"""
The evaluator's label-file contract.

F-01: the v1 labels were wrong on 23% of facings and the file recorded nothing
about where any of them came from, so a bad label could not be told from a good
one. `load_labels` now refuses a file whose rows carry no provenance.
"""

from __future__ import annotations

import json
import os
import sys
import tempfile
import unittest

current_dir = os.path.dirname(os.path.abspath(__file__))
if current_dir not in sys.path:
    sys.path.insert(0, current_dir)

from eval_identity import load_labels  # noqa: E402


def write_labels(payload) -> str:
    handle = tempfile.NamedTemporaryFile("w", suffix=".json", delete=False)
    json.dump(payload, handle)
    handle.close()
    return handle.name


class LoadLabelsTests(unittest.TestCase):
    def test_a_traced_label_file_loads(self):
        path = write_labels({
            "image": "add/image6.jpg",
            "facings": [{"index": 0, "label": "sku_l01", "source": "visual-audit"}],
        })
        self.addCleanup(os.unlink, path)
        self.assertEqual(len(load_labels(path)["facings"]), 1)

    def test_a_label_without_provenance_is_refused(self):
        path = write_labels({
            "image": "add/image6.jpg",
            "facings": [{"index": 0, "label": "sku_l01"}],
        })
        self.addCleanup(os.unlink, path)
        with self.assertRaises(SystemExit) as caught:
            load_labels(path)
        self.assertIn("source", str(caught.exception))

    def test_a_file_without_facings_is_refused(self):
        path = write_labels({"image": "add/image6.jpg"})
        self.addCleanup(os.unlink, path)
        with self.assertRaises(SystemExit):
            load_labels(path)


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