# SPDX-FileCopyrightText: 2022 James R. Barlow
# SPDX-License-Identifier: MIT
"""Tesseract no-op plugin.

To quickly run tests where getting OCR output is not necessary.

In generate_hocr mode, create a .hocr file that specifies no text found.

In 'pdf' mode, convert the image to PDF using another program.

In orientation check mode, report the orientation is upright.
"""

from __future__ import annotations

import pikepdf
from PIL import Image

from ocrmypdf import OcrEngine, OrientationConfidence, hookimpl

HOCR_TEMPLATE = '''<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
 <head>
  <title></title>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <meta name='ocr-system' content='tesseract 4.1.1' />
  <meta name='ocr-capabilities'
    content='ocr_page ocr_carea ocr_par ocr_line ocrx_word'/>
 </head>
 <body>
  <div class='ocr_page' id='page_1' title='image "x.tif"; bbox 0 0 {0} {1}; ppageno 0'>
   <div class='ocr_carea' id='block_1_1' title="bbox 0 1 {0} {1}">
    <p class='ocr_par' dir='ltr' id='par_1' title="bbox 0 1 {0} {1}">
     <span class='ocr_line' id='line_1' title="bbox 0 1 {0} {1}">
       <span class='ocrx_word' id='word_1' title="bbox 0 1 {0} {1}"> </span>
     </span>
    </p>
   </div>
  </div>
 </body>
</html>'''


class NoopOcrEngine(OcrEngine):
    @staticmethod
    def version():
        return '4.1.1'

    @staticmethod
    def creator_tag(options):
        tag = '-PDF' if options.pdf_renderer == 'sandwich' else '-hOCR'
        return f"NO-OP {tag} {NoopOcrEngine.version()}"

    def __str__(self):
        return f"NO-OP {NoopOcrEngine.version()}"

    @staticmethod
    def languages(options):
        return {'eng'}

    @staticmethod
    def get_orientation(input_file, options):
        return OrientationConfidence(angle=0, confidence=0.0)

    @staticmethod
    def get_deskew(input_file, options):
        return 0.0

    @staticmethod
    def generate_hocr(input_file, output_hocr, output_text, options):
        with (
            Image.open(input_file) as im,
            open(output_hocr, 'w', encoding='utf-8') as f,
        ):
            w, h = im.size
            f.write(HOCR_TEMPLATE.format(str(w), str(h)))
        with open(output_text, 'w') as f:
            f.write('')

    @staticmethod
    def generate_pdf(input_file, output_pdf, output_text, options):
        with Image.open(input_file) as im:
            dpi = im.info['dpi']
            pagesize = im.size[0] / dpi[0], im.size[1] / dpi[1]
        ptsize = pagesize[0] * 72, pagesize[1] * 72
        pdf = pikepdf.new()
        pdf.add_blank_page(page_size=ptsize)
        pdf.save(output_pdf, static_id=True)
        output_text.write_text('')


@hookimpl
def get_ocr_engine():
    return NoopOcrEngine()
