#!/usr/bin/env python3
# vim: fdm=indent ts=4

"""
Add a beacon measurement on top of the
simulated airshower.
"""

import numpy as np
import json
import h5py
import os.path as path
from copy import deepcopy as copy

from earsim import REvent, Antenna, block_filter
import lib

tx_fname = 'tx.json'
antennas_fname = 'antennas.hdf5'

def write_tx_file(fname, tx, f_beacon):
    with open(fname, 'w') as fp:
        return json.dump(
                dict(
                    f_beacon=f_beacon,
                    tx=dict(
                        x=tx.x,
                        y=tx.y,
                        z=tx.z,
                        name=tx.name
                        )
                    ),
                fp
                )

def read_tx_file(fname):
    with open(fname, 'r') as fp:
        data = json.load(fp)

    f_beacon = data['f_beacon']
    tx = Antenna(**data['tx'])

    return tx, f_beacon

def read_beacon_hdf5(fname, **h5ant_kwargs):
    with h5py.File(fname, 'r') as h5:
        tx = Antenna_from_h5ant(h5['tx'], traces_key=None)
        f_beacon = tx.attrs['f_beacon']

        antennas = []
        for k, h5ant in h5['antennas'].items():
            ant = Antenna_from_h5ant(h5ant, **h5ant_kwargs)

            antennas.append(ant)

    return f_beacon, tx, antennas

def Antenna_from_h5ant(h5ant, traces_key='traces', raise_exception=True, read_AxB=True, read_beacon_info=True):
    mydict = { k:h5ant.attrs.get(k) for k in ['x', 'y', 'z', 'name'] }
    ant = Antenna(**mydict)
    if h5ant.attrs:
        ant.attrs = {**h5ant.attrs}

    # Traces
    if traces_key is None:
        pass
    elif traces_key not in h5ant:
        if raise_exception:
            raise ValueError("Traces_key not in file")
    else:
        ant.t = h5ant[traces_key][0]
        ant.Ex = h5ant[traces_key][1]
        ant.Ey = h5ant[traces_key][2]
        ant.Ez = h5ant[traces_key][3]
        if len(h5ant[traces_key]) > 4:
            ant.beacon = h5ant[traces_key][4]

    # E_AxB
    if read_AxB and 'E_AxB' in h5ant:
        ant.t_AxB = h5ant['E_AxB'][0]
        ant.E_AxB = h5ant['E_AxB'][1]

    # Beacons
    if read_beacon_info and 'beacon' in h5ant:
        h5beacon = h5ant['beacon']

        beacon_info = {}
        for name in h5beacon.keys():
            beacon_info[name] = h5beacon[name].attrs

        ant.beacon_info = beacon_info

    return ant


def init_antenna_hdf5(fname, tx = None, f_beacon = None):
    with h5py.File(fname, 'w') as fp:
        if tx is not None or f_beacon is not None:
            tx_group = fp.create_group('tx')
            tx_attrs = tx_group.attrs

            if f_beacon is not None:
                tx_attrs['f_beacon'] = f_beacon

            if tx is not None:
                tx_attrs['x'] = tx.x
                tx_attrs['y'] = tx.y
                tx_attrs['z'] = tx.z
                tx_attrs['name'] = tx.name

    return fname

def append_antenna_hdf5(fname, antenna, columns = [], name='traces', prepend_time=True, overwrite=True, attrs_dict={}):
    if not overwrite:
        raise NotImplementedError

    with h5py.File(fname, 'a') as fp:
        if 'antennas' in fp.keys():
            if not overwrite:
                raise NotImplementedError
            group = fp['antennas']
        else:
            group = fp.create_group('antennas')


        if antenna.name in group:
            if not overwrite:
                raise NotImplementedError
            h5ant = group[antenna.name]
        else:
            h5ant = group.create_group(antenna.name)

        h5ant_attrs = h5ant.attrs
        h5ant_attrs['x'] = antenna.x
        h5ant_attrs['y'] = antenna.y
        h5ant_attrs['z'] = antenna.z
        h5ant_attrs['name'] = antenna.name

        for k,v in attrs_dict.items():
            h5ant_attrs[k] = v

        if name in h5ant:
            if not overwrite:
                raise NotImplementedError
            del h5ant[name]

        dset = h5ant.create_dataset(name, (len(columns) + 1*prepend_time, len(columns[0])), dtype='f')

        if prepend_time:
            dset[0] = antenna.t

        for i, col in enumerate(columns, 1*prepend_time):
            dset[i] = col

if __name__ == "__main__":
    from os import path

    remake_tx = True

    fname = "ZH_airshower/mysim.sry"
    tx = Antenna(x=-500,y=0,z=0,name='tx') # m
    f_beacon = 51.53e-3 # GHz

    # Bandpass for E field blockfilter
    low_bp = 0.03 # GHz
    high_bp = 0.08 # GHz

    beacon_amplitudes = 1e-6*np.array([1e2, 0, 0]) # mu V/m
    beacon_radiate_rsq = True

    if beacon_radiate_rsq:
        # Move tx out, and magnify beacon_amplitude (at tx)
        tx = Antenna(x=-20e3,y=0,z=0,name='tx') # m
        dist = lib.distance(tx, Antenna(x=0, y=0, z=0))

        ampl = max(1, dist**2)

        beacon_amplitudes *= ampl

    ####
    fname_dir = path.dirname(fname)
    tx_fname = path.join(fname_dir, tx_fname)
    antennas_fname = path.join(fname_dir, antennas_fname)

    if not path.isfile(tx_fname) or remake_tx:
        write_tx_file(tx_fname, tx, f_beacon)
    else:
        tx, f_beacon = read_tx_file(tx_fname)

    # read in antennas
    ev = REvent(fname)
    N_antennas = len(ev.antennas)

    # initialize hdf5 file
    init_antenna_hdf5(antennas_fname, tx, f_beacon)

    # make beacon per antenna
    for i, antenna in enumerate(ev.antennas):
        t0 = lib.distance(tx, antenna)/3e8 * 1e9 # ns

        beacon = lib.beacon_from(tx, antenna, f_beacon, antenna.t, t0=t0, c_light=np.inf, radiate_rsq=beacon_radiate_rsq)

        E = np.array([antenna.Ex, antenna.Ey, antenna.Ez, beacon])

        # add to relevant polarisation
        # and apply block filter
        dt = antenna.t[1] - antenna.t[0]
        for j, _ in enumerate(beacon_amplitudes):
            E[j] += block_filter(beacon_amplitudes[j]*beacon, dt, low_bp, high_bp)

        append_antenna_hdf5( antennas_fname, antenna, E, name='traces', prepend_time=True, attrs_dict=dict(t0=t0))

        # Save E field in E_AxB
        E = [np.dot(ev.uAxB,[ex,ey,ez]) for ex,ey,ez in zip(E[0], E[1], E[2])]

        append_antenna_hdf5( antennas_fname, antenna, [E], name='E_AxB', prepend_time=True)


    print("Antenna HDF5 file written as " + str(antennas_fname))