"""Unit tests for the D-memo ingester (canlex/dmemo.py). Offline only.

Covers the two failure modes that cost the corpus on 2026-07-27: CBSA replaced
the static index with a JSON-fed DataTable (the link-scrape found zero memos),
and the ingester wrote that empty result straight over 1,870 good chunks.
"""
import json
import unittest

from canlex import dmemo


class DatasourceUrlTests(unittest.TestCase):
    RAW = json.dumps({"data": [
        {"NUMBER": '<a href="/publications/dm-md/d1/d1-2-1-eng.html">D1-2-1</a>',
         "STATUS": "Active"},
        {"NUMBER": '<a href="/publications/dm-md/d8/d8-2-2-eng.html">D8-2-2</a>',
         "STATUS": "Active"},
        {"NUMBER": "D8-11-1", "STATUS": "Cancelled"},
        {"NUMBER": '<a href="/publications/dm-md/d10/d10-14-48-eng.html">'
                   'D10-14-48</a>', "STATUS": "Cancelled"},
    ]}).encode("utf-8")

    def test_extracts_absolute_urls(self):
        self.assertEqual(
            dmemo.datasource_urls(self.RAW),
            ["https://www.cbsa-asfc.gc.ca/publications/dm-md/d1/d1-2-1-eng.html",
             "https://www.cbsa-asfc.gc.ca/publications/dm-md/d8/d8-2-2-eng.html"])

    def test_cancelled_memos_are_skipped_even_when_still_linked(self):
        # Retired guidance must not surface as if it were current.
        self.assertNotIn("d10-14-48", " ".join(dmemo.datasource_urls(self.RAW)))

    def test_deduplicates(self):
        row = {"NUMBER": '<a href="/publications/dm-md/d1/d1-2-1-eng.html">x</a>',
               "STATUS": "Active"}
        raw = json.dumps({"data": [row, row]}).encode("utf-8")
        self.assertEqual(len(dmemo.datasource_urls(raw)), 1)

    def test_empty_datasource_yields_nothing(self):
        self.assertEqual(dmemo.datasource_urls(b'{"data": []}'), [])


class IndexFallbackTests(unittest.TestCase):
    def test_scrapes_links_off_the_legacy_index(self):
        html = ('<a href="/publications/dm-md/d1/d1-2-1-eng.html">D1-2-1</a>'
                '<a href="/publications/dm-md/menu-eng.html">menu</a>')
        self.assertEqual(
            dmemo.index_urls(html),
            ["https://www.cbsa-asfc.gc.ca/publications/dm-md/d1/d1-2-1-eng.html"])

    def test_rebuilt_index_has_no_links_to_find(self):
        # What CBSA now serves: an empty table, memo rows loaded by JS.
        self.assertEqual(dmemo.index_urls('<table id="dmemo-tbl"></table>'), [])


class PreserveFailedTests(unittest.TestCase):
    STORED = [{"section": "D10-14-3", "text": "seasonal duties"},
              {"section": "D10-14-3", "text": "part two"},
              {"section": "D1-2-1", "text": "special services"}]

    def test_unfetchable_memo_keeps_its_last_good_chunks(self):
        failures = [("https://x/publications/dm-md/d10/d10-14-3-eng.html", "404")]
        chunks, preserved = dmemo.preserve_failed([], failures, self.STORED)
        self.assertEqual(preserved, ["D10-14-3"])
        self.assertEqual(len(chunks), 2)

    def test_freshly_parsed_chunks_win_over_stored(self):
        fresh = [{"section": "D10-14-3", "text": "new text"}]
        failures = [("https://x/publications/dm-md/d10/d10-14-3-eng.html", "404")]
        chunks, preserved = dmemo.preserve_failed(fresh, failures, self.STORED)
        self.assertEqual(preserved, [])
        self.assertEqual(chunks, fresh)

    def test_memo_we_never_had_cannot_be_preserved(self):
        failures = [("https://x/publications/dm-md/d8/d8-2-2-eng.html", "404")]
        chunks, preserved = dmemo.preserve_failed([], failures, self.STORED)
        self.assertEqual((chunks, preserved), ([], []))

    def test_nothing_happens_without_failures(self):
        fresh = [{"section": "D1-2-1", "text": "x"}]
        chunks, preserved = dmemo.preserve_failed(fresh, [], self.STORED)
        self.assertEqual((chunks, preserved), (fresh, []))


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