"""Tests guarding CLI help text — examples must render and stay clean."""

from __future__ import annotations

import io
import unittest
from contextlib import redirect_stdout

from zsgdp.cli import _epilog, main


def _capture_help(argv: list[str]) -> str:
    """Run `zsgdp <argv> --help` and return captured stdout. SystemExit is normal."""

    buffer = io.StringIO()
    with redirect_stdout(buffer):
        try:
            main(argv + ["--help"])
        except SystemExit:
            pass
    return buffer.getvalue()


class EpilogFormatterTests(unittest.TestCase):
    def test_epilog_dedents_indented_source_string(self):
        rendered = _epilog(
            """
            zsgdp parse --input ./a --output ./b
            zsgdp parse --input ./c --output ./d
            """
        )
        # No double-indentation; first non-blank line begins with two spaces only.
        lines = rendered.splitlines()
        self.assertEqual(lines[0], "Examples:")
        self.assertTrue(lines[1].startswith("  zsgdp parse"))
        # No source-indent leak.
        self.assertNotIn("    zsgdp", rendered)

    def test_epilog_preserves_blank_lines_as_separators(self):
        rendered = _epilog(
            """
            line one

            line two
            """
        )
        self.assertIn("\n\n", rendered)


class SubcommandHelpTests(unittest.TestCase):
    def test_top_level_help_lists_examples_section(self):
        text = _capture_help([])
        self.assertIn("Examples:", text)
        self.assertIn("zsgdp parse", text)
        self.assertIn("docs/space_smoke.md", text)

    def test_parse_help_has_examples(self):
        text = _capture_help(["parse"])
        self.assertIn("Examples:", text)
        self.assertIn("zsgdp parse --input", text)
        self.assertIn("--config configs/docling.yaml", text)

    def test_benchmark_help_covers_three_dataset_modes(self):
        text = _capture_help(["benchmark"])
        self.assertIn("Examples:", text)
        self.assertIn("--dataset omnidocbench", text)
        self.assertIn("--dataset doclaynet", text)

    def test_benchmark_ablate_shows_merged_arm_pattern(self):
        text = _capture_help(["benchmark-ablate"])
        self.assertIn("--parser docling --parser pymupdf", text)
        self.assertIn("--no-merged", text)

    def test_run_gpu_tasks_documents_dry_run_vs_execute(self):
        text = _capture_help(["run-gpu-tasks"])
        self.assertIn("Dry-run", text)
        self.assertIn("--execute", text)

    def test_combine_benchmarks_shows_label_pairing(self):
        text = _capture_help(["combine-benchmarks"])
        self.assertIn("--label omnidocbench", text)
        self.assertIn("--label doclaynet", text)

    def test_preflight_help_documents_skip_flags(self):
        text = _capture_help(["preflight"])
        self.assertIn("--benchmark", text)
        self.assertIn("--skip-unit", text)


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