import tempfile
import unittest
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import patch

from PIL import Image
from reportlab.pdfgen import canvas

from copienator.commands.reading_grouped_annotations import (
    context_content_key, get_extra_pdfs_as_images, save_paginated_pdf,
)


class PdfSupplementTests(unittest.TestCase):
    def setUp(self):
        temporary = tempfile.TemporaryDirectory()
        self.addCleanup(temporary.cleanup)
        self.root = Path(temporary.name)
        (self.root / "Text2").mkdir()
        (self.root / "Sol2").mkdir()
        self.labels = ["Q1", "Q2", "Q3"]
        self.rendered = []

        def render(path):
            self.rendered.append(Path(path).name)
            return Image.new("RGB", (100, 30), "white"), 30, 100

        self.renderer = SimpleNamespace(make_base_image=render)

    def pdf(self, folder, name, text):
        path = self.root / folder / name
        document = canvas.Canvas(str(path))
        document.drawString(20, 800, text)
        document.save()
        return path

    def extras(self, label, seen):
        return get_extra_pdfs_as_images(
            self.root, label, self.renderer, self.labels, seen_contexts=seen,
        )

    def test_content_deduplication_across_ranges_and_copy_reset(self):
        self.pdf("Text2", "CTXT Q1 -> Q2.pdf", "Bob   collects coupons: N >= 1")
        self.pdf("Text2", "CTXT Q2 -> Q3.pdf", "Bob collects coupons: N >= 1")
        self.pdf("Text2", "CTXT Q2 -> Q2.pdf", "Bob collects coupons: N >= 2")
        seen = set()
        self.assertEqual(len(self.extras("Q1", seen)), 1)
        self.assertEqual(len(self.extras("Q2", seen)), 1)
        self.assertEqual(len(self.extras("Q3", seen)), 0)
        self.assertEqual(len(seen), 2)
        self.assertEqual(len(self.extras("Q3", set())), 1)

    def test_first_retained_question_gets_context_and_semantic_borders(self):
        self.pdf("Text2", "CTXT Q1 -> Q3.pdf", "Context")
        self.pdf("Text2", "CTXT Q2 -> Q3.pdf", "Other context")
        self.pdf("Text2", "Q2.pdf", "Question")
        self.pdf("Sol2", "Q2.pdf", "Solution")
        # Q1 was filtered out; it never consumes the shared context.
        images = self.extras("Q2", set())
        self.assertEqual([i.getpixel((0, 0)) for i in images],
                         [(255, 255, 255), (255, 255, 255), (0, 0, 0), (0, 0, 255)])
        self.assertTrue(all(i.getpixel((50, 15)) == (255, 255, 255) for i in images))

    def test_missing_question_does_not_shift_solution_border(self):
        self.pdf("Text2", "CTXT Q1 -> Q3.pdf", "Context")
        self.pdf("Sol2", "Q2.pdf", "Solution")
        images = self.extras("Q2", set())
        self.assertEqual([i.getpixel((0, 0)) for i in images],
                         [(255, 255, 255), (0, 0, 255)])

    def test_unrendered_context_is_not_consumed(self):
        self.pdf("Text2", "CTXT Q1 -> Q3.pdf", "Context")
        seen = set()
        with patch.object(self.renderer, "make_base_image", return_value=(None, 0, 0)):
            self.assertEqual(self.extras("Q1", seen), [])
        self.assertFalse(seen)
        self.assertEqual(len(self.extras("Q2", seen)), 1)

    def test_missing_solution_does_not_shift_border_to_student_answer(self):
        self.pdf("Text2", "Q2.pdf", "Question")
        images = self.extras("Q2", set())
        answer = Image.new("RGB", (100, 200), "white")
        captured = []

        def save(page, *args, **kwargs):
            captured.extend([page.copy(), *kwargs['append_images']])

        with patch.object(Image.Image, "save", save):
            save_paginated_pdf([images + [answer], [answer]], self.root / "out.pdf")
        self.assertEqual(len(captured), 2)
        self.assertEqual(captured[0].getpixel((11, 7)), (0, 0, 0))
        self.assertEqual(captured[0].getpixel((11, 37)), (255, 255, 255))
        self.assertEqual(captured[1].getpixel((11, 7)), (255, 255, 255))
        self.assertEqual(answer.getpixel((0, 0)), (255, 255, 255))

    def test_empty_extracted_text_does_not_merge_distinct_contexts(self):
        paths = []
        for name, color in [("a.pdf", "red"), ("b.pdf", "blue")]:
            path = self.root / name
            document = canvas.Canvas(str(path))
            document.setFillColor(color)
            document.rect(20, 20, 100, 100, fill=1)
            document.save()
            paths.append(path)
        self.assertNotEqual(context_content_key(paths[0]), context_content_key(paths[1]))


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