#!/usr/bin/env python
# Copyright (C) 2015 Alexander Harvey Nitz
#
# 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 3 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.,
# 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

"""Create a workflow for following up missed loud injections."""

import os
import argparse
import logging
import copy
import numpy
import h5py
import pycbc.workflow as wf
import pycbc.workflow.minifollowups as mini
import pycbc.version
from pycbc.types import MultiDetOptionAction
from pycbc.events import select_segments_by_definer, coinc
from pycbc.results import layout
from pycbc.detector import Detector
from pycbc.workflow.core import resolve_url_to_file
from pycbc.io.hdf import SingleDetTriggers, HFile


legal_distance_types = [
    'decisive_optimal_snr',
    'comb_optimal_snr',
    'dec_chirp_distance'
]


def sort_injections(args, inj_group, missed):
    """Return an array of indices to sort the missed injections from most to
    least likely to be detected, according to a metric of choice.

    Parameters
    ----------
    args : object
        CLI arguments parsed by argparse. Must have a `distance_type` attribute
        to specify how to sort, which must be one of the values in
        `legal_distance_types`.
    inj_group : h5py group object
        HDF5 group object containing the injection definition.
    missed : array
        Array of indices of missed injections into `inj_group`.

    Returns
    -------
    missed_sorted : array
        Array of indices of missed injections sorted as requested.
    """
    if not hasattr(args, 'distance_type'):
        raise ValueError('Distance type not provided')
    if args.distance_type not in legal_distance_types:
        raise ValueError(
            f'Invalid distance type "{args.distance_type}", '
            f'allowed types are {", ".join(legal_distance_types)}'
        )

    if 'optimal_snr' in args.distance_type:
        optimal_snrs = [
            inj_group[dsn][:][missed] for dsn in inj_group.keys()
            if dsn.startswith('optimal_snr_')
        ]
        assert optimal_snrs, 'These injections do not have optimal SNRs'

    if args.distance_type == 'decisive_optimal_snr':
        # descending order of decisive (2nd largest) optimal SNR
        dec_snr = numpy.array([
            sorted(snrs)[-2] for snrs in zip(*optimal_snrs)
        ])
        if args.maximum_decisive_snr is not None:
            # By setting to 0, these injections will not be considered
            dec_snr[dec_snr > args.maximum_decisive_snr] = 0
        sorter = dec_snr.argsort()[::-1]
        return missed[sorter]

    if args.distance_type == 'comb_optimal_snr':
        # descending order of network optimal SNR
        optimal_snrs = numpy.vstack(optimal_snrs)
        net_opt_snrs_squared = (optimal_snrs ** 2).sum(axis=0)
        sorter = net_opt_snrs_squared.argsort()[::-1]
        return missed[sorter]

    if args.distance_type == 'dec_chirp_distance':
        # ascending order of decisive (2nd smallest) chirp distance
        from pycbc.conversions import mchirp_from_mass1_mass2, chirp_distance

        eff_dists = []
        for ifo in args.single_detector_triggers:
            eff_dist = Detector(ifo).effective_distance(
                inj_group['distance'][:][missed],
                inj_group['ra'][:][missed],
                inj_group['dec'][:][missed],
                inj_group['polarization'][:][missed],
                inj_group['tc'][:][missed],
                inj_group['inclination'][:][missed]
            )
            eff_dists.append(eff_dist)
        dec_eff_dist = sorted(eff_dists)[-2]
        mchirp = mchirp_from_mass1_mass2(
            inj_group['mass1'][:][missed],
            inj_group['mass2'][:][missed]
        )
        dec_chirp_dist = chirp_distance(dec_dist, mchirp)
        sorter = dec_chirp_dist.argsort()
        return missed[sorter]


parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('--version', action='version', version=pycbc.version.git_verbose_msg)
parser.add_argument('--bank-file',
                    help="HDF format template bank file")
parser.add_argument('--injection-file',
                    help="HDF format injection results file")
parser.add_argument('--injection-xml-file',
                    help="XML format injection file")
parser.add_argument('--single-detector-triggers', nargs='+', action=MultiDetOptionAction,
                    help="HDF format merged single detector trigger files")
parser.add_argument('--inspiral-segments',
                    help="xml segment files containing the inspiral analysis times")
parser.add_argument('--inspiral-data-read-name',
                    help="Name of inspiral segmentlist containing data read in "
                         "by each analysis job.")
parser.add_argument('--inspiral-data-analyzed-name',
                    help="Name of inspiral segmentlist containing data "
                         "analyzed by each analysis job.")
parser.add_argument('--inj-window', type=int, default=0.5,
                    help="Time window in which to look for injection triggers")
parser.add_argument('--ifar-threshold', type=float, default=None,
                    help="If given also followup injections with ifar smaller "
                         "than this threshold.")
parser.add_argument('--maximum-decisive-snr', type=float, default=None,
                    help="If given, only followup injections where the "
                         "decisive SNR is smaller than this value.")
parser.add_argument('--nearby-triggers-window', type=float, default=0.05,
                    help="Maximum time difference between the missed "
                         "injection and the loudest SNR nearby trigger to "
                         "display, seconds. Default=0.05")
parser.add_argument('--distance-type',
                    required=True,
                    choices=legal_distance_types,
                    help="How to sort missed injections from most to least "
                         "likely to be detected")
wf.add_workflow_command_line_group(parser)
wf.add_workflow_settings_cli(parser, include_subdax_opts=True)
args = parser.parse_args()

logging.basicConfig(format='%(asctime)s:%(levelname)s : %(message)s',
                    level=logging.INFO)

workflow = wf.Workflow(args)

wf.makedir(args.output_dir)

# create a FileList that will contain all output files
layouts = []

tmpltbank_file = resolve_url_to_file(os.path.abspath(args.bank_file))
injection_file = resolve_url_to_file(os.path.abspath(args.injection_file))
injection_xml_file = resolve_url_to_file(os.path.abspath(args.injection_xml_file))
insp_segs = resolve_url_to_file(os.path.abspath(args.inspiral_segments))

single_triggers = []
insp_data_seglists = {}
insp_analysed_seglists = {}
for ifo in args.single_detector_triggers:
    fname = args.single_detector_triggers[ifo]
    strig_file = resolve_url_to_file(os.path.abspath(fname),
                                     attrs={'ifos': ifo})
    single_triggers.append(strig_file)
    insp_data_seglists[ifo] = select_segments_by_definer(
        args.inspiral_segments,
        segment_name=args.inspiral_data_read_name,
        ifo=ifo
    )
    insp_analysed_seglists[ifo] = select_segments_by_definer(
        args.inspiral_segments,
        segment_name=args.inspiral_data_analyzed_name,
        ifo=ifo
    )
    # NOTE: make_singles_timefreq needs a coalesced set of segments. If this is
    #       being used to determine command-line options for other codes,
    #       please think if that code requires coalesced, or not, segments.
    insp_data_seglists[ifo].coalesce()
    insp_analysed_seglists[ifo].coalesce()

f = h5py.File(args.injection_file, 'r')
inj_def = f['injections']
missed = f['missed/after_vetoes'][:]
if args.ifar_threshold is not None:
    try:  # injections may not have (inclusive) IFAR present
        ifars = f['found_after_vetoes']['ifar'][:]
    except KeyError:
        ifars = f['found_after_vetoes']['ifar_exc'][:]
        logging.warning('Inclusive IFAR not found, using exclusive')
    lgc_arr = ifars < args.ifar_threshold
    missed = numpy.append(missed,
                          f['found_after_vetoes']['injection_index'][lgc_arr])

# Get the trigger SNRs and times
# But only ones which are within a small window of the missed injection
missed_inj_times = numpy.sort(inj_def['tc'][:][missed])

# Note: Adding Earth diameter in light seconds to the window here
# to allow for different IFO's arrival times of the injection
safe_window = args.nearby_triggers_window + 0.0425

def nearby_missedinj(endtime, snr):
    """
    Convenience function to check if trigger times are within a small
    window of the injections

    Parameters
    ----------
    endtime: numpy array
        Trigger times to be checked against the missed injection times

    snr: numpy array
        Required by design of the HFile.select method but not used,
        SNR of the triggers

    Returns
    -------
    boolean array
        True for triggers which are close to any missed injection
    """
    left = numpy.searchsorted(missed_inj_times - safe_window, endtime)
    right = numpy.searchsorted(missed_inj_times + safe_window, endtime)
    return left != right

trigger_idx = {}
trigger_snrs = {}
trigger_times = {}
for trig in single_triggers:
    ifo = trig.ifo
    with HFile(trig.lfn, 'r') as trig_f:
        trigger_idx[ifo], trigger_times[ifo], trigger_snrs[ifo] = \
            trig_f.select(
                nearby_missedinj,
                f'{ifo}/end_time',
                f'{ifo}/snr',
                return_indices=True)

# figure out how many injections to follow up
num_events = int(workflow.cp.get_opt_tags(
    'workflow-injection_minifollowups',
    'num-events',
    ''
))
if len(missed) < num_events:
    num_events = len(missed)

# sort the injections
missed = sort_injections(args, inj_def, missed)

# loop over sorted missed injections to be followed up
found_inj_idxes = f['found_after_vetoes/injection_index'][:]
for num_event in range(num_events):
    files = wf.FileList([])

    injection_index = missed[num_event]
    time = inj_def['tc'][injection_index]
    lon = inj_def['ra'][injection_index]
    lat = inj_def['dec'][injection_index]

    ifo_times = ''
    inj_params = {}
    for val in ['mass1', 'mass2', 'spin1z', 'spin2z', 'tc']:
        inj_params[val] = inj_def[val][injection_index]
    for single in single_triggers:
        ifo = single.ifo
        det = Detector(ifo)
        ifo_time = time + det.time_delay_from_earth_center(lon, lat, time)
        for seg in insp_analysed_seglists[ifo]:
            if ifo_time in seg:
                break
        else:
            ifo_time = -1.0

        ifo_times += ' %s:%s ' % (ifo, ifo_time)
        inj_params[ifo + '_end_time'] = ifo_time
    all_times = [inj_params[sngl.ifo + '_end_time'] for sngl in single_triggers]
    inj_params['mean_time'] = coinc.mean_if_greater_than_zero(all_times)[0]

    layouts += [(mini.make_inj_info(workflow, injection_file, injection_index, num_event,
                               args.output_dir, tags=args.tags + [str(num_event)])[0],)]
    if injection_index in found_inj_idxes:
        trig_id = numpy.where(found_inj_idxes == injection_index)[0][0]
        layouts += [(mini.make_coinc_info
                     (workflow, single_triggers, tmpltbank_file,
                      injection_file, args.output_dir, trig_id=trig_id,
                      file_substring='found_after_vetoes',
                      title="Details of closest event",
                      tags=args.tags + [str(num_event)])[0],)]

    for sngl in single_triggers:
        # Find the triggers close to this injection at this IFO
        ifo = sngl.ifo
        trig_tdiff = abs(inj_params[ifo + '_end_time'] - trigger_times[ifo])
        nearby = trig_tdiff < args.nearby_triggers_window
        if not any(nearby):
            # If there are no triggers in the defined window,
            # do not print any info
            continue
        # Find the loudest SNR in this window
        loudest = numpy.argmax(trigger_snrs[ifo][nearby])
        # Convert to the indexin the trigger file
        nearby_trigger_idx = trigger_idx[ifo][nearby][loudest]
        # Make the info snippet
        sngl_info = mini.make_sngl_ifo(workflow, sngl, tmpltbank_file,
            nearby_trigger_idx, args.output_dir, ifo,
            title=f"Parameters of loudest SNR nearby trigger in {ifo}",
            tags=args.tags + [str(num_event)])[0]
        layouts += [(sngl_info,)]

    files += mini.make_trigger_timeseries(workflow, single_triggers,
                              ifo_times, args.output_dir,
                              tags=args.tags + [str(num_event)])

    for single in single_triggers:
        checkedtime = time
        if (inj_params[single.ifo + '_end_time'] == -1.0):
            checkedtime = inj_params['mean_time']
        for seg in insp_analysed_seglists[single.ifo]:
            if checkedtime in seg:
                files += mini.make_singles_timefreq(workflow, single, tmpltbank_file,
                                checkedtime, args.output_dir,
                                data_segments=insp_data_seglists[single.ifo],
                                tags=args.tags + [str(num_event)])
                files += mini.make_qscan_plot\
                    (workflow, single.ifo, checkedtime, args.output_dir,
                     data_segments=insp_data_seglists[single.ifo],
                     injection_file=injection_xml_file,
                     tags=args.tags + [str(num_event)])
                break
        else:
            logging.info(
                'Trigger time %s is not valid in %s, skipping singles plots',
                checkedtime, single.ifo
            )

    _, norm_plot = mini.make_single_template_plots(workflow, insp_segs,
                            args.inspiral_data_read_name,
                            args.inspiral_data_analyzed_name, inj_params,
                            args.output_dir, inj_file=injection_xml_file,
                            tags=args.tags+['INJ_PARAMS',str(num_event)],
                            params_str='injection parameters as template, ' +\
                                       'here the injection is made as normal',
                            use_exact_inj_params=True)
    files += norm_plot

    _, inv_plot = mini.make_single_template_plots(workflow, insp_segs,
                            args.inspiral_data_read_name,
                            args.inspiral_data_analyzed_name, inj_params,
                            args.output_dir, inj_file=injection_xml_file,
                            tags=args.tags + ['INJ_PARAMS_INVERTED',
                                              str(num_event)],
                            params_str='injection parameters as template, ' +\
                                       'here the injection is made inverted',
                            use_exact_inj_params=True)
    files += inv_plot

    _, noinj_plot = mini.make_single_template_plots(workflow, insp_segs,
                            args.inspiral_data_read_name,
                            args.inspiral_data_analyzed_name, inj_params,
                            args.output_dir, inj_file=injection_xml_file,
                            tags=args.tags + ['INJ_PARAMS_NOINJ',
                                              str(num_event)],
                            params_str='injection parameters, here no ' +\
                                       'injection was actually performed',
                            use_exact_inj_params=True)
    files += noinj_plot

    for curr_ifo in args.single_detector_triggers:
        single_fname = args.single_detector_triggers[curr_ifo]
        hd_sngl = SingleDetTriggers(single_fname, args.bank_file, None, None,
                                    None, curr_ifo)
        end_times = hd_sngl.end_time
        # Use SNR here or NewSNR??
        snr = hd_sngl.snr
        lgc_mask = abs(end_times - inj_params['tc']) < args.inj_window

        if len(snr[lgc_mask]) == 0:
            continue

        snr_idx = numpy.arange(len(lgc_mask))[lgc_mask][snr[lgc_mask].argmax()]
        hd_sngl.mask = [snr_idx]
        curr_params = copy.deepcopy(inj_params)
        curr_params['mass1'] = hd_sngl.mass1[0]
        curr_params['mass2'] = hd_sngl.mass2[0]
        curr_params['spin1z'] = hd_sngl.spin1z[0]
        curr_params['spin2z'] = hd_sngl.spin2z[0]
        curr_params['f_lower'] = hd_sngl.f_lower[0]
        # don't require precessing template info if not present
        try:
            curr_params['spin1x'] = hd_sngl.spin1x[0]
            curr_params['spin2x'] = hd_sngl.spin2x[0]
            curr_params['spin1y'] = hd_sngl.spin1y[0]
            curr_params['spin2y'] = hd_sngl.spin2y[0]
            curr_params['inclination'] = hd_sngl.inclination[0]
        except KeyError:
            pass
        try:
            # Only present for precessing search
            curr_params['u_vals'] = hd_sngl.u_vals[0]
        except:
            pass

        curr_tags = ['TMPLT_PARAMS_%s' %(curr_ifo,)]
        curr_tags += [str(num_event)]
        _, loudest_plot = mini.make_single_template_plots(workflow, insp_segs,
                                args.inspiral_data_read_name,
                                args.inspiral_data_analyzed_name, curr_params,
                                args.output_dir, inj_file=injection_xml_file,
                                tags=args.tags + curr_tags,
                                params_str='loudest template in %s' % curr_ifo )
        files += loudest_plot

    layouts += list(layout.grouper(files, 2))

workflow.save()
layout.two_column_layout(args.output_dir, layouts)
