"""
    Copyright (c) 2019 Contributors as noted in the AUTHORS file
    This file is part of ggm, the GILGAMESH core engine in Python.
    ggm is free software; you can redistribute it and/or modify it under
    the terms of the GNU Lesser General Public License (GPL) as published
    by the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
    As a special exception, the Contributors give you permission to link
    this library with independent modules to produce an executable,
    regardless of the license terms of these independent modules, and to
    copy and distribute the resulting executable under terms of your choice,
    provided that you also meet, for each linked independent module, the
    terms and conditions of the license of that module. An independent
    module is a module which is not derived from or based on this library.
    If you modify this library, you must extend this exception to your
    version of the library.
    ggm is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
    License for more details.
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""
import sys, os
import zmq
import asyncio
import sqlite3

from ..lib.kernel import GK
from ..lib.kontext import Kontext

import time
from pprint import pprint

class SSqlite(GK):
    def __init__(self, *args, **kwargs):
        GK.__init__(self, *args, **kwargs)

        self.DB = "ipc:///tmp/series_out"
        self.data_path = kwargs['data_path']
        try:
            os.makedirs(self.data_path)
        except OSError as e:
            pass

        self.DOUT = "ipc:///tmp/data_out"
        self.receiver = self.context.socket(zmq.PULL)
        self.receiver.connect(self.DOUT)
        self.loop.create_task(self.write_data())

        self.loop.create_task(self.query_task())

    async def query_task(self):
        """
        task for answering queries
        """
        dbq = self.context.socket(zmq.REP)
        dbq.connect(self.DB)
        while True:
            raw = await dbq.precv()
            try:
                sig = raw.pop(0)
                dev_id = raw.pop(0)

                #db = sqlite3.connect(f'./{dev_id}.db', detect_types=sqlite3.PARSE_DECLTYPES)
                if sig != 'insert':
                    db = sqlite3.connect(f'file:{self.data_path}/{dev_id}.db?mode=ro', uri=True)
                else:
                    db = sqlite3.connect(f'{self.data_path}/{dev_id}.db')

                if sig in ['get', 'chunk']:
                    db.row_factory = self.get_factory

                cur = db.cursor()
                reply = {}

                #print(sig)
                #print(raw)
                if sig == 'measurements':
                    colls = []
                    query = f'SELECT name FROM sqlite_master WHERE type="table"'
                    cur.execute(query)
                    measurements = [i[0] for i in cur.fetchall()]
                    await dbq.psnd(measurements)
                    del measurements
                    cur.close()
                    db.close()
                    continue

                elif sig == 'count':
                    measurement = raw.pop(0)
                    query = f'SELECT count(*) FROM {measurement} '
                    try:
                        tmp = raw.pop(0)
                        if 'start' in tmp.keys():
                            query = query+f"WHERE time >= '{tmp['start']}' "
                            if 'stop' in tmp.keys():
                                query = query+f"AND time < '{tmp['stop']}' "
                    except:
                        pass
                    cur.execute(query)
                    count = [i[0] for i in cur.fetchall()]
                    await dbq.psnd(count)
                    del count
                    cur.close()
                    db.close()
                    continue

                elif sig == 'get':
                    measurement = raw.pop(0)
                    tmp = raw.pop(0)

                    query = f'SELECT * FROM "{measurement}" '

                    if tmp == 'head':
                        query = query+'ORDER BY time DESC LIMIT 1'

                    elif tmp == 'tail':
                        query = query+'ORDER BY time ASC LIMIT 1'

                    elif tmp == 'all':
                        query = query+'ORDER BY time DESC LIMIT 1000'

                    elif isinstance(tmp, dict):
                        if 'start' in tmp.keys():
                            query = query+f"WHERE time >= '{tmp['start']}' "
                            if 'stop' in tmp.keys():
                                query = query+f"AND time < '{tmp['stop']}' "
                        query = query+ f'ORDER BY time DESC LIMIT 1000'

                    else:
                        await dbq.psnd({'Error': True, 'Reason': 'Did not get get!' })
                        continue

                    records = []
                    cur.execute(query)
                    records = cur.fetchall()
                    await dbq.psnd(records)
                    del records
                    cur.close()
                    db.close()
                    continue

                elif sig == 'delete':
                    measurement = raw.pop(0)

                    thresh = self.iso_5min_ago()
                    query = f'SELECT deleteable FROM "{measurement}" where time >= "{thresh}" AND deleteable IS NOT NULL ORDER BY time DESC'
                    cur.execute(query)
                    records = cur.fetchall()
                    if records:
                        query = f'DROP TABLE "{measurement}"'
                        cur.execute(query)
                        db.commit()
                        await dbq.psend_noerr(f'Deletion of {measurement} successful.')
                    else:
                        await dbq.psend_err(f'{measurement} is not deleteable.')

                    del records
                    cur.close()
                    db.close()
                    continue

                elif sig == 'chunk':
                    tic = time.time()
                    measurement = raw.pop(0)
                    tmp = raw.pop(0)

                    try:
                        offset = tmp['offset']
                        limit = tmp['limit']
                    except Exception as e:
                        await dbq.psend_err(str(e))

                    # get table column names and types
                    query = f'PRAGMA table_info({measurement})'
                    cur.execute(query)
                    records = cur.fetchall()
                    clist = [i['tags'] for i in records]

                    cols = []
                    if 'cols' in tmp:
                        clist = ['time']
                        for i in records:
                            if i['name'] in tmp['cols']:
                                clist.append(i['name'])
                        # FIXME sql-injection-city
                        cols_str = [f'"{col}"' for col in clist[1:]]
                        query = f'SELECT time, {", ".join(cols_str)} FROM "{measurement}" '
                    else:
                        query = f'SELECT * FROM "{measurement}" '

                    if 'start' in tmp.keys():
                        query = query+f"WHERE time > '{tmp['start']}' "
                        if 'stop' in tmp.keys():
                            query = query+f"AND time <= '{tmp['stop']}' "

                    query = query+ f"ORDER BY time DESC LIMIT {limit} OFFSET {offset}"

                    records = []
                    cur.execute(query)
                    records = cur.fetchall()

                    # get last metadata if necessary
                    meta_list = []
                    for c in clist:
                        if c['type'] not in ['TIMESTAMP', 'FLOAT']:
                            meta_list.append(c['name'])

                    if (meta_list and records):
                        if not any(list(records[-1]['tags'].values())):
                            if len(meta_list) > 1:
                                query = f'SELECT {", ".join(meta_list)} FROM "{measurement}" WHERE time < "{records[-1]["time"]}" AND COALESCE({", ".join(meta_list)}) IS NOT NULL ORDER BY time DESC LIMIT 1'
                            else:
                                query = f'SELECT {meta_list[0]} FROM "{measurement}" WHERE time < "{records[-1]["time"]}" AND {meta_list[0]} IS NOT NULL ORDER BY time DESC LIMIT 1'
                            cur.execute(query)
                            meta_data = cur.fetchone()
                            if meta_data:
                                records[-1]['tags'].update(meta_data['tags'])

                    # log slow querys
                    toc = time.time()
                    if toc-tic > 2.00:
                        self.glog.info(f'Slow chunk query ({dev_id} {measurement}): {round((toc-tic), 3)} s')

                    await dbq.psnd(records)
                    del records
                    cur.close()
                    db.close()
                    continue

                else:
                    await dbq.psend_err('SSQLite Driver does not understand.')

            except Exception as e:
                self.glog.error(f'Malformed query? --- {e}')
                #self.glog.error(f'Malformed query? --- {e} --- {sig} {dev_id} {measurement}')
                await dbq.psend_err(str(e))

    async def write_data(self):
        while True:
            raw = await self.receiver.precv()

            try:
                dev_id = raw.pop(0)
                measurement = raw.pop(0)
                data = raw.pop(0)
            except Exception as e:
                self.glog.error(f"Error while parsing incoming Data: {e}")
                continue

            # FIXME should not happen anymore -- remove when sure..
            if len(data) == 0:
                self.glog.debug(f"incoming data empty: {dev_id} {measurement}")
                continue

            db = sqlite3.connect(f'{self.data_path}/{dev_id}.db', timeout=10)
            cur = db.cursor()
            self.alter_insert(cur, measurement, data)
            db.commit()
            cur.close()
            db.close()

    def alter_insert(self, cur, measurement, data):
        """
        """
        try:
            cur.execute(f'CREATE TABLE IF NOT EXISTS "{measurement}" (time TIMESTAMP)')
        except Exception as e:
            self.glog.error(f"could not create table while inserting: {e}")
            return

        #pprint(data)
        clist = ['time']
        clist_str = ['time']
        try:
            # get table column names and types
            query = f'PRAGMA table_info({measurement})'
            cur.execute(query)
            records = cur.fetchall()
            col_exists = [i[1] for i in records]
        except Exception as e:
            self.glog.error(f"could not get table info while inserting: {e}")
            return

        try:
            for col in data[0]['fields']:
                clist.append(col)
                clist_str.append(f'"{col}"')
                if col not in col_exists:
                    cur.execute(f'ALTER TABLE "{measurement}" ADD COLUMN "{col}" FLOAT')
        except Exception as e:
            self.glog.error(f"could not add missing field while inserting: {e}")
            return

        try:
            for col in data[0]['tags']:
                clist.append(col)
                clist_str.append(f'"{col}"')
                if col not in col_exists:
                    cur.execute(f'ALTER TABLE "{measurement}" ADD COLUMN "{col}" VARCHAR(128)')
        except Exception as e:
            self.glog.error(f"could not add missing tag while inserting: {e}")
            return

        # fkn query
        q = f'INSERT INTO "{measurement}" ' + f"({', '.join(clist_str)}) VALUES ({', '.join([':'+p for p in clist])})"
        data = self.flatten_points(data)
        try:
            cur.executemany(q, data)
            return
        except Exception as e:
            self.glog.error(f'Could not save data to DB! --- {e}')
            return

    def get_factory(self, cursor, row):
        d = dict()
        d['fields'] = dict()
        d['tags'] = dict()

        for idx, col in enumerate(cursor.description):
            if col[0] == 'time':
                d[col[0]] = row[idx]
            elif isinstance(row[idx], float):
                d['fields'][col[0]] = row[idx]
            elif isinstance(row[idx], str):
                d['tags'][col[0]] = row[idx]
        return d

def ssqlite_process(kcfg):
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    kcfg['context'] = Kontext()
    kcfg['loop'] = loop
    
    ssqlite = SSqlite(**kcfg)
    ssqlite.start()
