"""Migration safety checks. Full source-bound data validation runs during generation."""
from pathlib import Path
import csv
import json
import subprocess
import sys
import tempfile
import unittest
import pyarrow as pa
import build_selected_front_projection as view

class ProjectionMigrationTests(unittest.TestCase):
    def test_csv_retains_null_empty_and_numeric_values_without_image_bytes(self):
        table = pa.table({"file_name": ["a.mp4", "b.mp4"],
                          "image": pa.array([{"bytes": b"opaque", "path": "work.jpg"}, None],
                                            type=pa.struct([("bytes", pa.binary()), ("path", pa.string())])),
                          "work_id": ["tlaw-a", ""],
                          "Source photograph URL": ["https://example.invalid/source", None],
                          "display_width_px": pa.array([100, None], type=pa.int64())})
        with tempfile.TemporaryDirectory() as d:
            path = Path(d)/"scalar.csv"
            result = view.write_scalar_csv(table, path)
            self.assertTrue(result["typed_scalar_roundtrip_exact"])
            with path.open(newline="") as f: rows = list(csv.DictReader(f))
            self.assertNotIn("image", rows[0])
            self.assertEqual(rows[1]["work_id"], "")
            self.assertEqual(rows[1]["Source photograph URL"], view.CSV_NULL)
            self.assertEqual(rows[1]["display_width_px"], view.CSV_NULL)

    def test_legacy_cli_fails_without_writing_even_if_output_is_preexisting(self):
        script = Path(__file__).with_name("build_recording_reference_view.py")
        with tempfile.TemporaryDirectory() as d:
            root = Path(d); output = root/"recording_physical_references.csv"
            output.write_bytes(b"preserved existing export")
            result = subprocess.run([sys.executable, str(script), "--root", str(root),
                                     "--source-revision", view.BASE_REVISION, "--output", str(output)],
                                    capture_output=True)
            self.assertNotEqual(result.returncode, 0)
            self.assertEqual(output.read_bytes(), b"preserved existing export")

    def test_source_url_requires_exact_manifest_work_hash_and_path(self):
        item = {"work_id": "tlaw-a", "source_photograph_sha256": "1"*64,
                "existing_main_source_path": "Physical_References/Photographs/images/tlaw-a/a.jpg"}
        with self.assertRaises(ValueError): view.original_url(item, {}, view.BASE_REVISION)
        wrong = {("tlaw-a", "1"*64): [{"image_path": "Physical_References/Photographs/images/tlaw-a/b.jpg"}]}
        with self.assertRaises(ValueError): view.original_url(item, wrong, view.BASE_REVISION)
        self.assertEqual(view.original_url({"existing_main_source_path": None}, {}, view.BASE_REVISION), (None, None))

    def test_csv_null_token_collision_is_rejected(self):
        table = pa.table({"image": [None], "work_id": [view.CSV_NULL]})
        with tempfile.TemporaryDirectory() as d:
            with self.assertRaises(ValueError): view.write_scalar_csv(table, Path(d)/"bad.csv")

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