"""
pydoc – Create a simple HTML website from multiple Markdown files
with Python using Pandoc

Copyright (c) 2023 Helmut Kaczmarek <code@helmutkaczmarek.de>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

import os
import shutil
import subprocess
import configparser

# Load settings from the configuration file
def load_settings(config_path):    
    config = configparser.ConfigParser()
    config.read(config_path)
    settings = config['Settings']
    return settings

# Function for converting the Markdown files to HTML
def convert_to_html(markdown_file, html_file, template_file):
    pandoc_cmd = [
        'pandoc', markdown_file, '-o', html_file,
        '--template', template_file
    ]
    subprocess.run(pandoc_cmd)

# Function for processing the Markdown files
def process_markdown_files(src_dir, dest_dir, settings):
    converted_count = 0
    template_file = settings['template_file']
    css_path = settings['css_path']
    
    for root, _, files in os.walk(src_dir):
        for file in files:
            if file.lower().endswith('.md'):
                markdown_path = os.path.join(root, file)
                relative_path = os.path.relpath(markdown_path, src_dir)
                html_path = os.path.join(dest_dir, os.path.splitext(relative_path)[0] + '.html')

                if not os.path.exists(markdown_path):
                    if os.path.exists(html_path):
                        os.remove(html_path)
                    continue

                os.makedirs(os.path.dirname(html_path), exist_ok=True)
                print(f"Converting {markdown_path} to {html_path}")
                convert_to_html(markdown_path, html_path, template_file)
                converted_count += 1

    return converted_count

# Copy asset files from source to destination directory
def copy_assets(src_dir, dest_dir):
    for item in os.listdir(src_dir):
        src_item = os.path.join(src_dir, item)
        dest_item = os.path.join(dest_dir, item)
        if os.path.isfile(src_item):
            shutil.copy(src_item, dest_item)
        elif os.path.isdir(src_item):
            shutil.copytree(src_item, dest_item, dirs_exist_ok=True)

# Main function
def main():
    try:
        settings = load_settings('settings.conf')
        
        markdown_dir = settings['markdown_dir']
        html_dir = settings['html_dir']
        assets_dir = settings['assets_dir']
        
        print("Starting Pydoc...")
        
        # Backup original content of the template file
        original_template_content = None
        with open(settings['template_file'], 'r', encoding='utf-8') as f:
            original_template_content = f.read()
            
        # Update template file to include the correct CSS path
        updated_template_content = original_template_content.replace('{{ css_path }}', settings['css_path'])
        with open(settings['template_file'], 'w', encoding='utf-8') as f:
            f.write(updated_template_content)
        
        # Delete and create HTML directory
        shutil.rmtree(html_dir, ignore_errors=True)
        os.makedirs(html_dir, exist_ok=True)
        
        # Convert markdown files
        num_converted = process_markdown_files(markdown_dir, html_dir, settings)
        
        # Copy asset files
        copy_assets(assets_dir, html_dir)
        
        # Restore original content of the template file
        with open(settings['template_file'], 'w', encoding='utf-8') as f:
            f.write(original_template_content)
        
        if num_converted > 0:
            print(f"Finished converting {num_converted} files and copying assets. Everything seems to be finde. Note: If the CSS in subdirectories does not look as expected, check whether the full path to the style sheet is specified in 'css_path' (see 'settings.conf').")
        else:
            print("No files converted. Check the source directories.")
        
        # Check if Pandoc template file contains "{{ css_path }}"
        if '<link rel="stylesheet" href="{{ css_path }}">' not in original_template_content:
            print("INFO: The template.txt should contain '{{ css_path }}' as a placeholder for the path to the CSS file, so that the paths to the CSS file in subdirectories are set correctly.")
    except FileNotFoundError:
        print("Cannot convert Markdown files. Missing configuration file. Here is an example for 'settings.conf':\n"
            "\n"
            "[Settings]\n"
            "markdown_dir = C:\\Path\\to\\Markdown\n"
            "html_dir = C:\\Path\\To\\HTML\n"
            "assets_dir = C:\\Path\\To\\Assets\n"
            "template_file = C:\\Path\\to\\template.txt\n"
            "css_path = C:\\Path\\to\\style.css # The full path to the CSS file is important for the style sheet to work in subdirectories.")
    except (KeyError, ValueError, configparser.MissingSectionHeaderError):
        print("There are problems in the 'settings.conf'. Maybe a typo crept in? Here is an example for 'settings.conf':\n"
            "\n"
            "[Settings]\n"
            "markdown_dir = C:\\Path\\to\\Markdown\n"
            "html_dir = C:\\Path\\To\\HTML\n"
            "assets_dir = C:\\Path\\To\\Assets\n"
            "template_file = C:\\Path\\to\\template.txt\n"
            "css_path = C:\\Path\\to\\style.css # The full path to the CSS file is important for the style sheet to work in subdirectories.")

if __name__ == "__main__":
    main()