from telegram.ext import RegexHandler
from .rendering import get_png
from .static import static_content

def handle_exception_in_get_png(bot, update, exception, text):
	update.message.reply_text("**Error** while processing '__{}__'.\n\nException was: **{}**.".format(text, exception), parse_mode = "Markdown")

def render_math(bot, update):
	text = update.message.text[len("/rmath"):]
	tex = "${}$".format(text)

	try:
		png = get_png(tex)
	except Exception as e:
		handle_exception_in_get_png(bot, update, e, tex)
		return
	
	update.message.reply_photo(png, caption = "{}".format(text))

def render_math_caption(bot, update):
	text = update.message.text[len("/rmath"):]

	if( not ("<" in text and ">" in text)):
		update.message.reply_text("**Error**: missing caption seperators: < and >", parse_mode = "Markdown")
		return

	caption = text[text.index("<") + 1:text.index(">")]
	text = text[text.index(">") + 1:]

	tex = "${}$".format(text)

	try:
		png = get_png(tex)
	except Exception as e:
		handle_exception_in_get_png(bot, update, e, tex)
		return
	
	update.message.reply_photo(png, caption = "{}\n\nLaTeX: {}".format(caption, text))

def help(bot, update):
	update.message.reply_text(static_content.help_text, parse_mode = "Markdown")