#!python
## Copyright (c) 2021 Thakee Nathees
## Licensed under: MIT License

from markdown import markdown
from os.path import join
import os, sys, shutil

## TODO: This is a quick and dirty script to generate html
##       from markdown. Refactor this file in the future.

## Usage:
##   to generate pages : python generate.py
##   to clean pages    : python generate.py (-c, --clean)

TEMPLATE_PATH = 'static/template.html'
ROOT_URL      = 'http://localhost:8000/'
ROOT_URL      = 'https://thakeenathees.github.io/pocketlang/'

## Home page should be in the SOURCE_DIR.
HOME_PAGE  = 'home.md'
TRY_PAGE   = 'try it now.html'
SOURCE_DIR = 'pages/'
TARGET_DIR = 'build/'
STATIC_DIR = 'static/'

## Additional source files of wasm try online page.
WASM_SOURCE_FILES = '''\
	<script type="text/javascript"         src="{{ STATIC_DIR }}codejar/codejar.js"></script>
    <script type="text/javascript"         src="{{ STATIC_DIR }}codejar/linenumbers.js"></script>
    <link rel="stylesheet" type="text/css" href="{{ STATIC_DIR }}codejar/style.css" />
    
    <script type="text/javascript"         src="{{ STATIC_DIR }}prism/prism.js"></script>
    <link rel="stylesheet" type="text/css" href="{{ STATIC_DIR }}prism/prism.css" />
	
	<script type = "text/javascript">
		var runSource;
		window.onload = function() { // called after index.html is loaded -> Module is defined.
			runSource = Module.cwrap('runSource', 'number', ['string']);
			document.getElementById("run-button").onclick = function() {
				document.getElementById('output').innerText = '';
				const source = document.querySelector('.editor').textContent;
				runSource(source);
			}
		}
    </script>
'''

## Navigation pages in order. Should match the path names.
PAGES = [
	('Getting Started', [
		TRY_PAGE,
		'build from source.md',
		'contributing.md',
	]),
	
	('Language API', [
		'variables.md',
		'functions.md',
	]),
]

def new_context():
	return {
		'{{ TITLE }}'      : '',
		'{{ NAVIGAION }}'  : '',
		'{{ CONTENT }}'    : '',
		'{{ HOME_URL }}'   : '',
		'{{ STATIC_DIR }}' : '',
	}

def main():
	
	## Remove generated files and create empty target dir with static files.
	if os.path.exists(TARGET_DIR):
		remove_ignore = ( '.git', )
		for _dir in os.listdir(TARGET_DIR):
			if _dir in remove_ignore: continue
			if os.path.isdir(join(TARGET_DIR,_dir)):
				shutil.rmtree(join(TARGET_DIR, _dir))
			else:
				os.remove(join(TARGET_DIR, _dir))

	shutil.copytree(STATIC_DIR, join(TARGET_DIR, STATIC_DIR))
	open(join(TARGET_DIR, '.nojekyll'), 'w').close()
	
	## Initialize the template and navigation.
	template = ''
	navigation = generate_navigation()
	with open(TEMPLATE_PATH, 'r') as f:
		template = f.read()
		
	## Generate the home page.
	index_html = join(TARGET_DIR, 'index.html')
	ctx = generate_page_context(join(SOURCE_DIR, HOME_PAGE), index_html, navigation)
	write_page(ctx, template, index_html)
	
	for entry in PAGES:
		_dir = entry[0]
		for file in entry[1]:
			ext = get_validated_ext(file)
			path = join(SOURCE_DIR, _dir, file)
			
			dst = ''
			if ext == '.md' : dst = join(TARGET_DIR, _dir, file.replace('.md', '.html'))
			else: dst = join(TARGET_DIR, _dir, file)
			ctx = generate_page_context(path, dst, navigation)
			
			_template = template
			if file == TRY_PAGE:
				_template = template.replace('{{ WASM_SOURCE_FILES }}', WASM_SOURCE_FILES)
			
			write_page(ctx, _template, dst)
	pass

def generate_navigation():
	navigation = ''
	for entry in PAGES:
		_dir = entry[0]
		navigation += '<div class="navigation">\n'
		navigation += '<h3><strong>%s</strong></h3>\n' % (_dir)
		navigation += '<ul class="menu">\n'
		
		for file in entry[1]:
			ext = get_validated_ext(file)
			
			link = '' ## Assuming that file name don't contain '.md' at the middle.
			if ext == '.md': link = join(ROOT_URL, _dir, file.replace('.md', '.html'))
			else: link = join(ROOT_URL, _dir, file)
			link = link.replace('\\', '/')
			
			title = file.replace(ext, '')
			navigation += '<li><a href="%s">%s</a></li>\n' % (link, title)
			
		navigation += '</ul>\n'
		navigation += '</div>\n'
	return navigation
	

def generate_page_context(src, dst, navigation):
	title = path_to_title(src)
	static_dir = relative_static_dir(dst)
	content = path_to_content(src)
	ctx = new_context()
	ctx[ '{{ TITLE }}'     ]   = title
	ctx[ '{{ NAVIGAION }}' ]   = navigation
	ctx[ '{{ CONTENT }}'   ]   = content
	ctx[ '{{ HOME_URL }}'  ]   = ROOT_URL + 'index.html'
	ctx[ '{{ STATIC_DIR }}']   = static_dir
	return ctx;

def get_validated_ext(path)	:
	ext = ''
	if path.endswith('.md'): ext = '.md'
	elif path.endswith('.html'): ext = '.html'
	else: raise Exception('Expected .md / .html file.')
	return ext

## Get the title from the src path.
def path_to_title(path):
	ext = get_validated_ext(path)
	title = os.path.basename(path).replace(ext, '').title()
	title += ' - PocketLang'
	return title

## Return the static dir relative path.
def relative_static_dir(dst):
	_dir = os.path.dirname(dst)
	static_dir = os.path.relpath(join(TARGET_DIR, STATIC_DIR), _dir)
	static_dir = static_dir.replace('\\', '/')
	if static_dir[-1] != '/':
		static_dir += '/'
	return static_dir

## Generate html content from the markdown source path.
## If the path is an .html file return it's content.
def path_to_content(src):
	
	text = ''
	with open(src, 'r') as home_md:
		text = home_md.read()
		
	## If html file we're done.
	if get_validated_ext(src) == '.html':
		return text
	
	content = markdown(text, extensions=['codehilite', 'fenced_code'])
	
	## FIXME: I should create a pygment lexer.
	## A dirty way to inject our keyword (to ruby's).
	addnl_keywords = [
		'null', 'from', 'import', 'as', 'func', 'native', 'elif', 'continue'
	]
	not_keyword = [
		 'alias', 'begin', 'case', 'class', 'next', 'nil', 'redo', 'rescue',
		 'retry', 'elsif', 'ensure', 'undef', 'unless', 'super', 'until', 'when',
		  'defined',
	]

	for kw in addnl_keywords:
		content = content.replace('<span class="n">%s</span>' % kw, 
								   '<span class="k">%s</span>' % kw)
	for nk in not_keyword:
		content = content.replace('<span class="k">%s</span>' % nk, 
								  '<span class="n">%s</span>' % nk)
	return content

def write_page(ctx, template, dst):
	_dir = os.path.dirname(dst)
	if _dir not in ('.', './', '') and not os.path.exists(_dir):
		os.makedirs(os.path.dirname(dst))
		
	page = template
	for key, value in ctx.items():
		page = page.replace(key, value)
		
	page = page.replace('{{ WASM_SOURCE_FILES }}', '')
		
	with open(dst, 'w') as f:
		f.write(page)
	

if __name__ == '__main__':
	main()
	print('Static pages generated.')