import json
import tempfile
import unittest

from pathlib import Path

import easygraph as eg


MOCK_HIF_DATA = {
    "metadata": {"name": "test_organism", "description": "Simulation for unit test"},
    "network-type": "directed",
    "nodes": [
        {"node": "n1", "weight": 1.0, "attrs": {"name": "Node A"}},
        {"node": "n2", "weight": 1.0, "attrs": {"name": "Node B"}},
    ],
    "edges": [{"edge": "e1", "weight": 1.0, "attrs": {"name": "Edge Alpha"}}],
    "incidences": [
        {"edge": "e1", "node": "n1", "weight": 1.0, "direction": "tail"},
        {"edge": "e1", "node": "n2", "weight": 1.0, "direction": "head"},
    ],
}


class HIFTest(unittest.TestCase):
    def setUp(self):
        self.temp_dir = tempfile.TemporaryDirectory()
        self.temp_dir_path = Path(self.temp_dir.name)

        self.input_file = self.temp_dir_path / "input_mock.hif.json"
        self.output_file = self.temp_dir_path / "output_result.hif.json"

        with open(self.input_file, "w", encoding="utf-8") as f:
            json.dump(MOCK_HIF_DATA, f)

    def tearDown(self):
        self.temp_dir.cleanup()

    def test_hif_roundtrip_preservation(self):
        """
        Test that custom attributes are preserved AND the generated
        EasyGraph object is structurally valid.
        """
        hg = eg.hif_to_hypergraph(filename=self.input_file)

        self.assertEqual(hg.num_v, 2, "Loaded graph should have 2 nodes")
        self.assertEqual(hg.num_e, 1, "Loaded graph should have 1 edge")

        node_names = [props.get("name") for props in hg.v_property]
        self.assertEqual(
            node_names,
            ["Node A", "Node B"],
            "HIF attrs.name should be preserved in v_property",
        )

        hif_node_ids = [node["node"] for node in hg.custom_hif_nodes]
        self.assertEqual(
            hif_node_ids,
            ["n1", "n2"],
            "Original HIF node IDs should be preserved separately",
        )

        edges = hg.e[0]
        self.assertEqual(len(edges), 1, "Should have 1 edge group")
        self.assertEqual(len(edges[0]), 2, "Edge e1 should connect 2 nodes")

        self.assertTrue(
            hasattr(hg, "custom_hif_incidences"), "Failed to attach custom incidences"
        )
        self.assertTrue(hasattr(hg, "metadata"), "Failed to attach metadata")

        eg.hypergraph_to_hif(hg, filename=self.output_file)

        with open(self.output_file, "r", encoding="utf-8") as f:
            res = json.load(f)

            output_node_ids = [node["node"] for node in res["nodes"]]
            self.assertEqual(
                output_node_ids,
                ["n1", "n2"],
                "Original HIF node IDs should survive roundtrip export",
            )

            first_incidence = res["incidences"][0]
            self.assertIn(
                "direction", first_incidence, "'direction' field lost in roundtrip"
            )
            self.assertIn(first_incidence["direction"], ["tail", "head"])

            self.assertNotIn(
                "default_attrs",
                res["metadata"],
                "'default_attrs' was forced into metadata",
            )
            self.assertEqual(res["metadata"]["name"], "test_organism")

    def test_manual_graph_export(self):
        """Test exporting a manually created Hypergraph (not loaded from file)."""
        hg = eg.Hypergraph(
            num_v=5, e_list=[(0, 1, 2), (2, 3), (2, 3), (0, 4)], merge_op="sum"
        )
        hg.metadata = {"created_by": "manual_test"}

        eg.hypergraph_to_hif(hg, filename=self.output_file)

        with open(self.output_file, "r", encoding="utf-8") as f:
            data = json.load(f)
            self.assertEqual(len(data["nodes"]), 5)
            self.assertEqual(len(data["edges"]), 3)
            self.assertEqual(data["metadata"]["created_by"], "manual_test")

            weights = [e["weight"] for e in data["edges"]]
            self.assertIn(2.0, weights, "Merged edge weight should be 2.0")


if __name__ == "__main__":
    unittest.main()