from __future__ import annotations

import json
import tempfile
import unittest
from pathlib import Path

from us_cpa.sources import (
    AuthorityRank,
    SourceDescriptor,
    TaxYearCorpus,
    authority_rank_for,
    bootstrap_irs_catalog,
    build_irs_prior_pdf_url,
)


class SourceCatalogTests(unittest.TestCase):
    def test_build_irs_prior_pdf_url_uses_expected_pattern(self) -> None:
        self.assertEqual(
            build_irs_prior_pdf_url("f1040", 2025),
            "https://www.irs.gov/pub/irs-prior/f1040--2025.pdf",
        )
        self.assertEqual(
            build_irs_prior_pdf_url("i1040gi", 2025),
            "https://www.irs.gov/pub/irs-prior/i1040gi--2025.pdf",
        )

    def test_authority_ranking_orders_irs_before_primary_law(self) -> None:
        self.assertEqual(authority_rank_for("irs_form"), AuthorityRank.IRS_FORM)
        self.assertEqual(
            authority_rank_for("treasury_regulation"),
            AuthorityRank.TREASURY_REGULATION,
        )
        self.assertLess(
            authority_rank_for("irs_form"), authority_rank_for("internal_revenue_code")
        )

    def test_bootstrap_catalog_builds_tax_year_specific_urls(self) -> None:
        catalog = bootstrap_irs_catalog(2025)

        self.assertGreaterEqual(len(catalog), 5)
        self.assertEqual(catalog[0].url, "https://www.irs.gov/pub/irs-prior/f1040--2025.pdf")
        self.assertTrue(any(item.slug == "i1040gi" for item in catalog))


class TaxYearCorpusTests(unittest.TestCase):
    def test_tax_year_layout_is_deterministic(self) -> None:
        with tempfile.TemporaryDirectory() as temp_dir:
            corpus = TaxYearCorpus(cache_root=Path(temp_dir))
            paths = corpus.paths_for_year(2025)

            self.assertEqual(paths.year_dir, Path(temp_dir) / "tax-years" / "2025")
            self.assertEqual(paths.irs_dir, paths.year_dir / "irs")
            self.assertEqual(paths.manifest_path, paths.year_dir / "manifest.json")

    def test_download_catalog_writes_files_and_manifest(self) -> None:
        with tempfile.TemporaryDirectory() as temp_dir:
            corpus = TaxYearCorpus(cache_root=Path(temp_dir))
            catalog = [
                SourceDescriptor(
                    slug="f1040",
                    title="Form 1040",
                    source_class="irs_form",
                    media_type="application/pdf",
                    url=build_irs_prior_pdf_url("f1040", 2025),
                ),
                SourceDescriptor(
                    slug="i1040gi",
                    title="Instructions for Form 1040",
                    source_class="irs_instructions",
                    media_type="application/pdf",
                    url=build_irs_prior_pdf_url("i1040gi", 2025),
                ),
            ]

            def fake_fetch(url: str) -> bytes:
                return f"downloaded:{url}".encode()

            manifest = corpus.download_catalog(2025, catalog, fetcher=fake_fetch)

            self.assertEqual(manifest["taxYear"], 2025)
            self.assertEqual(manifest["sourceCount"], 2)
            self.assertTrue(corpus.paths_for_year(2025).manifest_path.exists())

            first = manifest["sources"][0]
            self.assertEqual(first["slug"], "f1040")
            self.assertEqual(first["authorityRank"], int(AuthorityRank.IRS_FORM))
            self.assertTrue(Path(first["localPath"]).exists())

            saved = json.loads(corpus.paths_for_year(2025).manifest_path.read_text())
            self.assertEqual(saved["sourceCount"], 2)
            self.assertEqual(saved["sources"][1]["slug"], "i1040gi")


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