import shutil
import subprocess
import sys
import tempfile
import unittest
from pathlib import Path
from unittest.mock import patch

from PIL import Image, ImageDraw, ImageFont, PdfParser

sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "scripts"))
from scan_document import create_document, check_ocr


class ScanOcrTest(unittest.TestCase):
    def test_missing_language_is_reported_before_processing(self):
        with patch("scan_document.run_ocr_command", return_value="List of available languages (1):\neng\n"):
            with self.assertRaisesRegex(RuntimeError, "deu"):
                check_ocr("deu+eng")
        with self.assertRaises(ValueError):
            check_ocr("--bad-language")

    @unittest.skipUnless(shutil.which("tesseract") and shutil.which("pdftotext"), "Tesseract and Poppler required")
    def test_ocr_keeps_receipt_canvas_blank_back_and_page_order_with_real_extractable_text(self):
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            pages = []
            for index, text in enumerate(["FEDEO Bon 12345", "", "Zweite Seite 24680"]):
                page = root / f"page-{index}.png"
                image = Image.new("RGB", (1240, 1754), (45, 45, 45) if index == 0 else "white")
                draw = ImageDraw.Draw(image)
                if index == 0:
                    draw.rectangle((260, 150, 1000, 1550), fill="white")
                if text:
                    draw.text((300, 300), text, fill="black", font=ImageFont.load_default(size=44))
                    draw.text((300, 390), "Summe EUR 12,34", fill="black", font=ImageFont.load_default(size=36))
                image.save(page)
                pages.append(page)
            output = root / "searchable.pdf"
            result = create_document(pages, output, 150, ocr=True, background_cleanup=True)
            self.assertEqual(result["pageCount"], 3)
            with PdfParser.PdfParser(filename=str(output)) as pdf:
                self.assertEqual(len(pdf.pages), 3)
                for reference in pdf.pages:
                    box = pdf.read_indirect(reference)[b"MediaBox"]
                    self.assertAlmostEqual(box[2], 1240 * 72 / 150, delta=.1)
                    self.assertAlmostEqual(box[3], 1754 * 72 / 150, delta=.1)
            text = subprocess.check_output(["pdftotext", str(output), "-"], text=True)
            extracted = text.split("\f")
            self.assertIn("12345", extracted[0])
            self.assertEqual(extracted[1].strip(), "")
            self.assertIn("24680", extracted[2])
            self.assertTrue(all(page.exists() for page in pages))

    def test_ocr_failure_never_publishes_a_partial_document_or_removes_raw_pages(self):
        with tempfile.TemporaryDirectory() as directory:
            root = Path(directory)
            page = root / "raw.png"
            Image.new("RGB", (400, 600), "white").save(page)
            output = root / "failed.pdf"
            with patch("scan_document.check_ocr"), patch("scan_document.run_ocr_command", side_effect=RuntimeError("OCR failed")):
                with self.assertRaisesRegex(RuntimeError, "OCR failed"):
                    create_document([page], output, 300, ocr=True)
            self.assertFalse(output.exists())
            self.assertFalse(output.with_name("failed.pdf.partial").exists())
            self.assertTrue(page.exists())
            self.assertEqual(list(root.glob("prepared-*")), [])


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