"""Integration test: legacy Exa Search flows upgrade cleanly to the lfx-exa bundle.

Mirror of ``test_pilot_arxiv_upgrade.py`` against ``ExaSearchToolkit``.
Exa graduated from the manifest-less ``lfx-bundles`` metapackage to the
standalone ``lfx-exa`` distribution when the component was modernized
onto the ``exa-py`` SDK; the bundle name (``exa``) and class name are
unchanged, so the canonical ID -- and the migration entries added when
the provider was first consolidated -- are stable across the move.

Verifies the save/upgrade/load contract for flows referencing
``ExaSearchToolkit`` from the pre-extraction Langflow:

    1. A saved flow uses the legacy bare class name ``ExaSearchToolkit``.
    2. The migration table rewrites it to the canonical namespaced ID
       ``ext:exa:ExaSearchToolkit@official``.
    3. A second flow uses the legacy import path
       ``lfx.components.exa.exa_search.ExaSearchToolkit``; same outcome.
    4. The lfx-exa distribution is importable AND ships the manifest in
       a location ``importlib.metadata.files`` can discover (or, for
       editable installs, that ``direct_url.json`` resolves).
"""

from __future__ import annotations

import json
from importlib import metadata as importlib_metadata
from pathlib import Path

import pytest
from lfx.extension.migration.loader import load_migration_table

REPO_ROOT = Path(__file__).resolve().parents[5]
TABLE_PATH = REPO_ROOT / "src" / "lfx" / "src" / "lfx" / "extension" / "migration" / "migration_table.json"
EXPECTED_TARGET = "ext:exa:ExaSearchToolkit@official"


@pytest.fixture(scope="module")
def migration_table():
    table, error = load_migration_table(TABLE_PATH)
    assert error is None, f"failed to load migration table: {error}"
    assert table is not None
    return table


def _saved_flow_node(node_id: str, type_value: str) -> dict:
    """Build a minimal saved-flow node skeleton for testing."""
    return {
        "id": node_id,
        "type": "genericNode",
        "data": {
            "id": node_id,
            "type": type_value,
            "node": {"template": {}},
        },
    }


def _saved_flow(*nodes: dict) -> dict:
    """Wrap nodes in the canonical Langflow flow envelope."""
    return {"data": {"nodes": list(nodes), "edges": []}}


@pytest.mark.integration
def test_legacy_bare_name_flow_upgrades(migration_table) -> None:
    """A flow saved with the bare class name upgrades to the canonical ID."""
    from lfx.extension.migration.rewrite import migrate_flow_payload

    flow = _saved_flow(_saved_flow_node("exa-1", "ExaSearchToolkit"))

    report = migrate_flow_payload(flow, table=migration_table)

    assert report.rewritten_count == 1, "exactly one node should rewrite"
    assert flow["data"]["nodes"][0]["data"]["type"] == EXPECTED_TARGET
    [record] = report.records
    assert record.legacy_form_kind == "bare_class_name"
    assert record.new_value == EXPECTED_TARGET


@pytest.mark.integration
def test_legacy_import_path_flow_upgrades(migration_table) -> None:
    """A flow saved with the dotted import path upgrades cleanly."""
    from lfx.extension.migration.rewrite import migrate_flow_payload

    flow = _saved_flow(
        _saved_flow_node(
            "exa-2",
            "lfx.components.exa.exa_search.ExaSearchToolkit",
        )
    )

    report = migrate_flow_payload(flow, table=migration_table)
    assert report.rewritten_count == 1
    assert flow["data"]["nodes"][0]["data"]["type"] == EXPECTED_TARGET
    assert report.records[0].legacy_form_kind == "import_path"


@pytest.mark.integration
def test_short_import_path_flow_upgrades(migration_table) -> None:
    """Package-level import-path form (re-exported by ``__init__.py``) also upgrades."""
    from lfx.extension.migration.rewrite import migrate_flow_payload

    flow = _saved_flow(_saved_flow_node("exa-3", "lfx.components.exa.ExaSearchToolkit"))

    report = migrate_flow_payload(flow, table=migration_table)
    assert report.rewritten_count == 1
    assert flow["data"]["nodes"][0]["data"]["type"] == EXPECTED_TARGET


@pytest.mark.integration
def test_lfx_exa_distribution_is_importable() -> None:
    """The bundle's package is importable in the development workspace.

    Catches the case where the package layout drifts from what
    ``langflow.extensions`` references in the entry-point.

    Skipped when the bundle is not installed in the test environment
    (lfx's own venv does not list lfx-exa as a dep); the langflow
    workspace venv pulls it in transitively from langflow's pyproject.
    """
    try:
        from lfx_exa import ExaSearchToolkit
    except ImportError:
        pytest.skip("lfx-exa not installed in this test environment")

    # The class must round-trip its canonical class name (used by the
    # migration table's ``bare_class_name`` entry).
    assert ExaSearchToolkit.__name__ == "ExaSearchToolkit"


def _is_editable_install(dist: importlib_metadata.Distribution) -> bool:
    """Detect an editable install (``pip install -e``)."""
    direct_url = dist.read_text("direct_url.json")
    if not direct_url:
        return False
    try:
        payload = json.loads(direct_url)
    except json.JSONDecodeError:
        return False
    return bool(payload.get("dir_info", {}).get("editable"))


@pytest.mark.integration
def test_lfx_exa_ships_manifest() -> None:
    """``importlib.metadata`` can find ``extension.json`` for the installed dist.

    This is the contract :func:`load_installed_extensions` reads at
    server startup; if the wheel doesn't include the manifest, the bundle
    never registers and ``pip install langflow`` silently fails to pull
    in the bundle.
    """
    try:
        dist = importlib_metadata.distribution("lfx-exa")
    except importlib_metadata.PackageNotFoundError:
        pytest.skip("lfx-exa not installed in this test environment")

    if _is_editable_install(dist):
        # Editable install: walk the source tree to verify manifest layout.
        import lfx_exa

        package_dir = Path(lfx_exa.__file__).parent
        manifest_path = package_dir / "extension.json"
        assert manifest_path.is_file(), (
            f"lfx-exa source tree at {package_dir} does not ship "
            "extension.json next to __init__.py; the wheel build will "
            "not include it either.  Check pyproject's "
            "[tool.hatch.build.targets.wheel] include rules."
        )
    else:
        # Non-editable wheel install: assert dist.files surfaces the manifest.
        files = dist.files or []
        manifests = [f for f in files if f.parts and f.parts[-1] == "extension.json"]
        assert manifests, (
            "lfx-exa distribution does not ship extension.json in its "
            "wheel; the loader will skip it.  Check pyproject's "
            "[tool.hatch.build.targets.wheel] include rules."
        )
        manifest_path = Path(dist.locate_file(manifests[0]))

    # Round-trip the manifest: it must parse, declare lfx.compat=['1'],
    # and point at a bundle named 'exa'.
    manifest = json.loads(manifest_path.read_text(encoding="utf-8"))
    assert manifest["id"] == "lfx-exa"
    assert manifest["lfx"]["compat"] == ["1"]
    assert any(b["name"] == "exa" for b in manifest["bundles"])