#!/bin/bash
#
# Restores a composed MySQL/MariaDB database from a dump file.
# Gets all necessary data from the docker-compose.yml file.
#
# This is a wrapper script to the system-wide mysql_restoredb tool.
# Database recovey with the necessary user management and grants
# requires superuser privileges in MySQL, but simple data recovery
# is possible if the user and privileges are already set.
#
# You have to call this script as a Docker manager user (member of the
# 'docker' Linux group). The worker tool must be available somewhere
# in PATH. At least 5.7.6 MySQL or at least 10.1.3 MariaDB is required.
#
# Usage:
# $0 path_to_the_dumpfile [ path_to_the_service's_base ]
#
# Author: Kovács Zoltán <kovacsz@marcusconsulting.hu>
# License: GNU/GPL v3+ (https://www.gnu.org/licenses/gpl-3.0.en.html)
#
# 2025-02-26 v0.1 Forked from the Smartfront repository and rewritten.

# Accepted environment variables and their defaults.
#
PAR_SERVICE=${SERVICE:-"database"}		# Database container's name

# Other initialisations.
#
BACKUPFOLDER="storage/backups/dumps"		# Skeleton's default dump folder
PROP_DBAPASS="MYSQL_ROOT_PASSWORD"		# DB admin password property
PROP_DBNAME="MYSQL_DATABASE"			# DB name property
PROP_DBPASS="MYSQL_PASSWORD"			# DB password property
PROP_DBUSER="MYSQL_USER"			# DB username property
USER=${USER:-LOGNAME}                           # Fix for cron enviroment only
YMLFILE="docker-compose.yml"

# Basic environment settings.
#
LANG=C
LC_ALL=C

# Messages.
#
MSG_BADDUMP="Fatal: doesn't exist or doesn't a dumpfile:"
MSG_DOCKERGRPNEED="You must be a member of the docker group."
MSG_DOESNOTRUN="This service doesn't run."
MSG_MISSINGDEP="Fatal: missing dependency"
MSG_MISSINGCONF="Fatal: missing config file"
MSG_MISSINGYML="Fatal: didn't find the $YMLFILE file"
MSG_NOLOCATE="Cannot locate the database container."
MSG_NOPARAM="Missing environment parameter"

MSG_USAGE="Usage: $0 dump_pathname [ composition_base_pathname ]\n"
MSG_USAGE+="ENVVAR:\n"
MSG_USAGE+="SERVICE       \tDatabase service's name in composition\n"

# Checks the dependencies.
#
TR=$(which tr 2>/dev/null)
if [ -z "$TR" ]; then echo "$MSG_MISSINGDEP tr."; exit 1 ; fi
for item in basename cat cut date dirname docker \
            grep id mysql_restoredb readlink tail xargs
do
    if [ -n "$(which $item)" ]
    then export $(echo $item | "$TR" '[:lower:]' '[:upper:]' | "$TR" '-' '_')=$(which $item)
    else echo "$MSG_MISSINGDEP $item." >&2; exit 1; fi
done
# All dependencies are available via "$THECOMMAND" (upper case) call.
#
# Let's find which version of docker-compose is installed.
if [ $($DOCKER compose version >/dev/null 2>&1; echo $?) -eq 0 ]; then
    # We'll use v2 if it is available.
    DOCKER_COMPOSE="$DOCKER"
    commandstring="compose"
else
    # Otherwise falling back to v1.
    DOCKER_COMPOSE="$(which docker-compose)"
    commandstring=""
fi
# One of the two is mandatory.
if [ -z "$DOCKER_COMPOSE" ];then echo "$MSG_MISSINGDEP docker-compose" >&2; exit 1; fi
# Below docker-compose should be called as "$DOCKER_COMPOSE" $commandstring sequence.

# Where I'm?
# https://gist.github.com/TheMengzor/968e5ea87e99d9c41782
SOURCE="$0"
while [ -h "$SOURCE" ]; do
    # resolve $SOURCE until the file is no longer a symlink
    SCRPATH="$( cd -P "$("$DIRNAME" "$SOURCE" )" && echo "$PWD" )" #"
    SOURCE="$("$READLINK" "$SOURCE")"
    # if $SOURCE was a relative symlink, we need to resolve it
    # relative to the path where the symlink file was located
    [[ $SOURCE != /* ]] && SOURCE="$SCRPATH/$SOURCE"
done; SCRPATH="$( cd -P "$("$DIRNAME" "$SOURCE" )" && echo "$PWD" )" #"

# Need to be root or a Docker manager user.
#
[[ "$USER" != 'root' ]] \
&& [[ -z "$(echo "$("$ID" -Gn "$USER") " | "$GREP" ' docker ')" ]] \
&& echo "$MSG_DOCKERGRPNEED" >&2 && exit 1 #"

# Gets the command line parameters.
#
# DUMPFILE is mandatory
if [ -n "$1" ]; then DUMPFILE="$1"; shift
else echo -e "$MSG_USAGE" >&2; exit 1; fi
# SERVICE_BASE is optional
if [ -n "$1" ]; then SERVICE_BASE="$1"; shift; fi
# We've read the unchecked command line parameters.

# Searches the base folder, containing the YMLFILE.
#
if [ -z "$SERVICE_BASE" ]; then
    # Called from the base folder (./)?
    TEST_DIR="$SCRPATH"
    [[ -z "$SERVICE_BASE" ]] && [[ -r "$TEST_DIR/$YMLFILE" ]] && SERVICE_BASE="$TEST_DIR"
    # Called from ./tools?
    TEST_DIR="$("$DIRNAME" "$TEST_DIR")"
    [[ -z "$SERVICE_BASE" ]] && [[ -r "$TEST_DIR/$YMLFILE" ]] && SERVICE_BASE="$TEST_DIR"
    # Called from ./tools/*.d?
    TEST_DIR="$("$DIRNAME" "$TEST_DIR")"
    [[ -z "$SERVICE_BASE" ]] && [[ -r "$TEST_DIR/$YMLFILE" ]] && SERVICE_BASE="$TEST_DIR"
fi
# On failure gives it up here.
if [ -z "$SERVICE_BASE" -o ! -r "$SERVICE_BASE/$YMLFILE" ]; then
    echo "$MSG_MISSINGYML" >&2; exit 1
fi
# Sets the absolute path.
YMLFILE="$SERVICE_BASE/$YMLFILE"
# We've the YMLFILE.

# Finds the DUMPFILE to use.
#
# The DUMPFILE must point to a readable file.
# If doesn't it tries the skeleton's standard backup folder as well.
if [ ! -r "$DUMPFILE" ]
then DUMPFILE="$("$DIRNAME" "$SERVICE_BASE")/$BACKUPFOLDER/$DUMPFILE"; fi
# If it is an existing symlink dereferences it to ensure, it points to a file.
if [ -h "$DUMPFILE" ]; then
    if [[ "$("$READLINK" "$DUMPFILE")" != /* ]]
    # relative path in symlink
    then DUMPFILE="$("$DIRNAME" "$DUMPFILE")/$("$READLINK" "$DUMPFILE")"
    # absolute path in symlink
    else DUMPFILE="$("$READLINK" "$DUMPFILE")"; fi
fi
# Let's check it!
if [ ! -r "$DUMPFILE" -o  ! -f "$DUMPFILE" ]
then echo -e "$MSG_BADDUMP $DUMPFILE"; exit 1; fi
# We've an existing dumpfile.

# The composition must be running - silently gives up here if not.
#
[[ -z "$(cd "$SERVICE_BASE"; "$DOCKER_COMPOSE" $commandstring ps --services --filter "status=running")" ]] \
&& exit 1

# Parses the YMLFILE for parameters to use.
#
function parse { [[ -z "$1" ]] && return
    # Gets the live lines containing the parameter.
    value=$("$CAT" "$YMLFILE" | "$GREP" -ve '^#' | \
            "$GREP" -e "^ *$1" | "$TR" -d '\r')
    # If multiple the last one to consider.
    value=$(echo -e  "$value" | "$TAIL" -n1)
    # Right side of the colon W/O leading and trailing spaces and quotes.
    value=$(echo -ne "$value" | "$CUT" -d':' -f2 | "$XARGS")
    # Removes the trailing semicolon (if any).
    value=${value%;*}
    echo -e "$value"; return
}
# These parameters are mandatory.
MYCONTAINER="$PAR_SERVICE" # TODO: guess from the yml
if [ -z "$MYCONTAINER" ]; then echo "$MSG_NOPARAM PAR_SERVICE" >&2; exit 1; fi1; fi
MYDATABASE="$(parse "$PROP_DBNAME")"
if [ -z "$MYDATABASE" ]; then echo "$MSG_NOPARAM $PROP_DBNAME" >&2; exit 1; fi
MYUSER="$(parse "$PROP_DBUSER")"
if [ -z "$MYUSER" ]; then echo "$MSG_NOPARAM $PROP_DBUSER" >&2; exit 1; fi
MYPASSWORD="$(parse "$PROP_DBPASS")"
if [ -z "$MYPASSWORD" ]; then echo "$MSG_NOPARAM $PROP_DBPASS" >&2; exit 1; fi
# These are optional.
MYDBAUSER="root"
MYDBAPASSWORD="$(parse "$PROP_DBAPASS")"
# We've the configuration parsed.

# Converts the database service name to an actual running container's name.
#
MYCONTAINER="$("$DOCKER" inspect -f '{{.Name}}' $(cd "$SERVICE_BASE"; "$DOCKER_COMPOSE" $commandstring ps -q "$MYCONTAINER") | "$CUT" -c2-)"
# Gives up here if failed.
if [ -z "$MYCONTAINER" ]; then echo "$MSG_NOLOCATE" >&2; exit 1; fi

# Calls the worker script to make the job.
#
export MYDBAUSER MYDBAPASSWORD MYPASSWORD
"$MYSQL_RESTOREDB" -C "$MYCONTAINER" -U "$MYUSER" "$MYDATABASE" "$DUMPFILE"

# That's all, Folks! :)