"""`graphify extract` frees its whole-graph intermediates without changing output.

The Python parse memo pinned every tree-sitter tree (and its node wrappers)
after AST extraction, and to_json kept copies of the old and new graphs alive
through the write. Releasing them early must not change a byte of graph.json.
"""
from __future__ import annotations

import json
import shutil

import networkx as nx
import pytest

import graphify.__main__ as mainmod
import graphify.export as export_mod
from graphify.export import to_json

# to_json output for _graph() below, as written before the memory changes.
EXPECTED_GRAPH_JSON = (
    '{"directed":false,"multigraph":false,"graph":{"hyperedges":[{"id":"h1","nodes":["a","b","c"],'
    '"relation":"group"}],"schema_version":1},"nodes":[{"id":"a","label":"A","community":0,'
    '"file_type":"code","norm_label":"a","source_file":"a.py"},{"id":"b","label":"B","community":0,'
    '"file_type":"code","norm_label":"b","source_file":"b.py"},{"id":"c","label":"C","community":1,'
    '"file_type":"document","norm_label":"c","source_file":"c.md"}],"links":[{"source":"b",'
    '"target":"a","relation":"calls","confidence":"EXTRACTED","confidence_score":1.0},'
    '{"source":"b","target":"c","relation":"references","confidence":"INFERRED",'
    '"confidence_score":0.55}],"hyperedges":[{"id":"h1","nodes":["a","b","c"],"relation":"group"}],'
    '"built_at_commit":"abc"}'
)


def _graph(*, hyperedges: bool = True) -> nx.Graph:
    G = nx.Graph()
    # `id` stored inline on one node: canonicalization must still put it first.
    G.add_node("b", label="B", file_type="code", source_file="b.py", id="b")
    G.add_node("a", label="A", file_type="code", source_file="a.py")
    G.add_node("c", label="C", file_type="document", source_file="c.md")
    G.add_edge("a", "b", relation="calls", confidence="EXTRACTED", _src="b", _tgt="a")
    G.add_edge("b", "c", relation="references", confidence="INFERRED")
    if hyperedges:
        G.graph["hyperedges"] = [{"id": "h1", "nodes": ["a", "b", "c"], "relation": "group"}]
    return G


def test_to_json_bytes_unchanged_on_forced_and_guarded_writes(tmp_path, monkeypatch):
    monkeypatch.setattr(export_mod, "_graphify_version", lambda: None)
    communities = {0: ["a", "b"], 1: ["c"]}
    forced = tmp_path / "forced.json"
    assert to_json(_graph(), communities, str(forced), force=True, built_at_commit="abc")
    assert forced.read_text(encoding="utf-8") == EXPECTED_GRAPH_JSON

    # The guarded write parses the existing file and frees it before exporting.
    guarded = tmp_path / "guarded.json"
    shutil.copy(forced, guarded)
    assert to_json(_graph(), communities, str(guarded), force=False, built_at_commit="abc")
    assert guarded.read_bytes() == forced.read_bytes()


def test_to_json_hyperedge_wipe_warning_still_reads_previous_graph(tmp_path, capsys):
    out = tmp_path / "graph.json"
    to_json(_graph(), {0: ["a", "b", "c"]}, str(out), force=True, built_at_commit="abc")
    assert to_json(_graph(hyperedges=False), {0: ["a", "b", "c"]}, str(out),
                   force=True, built_at_commit="abc")
    assert "already holds 1 hyperedge(s)" in capsys.readouterr().err
    assert json.loads(out.read_text(encoding="utf-8"))["hyperedges"] == []


def test_extract_cli_releases_python_parse_memo(tmp_path, monkeypatch):
    pytest.importorskip("tree_sitter_python")
    from graphify.extractors.resolution import _parse_python_tree_cached

    corpus = tmp_path / "corpus"
    corpus.mkdir()
    (corpus / "a.py").write_text("def helper():\n    return 1\n", encoding="utf-8")
    (corpus / "b.py").write_text(
        "from a import helper\n\ndef run():\n    return helper()\n", encoding="utf-8"
    )
    out_dir = tmp_path / "out"
    monkeypatch.setattr(mainmod, "_check_skill_version", lambda _: None)
    monkeypatch.setattr(
        mainmod.sys, "argv",
        ["graphify", "extract", str(corpus), "--code-only", "--out", str(out_dir)],
    )
    _parse_python_tree_cached.cache_clear()
    try:
        mainmod.main()
    except SystemExit as exc:
        assert exc.code in (None, 0), f"unexpected exit code {exc.code}"

    assert (out_dir / "graphify-out" / "graph.json").exists()
    # Both resolution passes parse a.py and b.py through the memo; it must be
    # empty once the command is done with it (it held 2 trees before).
    assert _parse_python_tree_cached.cache_info().currsize == 0


@pytest.mark.parametrize("release", [False, True])
def test_extract_parse_memo_release_is_opt_in(tmp_path, release):
    pytest.importorskip("tree_sitter_python")
    from graphify.extract import extract
    from graphify.extractors.resolution import _parse_python_tree_cached

    (tmp_path / "a.py").write_text("def helper():\n    return 1\n", encoding="utf-8")
    (tmp_path / "b.py").write_text("from a import helper\n", encoding="utf-8")
    _parse_python_tree_cached.cache_clear()
    extract([tmp_path / "a.py", tmp_path / "b.py"], cache_root=tmp_path / "out",
            root=tmp_path, release_parse_memo=release)
    # Long-lived callers (watch, MCP) keep the memo warm for their next run.
    assert _parse_python_tree_cached.cache_info().currsize == (0 if release else 2)