"""
Tests various capabilities of the libEnsemble fast_alloc alloc_f

Execute via one of the following commands (e.g. 3 workers):
   mpiexec -np 4 python test_fast_alloc.py
   python test_fast_alloc.py --nworkers 3 --comms local

The number of concurrent evaluations of the objective function will be 4-1=3.
"""

# Do not change these lines - they are parsed by run-tests.sh
# TESTSUITE_COMMS: mpi local
# TESTSUITE_NPROCS: 2 4

import sys
import gc
import numpy as np

# Import libEnsemble items for this test
from libensemble.libE import libE
from libensemble.sim_funcs.six_hump_camel import six_hump_camel_simple as sim_f
from libensemble.gen_funcs.sampling import uniform_random_sample as gen_f
from libensemble.alloc_funcs.fast_alloc import give_sim_work_first as alloc_f
from libensemble.alloc_funcs.only_one_gen_alloc import ensure_one_active_gen as alloc_f2
from libensemble.tools import parse_args, add_unique_random_streams

nworkers, is_manager, libE_specs, _ = parse_args()

num_pts = 30 * (nworkers)

sim_specs = {
    "sim_f": sim_f,
    "in": ["x"],
    "out": [("f", float), ("large", float, 1000000)],
    "user": {},
}

gen_specs = {
    "gen_f": gen_f,
    "in": ["sim_id"],
    "out": [("x", float, (2,))],
    "user": {
        "gen_batch_size": num_pts,
        "lb": np.array([-3, -2]),
        "ub": np.array([3, 2]),
    },
}

persis_info = add_unique_random_streams({}, nworkers + 1)

exit_criteria = {"sim_max": 2 * num_pts, "wallclock_max": 300}

if libE_specs["comms"] == "tcp":
    # Can't use the same interface for manager and worker if we want
    # repeated calls to libE -- the manager sets up a different server
    # each time, and the worker will not know what port to connect to.
    sys.exit("Cannot run with tcp when repeated calls to libE -- aborting...")

for time in np.append([0], np.logspace(-5, -1, 5)):
    print("Starting for time: ", time, flush=True)
    if time == 0:
        alloc_specs = {"alloc_f": alloc_f2, "out": []}
    else:
        alloc_specs = {"alloc_f": alloc_f, "out": [], "user": {"num_active_gens": 1}}

    for rep in range(1):
        sim_specs["user"]["pause_time"] = time

        if time == 0:
            sim_specs["user"].pop("pause_time")
            gen_specs["user"]["gen_batch_size"] = num_pts // 2

        persis_info["next_to_give"] = 0
        persis_info["total_gen_calls"] = 1

        H, persis_info, flag = libE(sim_specs, gen_specs, exit_criteria, persis_info, alloc_specs, libE_specs)

        if is_manager:
            assert flag == 0
            assert len(H) == 2 * num_pts

        del H
        gc.collect()  # If doing multiple libE calls, users might need to clean up their memory space.
