#!/bin/sh

# This script verifies that the postgresql data directory has been correctly
# initialized.  We do not want to automatically initdb it, because that has
# a risk of catastrophic failure (ie, overwriting a valuable database) in
# corner cases, such as a remotely mounted database on a volume that's a
# bit slow to mount.  But we can at least emit a message advising newbies
# what to do.
#
# It's used directly from the systemd service file as a prelaunch check.
# under sysv init it is called by the sysv init script as a sanity check.

PGDATA="$1"

if [ -z "$PGDATA" ]
then
    echo "Usage: $0 database-path"
    exit 1
fi

# PGVERSION is the full package version, e.g., 9.4.0
# Note: the specfile inserts the correct value during package build
PGVERSION=__RPM_PGVERSION__
# PGMAJORVERSION is major version, e.g., 9.4 (this should match PG_VERSION)
PGMAJORVERSION=__RPM_PGMAJORVERSION__
# PREVMAJORVERSION is the previous major version, e.g., 9.3, for upgrades
# Note: the specfile inserts the correct value during package build
PREVMAJORVERSION=__RPM_PREVMAJORVERSION__
# PGDOCDIR is the directory containing the package's documentation
# Note: the specfile inserts the correct value during package build
PGDOCDIR=__RPM_PGDOCDIR__
# Where to find Pg binaries for our version
PGENGINE=__RPM_PGENGINE__
PGPACKAGENAME=__RPM_PGPACKAGENAME__

# Check for the PGDATA structure
if [ -f "$PGDATA/PG_VERSION" ] && [ -d "$PGDATA/base" ]
then
    # Check version of existing PGDATA
    if [ x`cat "$PGDATA/PG_VERSION"` = x"$PGMAJORVERSION" ]
    then
        : A-OK
    else
        OLDVER="$(cat "$PGDATA/PG_VERSION")"
        MAJOR1=${OLDVER/%.*}
        MAJOR2=${OLDVER/#*.}
        if [ -n "$MAJOR1" -a -n "$MAJOR2" ]; then
            if [ "$MAJOR1" > 8 ] || [ "$MAJOR1" = 8 -a "$MAJOR2" >= 4 ]; then
                # Old version is 8.4 or newer, pg_upgrade should work
                echo $"An old version, $OLDVER, of the database format was found."
                echo $"Use \"${PGPACKAGENAME}-setup upgrade postgresql-${OLDVER}\" to upgrade to version $PGMAJORVERSION"
                echo $"or dump and reload to upgrade."
                echo $"See $PGDOCDIR/README.rpm-dist for more information."
                #exit 1
            fi
        fi
        echo $"An old version, $OLDVER, of the database format was found."
        echo $"pg_upgrade is not supported for this version."
        echo $"You need to dump and reload before using PostgreSQL $PGMAJORVERSION."
        echo $"See $PGDOCDIR/README.rpm-dist for more information."
        #exit 1
else
    # No existing PGDATA! Warn the user to initdb it.
    echo $"\"$PGDATA\" is missing or empty."
    echo $"Use \"$PGENGINE/postgresql94-setup initdb\" to initialize the database cluster."
    echo $"See $PGDOCDIR/README.rpm-dist for more information."
    exit 1
fi

exit 0