# coding=utf-8
#
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT

import datetime
import sys

import prettytable
from sqlalchemy import or_
from sqlalchemy.orm import sessionmaker

import lvestats.lib.commons.decorators
from lvestats.lib import dbengine, uidconverter
from lvestats.lib.commons import dateutil
from lvestats.lib.jsonhandler import prepare_data_json
from lvestats.lib.parsers.lve_read_snapshot_argparse import lve_read_snapshot_parser
from lvestats.lib.snapshot import Snapshot
from lvestats.orm.incident import incident

REPORT_HEADER = 'Snapshots collected starting from %s to %s for lve id %d @ %s:\n'
REPORT_FOOTER = 'Done..\n'

DEFAULT_SERVER_ID = 'localhost'  # used when nothing is configured or specified in cmdline


def _calculate_period(opts):
    if opts.period:
        start, end = opts.period
    elif opts.timestamp:
        start = opts.timestamp
        end = start + 0.999999
    else:
        try:
            start = dateutil.parse_date(" ".join(opts.ffrom))
            end = dateutil.parse_date(" ".join(opts.to))
        except ValueError:
            print('please use [YY]YY-MM-DD[ HH:MM] format for --from and --to')
            return None, None
    return start, end


@lvestats.lib.commons.decorators.no_sigpipe
def snapshot_reader_main(config, argv_=None):
    parser = lve_read_snapshot_parser()
    opts = parser.parse_args(argv_)

    if not opts.id and not opts.user:
        parser.print_help()
        print('One of -u --user or -i --id should be specified')
        return 1

    try:
        engine = dbengine.make_db_engine(config)
    except dbengine.MakeDbException as e:
        print(e)
        return 1

    server_id = config.get('server_id', DEFAULT_SERVER_ID)

    if opts.user:
        uid = uidconverter.username_to_uid(opts.user, server_id, server_id, engine)
        if uid is None:
            print(f'User {opts.user}@{server_id} not found')
            return 1
    else:
        uid = opts.id
    start, end = _calculate_period(opts)
    if start is None and end is None:
        return 1
    lve_read_snapshot = LVEReadSnaphot(
        engine,
        start,
        end,
        uid,
        server_id,
        opts.output,
        opts.json,
    )
    if opts.list:
        lve_read_snapshot.list()  # show snapshots timestamps list
    elif opts.stats:
        lve_read_snapshot.stats(opts.unit)
    else:
        lve_read_snapshot.run()


def _try_convert_to_timestamp(o):
    """
    Convert local datetime to unix timestamp, or just passes
    unix timestamp as output if specified.

    :param o:
    :return:
    """
    if isinstance(o, datetime.datetime):
        return dateutil.gm_datetime_to_unixtimestamp(dateutil.local_to_gm(o))
    return o


class LVEReadSnaphot(object):
    def __init__(self, engine, start, end, uid, server_id, output_file, do_json):
        """

        :param start: datetime.datetime | int (unix timestamp)
        :param end: datetime.datetime | int (unix timestamp)
        :param uid:
        :param server_id:
        :param output_file: filename
        :param do_json: boolean
        """
        self.engine = engine
        self.do_json = do_json
        self.output_file = output_file
        self.uid = uid
        self.start = _try_convert_to_timestamp(start)
        self.end = _try_convert_to_timestamp(end)
        self.server_id = server_id
        # Faults names dictionary
        self.fault_names = {
            'cpu_fault': 'CPU',
            'mem_fault': 'Virtual memory',
            'mep_fault': 'EP',
            'memphy_fault': 'Physical memory',
            'nproc_fault': 'NPROC',
            'io_fault': 'IO',
            'iops_fault': 'IOPS'
        }

    def get_incidents(self, session):
        return session.query(incident).filter(incident.uid == self.uid,
                                              incident.server_id == self.server_id,
                                              or_(incident.incident_start_time.between(self.start, self.end),
                                                  incident.incident_end_time.between(self.start, self.end))
                                              ).order_by(incident.incident_start_time).all()

    def stats_by_incident(self, session):
        result = []
        for i in self.get_incidents(session):
            result.append({'from': i.incident_start_time,
                           'to': max(i.dump_time, i.incident_end_time or 0),
                           'incidents': 1,
                           'snapshots': i.snapshot_count,
                           'duration': self.get_duration(i)
                           })
        return result

    @staticmethod
    def get_duration(i, from_=0, to_=sys.maxsize):
        from_ = max(i.incident_start_time, from_)
        to_ = min(max(i.dump_time, i.incident_end_time or 0), to_)
        return to_ - from_

    @staticmethod
    def get_incident_count(incidents, pos, from_ts, to_ts):
        count = 0
        duration = 0
        while pos < len(incidents):
            i = incidents[pos]
            if i.dump_time < from_ts:
                pos += 1
                continue
            if i.incident_start_time > to_ts:
                break  # we are done
            count += 1
            pos += 1
            duration += LVEReadSnaphot.get_duration(i, from_ts, to_ts)
        if count == 0:
            return 0, 0, pos
        else:
            return count, duration, pos - 1

    def stats_by_time_unit(self, session, time_unit):
        incidents = self.get_incidents(session)
        snapshot_files = Snapshot({'uid': self.uid}).get_file_list()
        result = []
        from_ts = self.start
        pos = 0
        while from_ts < self.end:
            to_ts = min(from_ts + time_unit, self.end)
            incident_count, duration, pos = self.get_incident_count(incidents, pos, from_ts, to_ts)
            if incident_count == 0:  # skip this one, we have nothing here
                from_ts = to_ts
                continue
            snapshots = Snapshot.snapshot_filter(snapshot_files, from_ts, to_ts)
            if len(snapshots) == 0:
                snapshots.append(0)  # always show like there is at least one snapshot
            result.append({'from': from_ts,
                           'to': to_ts,
                           'incidents': incident_count,
                           'snapshots': len(snapshots),
                           'duration': duration
                           })
            from_ts = to_ts
        return result

    def print_stats_json(self, stats):
        data = {
            'from': self.start,
            'to': self.end,
            'stats': stats
        }

        out = self.open()
        out.write(prepare_data_json(data))
        out.write('\n')
        out.flush()

    def print_stats(self, stats):
        out = self.open()

        out.write(f'Stats from {dateutil.ts_to_iso(self.start)} to {dateutil.ts_to_iso(self.end)}\n')
        for stat in stats:
            out.write('---\n')
            out.write(f'\tfrom: {dateutil.ts_to_iso(stat["from"])}\n')
            out.write(f'\tto: {dateutil.ts_to_iso(stat["to"])}\n')
            out.write(f'\tincidents: {stat["incidents"]}\n')
            out.write(f'\tsnapshots: {stat["snapshots"]}\n')
            out.write(f'\tduration: {stat["duration"]} sec.\n')
        out.flush()

    def stats(self, stats_unit_str):
        try:
            time_unit = dateutil.parse_period2(stats_unit_str)
            if self.end - self.start < time_unit:
                # this prevents situations when we get stats for last 10 minutes, but group it by 1 day
                self.start = self.end - time_unit
            group_by_incident = False
        except ValueError:
            time_unit = None
            group_by_incident = stats_unit_str == 'auto'
            if not group_by_incident:
                raise

        session = sessionmaker(bind=self.engine)()
        try:
            if group_by_incident:
                stats = self.stats_by_incident(session)
            else:
                stats = self.stats_by_time_unit(session, time_unit)

            session.expunge_all()

            if self.do_json:
                self.print_stats_json(stats)
            else:
                self.print_stats(stats)
        finally:
            session.close()

    def run(self):
        snapshots = Snapshot({'uid': self.uid})
        self.report(snapshots.get_snapshots(self.start, self.end))

    def list(self):
        snapshots = Snapshot({'uid': self.uid})
        snapshots_list = snapshots.get_ts_list(self.start, self.end)
        out = self.open()
        if self.do_json:
            out.write(prepare_data_json(snapshots_list))
        else:
            out.write(
                f'Snapshots timestamp list; from {dateutil.ts_to_iso(self.start)} '
                f'to {dateutil.ts_to_iso(self.end)} for lve id {self.uid}\n'
            )
            for ts in snapshots_list:
                out.write(dateutil.ts_to_iso(ts))
                out.write('\n')
            out.write(REPORT_FOOTER)
        out.flush()

    def report(self, snapshots):
        out = self.open()

        if self.do_json:
            out.write(prepare_data_json({
                'snapshots': snapshots,
            }))
            out.write('\n')
            out.flush()
            return

        out.write(REPORT_HEADER % (dateutil.ts_to_iso(self.start), dateutil.ts_to_iso(self.end),
                                   self.uid, self.server_id))
        for snapshot_data in snapshots:
            self.format_snapshot(out, snapshot_data)
        out.write(REPORT_FOOTER)
        out.flush()

    def open(self):
        if self.output_file:
            try:
                return open(self.output_file, "w", encoding='utf-8')
            except IOError:
                pass  # maybe need error message # fixme --> if we are trying to write to a file, and cannot,
                # this is an error, we shouldn't write to stdout
        return sys.stdout

    @staticmethod
    def _process_data_aggregate(process_data):
        """
        Aggregates process data by PID by summing CPU % and MEM for same PIDs
        :param process_data: input data. Dictionary:
         { u'151048': {u'MEM': u'1', u'CMD': u'bash', u'PID': u'151048', u'CPU': u'0%'},
           u'151047': {u'MEM': u'1', u'CMD': u'su cltest1', u'PID': u'151047', u'CPU': u'0%'},
           u'153642': {u'MEM': u'1', u'CMD': u'./threads', u'PID': u'153640', u'CPU': u'0%'},
           u'153641': {u'MEM': u'1', u'CMD': u'./threads', u'PID': u'153640', u'CPU': u'0%'},
           u'153640': {u'MEM': u'1', u'CMD': u'./threads', u'PID': u'153640', u'CPU': u'5%'}
         }
        :return: Output data - List of dictionaries:
         [
           {u'MEM': u'1', u'CMD': u'bash', u'PID': u'151048', u'CPU': u'0%'},
           {u'MEM': u'1', u'CMD': u'su cltest1', u'PID': u'151047', u'CPU': u'0%'},
           {u'MEM': u'3', u'CMD': u'./threads', u'PID': u'153640', u'CPU': u'5%'},
         ]
        """
        # 1. Build thread dictionary as
        #  pid: {'PID', 'CMD', 'MEM', 'CPU'}
        #  and aggregate data
        thread_dict = {}
        for _, proc_data in process_data.items():
            if 'PID' not in proc_data:
                # old format snapshot, do not aggregate it
                # Example of old format snapshot:
                # {u'31228': {u'MEM': u'1', u'CMD': u'31228', u'IOPS': u'N/A', u'CPU': u'1%', u'IO': u'N/A'}}
                pid = proc_data['CMD']
                process_data_new = {}
                process_data_new['PID'] = pid
                process_data_new['MEM'] = proc_data['MEM']
                process_data_new['CMD'] = pid
                process_data_new['CPU'] = proc_data['CPU']
                thread_dict[pid] = process_data_new
                continue
            pid = proc_data['PID']
            # remove '%' from CPU value and convert CPU/MEM to integers
            if proc_data['CPU'] != 'N/A':
                proc_data['CPU'] = int(proc_data['CPU'].replace('%', ''))
            if proc_data['MEM'] != 'N/A':
                proc_data['MEM'] = int(proc_data['MEM'])
            if pid in thread_dict:
                # PID already present, add new data to it
                if proc_data['CPU'] != 'N/A':
                    if thread_dict[pid]['CPU'] != 'N/A':
                        thread_dict[pid]['CPU'] += proc_data['CPU']
                    else:
                        thread_dict[pid]['CPU'] = proc_data['CPU']
                if proc_data['MEM'] != 'N/A':
                    if thread_dict[pid]['MEM'] != 'N/A':
                        thread_dict[pid]['MEM'] += proc_data['MEM']
                    else:
                        thread_dict[pid]['MEM'] = proc_data['MEM']
            else:
                # PID absent, add it
                thread_dict[pid] = proc_data
        # 2. Build output list
        out_data = list(thread_dict.values())
        return out_data

    def format_snapshot(self, out, snapshot_data):
        out.write(f'>>> {dateutil.ts_to_iso(snapshot_data["dump_time"])}, UID {snapshot_data["uid"]}\n')

        out.write('\nFaults:\n')
        for k, v in snapshot_data['snap_faults'].items():
            out.write(f'\t* {self.fault_names.get(k, k)}: {v}\n')

        if snapshot_data['snap_sql']:
            out.write('\nSQL Queries:\n')
            sql_table = prettytable.PrettyTable(['CMD', 'Time', 'SQL-query'])
            list(map(sql_table.add_row, snapshot_data['snap_sql']))
            out.write(sql_table.get_string())

        out.write('\nProcesses:\n')
        # fields = ('PID', 'COM', 'SPEED', 'MEM', 'IO', 'IOPS')
        # table = prettytable.PrettyTable(fields=fields)
        fields = set()
        for data in list(snapshot_data['snap_proc'].values()):
            for key in list(data.keys()):
                fields.add(key)

        # Keys list for data extacting
        data_keys = list(['PID'])
        # Form table header: PID, CMD, Memory (Mb), CPU (%)
        table_columns = ['PID']
        if 'MEM' in fields:
            table_columns.append('Memory (Mb)')
            data_keys.append('MEM')
        if 'CPU' in fields:
            table_columns.append('CPU (%)')
            data_keys.append('CPU')
        if 'CMD' in fields:
            table_columns.append('CMD')
            data_keys.append('CMD')
        table = prettytable.PrettyTable(table_columns)
        # Left align for CMD column, if it present
        if 'CMD' in table_columns:
            table.align['CMD'] = 'l'
        # Do process data aggregation (CPU/MEM summing for all threads of same process)
        snap_proc_aggr = self._process_data_aggregate(snapshot_data['snap_proc'])
        for data in snap_proc_aggr:
            table.add_row([data.get(k, 'N/A') for k in data_keys])

        out.write(str(table))
        out.write('\n\n')

        if snapshot_data['snap_http']:
            out.write('Http requests:\n')
            http_table = prettytable.PrettyTable(['Pid', 'Domain', 'Http type', 'Path', 'Http version', 'Time'])
            list(map(http_table.add_row, snapshot_data['snap_http']))
            out.write(str(http_table))
            out.write('\n\n')