#!/bin/bash
# This file is part of GNU TALER.
# Copyright (C) 2023 Taler Systems SA
#
# TALER is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free Software
# Foundation; either version 2.1, or (at your option) any later version.
#
# TALER is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License along with
# TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
#
# @author Christian Grothoff
#
#
# Error checking on
set -eu

RESET_DB=0
SKIP_DBINIT=0
DBUSER="challenger-httpd"
CFGFILE="/etc/challenger/challenger.conf"



# Parse command-line options
while getopts 'c:hrsu:' OPTION; do
  case "$OPTION" in
  c)
    CFGFILE="$OPTARG"
    ;;
  h)
    echo 'Supported options:'
    echo "  -c FILENAME  -- write configuration to FILENAME (default: $CFGFILE)"
    echo "  -h           -- print this help text"
    echo "  -r           -- reset database (dangerous)"
    echo "  -s           -- skip database initialization"
    echo "  -u USER      -- challenger-httpd to be run by USER (default: $DBUSER)"
    exit 0
    ;;
  r)
    RESET_DB="1"
    ;;
  s)
    SKIP_DBINIT="1"
    ;;
  u)
    DBUSER="$OPTARG"
    ;;
  ?)
    echo "Unrecognized command line option '$OPTION'" 1>&2
    exit 1
    ;;
  esac
done

if ! id postgres >/dev/null;
then
  echo "Could not find 'postgres' user. Please install Postgresql first"
  exit 1
fi

if [ "$(id -u)" -ne 0 ];
then
  echo "This script must be run as root"
  exit 1
fi

if [ 0 = "$SKIP_DBINIT" ];
then
    if ! challenger-dbinit -v 2>/dev/null;
    then
	echo "Required 'challenger-dbinit' not found. Please fix your installation."
	exit 1
    fi
    DBINIT=$(which challenger-dbinit)
fi

if ! id "$DBUSER" >/dev/null;
then
    echo "Could not find '$DBUSER' user. Please create it up first"
    exit 1
fi

echo "Setting up database user $DBUSER." 1>&2

if ! sudo -i -u postgres createuser "$DBUSER" 2>/dev/null;
then
    echo "Database user '$DBUSER' already existed. Continuing anyway." 1>&2
fi

DBPATH=$(challenger-config \
  -c "$CFGFILE" \
  -s challengerdb-postgres \
  -o CONFIG)

if ! echo "$DBPATH" | grep "postgres://" >/dev/null;
then
    echo "Invalid database configuration value '$DBPATH'." 1>&2
    exit 1
fi

# Drop the query string ('?host=/var/run/postgresql') *first*: it may contain
# slashes, and the greedy 'postgres:\/\/.*\/' would then match up to the last
# slash of the socket path and yield 'postgresql' as the database name --
# which is what '-r' would proceed to drop.  Only the authority part (which
# never contains a slash) is stripped from the front.
DBNAME=$(echo "$DBPATH" |
  sed \
    -e "s/?.*//" \
    -e "s/^postgres:\/\/[^\/]*\///")

if sudo -i -u postgres psql "$DBNAME" </dev/null 2>/dev/null;
then
    if [ 1 = "$RESET_DB" ];
    then
	echo "Deleting existing database '$DBNAME'." 1>&2
	if ! sudo -i -u postgres dropdb "$DBNAME";
	then
	    echo "Failed to delete existing database '$DBNAME'"
	    exit 1
	fi
	DO_CREATE=1
    else
	echo "Database '$DBNAME' already exists, continuing anyway."
	DO_CREATE=0
    fi
else
    DO_CREATE=1
fi

if [ 1 = "$DO_CREATE" ];
then
    echo "Creating database '$DBNAME'." 1>&2

    if ! sudo -i -u postgres createdb -O "$DBUSER" "$DBNAME";
    then
	echo "Failed to create database '$DBNAME'"
	exit 1
    fi
fi

if [ 0 = "$SKIP_DBINIT" ];
then
    echo "Initializing database '$DBNAME'." 1>&2
    if ! sudo -u "$DBUSER" "$DBINIT" -c "$CFGFILE";
    then
	echo "Failed to initialize database schema"
	exit 1
    fi
fi

echo "Database configuration finished." 1>&2

exit 0
