import time
from pathlib import Path
from configparser import ConfigParser
from influx import InfluxDBWrapper, abs_range, round_range, Table


def summarize_tags(curves, remove_multiple=False):
    """summarize tags

    :param curves: list of curves (type Table)
    :param remove_multiple: True: remove non-unique values
    :return: dict <key> of comma separated values
    """
    result = {}
    for curve in curves:
        for k, v in curve.tags.items():
            result.setdefault(k, set()).add(str(v))
    if remove_multiple:
        return {k: ','.join(v) for k, v in result.items() if len(v) == 1}
    return {k: ','.join(v) for k, v in result.items()}


class SEHistory(InfluxDBWrapper):
    def __init__(self, dbname=None, instrument=None, access='readonly'):
        self.instrument = instrument
        parser = ConfigParser()
        parser.optionxform = str
        parser.read([Path('~/.sehistory').expanduser()])
        section = parser[dbname] if dbname else parser[parser.sections()[0]]
        super().__init__(*(section[k] for k in ('uri', 'token', 'org', 'bucket')), access=access)

    def curves(self, start=None, stop=None, measurement=('*.value', '*.target'), field='float',
               interval=None, add_prev=3600, add_end=False, merge=None, pivot=False, **kwds):
        """get curves

        :param start: start time (default: since ever)
        :param stop: end time (default: eternity = 1 year in the future)
        :param measurement: '<module>.<parameter>' (default: ['*.value', '*.target'])
        :param field: default 'float' (only numeric curves)
        :param interval: if given, the result is binned
        :param add_prev: amount of time to look back for the last previous point (default: 1 hr)
        :param add_end: whether to add endpoint at stop time (default: False)
        :param merge: None: no merge happens, else curves with the same final key are merged. 2 cases:
            one key (str): the name of final key. result will be a dict of <str> of <Table>
            a tuple of keys: the names of the final key elements. result: dict of <tuple> of Table
        :param pivot: sort values in to columns of one big table
        :param kwds: further selection criteria
        :return: a dict <key or tuple of key values> of <Table> or <Single>

        where <Table> is a list of tuples with some meta info (table.tags, table.column_names)
        and <Single> is a list (a single row of a table) with the same meta info

        when _field='float' (the default), the returned values are either a floats or None
        """
        tags = {k: v for k, v in (('_measurement', measurement), ('_field', field)) if v is not None}
        tags.update(kwds)
        start, stop = abs_range(start, stop)
        rstart, rstop = round_range(start, stop, interval)
        if rstart < rstop:
            result = self.query(rstart, rstop, interval, columns=None, **tags)
            # result = self.query(rstart, rstop, interval, columns=['stream', 'device'], **tags)
        else:
            result = {}
        start_row = {}
        if add_prev:
            prev_data = self.query(rstart - add_prev, rstart, single=1, **tags)
            for key, first in prev_data.items():
                curve = result.get(key)
                if first[1] is not None:
                    if curve:
                        if first[0] < curve[0][0]:
                            if pivot:
                                curve.insert(0, (rstart,) + tuple(first[1:]))
                                # start_row.setdefault(key[1:], {})[key[0]] = first[1]
                            else:
                                curve.insert(0, tuple(first))
                    else:
                        result[key] = table = Table(first.tags, first.key_names, first.column_names)
                        table.append(tuple(first))
        if add_end:
            self.complete(result, stop)
        if merge:
            single_merge = isinstance(merge, str)
            if single_merge:
                merge = [merge]
            rows = []
            common_tags = summarize_tags(result.values(), True)
            col_keys = {}
            col_info = {}
            for key, curve in result.items():
                merge_tags = {k: curve.tags.get(k, '') for k in merge}
                for k, v in zip(curve.key_names, key):
                    merge_tags.setdefault(k, v)
                merge_key = tuple(zip(*merge_tags.items()))  # (<keys tuple>, <values tuple>)
                info = col_info.get(merge_key)
                if info is None:
                    col_idx = len(col_keys) + 1
                    col_keys[col_idx] = merge_key
                    col_info[merge_key] = info = [col_idx, []]
                else:
                    col_idx = info[0]
                info[1].append(curve)
                assert curve.column_names[1] == '_value'
                for row in curve:
                    rows.append((row[0], row[1], col_idx))
                # merged.append((merge_key, curve))
            rows.sort(key=lambda x: x[0])
            if pivot:
                header = []
                for merge_key, (col_idx, curves) in col_info.items():
                    tags = summarize_tags(curves)
                    primary = tags.pop(merge[0], None)
                    primary = [primary] if primary else []
                    header.append(' '.join(primary + [f"{k}={v}" for k, v in tags.items() if k not in common_tags]))
                result = Table(common_tags, (), ('_time',) + tuple(header))
                values = [0] + [None] * len(col_keys)
                for row in rows:
                    col_nr = row[2]
                    values[col_nr] = row[1]
                    if row[0] > values[0]:
                        values[0] = row[0]
                        result.append(tuple(values))
                    elif row[0] < values[0]:
                        raise ValueError(f'{rstart} {values[0]} {row[0]}')
            else:
                result = {}
                by_idx = {}
                for merge_key, (col_idx, curves) in col_info.items():
                    tags = summarize_tags(curves)
                    print('TAGS', tags)
                    primary = tags.get(merge[0], '_value')
                    table = Table(tags, merge_key[0], ('_time', primary))
                    result[primary if single_merge else merge_key[1][:len(merge)]] = table
                    by_idx[col_idx] = table
                for row in rows:
                    by_idx[row[2]].append((row[0], row[1]))
        return result

    @staticmethod
    def complete(curve_dict, end_time=0, tag=None):
        """complete to end_time

        if tag is given, end_time is a dict <tag value> of <end time>
        """
        if tag is None:
            end_time_dict = {}
        else:
            end_time_dict, end_time = end_time, 0
        for curve in curve_dict.values():
            if len(curve):
                tlast, value = curve[-1]
                etime = end_time_dict.get(curve.tags.get(tag), end_time)
                if value is not None and tlast < etime:
                    curve.append((etime, value))

    def export(self, start, stop, measurement=('*.value', '*.target'), field='float',
               interval=None, add_prev=3600, add_end=False, timeoffset=None, none='', **tags):
        result = self.curves(start, stop, measurement, field, interval, add_prev, add_end,
                             merge=('_measurement', 'device', 'stream'), pivot=True, **tags)
        if timeoffset is None:
            timeoffset = int(start)
        result.tags.pop('_field', None)
        rows = [f"# {' '.join(f'{k}={v}' for k, v in result.tags.items())}"]
        rows.extend(f'# col {i} {k}' for i, k in enumerate(result.column_names))
        rows.extend(result.to_csv_rows(timeoffset, none=none))
        rows.append('')
        return '\n'.join(rows)

    def add_float(self, value, key, tags, ts):
        self._add_point('.'.join(key), 'float', -0.0 if value is None else float(value), ts, tags)

    def add_error(self, value, key, tags, ts):
        self._add_point('.'.join(key), 'error', '' if value is None else str(value), ts, tags)

    def get_instrument(self, stream, ts=None, **tags):
        if ts is None:
            ts = int(time.time())
        reply = self.query(None, int(ts) + 1, _measurement='_stream_', _field='on',
                           stream=stream, single=1, **tags)
        if reply:
            entry = sorted(reply.values(), key=lambda r: r[0])[-1]
            return entry.tags.get('instrument', self.instrument), entry[0]
        return None, None

    def get_streams(self, instrument=None, ts=None, **tags):
        """get streams for one or all instruments

        :param instrument: None when looking for all instruments
        :param ts: the time or None when now
        :return: dict <stream> of <instrument> or '0' when instrument is not known
        """
        if ts is None:
            ts = int(time.time())
        reply = self.query(None, int(ts) + 1, _measurement='_stream_', _field='on',
                           single=1, instrument=instrument, **tags)
        all_entries = {}
        for entry in reply.values():
            all_entries.setdefault(entry.tags.get('stream'), []).append(entry)
        result = {}
        for stream, entries in all_entries.items():
            entry = sorted(entries, key=lambda r: r[0])[-1]
            if entry[1]:  # on=True
                result[stream] = entry.tags
        return result

    def get_experiments(self, start=None, end=None, **tags):
        """get experiments (periods with the same device/stream/instrument combination)

        :param start, end: the time period
        :return: list of tuple(<device>, <stream>, <instrument>)
        """

        interval = 1
        gap = 600
        entries = {}
        end = time.time() + 60
        for rows, key, (tags, _, _) in self.query_gen(
                start, end, _measurement='_stream_', _field='on', interval=interval,
                stream=None, device=None, instrument=None):
            stream = tags.get('stream')
            instrument = tags.get('instrument')
            device = tags.get('device')
            elist = entries.setdefault(instrument or stream, [])
            for row in rows:
                elist.append(row[:2] + (stream, device))
        result = []
        for ins, rows in entries.items():
            rows.sort()
            current = {}  # dict <stream> of [<device>, <start>, <end>]
            chunks = [current]
            for ts, flag, stream, device in rows:
                if flag:
                    prev = current.get(stream)
                    if prev:
                        if device == prev[0] and prev[1] + gap < ts < prev[2] + gap:
                            prev[2] = ts
                            continue
                        current = {}
                        chunks.append(current)
                    current[stream] = [device or stream, ts, end]
                else:
                    prev = current.get(stream)
                    if prev:
                        prev[2] = ts
            prevchange = 0
            prevdevices = {}  # dict <stream> of <device>
            for chunk in chunks:
                if chunk:
                    devices = {k: v[0] for k, v in chunk.items() if v[0]}
                    start = min(t[1] for t in chunk.values())
                    if start > prevchange + gap or any(v != devices.get(k) for k, v in prevdevices.items()):
                        prevchange = start
                        prevdevices = devices
                        result.append((start, max(t[2] for t in chunk.values()), ins, devices))
        result.sort()
        for start, end, ins, devices in result:
            print(' .. '.join(time.strftime('%Y-%m-%d-%H:%M', time.localtime(t)) for t in (start, end)),
                  ins, devices)
        return result

    def set_instrument(self, stream, value, ts=None, guess=True, **tags):
        """set stream and instrument on or off

        :param stream: the uri of the stream
        :param value: instrument, "0" when unknown or None when switching to off
        :param ts: the time or None when now
        :param guess: when instrument is undefined, take from previous
        """
        prev, prevts = self.get_instrument(stream, ts, **tags)
        if prevts is not None:
            if prev in (None, '0'):
                ts = prevts + 0.001
            else:
                if value == '0' and guess:
                    value = prev
                if ts < prevts:
                    ts = prevts + 0.001
        tags['stream'] = stream
        if value:
            tags['instrument'] = value
            flag = True
        else:
            tags['instrument'] = prev or '0'
            flag = False
        self._add_point('_stream_', 'on', flag, ts, tags)

    def add_stream(self, value, tags, key, ts):
        self.set_instrument(key, value, ts, **tags)