import tempfile
import unittest
from pathlib import Path

import pymupdf

from copienator.crop_exercise_bottoms import process_exercise_pdf


class CropExerciseBottomsTests(unittest.TestCase):
    def setUp(self):
        self.temp = tempfile.TemporaryDirectory()
        self.addCleanup(self.temp.cleanup)
        self.root = Path(self.temp.name)
        self.review = self.root / "review"

    def make_pdf(self, name: str, height: float, text_y: float, footer=True) -> Path:
        path = self.root / name
        with pymupdf.open() as document:
            page = document.new_page(width=600, height=height)
            page.insert_text((80, text_y), "student answer", fontsize=16)
            if footer:
                page.insert_text((20, height - 15), "9/9", fontsize=10)
            document.save(path)
        return path

    def test_short_page_is_skipped(self):
        source = self.make_pdf("short.pdf", 200, 100)
        destination = self.root / "out" / source.name
        records = process_exercise_pdf(
            source, destination, self.review, 800, dpi=150
        )
        self.assertEqual(records[0]["status"], "skipped-short")
        self.assertFalse(destination.exists())

    def test_isolated_page_number_allows_a_large_bottom_crop(self):
        source = self.make_pdf("large.pdf", 400, 100)
        destination = self.root / "out" / source.name
        records = process_exercise_pdf(
            source, destination, self.review, 800, dpi=150
        )
        self.assertEqual(records[0]["status"], "cropped")
        self.assertGreaterEqual(records[0]["bottom_removed_lines"], 4)
        with pymupdf.open(destination) as result:
            self.assertLess(result[0].rect.height, 250)
            self.assertAlmostEqual(result[0].rect.width, 600)

    def test_content_in_former_ignored_bottom_strip_is_retained(self):
        source = self.make_pdf("bottom-content.pdf", 400, 100, footer=False)
        with pymupdf.open(source) as doc:
            doc[0].insert_text((20, 399), "Ex 2", fontsize=10)
            doc.save(self.root / "bottom-label.pdf")
        records = process_exercise_pdf(
            self.root / "bottom-label.pdf", self.root / "retained.pdf",
            self.review, 800, dpi=150
        )
        self.assertEqual(records[0]["status"], "unchanged-small-crop")
        self.assertFalse((self.root / "retained.pdf").exists())

    def test_crop_smaller_than_four_lines_is_not_written(self):
        source = self.make_pdf("small.pdf", 400, 330, footer=False)
        destination = self.root / "out" / source.name
        records = process_exercise_pdf(
            source, destination, self.review, 800, dpi=150
        )
        self.assertEqual(records[0]["status"], "unchanged-small-crop")
        self.assertFalse(destination.exists())


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