#! /bin/sh

DECAY_TIME=30*86400
RUN_INCREMENT=86400
MAX_NRESULTS=10000
FILE_DELETE_READY=1
FILE_DELETE_DONE=2
FILE_DELETE_ERROR=3

dbhost=`grep db_host ../config.xml | tr '[\<\>]' '[  ]' | head -1 | awk '{print $2}'`
replica_dbhost=`grep replica_db_host ../config.xml | tr '[\<\>]' '[  ]' | head -1 | awk '{print $2}'`
dbuser=`grep db_user ../config.xml | tr '[\<\>]' '[  ]' | head -1 | awk '{print $2}'`
dbname=`grep db_name ../config.xml | tr '[\<\>]' '[  ]' | head -1 | awk '{print $2}'`

if test ! -z "${replica_dbhost}" ; then
  slave_gap=`mysql -E -h ${replica_dbhost} --execute="show slave status" | grep Seconds_Behind_Master | awk '{print $2}'`
fi

if test -z "${replica_dbhost}" || test "$slave_gap" = "NULL" || test $slave_gap -gt $RUN_INCREMENT ; then
  replica_dbhost=${dbhost}
fi

MYSQL="mysql -D $dbname -h $dbhost -u $dbuser -N -B"
MYSQL_R="mysql -D $dbname -h $replica_dbhost -u $dbuser -N -B"

function median_host_query() {
  $MYSQL --execute="
     create temporary table medians (id int auto_increment primary key)
       select $1 from host 
       where rpc_time>unix_timestamp(now())-($DECAY_TIME)
             and credit_per_cpu_sec>0
       order by $1;
     create temporary table ids
       select round(avg(id)-0.5) as id from medians;
     insert into ids select round(avg(id)+0.5) from medians;
     select avg($1) from medians where id in (
       select id from ids
     );
     drop table medians;
     drop table ids;"
}

function get_recent_credited_results() {
  $MYSQL_R --execute="
    set session transaction isolation level read uncommitted;
    create temporary table recent_results 
      select 
        granted_credit,
	cpu_time,
        hostid,
	p_fpops,
	p_iops
      from host,result where 
        file_delete_state in ($FILE_DELETE_READY,$FILE_DELETE_DONE) and
        granted_credit>0 and
        received_time>unix_timestamp(now())-$DECAY_TIME and
	unix_timestamp(result.mod_time)>unix_timestamp(now())-$RUN_INCREMENT and
	host.rpc_time>unix_timestamp(now())-$DECAY_TIME and
	appid=$1 and
	result.hostid=host.id
      limit $MAX_NRESULTS;
    create temporary table merged_results 
        select sum(granted_credit)/sum(cpu_time) as granted_rate,
	hostid,
	(p_fpops+p_iops)*5.787037037037e-13 as bench_rate 
    from recent_results 
    group by hostid;
    create temporary table medians (id int auto_increment primary key)
      select (bench_rate+1e-10)/(granted_rate+1e-10) as mult 
      from merged_results 
      order by mult; 
    create temporary table ids
      select round(avg(id)-0.5) as id from medians;
    insert into ids select round(avg(id)+0.5) from medians;
    select avg(mult) from medians where id in (
      select id from ids
    );
    drop table ids;
    drop table medians;
    drop table merged_results;
    drop table recent_results;"
}


appids=`$MYSQL --execute="select id from app where deprecated=0 and beta=0"`

for appid in $appids ; do
  ratio=`get_recent_credited_results $appid`

  nrows=`$MYSQL --execute="select count(id) from credit_multiplier where appid=$appid"`
  if [ $nrows = 0 ] ; then
    $MYSQL --execute="insert into credit_multiplier values (0,$appid,unix_timestamp(now())-86400,1.0)"
  fi

    last_value=`$MYSQL --execute="select multiplier from credit_multiplier where appid=$appid and (unix_timestamp(now())-time)=(select min(unix_timestamp(now())-time) from credit_multiplier where appid=$appid)"`
    echo -n "appid=${appid} last_value=${last_value}"
    last_time=`$MYSQL --execute="select unix_timestamp(now())-time from credit_multiplier where appid=$appid and (unix_timestamp(now())-time)=(select min(unix_timestamp(now())-time) from credit_multiplier where appid=$appid)"`
    echo -n "   desired_value=${ratio}"

    value=`$MYSQL --execute="select ($last_value*(($DECAY_TIME)-$last_time)+$ratio*$last_time)/($DECAY_TIME)"`
    echo -n "   new_value=${value}"
    echo

    $MYSQL --execute="insert into credit_multiplier values (0,$appid,unix_timestamp(now()),$value);"
done

exit 0