#!/usr/bin/env python3
# -*- python -*-

from mdbook_plugin import Plugin

import os
import re
import sqlite3
import subprocess
import sys

DITAA_TAG = r'ditaa(?: ((?:\w|-)+))?'

class DitaaPlugin(Plugin):
    def __init__(self):
        self.figure_count = 0
        self.cache = sqlite3.connect('.mdbook-ditaa.sqlite')
        try:
            self.cache.cursor().execute('CREATE TABLE diagrams(source text, svg text)')
        except:
            pass

    def expand_chapter_content(self, chapter):
        directory = os.path.dirname(chapter.source_path.value)
        chapter.content = self.expand_codeblock(DITAA_TAG, self.expand_ditaa, chapter.content, directory)

    def next_filename(self):
        self.figure_count = self.figure_count + 1
        return f'figure_{self.figure_count}'

    def expand_ditaa(self, m, directory):
        filename_base = m.group(1) or self.next_filename()
        filename = os.path.join(directory, filename_base + '.svg')
        sys.stderr.write(f'ditaa {filename} ...')

        ditaa_source = m.group(2)

        cached = list(self.cache.cursor().execute('SELECT svg FROM diagrams WHERE source = ?', (ditaa_source,)))
        if cached:
            svg = cached[0][0]
        else:
            svg = subprocess.check_output(['ditaa', '-T', '--svg', '-'], input=ditaa_source.encode('utf-8'))
            svg = svg.decode('utf-8')
            svg = re.sub(r'<\?xml.*?\?>', '', svg)
            svg = svg.strip()
            self.cache.cursor().execute('INSERT INTO diagrams VALUES (?, ?)', (ditaa_source, svg))
            self.cache.cursor().execute('COMMIT')

        # sourcedir = self.context['config']['book']['src']
        # baseurl = self.context['config']['output']['html']['site-url']

        # svgfilename = os.path.join(sourcedir, output_prefix, filename)
        # os.makedirs(os.path.dirname(svgfilename), exist_ok=True)

        # need_write = True
        # if os.path.exists(svgfilename):
        #     with open(svgfilename, 'rt') as f:
        #         existing = f.read()
        #     if existing == svg:
        #         need_write = False
        # if need_write:
        #     sys.stderr.write('updated\n')
        #     with open(svgfilename, 'wt') as f:
        #         f.write(svg)
        # else:
        #     sys.stderr.write('unchanged\n')

        # return f'<p><img class="ditaa" alt="{filename}" src="{os.path.join(baseurl, output_prefix, filename)}"></p>\n'

        sys.stderr.write('inlined\n')
        return f'<div class="ditaa figure-{filename_base}">{svg}</div>\n'

if __name__ == '__main__':
    DitaaPlugin().main(sys.argv)