"""Contract for render_sample: readable, deterministic PR-description samples."""
import datetime
import sys
import tempfile
import unittest
from pathlib import Path

import pyarrow as pa
import pyarrow.parquet as pq

sys.path.insert(0, str(Path(__file__).resolve().parent))

from render_sample import render, render_doc, sample_rows, truncate


def write_parquet(path, n, row_group_size):
    table = pa.table({
        "id": [f"src_{i}" for i in range(n)],
        "text": [f"Akapit pierwszy {i}.\n\nAkapit drugi." for i in range(n)],
        "source": ["src"] * n,
        "added": [datetime.date(2026, 7, 19)] * n,
        "created": [["2023-11-15", "2026-09-03"]] * n,
        "token_count": list(range(n)),
    })
    pq.write_table(table, path, row_group_size=row_group_size)


class RenderSampleTest(unittest.TestCase):
    def setUp(self):
        self.tmp = tempfile.TemporaryDirectory()
        self.path = Path(self.tmp.name) / "src.parquet"

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

    def test_block_layout_matches_pr24_format(self):
        row = {"id": "x", "text": "Line one.\n\nLine two.", "added": datetime.date(2026, 7, 19),
               "created": ["2023-11-15", "2026-09-03"], "token_count": 5}
        self.assertEqual(
            render_doc(row, 800),
            "```\nid: x\nadded: 2026-07-19\ncreated: 2023-11-15, 2026-09-03\ntoken_count: 5\n\n"
            "Line one.\n\nLine two.\n```",
        )

    def test_real_newlines_not_escaped(self):
        write_parquet(self.path, 5, 2)
        out = render(self.path, n=1)
        self.assertIn("\n\nAkapit drugi.", out)
        self.assertNotIn("\\n", out)

    def test_truncates_on_word_boundary(self):
        self.assertEqual(truncate("alpha beta gamma", 12), "alpha beta […]")
        self.assertEqual(truncate("short", 12), "short")
        self.assertEqual(truncate("x" * 20, 5), "xxxxx […]")

    def test_fence_outgrows_backticks_in_text(self):
        out = render_doc({"text": "code: ```py\nx```"}, 800)
        self.assertTrue(out.startswith("````\n") and out.endswith("\n````"))

    def test_deterministic_and_bounded(self):
        write_parquet(self.path, 50, 10)
        self.assertEqual(render(self.path, n=3, seed=1), render(self.path, n=3, seed=1))
        self.assertEqual(len(sample_rows(self.path, 3)), 3)
        ids = [r["id"] for r in sample_rows(self.path, 3)]
        self.assertEqual(len(set(ids)), 3)

    def test_fewer_row_groups_than_n(self):
        write_parquet(self.path, 6, 6)  # one row group
        self.assertEqual(len(sample_rows(self.path, 4)), 4)

    def test_n_larger_than_table(self):
        write_parquet(self.path, 2, 1)
        self.assertEqual(len(sample_rows(self.path, 10)), 2)

    def test_empty_parquet(self):
        pq.write_table(pa.table({"id": pa.array([], pa.string()), "text": pa.array([], pa.string())}), self.path)
        self.assertEqual(render(self.path), "")


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