#!/usr/bin/python

import sys, os, stat, time
import subprocess

PATH_MYSQL_DATA = '/srv/mysql'
PATH_AFS_BACKUP = '/afs/athena.mit.edu/contrib/sql/backup'
PATH_AFS_BACKUP_VOL = '/afs/athena.mit.edu/contrib/sql/.backup'
BACKUP_MAX_SIZE = 200*1024*1024

import MySQLdb, MySQLdb.cursors

def new_cursor(group='client'):
    return MySQLdb.connect('localhost', read_default_group=group, cursorclass=MySQLdb.cursors.DictCursor).cursor()

def use_db(cursor, db):
    cursor.execute('USE `%s`' % db)

def get_dbs(cursor, prefix=None):
    cursor.execute('SHOW DATABASES' + (prefix and (' LIKE \'%s%%\'' % prefix) or ''))
    return [x.values()[0] for x in cursor.fetchall() if x.values()[0] != 'information_schema']

def get_db_tables(cursor, db):
    cursor.execute('SHOW TABLES FROM `%s`' % db)
    return [(db, x.values()[0]) for x in cursor.fetchall()]

def get_db_tables_ft(cursor, db):
    r = []
    for table in get_db_tables(cursor, db):
        cursor.execute('SHOW INDEXES FROM `%s`.`%s`' % table)
        r.extend(set([(db, x['Table']) for x in cursor.fetchall() if x['Index_type'] == 'FULLTEXT']))
    return r

def get_db_tables_status(cursor, db):
    cursor.execute('SHOW TABLE STATUS FROM `%s`' % db)
    return dict([((db, x['Name']), x) for x in cursor.fetchall()])

def get_db_mtime(cursor, db):
    db_mtimes = filter(lambda x: not x is None, [status['Update_time'] for table, status in get_db_tables_status(cursor, db).items()])
    if len(db_mtimes):
        db_mtimes.sort(reverse=True)
        return db_mtimes[0]
    return 0

def get_db_size(cursor, db):
    return sum([status['Data_length']
                for table, status in get_db_tables_status(cursor, db).items()
                if status['Data_length']])

def get_db_tables_engines(cursor, db):
    return [(table, status['Engine']) for table, status in get_db_tables_status(cursor, db).items()]

def repair_table_quick(cursor, table):
    # REPAIR TABLE tbl QUICK
    # works when changing ft_min_word_len
    cursor.execute('REPAIR TABLE `%s`.`%s` QUICK' % table)

def repair_tables_from_stdin(cursor):
    while True:
        data = sys.stdin.readline()
        if not data:
            break
        data = data.strip()
        table = eval(data)
        print table
        repair_table_quick(cursor, table)

def db_backup_pre(cursor, db):
    db_size = get_db_size(cursor, db)
    if db_size < BACKUP_MAX_SIZE:
        if len(db.split('+')) <= 1:
            owner = 'root'
        else:
            owner = db.split('+')[0]
        db_mtime = get_db_mtime(cursor, db)
        db_path = '%s/%s/%s.sql.gz' % (PATH_AFS_BACKUP, owner.lower(), db)
        try:
            bk_mtime = os.stat(db_path)[stat.ST_MTIME]
        except:
            bk_mtime = 0
        if not db_mtime:
            r = (False, 'empty database')
        elif int(time.mktime(db_mtime.timetuple())) > bk_mtime:
            r = (True, db_path)
        else:
            r = (False, 'mtime: %s < %s' % (str(db_mtime),
                                            time.strftime('%Y-%m-%d %H:%M:%S',
                                                          time.localtime(bk_mtime))))
    else:
        r = (False, 'size: %.2fM > %dM' % (db_size/1024/1024, BACKUP_MAX_SIZE/1024/1024))
    return r

def db_backup_pstrip(path):
    r = path
    if r.startswith(PATH_AFS_BACKUP):
        r = r[len(PATH_AFS_BACKUP):]
    if r and r[0] == '/':
        r = r[1:]
    return r

def db_backup_mkdir(path):
    p = db_backup_pstrip(path)
    owner = p.split('/')[0]
    p_owner = '%s/%s' % (PATH_AFS_BACKUP, owner)
    p_owner_vol = '%s/%s/%s' % (PATH_AFS_BACKUP_VOL, owner[0], owner)
    if not os.path.islink(p_owner):
        os.symlink(p_owner_vol, p_owner)
    if not os.path.isdir(p_owner_vol):
        os.mkdir(p_owner_vol)
        subprocess.call(['fs', 'sa', p_owner_vol, 'system:anyuser', 'none'])
        subprocess.call(['fs', 'sa', p_owner_vol, 'system:authuser', 'none'])
        if owner == 'root':
            subprocess.call(['fs', 'sa', p_owner_vol, 'system:sql-backup', 'none'])
    #print owner
    #print ' ', p_owner
    #print ' ', p_owner_vol
    
def tables_in_ibdata(cursor):
    for db in get_dbs(cursor):
        table_engines = get_db_tables_engines(cursor, db)
        innodb_tables = [x[0] for x in table_engines \
                              if x[1] and x[1].lower() == 'innodb']
        for table in innodb_tables:
            path = '%s/%s/%s.ibd' % (PATH_MYSQL_DATA, table[0], table[1])
            if not os.path.isfile(path):
                yield '`%s`.`%s`' % table

if __name__ == '__main__':
    pass