#  -*- coding: utf-8 -*-
# *****************************************************************************
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program 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, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# Module authors:
#   Markus Zolliker <markus.zolliker@psi.ch>
# *****************************************************************************

import time
from secop.datatypes import get_datatype, IntRange, FloatRange, ScaledInteger,\
    EnumType, BoolType, StringType, TupleOf, StructOf
import histreader.histwriter as histwriter


def make_cvt_list(dt, tail=''):
    """create conversion list

    list of tuple (<conversion function>, <tail>, <curve options>)
    tail is a postfix to be appended in case of tuples and structs
    """ 
    if isinstance(dt, (EnumType, IntRange, BoolType)):
        return[(int, tail, dict(type='NUM'))]
    if isinstance(dt, (FloatRange, ScaledInteger)):
        return [(dt.import_value, tail, dict(type='NUM', unit=dt.unit, period=5) if dt.unit else {})]
    if isinstance(dt, StringType):
        return [(lambda x: x, tail, dict(type='STR'))]
    if isinstance(dt, TupleOf):
        items = enumerate(dt.members)
    elif isinstance(dt, StructOf):
        items = dt.members.items()
    else:
        return []   # ArrayType, BlobType and TextType are ignored: too much data, probably not used
    result = []
    for subkey, elmtype in items:
        for fun,  tail, opts in make_cvt_list(elmtype, '%s.%s' % (tail, subkey)):
            result.append((lambda v, k=subkey, f=fun: f(v[k]), tail, opts))
    return result


class HistWriter(histwriter.HistWriter):
    """extend writer to be used as an internal frappy connection"""
    def __init__(self, directory, predefined_names, dispatcher):
        super().__init__(directory)
        self.predefined_names = predefined_names
        self.cvt_lists = {}  # dict <mod:param> of <conversion list>
        self.activated = False
        self.dispatcher = dispatcher
        self._init_time = None
        print('HISTINIT')

    def init(self, msg):
        action, _, description = msg
        assert action == 'describing'
        self._init_time = time.time()

        for modname, moddesc in description['modules'].items():
            for pname, pdesc in moddesc['accessibles'].items():
                ident = key = modname + ':' + pname
                if pname.startswith('_') and pname[1:] not in self.predefined_names:
                    key = modname + ':' + pname[1:]
                dt = get_datatype(pdesc['datainfo'])
                cvt_list = make_cvt_list(dt, key)
                for _, hkey, opts in cvt_list:
                    if pname == 'value':
                        opts['period'] = opts.get('period', 0)
                        opts['show'] = True
                        opts['label'] = modname
                    elif pname == 'target':
                        opts['period'] = 0
                        opts['label'] = modname + '_target'
                        opts['show'] = True
                    self.put_def(hkey, opts)
                self.cvt_lists[ident] = cvt_list
        # self.put(self._init_time, 'STR', 'vars', ' '.join(vars))
        self.dispatcher.handle_activate(self, None, None)
        self._init_time = None
        return

    def send_reply(self, msg):
        action, ident, value = msg
        if not action.endswith('update'):
            print('unknown async message %r' % msg)
            return
        now = self._init_time or time.time()  # on initialisation, us the same timestamp for all
        if action == 'update':
            for fun, key, opts in self.cvt_lists[ident]:
                # we only look at the value, qualifiers are ignored for now
                # we do not use the timestamp here, as a potentially decreasing value might
                # bring the reader software into trouble
                self.put(now, key, str(fun(value[0])))

        else:  # error_update
            for _, key, _ in self.cvt_lists[ident]:
                old = self.cache.get(key)
                if old is None:
                    return  # ignore if this key is not yet used
                self.put(now, key, '')