from nbdev.export2html import *
from fastai2.core.imports import *

import nbformat, jupyter_contrib_nbextensions
from nbconvert.preprocessors import Preprocessor

from IPython.display import FileLink

class NBConvertor:
    
    def _exporter():
        exporter = MarkdownExporter(Config())
        exporter.exclude_input_prompt=True
        exporter.exclude_output_prompt=True
        exporter.template_file = 'jekyll.tpl'
        exporter.template_path.append(str((Path()/'local'/'notebook').absolute()))
        return exporter

    _re_title = re.compile(r'^\s*#\s+([^\n]*)\n')
    cell_type,outputs,source,code,text = 'cell_type','outputs','source','code','text'

    def process_output(c,s,o):
        if c[cell_type]!=code or o is None: return s,o
        def _f(x):
            if text not in x: return x
            x[text] = re.sub(r'^(.*\S)',r'> \1',x[text], flags=re.MULTILINE)
            return x
        return s,[_f(o_) for o_ in o]

    def process_title(c,s,o):
        if s.startswith('#hide'): return
        if c[cell_type] == code: return s,o
        if _re_title.search(s):
            s = '---\n' + _re_title.sub(r'title: "\1"', s) + '\n---'
            s = re.sub('^- ', '', s, flags=re.MULTILINE)
        return s,o

    def apply_all(x, fs, **kwargs):
        for f in fs:
            s,o = f(x, x[source], x.get(outputs,None), **kwargs) or (None,None)
            x[source]=s
            if s is None: x=None; break
            elif o is not None: x[outputs] = o
        return x

    def convert(fname, dest=None, cell_procs=None):
        fname = Path(fname)
        (fname.parent/'md_out').mkdir(exist_ok=True)
        if dest is None: dest = (fname.parent/'md_out'/fname.name).with_suffix('.md')
        if cell_procs is None: cell_procs = [process_title,process_output]
        with open(fname,'r') as f: nb = nbformat.reads(f.read(), as_version=4)
        nb['cells'] = [o for o in [apply_all(c, cell_procs) for c in nb['cells']] if o is not None]
        exp = _exporter()
        with open(dest,'w') as f: f.write(exp.from_notebook_node(nb)[0])

name = 'delegation'
convert(Path.cwd()/f'{name}.ipynb')