"""Tests for FileGraph backends (LocalFileGraph + NxFileGraph)."""

# pylint: disable=protected-access

import asyncio
import os
import tempfile

import pytest

from reme.components.file_graph import LocalFileGraph, NxFileGraph
from reme.enumeration import LinkScopeEnum
from reme.schema import FileLink, FileNode


class temp_chdir:
    """Context manager to temporarily chdir into a path and restore on exit."""

    def __init__(self, path):
        self.path = path
        self.old = None

    def __enter__(self):
        self.old = os.getcwd()
        os.chdir(self.path)
        return self

    def __exit__(self, *exc):
        os.chdir(self.old)


def make_node(path: str, links: list[tuple[str, str | None]] | None = None) -> FileNode:
    """Build a FileNode with the given outgoing (target_path, target_anchor) pairs."""
    return FileNode(
        path=path,
        st_mtime=1.0,
        links=[FileLink(source_path=path, target_path=t, target_anchor=a) for t, a in (links or [])],
    )


def test_file_node_loads_legacy_predicate_without_persisting_it():
    """Legacy predicates are accepted for compatibility but omitted from new snapshots."""
    node = FileNode.model_validate(
        {
            "path": "a.md",
            "st_mtime": 1.0,
            "links": [
                {
                    "source_path": "a.md",
                    "target_path": "b.md",
                    "target_anchor": "intro",
                    "predicate": "related",
                },
            ],
        },
    )
    assert node.links == [
        FileLink(source_path="a.md", target_path="b.md", target_anchor="intro", predicate="related"),
    ]
    assert "predicate" not in node.model_dump_json()


# Both backends should satisfy the same BaseFileGraph contract.
BACKENDS = [LocalFileGraph, NxFileGraph]


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_upsert_and_get_nodes(backend_cls):
    """upsert_nodes stores nodes; get_nodes returns them by path or all."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            n1 = make_node("a.md", [("b.md", None)])
            n2 = make_node("b.md")
            await graph.upsert_nodes([n1, n2])

            got_all = await graph.get_nodes()
            assert {n.path for n in got_all} == {"a.md", "b.md"}

            got_one = await graph.get_nodes(["a.md"])
            assert len(got_one) == 1
            assert got_one[0].path == "a.md"

            got_missing = await graph.get_nodes(["nope.md"])
            assert got_missing == []

            await graph.close()
            print(f"✓ test_upsert_and_get_nodes[{backend_cls.__name__}] passed")

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_upsert_replaces_old_links(backend_cls):
    """Re-upserting a node with new links replaces the old outgoing edges."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            await graph.upsert_nodes(
                [
                    make_node("a.md", [("b.md", None)]),
                    make_node("b.md"),
                    make_node("c.md"),
                ],
            )
            assert {lnk.target_path for lnk in await graph.get_outlinks("a.md")} == {"b.md"}

            # Replace a's link target from b → c
            await graph.upsert_nodes([make_node("a.md", [("c.md", None)])])
            assert {lnk.target_path for lnk in await graph.get_outlinks("a.md")} == {"c.md"}
            # b should no longer have a as an inlink
            assert await graph.get_inlinks("b.md") == []
            assert {lnk.source_path for lnk in await graph.get_inlinks("c.md")} == {"a.md"}

            await graph.close()
            print(f"✓ test_upsert_replaces_old_links[{backend_cls.__name__}] passed")

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_outlinks_include_virtual_targets(backend_cls):
    """get_outlinks(scope=ALL) surfaces edges into virtual targets too;
    scope=VIRTUAL isolates them; default scope=REAL hides them.

    A wikilink to a not-yet-indexed file is still real data the source
    contains — callers like the day-index aggregator and lint:dangling
    need to see it via the opt-in scopes.
    """

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            # a links to b (real) and ghost (virtual)
            await graph.upsert_nodes(
                [
                    make_node("a.md", [("b.md", None), ("ghost.md", None)]),
                    make_node("b.md"),
                ],
            )

            all_targets = {lnk.target_path for lnk in await graph.get_outlinks("a.md", scope=LinkScopeEnum.ALL)}
            assert all_targets == {"b.md", "ghost.md"}

            virtual_targets = {lnk.target_path for lnk in await graph.get_outlinks("a.md", scope=LinkScopeEnum.VIRTUAL)}
            assert virtual_targets == {"ghost.md"}

            # Default scope=REAL hides the dangling edge.
            real_targets = {lnk.target_path for lnk in await graph.get_outlinks("a.md")}
            assert real_targets == {"b.md"}

            await graph.close()
            print(f"✓ test_outlinks_include_virtual_targets[{backend_cls.__name__}] passed")

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_inlinks_visible_for_virtual_target(backend_cls):
    """Edges to a virtual target are queryable via get_inlinks(scope=VIRTUAL/ALL).

    The data model stores ``target → {sources}`` regardless of whether the
    target is a real node or a placeholder; scope=REAL hides virtual-target
    inlinks, VIRTUAL/ALL surface them so callers like graph_retarget_step
    can fix dangling references.
    """

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            # b doesn't exist yet — edge lives against a virtual placeholder.
            await graph.upsert_nodes([make_node("a.md", [("b.md", None)])])
            # Default (real only): b is virtual, so nothing.
            assert await graph.get_inlinks("b.md") == []
            # Opt-in virtual scope: surface the dangling inlink.
            inlinks = await graph.get_inlinks("b.md", scope=LinkScopeEnum.VIRTUAL)
            assert {lnk.source_path for lnk in inlinks} == {"a.md"}
            # ALL: equivalent here since b is purely virtual.
            inlinks_all = await graph.get_inlinks("b.md", scope=LinkScopeEnum.ALL)
            assert {lnk.source_path for lnk in inlinks_all} == {"a.md"}

            # Promoting b to real makes the inlink visible by default again,
            # and the virtual scope now returns nothing.
            await graph.upsert_nodes([make_node("b.md")])
            assert {lnk.source_path for lnk in await graph.get_inlinks("b.md")} == {"a.md"}
            assert await graph.get_inlinks("b.md", scope=LinkScopeEnum.VIRTUAL) == []

            await graph.close()
            print(f"✓ test_inlinks_visible_for_virtual_target[{backend_cls.__name__}] passed")

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_delete_keeps_inbound_view(backend_cls):
    """Deleting a node demotes it to virtual; with ``scope=VIRTUAL`` (or
    ``ALL``) the inbound view is preserved (sources still hold the link),
    and outlinks into the now-virtual target are surfaced — the link
    payload is what matters, virtuality is just an indexing artifact.
    Default scope (REAL) hides both views once the target is virtual.
    """

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            await graph.upsert_nodes(
                [
                    make_node("a.md", [("b.md", None)]),
                    make_node("b.md"),
                ],
            )
            assert {lnk.source_path for lnk in await graph.get_inlinks("b.md")} == {"a.md"}

            await graph.delete_nodes(["b.md"])
            # b is no longer a real node
            assert await graph.get_nodes(["b.md"]) == []
            # Default scope=REAL: virtual b has no visible inlinks.
            assert await graph.get_inlinks("b.md") == []
            # scope=VIRTUAL surfaces the preserved dangling reference.
            virtual_inlinks = await graph.get_inlinks("b.md", scope=LinkScopeEnum.VIRTUAL)
            assert {lnk.source_path for lnk in virtual_inlinks} == {"a.md"}
            # Default also hides a's outlink into virtual b; scope=ALL surfaces it.
            assert await graph.get_outlinks("a.md") == []
            all_outlinks = await graph.get_outlinks("a.md", scope=LinkScopeEnum.ALL)
            assert {lnk.target_path for lnk in all_outlinks} == {"b.md"}

            # Re-upsert b — inlinks visible by default again.
            await graph.upsert_nodes([make_node("b.md")])
            assert {lnk.source_path for lnk in await graph.get_inlinks("b.md")} == {"a.md"}

            await graph.close()
            print(f"✓ test_delete_keeps_inbound_view[{backend_cls.__name__}] passed")

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_delete_outgoing_links_cleared(backend_cls):
    """Deleting a source node drops its outgoing edges (no inlink left on its targets)."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            await graph.upsert_nodes(
                [
                    make_node("a.md", [("b.md", None)]),
                    make_node("b.md"),
                ],
            )
            await graph.delete_nodes(["a.md"])

            assert await graph.get_inlinks("b.md") == []

            await graph.close()
            print(f"✓ test_delete_outgoing_links_cleared[{backend_cls.__name__}] passed")

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_clear(backend_cls):
    """clear() removes all nodes and edges."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            await graph.upsert_nodes(
                [
                    make_node("a.md", [("b.md", None)]),
                    make_node("b.md"),
                ],
            )
            await graph.clear()
            assert await graph.get_nodes() == []

            await graph.close()
            print(f"✓ test_clear[{backend_cls.__name__}] passed")

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_rebuild_links_idempotent(backend_cls):
    """rebuild_links produces the same outlink/inlink view as the original upserts."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            await graph.upsert_nodes(
                [
                    make_node("a.md", [("b.md", None), ("c.md", "h")]),
                    make_node("b.md"),
                    make_node("c.md"),
                ],
            )

            before_out = sorted((lnk.target_path, lnk.target_anchor) for lnk in await graph.get_outlinks("a.md"))
            before_in = sorted(lnk.source_path for lnk in await graph.get_inlinks("b.md"))

            await graph.rebuild_links()

            after_out = sorted((lnk.target_path, lnk.target_anchor) for lnk in await graph.get_outlinks("a.md"))
            after_in = sorted(lnk.source_path for lnk in await graph.get_inlinks("b.md"))

            assert before_out == after_out
            assert before_in == after_in

            await graph.close()
            print(f"✓ test_rebuild_links_idempotent[{backend_cls.__name__}] passed")

    asyncio.run(run())


def test_nx_rebuild_links_repair_survives_restart():
    """A repaired NetworkX snapshot must not revert to stale serialized edges."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = NxFileGraph()
            await graph.start()
            await graph.upsert_nodes(
                [
                    make_node("a.md", [("c.md", None)]),
                    make_node("b.md"),
                    make_node("c.md"),
                ],
            )
            await graph.dump()

            # Model an old/torn snapshot: the node payload says a -> b while
            # the separately serialized NetworkX edge still says a -> c.
            graph._graph.nodes["a.md"]["node"] = make_node("a.md", [("b.md", None)])
            await graph.dump()
            await graph.close()

            repaired = NxFileGraph()
            await repaired.start()
            assert {link.target_path for link in await repaired.get_outlinks("a.md")} == {"c.md"}
            await repaired.rebuild_links()
            assert {link.target_path for link in await repaired.get_outlinks("a.md")} == {"b.md"}
            await repaired.close()

            reopened = NxFileGraph()
            await reopened.start()
            assert {link.target_path for link in await reopened.get_outlinks("a.md")} == {"b.md"}
            await reopened.close()

    asyncio.run(run())


def test_local_load_merged_state_survives_restart():
    """Loading a snapshot into a modified local graph must not suppress its later dump."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            seed = LocalFileGraph()
            await seed.start()
            await seed.upsert_nodes([make_node("a.md")])
            await seed.close()

            merged = LocalFileGraph()
            await merged.start()
            await merged.upsert_nodes([make_node("b.md")])
            await merged.load()
            assert {node.path for node in await merged.get_nodes()} == {"a.md", "b.md"}
            await merged.close()

            reopened = LocalFileGraph()
            await reopened.start()
            assert {node.path for node in await reopened.get_nodes()} == {"a.md", "b.md"}
            await reopened.close()

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_persistence_roundtrip(backend_cls):
    """close() dumps; a fresh instance loads the same nodes from disk."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            g1 = backend_cls()
            await g1.start()
            await g1.upsert_nodes(
                [
                    make_node("a.md", [("b.md", None)]),
                    make_node("b.md"),
                ],
            )
            await g1.close()  # triggers dump

            g2 = backend_cls()
            await g2.start()  # triggers load
            paths = sorted(n.path for n in await g2.get_nodes())
            assert paths == ["a.md", "b.md"]
            # Inlink relationship should also be reconstructable.
            assert {lnk.source_path for lnk in await g2.get_inlinks("b.md")} == {"a.md"}
            await g2.close()
            print(f"✓ test_persistence_roundtrip[{backend_cls.__name__}] passed")

    asyncio.run(run())


@pytest.mark.parametrize("backend_cls", BACKENDS)
def test_get_nodes_empty_inputs(backend_cls):
    """get_nodes([]) returns []; get_nodes(None) returns all."""

    async def run():
        with tempfile.TemporaryDirectory() as tmpdir, temp_chdir(tmpdir):
            graph = backend_cls()
            await graph.start()

            await graph.upsert_nodes([make_node("a.md")])
            assert await graph.get_nodes([]) == []
            assert len(await graph.get_nodes(None)) == 1

            await graph.close()
            print(f"✓ test_get_nodes_empty_inputs[{backend_cls.__name__}] passed")

    asyncio.run(run())


if __name__ == "__main__":
    print("\n=== FileGraph Tests ===")
    for backend in BACKENDS:
        test_upsert_and_get_nodes(backend)
        test_upsert_replaces_old_links(backend)
        test_outlinks_include_virtual_targets(backend)
        test_inlinks_visible_for_virtual_target(backend)
        test_delete_keeps_inbound_view(backend)
        test_delete_outgoing_links_cleared(backend)
        test_clear(backend)
        test_rebuild_links_idempotent(backend)
        test_persistence_roundtrip(backend)
        test_get_nodes_empty_inputs(backend)
    print("\n所有测试通过!")