"""
Github publishes the markdown documentation with jekyll enabled.
This extension does not publish any folder starting with `_`.
These folders need to be renamed.
"""
import os
import re


def rename_folder(root):
    """
    Renames all folder starting with `_`.
    Returns the list of renamed folders.
    """
    found = []
    for r, dirs, files in os.walk(root):
        for name in dirs:
            if name.startswith('_'):
                found.append((r, name))
    renamed = []
    for r, name in found:
        into = name.lstrip('_')
        renamed.append((r, name, into))
        full_src = os.path.join(r, name)
        full_into = os.path.join(r, into)
        if os.path.exists(full_into):
            raise RuntimeError("%r already exists, previous documentation should be removed.")
        print("rename %r" % full_src)
        os.rename(full_src, full_into)

    return renamed


def replace_files(root, renamed):
    subs = {r[1]: r[2] for r in renamed}
    reg = re.compile(
        "(\\\"[a-zA-Z0-9\\.\\/\\?\\:@\\-_=#]+\\.([a-zA-Z]){2,6}"
        "([a-zA-Z0-9\\.\\&\\/\\?\\:@\\-_=#])*\\\")")

    for r, dirs, files in os.walk(root):
        for name in files:
            if os.path.splitext(name)[-1] != '.html':
                continue
            full = os.path.join(r, name)
            with open(full, "r", encoding="utf-8") as f:
                content = f.read()
            find = reg.findall(content)
            repl = []
            for f in find:
                if f[0].startswith("http"):
                    continue
                for k, v in subs.items():
                    if k == v:
                        raise ValueError("%r == %r" % (k, v))
                    if ('"%s' % k) in f[0]:
                        repl.append((f[0], f[0].replace('"%s' % k, '"%s' % v)))
                    if ('/%s' % k) in f[0]:
                        repl.append((f[0], f[0].replace('/%s' % k, '/%s' % v)))
            if len(repl) == 0:
                continue
            print("update %r" % full)
            for k, v in repl:
                content = content.replace(k, v)
            with open(full, "w", encoding="utf-8") as f:
                f.write(content)


if __name__ == "__main__":
    import sys
    if len(sys.argv) > 1:
        root = sys.argv[-1]
    else:
        root = "../../build/docs/html"
    print('look into %r' % root)
    ren = rename_folder(root)
    if len(ren) == 0:
        ren = [('', '_static', 'static'),
               ('', '_images', 'images'),
               ('', '_downloads', 'downloads'),
               ('', '_sources', 'sources'),
               ('', '_modules', 'modules')]
    replace_files(root, ren)
    print('done.')