#!/usr/bin/env python
# coding: UTF-8

# pt-index-usage
#
# Copyright(c) 2015 Uptime Technologies, LLC.

import sys, os
libpath = os.path.abspath(os.path.dirname(sys.argv[0]) + "/../lib")
sys.path.append(libpath)

import getopt
import PsqlWrapper

class IndexUsage:
    def build_where_clause(self, where_clause, cond):
        if where_clause is None:
            where_clause = " where "
        else:
            where_clause = where_clause + " and "
        where_clause = where_clause + " " + cond
        return where_clause

    def __init__(self, psql, owner, schema, table, index, unused, debug=False):
        self.debug = debug

        self.psql = psql

        where_clause = None

        if schema is not None:
            where_clause = self.build_where_clause(where_clause, "s.schemaname = '" + schema + "'")

        if owner is not None:
            where_clause = self.build_where_clause(where_clause, "u.usename = '" + owner + "'")

        if table is not None:
            where_clause = self.build_where_clause(where_clause, "s.relname = '" + table + "'")

        if index is not None:
            where_clause = self.build_where_clause(where_clause, "s.indexrelname = '" + index + "'")

        if unused is True:
            where_clause = self.build_where_clause(where_clause, "idx_scan = 0")

        if where_clause is None:
            where_clause = ''

        # indislive: 9.3 or later
        indislive = ''
        if self.psql.get_version() >= 9.3:
            indislive = ' || case when indislive then \',\' else \'NOTLIVE\' end '

        self.query = ' \
select \
    s.indexrelid as "OID", \
    u.usename as "OWNER", \
    s.schemaname as "SCHEMA", \
    s.relname as "TABLE", \
    s.indexrelname as "INDEX", \
    pg_relation_size(s.indexrelid)/8192 as "BLKS", \
    idx_scan as "SCAN", \
    idx_tup_read as "T_READ", \
    idx_tup_fetch as "T_FTCH", \
    idx_blks_read as "B_READ", \
    idx_blks_hit as "B_HIT", \
    regexp_replace( \
       case when indisvalid then \',\' else \'INVALID,\' end || \
       case when indisready then \',\' else \'NOTREADY,\' end \
       %s , \
         \',+$\', \'\') as "STATUS", \
    coalesce(spcname, (select spcname from pg_database d left outer join pg_tablespace t on dattablespace = t.oid where datname = current_database())) as "TABLESPACE" \
  from \
    pg_stat_user_indexes s left outer join pg_statio_user_indexes s2 \
                               on s.indexrelid = s2.indexrelid \
                           left outer join pg_index i \
                               on s.indexrelid = i.indexrelid \
                           left outer join pg_class c \
                               on s.indexrelid = c.oid \
                           left outer join pg_user u \
                               on c.relowner = u.usesysid \
                           left outer join pg_tablespace t \
                               on c.reltablespace = t.oid \
%s \
 order by \
    2,3,4 \
;' % (indislive, where_clause)

        if self.debug is True:
            print self.query

    def get(self):
        rs = self.psql.execute_query(self.query)

        self.psql.print_result(rs)

        return True

def usage():
    print ""
    print "Usage: " + os.path.basename(sys.argv[0]) + " [option...]"
    print ""
    print "Options:"
    print "    -h, --host=HOSTNAME        Host name of the postgres server"
    print "    -p, --port=PORT            Port number of the postgres server"
    print "    -U, --username=USERNAME    User name to connect"
    print "    -d, --dbname=DBNAME        Database name to connect"
    print ""
    print "    -o, --owner=STRING         Owner name"
    print "    -n, --schema=STRING        Schema name"
    print "    -t, --table=STRING         Table name"
    print "    -i, --index=STRING         Index name"
    print ""
    print "    --help                     Print this help."
    print ""

if __name__ == "__main__":
    try:
        opts, args = getopt.getopt(sys.argv[1:], "h:p:U:d:o:n:t:i:u",
                                   ["help", "debug", "host=", "port=", "username=", "dbname=",
                                    "owner=", "schema=", "table=", "index=", "unused"])
    except getopt.GetoptError, err:
        print str(err)
        usage()
        sys.exit(2)

    host     = None
    port     = None
    username = None
    dbname   = None

    owner    = None
    schema   = None
    table    = None
    index    = None
    unused   = False

    debug    = None

    for o, a in opts:
        if o in ("-h", "--host"):
            host = a
        elif o in ("-p", "--port"):
            port = int(a)
        elif o in ("-U", "--username"):
            username = a
        elif o in ("-d", "--dbname"):
            dbname = a
        elif o in ("-o", "--owner"):
            owner = a
        elif o in ("-n", "--schema"):
            schema = a
        elif o in ("-t", "--table"):
            table = a
        elif o in ("-i", "--index"):
            index = a
        elif o in ("-u", "--unused"):
            unused = True
        elif o in ("--debug"):
            debug = True
        elif o in ("--help"):
            usage()
            sys.exit(0)
        else:
            print "unknown option: " + o + "," + a
            sys.exit(1)

    p = PsqlWrapper.PsqlWrapper(host=host, port=port, username=username, dbname=dbname, debug=debug)

    iu = IndexUsage(p, owner, schema, table, index, unused, debug=debug)
    if iu.get() is False:
        sys.exit(1)

    sys.exit(0)