#!/bin/bash

## Variables
VERSION=20181025.1620
CURDIR=$(dirname $0)
SCRIPT=$(basename $0 .sh)
WARN=10
CRIT=30
ARCH_RETENTION=1

## Functions
upper() { echo "$1" | tr '[:lower:]' '[:upper:]' ; }
lower() { echo "$1" | tr '[:upper:]' '[:lower:]' ; }
  
help() {
  cat <<EOF
Usage : $SCRIPT
Provide helpers for Oracle logshipping configuration and management

Commands :
  $actions

Options
   -f    : configuration file (default $configfile)
   -d    : database configuration
   -o    : archive retention in days (default: 1)
   -v    : verbose mode (optional)
   -i    : inline nagios mode (optional)
   -w    : warning threshold (optional)
   -c    : critical threshold (optional)
EOF
  exit 0
}

# arg1: section name
# arg2: variable name
# arg3: general variable name 
ini() {
  var=$(sed -n -e "/^\[$1\]/I,/^\[/ p" $configfile | grep -i ^$2[^a-zA-Z] | cut -d= -f2 | cut -d# -f1)
  test -z "$var" && test -n "$3" && var=$(ini general $3) 
  test -z "$var" && test "$1" != "general" && var=$(ini general $2)
  test "$1" == "general" && echo $var | xargs && exit
  
  # recursive template variables like {{ db_name }}
  IFS=$'\n'
  for m in $(echo $var | grep -Poi '{{(\s?[a-z_]*\s?)}}') ; do
    s=$(echo $m | grep -Poi '[a-z_]*')
    var=$(echo $var | sed "s/$m/$(ini $1 $s)/g")
  done
  echo $var | xargs
}

# arg1: message
# arg2: return value (null, 0:ok 1:warn 2:crit 3:unknown)
# arg3: exit or null
trace() {
  case "$2" in
    0) printf "\033[1;32m[OK]\033[0m\t%s\n" "$1" ;;
    1) printf "\033[1;33m[WARN]\t%s\033[0m\n" "$1" ;;
    2) printf "\033[1;31m[KO]\t%s\033[0m\n" "$1" ;;
    3) printf "\033[1;31m[UNKN]\t%s\033[0m\n" "$1" ;;
    *) printf "\033[1;34m----\t%s\033[0m\n" "$1" ;;
  esac

  if [[ -n "$3" ]] && [[ "$3" = "exit" ]] ; then
    exit 1
  fi
}

# arg1: connexion string
# arg2: password
# arg3: statement
sql() {
  cnx="$1" ; pwd="$2" ; shift 2
  result=$($SQLPLUS -L -S /nolog <<OEF
    SET HEAD OFF;
    CONNECT sys/$pwd@//$cnx as sysdba;
    $(echo "$@" | sed 's/;/;\n/g' | sed 's/--BLANK/\n/g')
OEF
)
  if [[ ! $result =~ 'TNS-' ]] && \
     [[ ! $result =~ 'ORA-' ]] && \
     [[ ! $result =~ 'SP2-' ]] ;
  then
    echo "$result"
  else
    (>&2 echo "---- SQL: $@")
    (>&2 echo "$result")
    return 1
  fi
}

# arg1: target connection string
# arg2: auxiliary connection string or 0
# arg2: password
# arg3: statement
rman() {
  target="$1" ; auxiliary="$2" ; pwd="$3" ; shift 3
  result=$($RMAN <<OEF
    CONNECT TARGET sys/$pwd@//$target;
    $(test ! "$auxiliary"  = "0" && echo CONNECT AUXILIARY sys/$pwd@//$auxiliary;)
    $(echo "$@" | sed 's/;/;\n/g')
OEF
)
  if [[ ! $result =~ 'TNS-' ]] && \
     [[ ! $result =~ 'ORA-' ]] && \
     [[ ! $result =~ 'SP2-' ]] ;
  then
    echo "$result"
  else
    (>&2 echo "---- SQL: $@")
    (>&2 echo "$result")
    return 1
  fi
}

# arg1: database config name
lag() {
  trace "Get sequence lag for: $1"
  prim_seq=$(sql $(ini $1 primary_cnx) $(ini $1 password) \
    $'select max(sequence#) from v$archived_log;')
  trace "Primary sequence is: $(echo $prim_seq)" "$(test -n "$prim_seq" && echo 0 || echo 1)"

  stdb_seq=$(sql $(ini $1 standby_cnx) $(ini $1 password) \
    $'select max(sequence#) from v$archived_log where applied=\'YES\';')
  trace "Standby sequence is: $(echo $stdb_seq)" "$(test -n "$stdb_seq" && echo 0 || echo 1)"

  if [[ $prim_seq -ge $stdb_seq ]] ; then
    diff_seq=$(expr ${prim_seq:-0} - ${stdb_seq:-0})
    trace "Lag: $diff_seq" "$(test $diff_seq -ge $CRIT && echo 2 || { test $diff_seq -ge $WARN && echo 1 || echo 0; })"
  else
    trace "Standby database has been activated" 1 "exit"
  fi
}

# arg1: database config name
inline_lag() {
  prim_seq=$(sql $(ini $1 primary_cnx) $(ini $1 password) \
    $'select min(seq) from (select max(sequence#) seq from gv$archived_log group by inst_id) a;')
  stdb_seq=$(sql $(ini $1 standby_cnx) $(ini $1 password) \
    $'select max(sequence#) from v$archived_log where applied=\'YES\';')

  if [[ $prim_seq -ge $stdb_seq ]] ; then
    diff_seq=$(expr ${prim_seq:-0} - ${stdb_seq:-0})
    echo "$1: $diff_seq"
  else
    echo "Standby database has been activated"
  fi
}

# arg1: database config name
load() {
  ORACLE_HOME=$(ini ${1:-general} orahome)
  ORACLE_BASE=$(ini ${1:-general} orabase)

  test -d $ORACLE_HOME && export ORACLE_HOME
  test -d $ORACLE_BASE && export ORACLE_BASE

  export RMAN=${ORACLE_HOME}/bin/rman
  export SQLPLUS=${ORACLE_HOME}/bin/sqlplus
  export NLS_DATE_FORMAT="YYYY/MM/DD HH24:MI:SS"  
}

# arg1: database config name
configured?() {
  if [[ ! "$(ini general databases)" =~ "$1" ]] || [[ -z "$1" ]] ; then
    echo "Database '$1' is not configured"
    exit 1
  fi
  load "$1"
}

# arg1: database config name
ssh?() {  
  for node in $(ini $1 primary_node) $(ini $1 standby_node); do
    ssh -q $node exit
    if [[ $? -gt 0 ]] ; then
      echo "SSH connectivity failed on $node with $(whoami) user"
      exit 1
    fi
  done
}

do_list() {
  echo "Available databases configuration :"
  for cfg in $(ini general databases) ; do
    cat <<EOF

  $cfg:
    - primary = $(ini $cfg primary_cnx)
    - standby = $(ini $cfg standby_cnx)
EOF
  done
}

# arg1: database config name (optional)
do_status() {
  if [[ -z "$1" ]] ; then
    for cfg in $(ini general databases) ; do
      load "$cfg"
      ${INLINE}lag $cfg
    done
  else
    configured? "$1"
    ${INLINE}lag "$1"
  fi
}

# arg1: database config name (optional)
do_recover() {
  if [[ -z "$1" ]] ; then
    for cfg in $(ini general databases) ; do
      recover "$cfg"
    done
  else
    recover "$1"
  fi
}

# arg1: database config name
recover() {
  configured? "$1"
  rman $(ini $1 standby_cnx) 0 $(ini $1 password) \
    $'CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON STANDBY;' \
    $'RECOVER DATABASE;' \
    $'CROSSCHECK ARCHIVELOG ALL;' \
    $'DELETE NOPROMPT ARCHIVELOG ALL COMPLETED BEFORE \'SYSDATE-'${ARCH_RETENTION}$'\';'
}

# arg1: database config name (optional)
do_rsync() {
  if [[ -z "$1" ]] ; then
    for cfg in $(ini general databases) ; do
      rsync_arch "$cfg"
    done
  else
    rsync_arch "$1"
  fi
}

# arg1: database config name
rsync_arch() {
  from=$(ini "$1" primary_nodes)
  if [[ -n "$from" ]] ; then
    # first available
    for node in $from ; do
      from=$(ssh $node hostname --fqdn 2>&1)
      test $? -eq 0 && break
    done
  else
    # no cluster configuration
    from=$(ini "$1" primary_node)
  fi

  remote_fra="$(ini "$1" primary_fra_dest fra_dest)/$1/archivelog"
  local_fra="$(ini "$1" standby_fra_dest fra_dest)/$1/archivelog"

  result=$(rsync -az --stats "$from:$remote_fra/" "$local_fra")
  n=$(echo "$result" | grep "files transferred" | cut -d: -f2)
  trace "Transfer $(echo $n) file(s) from $from into $local_fra" "$(echo $?)"
}

# arg1: database config name
do_open() {
  configured? "$1"
  sql $(ini $1 standby_cnx) $(ini $1 password) \
    $'RECOVER AUTOMATIC STANDBY DATABASE;--BLANK' \
    $'ALTER DATABASE OPEN READ ONLY;'
}

# arg1: database config name
do_activate() {
  configured? "$1"
  sql $(ini $1 standby_cnx) $(ini $1 password) \
    $'ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH;' \
    $'ALTER DATABASE ACTIVATE STANDBY DATABASE;' \
    $'ALTER DATABASE OPEN;'

  rman $(ini $1 standby_cnx) 0 $(ini $1 password) \
    $'CONFIGURE ARCHIVELOG DELETION POLICY CLEAR;'
}

configfile=$CURDIR/repctl.conf.sample
test -f $CURDIR/repctl.conf && configfile=$CURDIR/repctl.conf

actions="activate list open recover rsync status"
if [[ ! $actions =~ "$1" ]] || [[ -z "$1" ]] ; then
  help
fi
ACTION="$1"
shift

while getopts ":d:w:c:f:iv" opt; do
  case $opt in
    d) DBCONF=$OPTARG ;;
    c) CRIT=$OPTARG ;;
    i) INLINE=inline_ ;;
    f) configfile=$OPTARG ;;
    v) VERBOSE=0 ;;
    w) WARN=$OPTARG ;;
    :) echo "Option -$OPTARG requires an argument." ; exit 1;;
    *) echo "Invalid option -$OPTARG" ; exit 1;;
  esac
done

test ! $VERBOSE && exec 2> /dev/null
supported="11.2 12.2"

# call action logic
do_$ACTION $DBCONF