
/opt/xray-config/
/opt/backup-manager/
/etc/nftables.d/10-netmap.nft
"

C_EXCLUDE="
/opt/backup-manager/local_backups
/etc/xray/ipset
/etc/xray/ipnet
"

H_REPLACE="wpad dnsmasq"

DIR="/opt/backup-manager"
L_BACKUP_DIR="$DIR/local_backups"
SCR_BACKUP="$DIR/backup-configs.sh"
SCR_OPKG="$DIR/backup-opkg.sh"

mkdir -p "$L_BACKUP_DIR"

if [ "$STORAGE_TYPE" = "nfs" ]; then
    FULL_ADDR="${S_HOST}:${S_PATH}"
else
    FULL_ADDR="//${S_HOST}${S_PATH}"
fi

check_network() {
    printf "Checking network %s... " "$S_HOST"
    if ! ping -c 2 "$S_HOST" >/dev/null 2>&1; then
        echo "FAILED"
        echo "[!] Error: Remote host $S_HOST is unreachable."
        echo "    Check if the NAS is powered on and the IP/Hostname is correct."
        return 1
    fi
    echo "OK"
    return 0
}

check_dependencies() {
    printf "Checking %s dependencies... " "$STORAGE_TYPE"
    local pkgs=""
    [ "$STORAGE_TYPE" = "nfs" ] && pkgs="kmod-fs-nfs kmod-fs-nfs-v3 kmod-fs-nfs-v4 nfs-utils"
    [ "$STORAGE_TYPE" = "smb" ] && pkgs="kmod-fs-cifs cifs-utils"
    local missing=""
    for pkg in $pkgs; do
        opkg list-installed | grep -q "^$pkg " || missing="$missing $pkg"
    done
    if [ -n "$missing" ]; then
        echo " [!] Missing: $missing. Install them to use remote backup."
        return 1
    fi
    echo "OK"
    return 0
}

mount_share() {
    mkdir -p "$S_MOUNT"
    if grep -qs "$S_MOUNT" /proc/mounts; then
        umount -l "$S_MOUNT" >/dev/null 2>&1
    fi
    printf "Mounting %s storage... " "$STORAGE_TYPE"
    local mount_err
    if [ "$STORAGE_TYPE" = "nfs" ]; then
        mount_err=$(mount -t nfs "$FULL_ADDR" "$S_MOUNT" -o nolock,tcp 2>&1)
    else
        mount_err=$(mount -t cifs "$FULL_ADDR" "$S_MOUNT" -o user=$SMB_USER,pass=$SMB_PASS,vers=3.0,sec=ntlmssp 2>&1)
    fi
    if grep -qs "$S_MOUNT" /proc/mounts; then
        echo "OK"
        return 0
    else
        echo "FAILED"
        echo "[!] Error: Failed to mount $STORAGE_TYPE ($FULL_ADDR)"
        [ -n "$mount_err" ] && echo "    System message: $mount_err"
        return 1
    fi
}

manage_local_backups() {
    printf "Cleaning up local storage (keeping last %s)... " "$LOCAL_KEEP"
    local tail_val=$((LOCAL_KEEP + 1))
    ls -t "$L_BACKUP_DIR"/*.tar.gz 2>/dev/null | tail -n +$tail_val | xargs rm -f
    ls -t "$L_BACKUP_DIR"/*.lst 2>/dev/null | tail -n +$tail_val | xargs rm -f
    echo "OK"
}

clean_old_remote_backups() {
    printf "Cleaning up remote backups older than %s days... " "$HOST_KEEP"
    find "$S_MOUNT" -maxdepth 1 -type f \( -name "*.tar.gz" -o -name "*.lst" \) -mtime +$HOST_KEEP -exec rm -f {} \;
    echo "OK"
}

select_file() {
    local search_dir="$1"
    local ext="$2"
    echo "Select $ext file" >&2
    FILES=$(ls -t "$search_dir"/*"$ext" 2>/dev/null)
    [ -z "$FILES" ] && return 1
    i=1
    for f in $FILES; do
        echo " [$i] $(basename "$f") ($(du -sh "$f" | awk '{print $1}'))" >&2
        i=$((i+1))
    done
    printf "Selection (0 to cancel): " >&2
    read choice
    [ -z "$choice" ] || [ "$choice" -eq 0 ] || [ "$choice" -ge "$i" ] && return 1
    SELECTED_PATH=$(echo "$FILES" | sed -n "${choice}p")
}

case "$1" in
    backup)
        LOCAL_FILE="$L_BACKUP_DIR/backup_${HNAME}_${DATE}.tar.gz"
        LOCAL_LST="$L_BACKUP_DIR/packages_${HNAME}_${DATE}.lst"
        REMOTE_STATUS="FAILED"
        $SCR_BACKUP "$LOCAL_FILE" "$LOCAL_LST" "$SCR_OPKG" "$C_LIST" "$H_REPLACE" "$C_EXCLUDE"
        manage_local_backups
        if check_network && check_dependencies && mount_share; then
            printf "Copying to %s storage... " "$STORAGE_TYPE"
            if cp "$LOCAL_FILE" "$LOCAL_LST" "$S_MOUNT/"; then
                echo "OK"
                REMOTE_STATUS="OK"
                clean_old_remote_backups
            else
                echo "FAILED"
            fi
            sync
            umount "$S_MOUNT"
        else
            echo "    Backup remains only in $L_BACKUP_DIR"
        fi
        echo "Summary:"
        echo " [+] Local: $LOCAL_FILE"
        if [ "$REMOTE_STATUS" = "OK" ]; then
            echo " [+] Remote: ${S_HOST}:${S_PATH}/$(basename "$LOCAL_FILE")"
        else
            echo " [!] Remote: Not saved"
        fi
        ;;

    restore-pkgs)
        check_network && mount_share || { echo "Remote unavailable"; exit 1; }
        select_file "$S_MOUNT" ".lst"
        [ -n "$SELECTED_PATH" ] && $SCR_OPKG restore "$SELECTED_PATH" "$H_REPLACE"
        umount "$S_MOUNT"
        ;;

    restore-sys-net)
        check_network && mount_share || { echo "Remote unavailable"; exit 1; }
        select_file "$S_MOUNT" ".tar.gz"
        [ -n "$SELECTED_PATH" ] && sysupgrade -r "$SELECTED_PATH"
        umount "$S_MOUNT"
        ;;

    restore-sys-local)
        select_file "$L_BACKUP_DIR" ".tar.gz"
        [ -n "$SELECTED_PATH" ] && sysupgrade -r "$SELECTED_PATH"
        ;;

    restore)
        echo "1. Local storage ($L_BACKUP_DIR)"
        echo "2. Remote storage ($STORAGE_TYPE)"
        printf "Select source: "
        read s_choice
        R_DIR=""
        [ "$s_choice" -eq 1 ] && R_DIR="$L_BACKUP_DIR"
        [ "$s_choice" -eq 2 ] && { check_network && mount_share && R_DIR="$S_MOUNT"; }
        if [ -z "$R_DIR" ]; then
            echo " [!] Source unavailable or cancelled."
            exit 1
        fi
        echo "1. System configs (.tar.gz)"
        echo "2. Package list (.lst)"
        printf "Select type: "
        read t_choice
        case "$t_choice" in
            1)
                select_file "$R_DIR" ".tar.gz"
                if [ -n "$SELECTED_PATH" ]; then
                    [ "$s_choice" -eq 2 ] && { cp "$SELECTED_PATH" /tmp/restore.tar.gz; SELECTED_PATH="/tmp/restore.tar.gz"; umount "$S_MOUNT"; }
                    sysupgrade -r "$SELECTED_PATH"
                fi
                ;;
            2)
                select_file "$R_DIR" ".lst"
                if [ -n "$SELECTED_PATH" ]; then
                    $SCR_OPKG restore "$SELECTED_PATH" "$H_REPLACE"
                fi
                ;;
            *)
                echo "Cancelled."
                ;;
        esac
        grep -qs "$S_MOUNT" /proc/mounts && umount "$S_MOUNT"
        ;;

    *)
        echo "Usage: $0 {backup|restore}"
        exit 1
        ;;
esac