#!/bin/bash
#
# lib/databases/postgresql
# Functions to control the configuration and operation of the **PostgreSQL** database backend

# Dependencies:
#
# - DATABASE_{HOST,USER,PASSWORD} must be defined

# Save trace setting
_XTRACE_PG=$(set +o | grep xtrace)
set +o xtrace


MAX_DB_CONNECTIONS=${MAX_DB_CONNECTIONS:-200}
INSTALL_DATABASE_SERVER_PACKAGES=$(trueorfalse True INSTALL_DATABASE_SERVER_PACKAGES)

register_database postgresql


# Functions
# ---------

function get_database_type_postgresql {
    echo postgresql
}

# Get rid of everything enough to cleanly change database backends
function cleanup_database_postgresql {
    stop_service postgresql
    if is_ubuntu; then
        # Get ruthless with mysql
        apt_get purge -y postgresql*
        return
    elif is_fedora || is_suse; then
        uninstall_package postgresql-server
    else
        return
    fi
}

function recreate_database_postgresql {
    local db=$1
    # Avoid unsightly error when calling dropdb when the database doesn't exist
    psql -h$DATABASE_HOST -U$DATABASE_USER -dtemplate1 -c "DROP DATABASE IF EXISTS $db"
    createdb -h $DATABASE_HOST -U$DATABASE_USER -l C -T template0 -E utf8 $db
}

function configure_database_postgresql {
    local pg_conf pg_dir pg_hba check_role version
    echo_summary "Configuring and starting PostgreSQL"
    if is_fedora; then
        pg_hba=/var/lib/pgsql/data/pg_hba.conf
        pg_conf=/var/lib/pgsql/data/postgresql.conf
        if ! sudo [ -e $pg_hba ]; then
            sudo postgresql-setup initdb
        fi
    elif is_ubuntu; then
        version=`psql --version | cut -d ' ' -f3 | cut -d. -f1-2`
        if vercmp $version '>=' 9.3; then
            if [ -z "`pg_lsclusters -h`" ]; then
                echo 'No PostgreSQL clusters exist; will create one'
                sudo pg_createcluster $version main --start
            fi
        fi
        pg_dir=`find /etc/postgresql -name pg_hba.conf|xargs dirname`
        pg_hba=$pg_dir/pg_hba.conf
        pg_conf=$pg_dir/postgresql.conf
    elif is_suse; then
        pg_hba=/var/lib/pgsql/data/pg_hba.conf
        pg_conf=/var/lib/pgsql/data/postgresql.conf
        # initdb is called when postgresql is first started
        sudo [ -e $pg_hba ] || start_service postgresql
    else
        exit_distro_not_supported "postgresql configuration"
    fi
    # Listen on all addresses
    sudo sed -i "/listen_addresses/s/.*/listen_addresses = '*'/" $pg_conf
    # Set max_connections
    sudo sed -i "/max_connections/s/.*/max_connections = $MAX_DB_CONNECTIONS/" $pg_conf
    # Do password auth from all IPv4 clients
    sudo sed -i "/^host/s/all\s\+127.0.0.1\/32\s\+ident/$DATABASE_USER\t0.0.0.0\/0\tpassword/" $pg_hba
    # Do password auth for all IPv6 clients
    sudo sed -i "/^host/s/all\s\+::1\/128\s\+ident/$DATABASE_USER\t::0\/0\tpassword/" $pg_hba
    restart_service postgresql

    # Create the role if it's not here or else alter it.
    check_role=$(sudo -u root sudo -u postgres -i psql -t -c "SELECT 'HERE' from pg_roles where rolname='$DATABASE_USER'")
    if [[ ${check_role} == *HERE ]];then
        sudo -u root sudo -u postgres -i psql -c "ALTER ROLE $DATABASE_USER WITH SUPERUSER LOGIN PASSWORD '$DATABASE_PASSWORD'"
    else
        sudo -u root sudo -u postgres -i psql -c "CREATE ROLE $DATABASE_USER WITH SUPERUSER LOGIN PASSWORD '$DATABASE_PASSWORD'"
    fi
}

function install_database_postgresql {
    echo_summary "Installing postgresql"
    local pgpass=$HOME/.pgpass
    if [[ ! -e $pgpass ]]; then
        cat <<EOF > $pgpass
*:*:*:$DATABASE_USER:$DATABASE_PASSWORD
EOF
        chmod 0600 $pgpass
    else
        sed -i "s/:root:\w\+/:root:$DATABASE_PASSWORD/" $pgpass
    fi
    if [[ "$INSTALL_DATABASE_SERVER_PACKAGES" == "True" ]]; then
        if is_ubuntu; then
            install_package postgresql
        elif is_fedora || is_suse; then
            install_package postgresql-server
            if is_fedora; then
                sudo systemctl enable postgresql
            fi
        else
            exit_distro_not_supported "postgresql installation"
        fi
    fi
}

function install_database_python_postgresql {
    # Install Python client module
    pip_install_gr psycopg2
    ADDITIONAL_VENV_PACKAGES+=",psycopg2"
}

function database_connection_url_postgresql {
    local db=$1
    echo "$BASE_SQL_CONN/$db?client_encoding=utf8"
}


# Restore xtrace
$_XTRACE_PG

# Local variables:
# mode: shell-script
# End: