"""Cache keys: independent of the duration and the output naming, of whether a default is written
out, and consistent with which runs can continue one another."""
import copy
import hashlib
import json
import re

import yaml

from cymsim.cache import MODEL_VERSION, cache_key, key_fields
from cymsim.cli import main
from cymsim.config import ForceExciter, Hit, MalletExciter, SimulationConfig, StickExciter, default_config

# sha256 of the full default configuration. When this test fails, a default has changed or a field
# was added. If the results of some existing configuration change, bump MODEL_VERSION in cache.py;
# either way, update the fingerprint.
DEFAULTS_FINGERPRINT = "4b9d969c01b47ddabc6ee40ac7315d0c1ed1ac998f4a95b120ed4e668268672c"


def test_key_format():
    assert re.fullmatch(rf"v{MODEL_VERSION}/[0-9a-f]{{64}}", cache_key(SimulationConfig()))


def test_continuation_fields_do_not_change_the_key():
    a = default_config("stick")
    b = copy.deepcopy(a)
    b.numerics.duration = 7.5
    b.numerics.n_progress = 3
    b.output.prefix, b.output.wav, b.output.npz, b.output.cascade_plot = "other", False, False, False
    assert cache_key(a) == cache_key(b)


def test_written_out_defaults_do_not_change_the_key(tmp_path):
    full = tmp_path / "full.yaml"
    default_config("stick").to_yaml(full)                    # every field written out
    short = tmp_path / "short.yaml"
    h = default_config("stick").hits[0]
    short.write_text(yaml.safe_dump({"hits": [{"r": h.r, "phi": h.phi, "velocity": 7, "exciter": {"kind": "stick"}}]}))
    assert cache_key(SimulationConfig.from_yaml(full)) == cache_key(SimulationConfig.from_yaml(short))
    assert cache_key(SimulationConfig.from_yaml(full)) == cache_key(default_config("stick"))


def test_physical_and_numerical_changes_change_the_key():
    base = default_config("mallet")
    variants = []
    for change in (lambda c: setattr(c.hits[0], "velocity", 8.0001),
                   lambda c: setattr(c.hits[0], "exciter", StickExciter()),
                   lambda c: setattr(c.hits[0], "exciter", ForceExciter()),
                   lambda c: c.hits.append(Hit(time=0.5)),
                   lambda c: setattr(c.material, "E", 1.2e11),
                   lambda c: setattr(c.imperfections, "seed", 2),
                   lambda c: setattr(c.numerics, "dtype", "float64"),
                   lambda c: setattr(c.numerics, "steps_per_block", 10000),
                   lambda c: setattr(c.output, "probes", [(0.1, 0.0)]),
                   lambda c: setattr(c.output, "record_acceleration", True),
                   lambda c: setattr(c.listener, "position", (0.4, 0.3, 1.0))):
        c = copy.deepcopy(base)
        change(c)
        variants.append(cache_key(c))
    assert len(set(variants + [cache_key(base)])) == len(variants) + 1


def test_exciters_at_their_defaults_are_told_apart():
    keys = {cache_key(SimulationConfig(hits=[Hit(exciter=e)])) for e in (MalletExciter(), StickExciter(), ForceExciter())}
    assert len(keys) == 3
    assert key_fields(SimulationConfig(hits=[Hit(exciter=StickExciter())])) == {"hits": [{"exciter": {"kind": "stick"}}]}


def test_equal_keys_mean_continuable_runs():
    """The key and Simulator.check_resumable compare the same thing."""
    base = default_config("stick")
    cfgs = [base]
    for change in (lambda c: setattr(c.numerics, "duration", 1.0), lambda c: setattr(c.output, "prefix", "z"),
                   lambda c: setattr(c.hits[0], "phi", 1.0), lambda c: setattr(c.output, "displacement_rate", 0.0)):
        c = copy.deepcopy(base)
        change(c)
        cfgs.append(c)
    for a in cfgs:
        for b in cfgs:
            assert (cache_key(a) == cache_key(b)) == (a.identity_dict() == b.identity_dict())


def test_defaults_fingerprint():
    text = json.dumps(SimulationConfig().to_dict(), sort_keys=True, separators=(",", ":"))
    assert hashlib.sha256(text.encode()).hexdigest() == DEFAULTS_FINGERPRINT, (
        "the default configuration changed: bump MODEL_VERSION in cache.py if results of existing "
        "configurations change, then update DEFAULTS_FINGERPRINT")


def test_cli_cache_key(tmp_path, capsys):
    path = tmp_path / "c.yaml"
    default_config("stick").to_yaml(path)
    assert main(["cache-key", str(path), "--show"]) == 0
    out = capsys.readouterr().out.splitlines()
    assert out[0] == cache_key(default_config("stick"))
    assert '"hits": [' in "\n".join(out)