"""Tests for dry-run parsing and DAG restriction in :mod:`nix_estimator.graph`."""

from nix_estimator import graph

# --- captured `nix build --dry-run` text (issue #5) ------------------------

WARM = """\
this path will be fetched (0.02 MiB download, 0.10 MiB unpacked):
  /nix/store/aaa-hello-2.12.1
"""

PARTIAL = """\
these 2 derivations will be built:
  /nix/store/bbb-foo-1.0.drv
  /nix/store/ccc-bar-2.0.drv
these 3 paths will be fetched (1.0 MiB download):
  /nix/store/ddd-baz-3.0
"""

GARBAGE = """\
error: some totally unrelated failure with no dry-run structure
traceback blah blah
"""


def test_warm_cache_only_fetched_is_empty_set():
    # dry-run succeeded, nothing to build: distinct from a parse failure
    result = graph.parse_dry_run_text(WARM, returncode=0)
    assert result == set()


def test_partial_returns_only_built_drvs():
    result = graph.parse_dry_run_text(PARTIAL, returncode=0)
    assert result == {"bbb-foo-1.0.drv", "ccc-bar-2.0.drv"}


def test_garbage_without_header_and_failure_is_none():
    assert graph.parse_dry_run_text(GARBAGE, returncode=1) is None


def test_clean_exit_without_header_is_empty_not_none():
    # exit 0 but no recognizable header still counts as "nothing to build"
    assert graph.parse_dry_run_text("", returncode=0) == set()


# --- structured `nix build --dry-run --json` output (issue #8) -------------

JSON_PARTIAL = """\
[
  {"drvPath": "/nix/store/bbb-foo-1.0.drv", "outputs": {"out": "/nix/store/e-foo"}},
  {"drvPath": "/nix/store/ccc-bar-2.0.drv", "outputs": {"out": "/nix/store/f-bar"}}
]
"""

JSON_WARM = "[]"

JSON_ALT_KEY = '[{"drv": "/nix/store/ggg-qux-9.drv"}]'


def test_json_partial_returns_built_drvs():
    assert graph.parse_dry_run_json(JSON_PARTIAL) == {
        "bbb-foo-1.0.drv",
        "ccc-bar-2.0.drv",
    }


def test_json_warm_cache_is_empty_set():
    assert graph.parse_dry_run_json(JSON_WARM) == set()


def test_json_alternate_drv_key():
    assert graph.parse_dry_run_json(JSON_ALT_KEY) == {"ggg-qux-9.drv"}


def test_json_non_structured_is_none():
    # human text or an unexpected shape must fall back (None), not crash
    assert graph.parse_dry_run_json(WARM) is None
    assert graph.parse_dry_run_json('{"not": "a list"}') is None
    assert graph.parse_dry_run_json("not json at all") is None


def test_build_dag_empty_set_yields_no_nodes():
    closure = {"a.drv": {"inputDrvs": {}}, "b.drv": {"inputDrvs": {"a.drv": {}}}}
    preds, nodes = graph.build_dag(closure, set())
    assert nodes == set()
    assert preds == {}


# --- upstream-substitutable filtering (issue #22) --------------------------

# legacy schema: outputs.<name>.path holds the store path
LEGACY_DRV = {
    "outputs": {"out": {"path": "/nix/store/o1-foo"}},
    "inputDrvs": {},
}
# versioned (schema v3) shape still carries per-output `path`
VERSIONED_DRV = {
    "name": "bar",
    "outputs": {
        "out": {"path": "/nix/store/o2-bar"},
        "dev": {"path": "/nix/store/o3-bar-dev"},
    },
    "inputs": {"drvs": {}, "srcs": []},
}
# content-addressed / floating output: no path -> skipped
CA_DRV = {"outputs": {"out": {"hashAlgo": "sha256"}}}


def test_output_paths_legacy_schema():
    assert graph.output_paths(LEGACY_DRV) == ["/nix/store/o1-foo"]


def test_output_paths_versioned_multi_output():
    assert graph.output_paths(VERSIONED_DRV) == [
        "/nix/store/o2-bar",
        "/nix/store/o3-bar-dev",
    ]


def test_output_paths_ca_without_path_is_empty():
    assert graph.output_paths(CA_DRV) == []


# Real versioned schema (Nix 2.30+, schema v4) stores the output path BARE, with
# no /nix/store/ prefix — output_paths must normalize it so cache lookups work
# (issue #24).
VERSIONED_BARE_DRV = {
    "name": "bar",
    "outputs": {
        "out": {"path": "o2-bar"},
        "dev": {"path": "o3-bar-dev"},
    },
    "inputs": {"drvs": {}, "srcs": []},
}


def test_output_paths_versioned_bare_path_normalized():
    assert graph.output_paths(VERSIONED_BARE_DRV) == [
        "/nix/store/o2-bar",
        "/nix/store/o3-bar-dev",
    ]


def test_filter_drops_bare_output_paths_via_full_path_query(monkeypatch):
    # End-to-end: a drv whose outputs are bare must still be matched against a
    # cache oracle that keys by full /nix/store/ path (issue #24).
    drv = {"outputs": {"out": {"path": "aaa-cached"}}, "inputDrvs": {}}
    closure = {"aaa-cached.drv": drv}
    monkeypatch.setattr(
        graph,
        "substitutable_paths",
        lambda paths, cache_url=None, **k: {"/nix/store/aaa-cached"},
    )
    reduced, changed = graph.filter_upstream_substitutable(closure, None)
    assert changed is True
    assert reduced == set()


def test_filter_drops_fully_substitutable_keeps_partial_and_none():
    closure = {
        "foo.drv": LEGACY_DRV,  # single out, will be cached -> dropped
        "bar.drv": VERSIONED_DRV,  # two outs, only one cached -> kept
        "baz.drv": {"outputs": {"out": {"path": "/nix/store/o4-baz"}}},  # kept
    }

    def fake_query(paths, cache_url):
        # exercises the map-to-output-path logic: caller must have collected
        # exactly the outputs of the candidate drvs
        assert "/nix/store/o1-foo" in paths
        assert "/nix/store/o2-bar" in paths and "/nix/store/o3-bar-dev" in paths
        return {"/nix/store/o1-foo", "/nix/store/o2-bar"}

    reduced, changed = graph.filter_upstream_substitutable(
        closure, None, _query=fake_query
    )
    assert reduced == {"bar.drv", "baz.drv"}
    assert changed is True


def test_filter_respects_to_build_set(monkeypatch):
    closure = {
        "foo.drv": LEGACY_DRV,
        "bar.drv": VERSIONED_DRV,
        "baz.drv": {"outputs": {"out": {"path": "/nix/store/o4-baz"}}},
    }
    monkeypatch.setattr(
        graph, "substitutable_paths", lambda paths, cache_url: {"/nix/store/o1-foo"}
    )
    # only foo,bar considered; foo fully cached -> dropped, bar kept
    reduced, changed = graph.filter_upstream_substitutable(
        closure, {"foo.drv", "bar.drv"}
    )
    assert reduced == {"bar.drv"}
    assert changed is True


def test_filter_no_op_when_cache_knows_nothing():
    closure = {"foo.drv": LEGACY_DRV, "bar.drv": VERSIONED_DRV}
    reduced, changed = graph.filter_upstream_substitutable(
        closure, None, _query=lambda paths, cache_url: set()
    )
    assert reduced == {"foo.drv", "bar.drv"}
    assert changed is False


def test_parse_path_info_object_and_list_shapes():
    obj = '{"/nix/store/o1-foo": {"narSize": 1}, "/nix/store/o2-bar": null}'
    assert graph._parse_path_info(obj, ["/nix/store/o1-foo", "/nix/store/o2-bar"]) == {
        "/nix/store/o1-foo"
    }
    lst = '[{"path": "/nix/store/o1-foo", "valid": true}]'
    assert graph._parse_path_info(lst, ["/nix/store/o1-foo"]) == {"/nix/store/o1-foo"}
    assert graph._parse_path_info("not json", ["/nix/store/o1-foo"]) == set()


def test_build_dag_none_costs_whole_closure():
    closure = {
        "a.drv": {"inputDrvs": {}},
        "b.drv": {"inputDrvs": {"/nix/store/x-a.drv": {}}},
    }
    _, nodes = graph.build_dag(closure, None)
    assert nodes == {"a.drv", "b.drv"}