#!/usr/bin/env python3


from bs4 import BeautifulSoup as bs
import subprocess
import frontmatter
import magic
import sys
import pathlib
import pypandoc
import shutil
import os
import regex as re
import json
import yaml


TEXT_ARTICLE_TEMPLATE_FOOT = None
TEXT_ARTICLE_TEMPLATE_HEAD = None
INDEX_TEMPLATE_FOOT = None
INDEX_TEMPLATE_HEAD = None
EXTRA_INDEX_CONTENT = None

N2W_COMMIT = ""
# how many characters of a commit to show on landing page
COMMIT_SHA1_NCHARS = 7


def is_plaintext(filename):
    return re.match(r'^text/', magic.from_file(str(filename), mime=True)) is not None

def get_files(folder):
    markdown = []
    plaintext = []
    other = []

    for root, folders, files in os.walk(folder):
        for filename in files:
            if '/.git' in root:
                continue
            name = os.path.join(root, filename)
            if pathlib.Path(name).suffix == '.md':
                markdown.append(name)
            elif is_plaintext(name):
                plaintext.append(name)
                other.append(name)
            else:
                other.append(name)

    return markdown, plaintext, other

def get_inherited_tags(file, base_folder):
    tags = []
    folder = pathlib.Path(file)

    while folder != base_folder.parent:
        print(f"get_inherited_tags {folder=}")
        folder = pathlib.Path(folder).parent
        folder_metadata = folder.joinpath('.n2w.yml')
        if not folder_metadata.exists():
            continue

        with open(folder.joinpath('.n2w.yml')) as fp:
            folder_properties = yaml.safe_load(fp)

        tags += folder_properties.get('itags')

    print(f"get_inherited_tags {tags=}")
    return list(set(tags))


def git_head_sha1(working_dir):
    git_response = subprocess.run(
            [ 'git', f"--git-dir={working_dir.joinpath('.git')}", 'rev-parse', 'HEAD' ],
            stdout=subprocess.PIPE
    ).stdout.decode('utf-8')

    return git_response.strip()


def git_filehistory(working_dir, filename):
    print(f"{pathlib.Path(filename).relative_to(working_dir)=}")
    git_response = subprocess.run(
            [
                'git',
                f"--git-dir={working_dir.joinpath('.git')}",
                "log",
                "-p",
                "--",
                pathlib.Path(filename).relative_to(working_dir)
            ],
            stdout=subprocess.PIPE
    )

    filehistory = [f"File history not available: git log returned code {git_response.returncode}."
    "\nIf this is not a git repository, this is not a problem."]

    if git_response.returncode == 0:
        filehistory = git_response.stdout.decode('utf-8')
        temp = re.split(
                r'(commit [a-f0-9]{40})',
                filehistory,
                flags=re.IGNORECASE
        )

        for t in temp:
            if t == '':
                temp.remove(t)
        filehistory = []
        for i in range(0, len(temp)-1, 2):
            filehistory.append(f"{temp[i]}{temp[i+1]}")

    if filehistory == "":
        filehistory = ["This file has no history (it may not be part of the git repository)."]

    filehistory = [ x.replace("<", "&lt;").replace(">", "&gt;") for x in filehistory]

    filehistory = "<pre>\n" + "</pre><pre>\n".join(filehistory) + "</pre>"

    return filehistory


def get_dirs_to_index(folder):
    r = []

    for root, folders, files in os.walk(folder):
        if pathlib.Path(os.path.join(root, folder)).is_relative_to(folder.joinpath('permalink')):
            continue
        [r.append(os.path.join(root, folder)) for folder in folders]

    return r


def update_required(src_filename, output_filename):
    return not os.path.exists(output_filename) or os.path.getmtime(src_filename) > os.path.getmtime(output_filename)


def get_args():
    """ Get command line arguments """

    import argparse
    parser = argparse.ArgumentParser()
    parser.add_argument('notes', type=pathlib.Path)
    parser.add_argument('-o', '--output-dir', type=pathlib.Path, default='web')
    parser.add_argument('-t', '--template', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/templates/article.html'))
    parser.add_argument('-H', '--template-text-head', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/templates/textarticlehead.html'))
    parser.add_argument('-f', '--template-text-foot', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/templates/textarticlefoot.html'))
    parser.add_argument('-i', '--template-index-head', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/templates/indexhead.html'))
    parser.add_argument('-I', '--template-index-foot', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/templates/indexfoot.html'))
    parser.add_argument('-s', '--stylesheet', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/styles.css'))
    parser.add_argument('--home_index', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/templates/home_index.html'))
    parser.add_argument('--permalink_index', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/templates/permalink_index.html'))
    parser.add_argument('-e', '--extra-index-content', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/templates/extra_index_content.html'))
    parser.add_argument('-n', '--index-article-names', action='append', default=['index.md'])
    parser.add_argument('-F', '--force', action="store_true", help="Generate new output html even if source file was modified before output html")
    parser.add_argument('--fuse', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/fuse.js'))
    parser.add_argument('--searchjs', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/search.js'))
    parser.add_argument('--permalinkjs', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/permalink.js'))
    parser.add_argument('--tocsearchjs', type=pathlib.Path, default=pathlib.Path('/opt/notes2web/toc_search.js'))
    parser.add_argument('--toc-depth', type=int, default=6, dest='toc_depth')
    return parser.parse_args()


def main(args):
    """ Entry point for script """

    with open(args.template_text_foot) as fp:
        TEXT_ARTICLE_TEMPLATE_FOOT = fp.read()

    with open(args.template_text_head) as fp:
        TEXT_ARTICLE_TEMPLATE_HEAD = fp.read()

    with open(args.template_index_foot) as fp:
        INDEX_TEMPLATE_FOOT = fp.read()

    with open(args.template_index_head) as fp:
        INDEX_TEMPLATE_HEAD = fp.read()

    with open(args.extra_index_content) as fp:
        EXTRA_INDEX_CONTENT = fp.read()

    if args.output_dir.is_file():
        print(f"Output directory ({args.output_dir}) cannot be a file.")

    args.output_dir.mkdir(parents=True, exist_ok=True)

    notes_license = "This note has no copyright license.",
    print(f"{notes_license=}")
    license_path = args.notes.joinpath("LICENSE")
    if license_path.exists():
        with open(license_path) as fp:
            notes_license = fp.read()

    markdown_files, plaintext_files, other_files = get_files(args.notes)

    all_entries=[]
    dirs_with_index_article = []
    tag_dict = {}
    permalink_to_filepath = {}

    print(f"{markdown_files=}")
    for filename in markdown_files:
        print(f"{filename=}")

        # calculate output filename
        output_filename = args.output_dir.joinpath('notes').joinpath(
            pathlib.Path(filename).relative_to(args.notes)
        ).with_suffix('.html')
        if os.path.basename(filename) in args.index_article_names:
            output_filename = output_filename.parent.joinpath('index.html')
            dirs_with_index_article.append(str(output_filename.parent))
        print(f"{output_filename=}")

        # extract tags from frontmatter, save to tag_dict
        fm = frontmatter.load(filename)
        if isinstance(fm.get('tags'), list):
            for tag in list(set(fm.get('tags') + get_inherited_tags(filename, args.notes))):
                t = {
                    'path': str(pathlib.Path(output_filename).relative_to(args.output_dir)),
                    'title': fm.get('title') or pathlib.Path(filename).name
                }
                if tag in tag_dict.keys():
                    tag_dict[tag].append(t)
                else:
                    tag_dict[tag] = [t]

        # find headers in markdown
        with open(filename) as fp:
            lines = fp.read().split('\n')
        header_lines = []
        for line in lines:
            if re.match('^#{1,6} \S', line):
                header_lines.append(" ".join(line.split(" ")[1:]))

        all_entries.append({
            'path': '/' + str(pathlib.Path(*pathlib.Path(output_filename).parts[1:])),
            'title': fm.get('title') or pathlib.Path(filename).name,
            'tags': list(set(fm.get('tags'))),
            'headers': header_lines,
            'uuid': fm.get('uuid')
        })

        if 'uuid' in fm.keys():
            permalink_to_filepath[fm['uuid']] = all_entries[-1]['path']

        # update file if required
        if update_required(filename, output_filename) or args.force:
            filehistory = git_filehistory(args.notes, filename)
            with open(filename) as fp:
                article = frontmatter.load(fp)

            article['tags'] += get_inherited_tags(filename, args.notes)
            article['tags'] = sorted(list(set(article['tags'])))
            article['filehistory'] = filehistory
            article['licenseFull'] = notes_license
            html = pypandoc.convert_text(frontmatter.dumps(article), 'html', format='md', extra_args=[
                f'--template={args.template}',
                '--mathjax',
                '--toc', f'--toc-depth={args.toc_depth}'
            ])
            pathlib.Path(output_filename).parent.mkdir(parents=True, exist_ok=True)

            with open(output_filename, 'w+') as fp:
                fp.write(html)

    print(f"{plaintext_files=}")
    for filename in plaintext_files:
        filehistory = git_filehistory(args.notes, filename)
        title = os.path.basename(filename)
        output_filename = str(
            args.output_dir.joinpath('notes').joinpath(
                pathlib.Path(filename).relative_to(args.notes)
            )
        ) + '.html'
        print(f"{output_filename=}")

        pathlib.Path(output_filename).parent.mkdir(parents=True, exist_ok=True)
        html = re.sub(r'\$title\$', title, TEXT_ARTICLE_TEMPLATE_HEAD)
        html = re.sub(r'\$h1title\$', title, html)
        html = re.sub(r'\$raw\$', os.path.basename(filename), html)
        html = re.sub(r'\$licenseFull\$', notes_license, html)
        html = html.replace('$filehistory$', filehistory)
        with open(filename) as fp:
            html += fp.read().replace("<", "&lt;").replace(">", "&gt;")
        html += TEXT_ARTICLE_TEMPLATE_FOOT

        with open(output_filename, 'w+') as fp:
            fp.write(html)
        all_entries.append({
            'path': str(pathlib.Path(*pathlib.Path(output_filename).parts[1:])),
            'title': title,
            'tags': [get_inherited_tags(filename, args.notes)],
            'headers': []
        })

    print(f"{other_files=}")
    for filename in other_files:
        output_filename = str(
            args.output_dir.joinpath('notes').joinpath(
                pathlib.Path(filename).relative_to(args.notes)
            )
        )
        title = os.path.basename(filename)
        pathlib.Path(output_filename).parent.mkdir(parents=True, exist_ok=True)
        all_entries.append({
            'path': str(pathlib.Path(*pathlib.Path(output_filename).parts[1:])),
            'title': title,
            'tags': [get_inherited_tags(filename, args.notes)],
            'headers': []
        })
        shutil.copyfile(filename, output_filename)

    tagdir = args.output_dir.joinpath('.tags')
    tagdir.mkdir(parents=True, exist_ok=True)

    for tag in tag_dict.keys():
        html = re.sub(r'\$title\$', f'{tag}', INDEX_TEMPLATE_HEAD)
        html = re.sub(r'\$h1title\$', f'tag: {tag}', html)
        html = re.sub(r'\$extra_content\$', '', html)

        for entry in tag_dict[tag]:
            html += f"<div class=\"article\"><a href=\"/{entry['path']}\">{entry['title']}</a></div>"
        html += INDEX_TEMPLATE_FOOT

        with open(tagdir.joinpath(f'{tag}.html'), 'w+') as fp:
            fp.write(html)



    dirs_to_index = [args.output_dir.name] + get_dirs_to_index(args.output_dir)
    print(f"{dirs_to_index=}")
    print(f"{dirs_with_index_article=}")

    for d in dirs_to_index:
        print(f"{d in dirs_with_index_article=} {d=}")
        if d in dirs_with_index_article:
            continue

        directory = pathlib.Path(d)
        paths = os.listdir(directory)
        #print(f"{paths=}")

        indexentries = []
        
        for p in paths:
            path = pathlib.Path(p)
            #print(f"{path=}")
            if p in [ 'index.html', '.git' ]:
                continue

            fullpath = directory.joinpath(path)
            title = path.name
            if path.suffix == '.html':
                with open(fullpath) as fp:
                    soup = bs(fp.read(), 'html.parser')

                try:
                    title = soup.find('title').get_text() or pathlib.Path(path).name
                except AttributeError:
                    title = pathlib.Path(path).stem
            elif fullpath.is_dir():
                title = path
            elif is_plaintext(fullpath):
                # don't add plaintext files to index, since they have a html wrapper
                continue

            if str(title).strip() == '':
                title = path

            indexentries.append({
                'title': str(title),
                'path': './' + str(path),
                'isdirectory': fullpath.is_dir()
                })

        indexentries.sort(key=lambda entry: str(entry['title']).lower())
        indexentries.sort(key=lambda entry: entry['isdirectory'], reverse=True)
        
        html = re.sub(r'\$title\$', str(directory), INDEX_TEMPLATE_HEAD)
        html = re.sub(r'\$h1title\$', str(directory), html)
        html = re.sub(r'\$extra_content\$',
                EXTRA_INDEX_CONTENT if directory == args.notes else '',
                html
                )

        for entry in indexentries:
            html += (
                    '<li class="article">'
                        f'<a href="{entry["path"]}"><p>'
                            f'{entry["title"]}{"/" if entry["isdirectory"] else ""}'
                        '</p></a>'
                    '</li>'
            )
        html += INDEX_TEMPLATE_FOOT

        with open(directory.joinpath('index.html'), 'w+') as fp:
            fp.write(html)

    shutil.copyfile(args.stylesheet, args.output_dir.joinpath('styles.css'))
    shutil.copyfile(args.fuse, args.output_dir.joinpath('fuse.js'))
    shutil.copyfile(args.searchjs, args.output_dir.joinpath('search.js'))
    shutil.copyfile(args.tocsearchjs, args.output_dir.joinpath('toc_search.js'))
    shutil.copyfile(args.permalinkjs, args.output_dir.joinpath('permalink.js'))
    with open(args.output_dir.joinpath('index.html'), 'w+') as fp:
        with open(args.home_index) as fp2:
            html = re.sub(r'\$title\$', args.output_dir.parts[0], fp2.read())
            html = re.sub(r'\$h1title\$', args.output_dir.parts[0], html)
            html = re.sub(r'\$n2w_commit\$', N2W_COMMIT[0:COMMIT_SHA1_NCHARS], html)
            html = re.sub(r'\$notes_git_head_sha1\$', git_head_sha1(args.notes)[0:COMMIT_SHA1_NCHARS], html)

        html = re.sub(r'\$data\$', json.dumps(all_entries), html)

        fp.write(html)
    permalink_dir = args.output_dir.joinpath('permalink')
    permalink_dir.mkdir(exist_ok=True)
    with open(args.permalink_index) as fp:
        html = re.sub(r'\$data\$', json.dumps(permalink_to_filepath), fp.read())
    with open(permalink_dir.joinpath('index.html'), 'w+') as fp:
        fp.write(html)
    print(tag_dict)

    return 0


if __name__ == '__main__':
    try:
        sys.exit(main(get_args()))
    except KeyboardInterrupt:
        sys.exit(0)