import logging.handlers

import time

from datetime import datetime, timedelta

from psycopg2 import ProgrammingError

class RunQueryTool(ToolBase):

    """

    Execute configured queries in target database.

    """

    def __init__(self):

        self.target_isolation_level = 'autocommit'

    def specify_args(self):

        self.parser.add_argument('-q', dest='queries', metavar='QUERY', nargs='*', help='Queries to run.')

        self.parser.add_argument('-f', dest='file', metavar='FILE', help='Read query from file.')

        self.parser.add_argument('--one-query-per-line', action='store_true', help='When reading queries from file, consider each line as separate query.')

        self.parser.add_argument('-p', '--parameter', dest='parameters', metavar='PARAM=VALUE', nargs='*',

            help="If query should be used as format template, these parameters will be substituted.")

        self.parser.add_argument('--output-file', dest='output_file', metavar='OUTPUT_FILE', help='Write query result in specified file.')

        self.parser.add_argument('--format', dest='format', metavar='FORMAT', help='Format string for each line in output file (using Python\'s format()).')

        self.config.add_option('queries', type=list, default=[])

        self.config.add_option('log_path', type=str)

    def load_args(self, args=None, config_file=None):

        self.queries = self.args.queries or self.config.queries

        # read query from file

        if self.args.file:

            with open(self.args.file, 'r', encoding='utf8') as f:

                data = f.read()

            if self.args.one_query_per_line:

                file_queries = [ln for ln in data.splitlines() if not ln.lstrip().startswith('--')]

                self.queries = file_queries + self.queries

            else:

                self.queries.insert(0, data)

        # prepare parameters

        self._prepare_parameters(self.args.parameters)

    def init_logging(self):

        ToolBase.init_logging(self)

        if self.config.log_path:

            self.init_file_logs(self.config.log_path)

    def init_file_logs(self, path):

        format = logging.Formatter('%(asctime)s %(levelname)-5s %(message)s', '%y-%m-%d %H:%M:%S')

        handler = logging.handlers.TimedRotatingFileHandler(path+'/main.log', when='midnight', backupCount=5)

        handler.setFormatter(format)

        handler.setLevel(logging.DEBUG)

        logging.getLogger('main').addHandler(handler)

        format = logging.Formatter('%(asctime)s %(message)s', '%y-%m-%d %H:%M:%S')

        handler = logging.handlers.TimedRotatingFileHandler(path+'/pgnotices.log', when='midnight', backupCount=5)

        handler.setFormatter(format)

        handler.setLevel(logging.DEBUG)

        logging.getLogger('pgmanager_notices').addHandler(handler)

    def main(self):

        """Execute the queries."""

        for q in self.queries:

            if self.parameters:

                q = q.format(**self.parameters)

            self.log.info('%s', q if len(q) < 100 else q[:100]+'...')

            with self.pgm.cursor('target') as curs:

                curs.execute(q)

                self.log.info('Rows affected: %d', curs.rowcount)

                try:

                    rows = curs.fetchall_dict()

                    self._write_output_file(rows)

                except ProgrammingError:

                    pass

        self.log.info('Done')

    def _write_output_file(self, rows):

        if not self.args.output_file:

            return

        with open(self.args.output_file, 'w', encoding='utf8') as f:

            for row in rows:

                print(self.args.format.format(row), file=f)

    def _prepare_parameters(self, parameters):

        self.parameters = {}

        for parameter in parameters or ():

            name, value = parameter.split('=', 1)

            self.parameters[name] = value

cls = RunQueryTool