#!/usr/bin/env python3

import pygments
from pygments.formatters import HtmlFormatter
from pygments.lexers import get_lexer_for_filename
from pygments.lexers.special import TextLexer
from pygments.util import ClassNotFound
from starlette.applications import Starlette
from starlette.responses import HTMLResponse
from starlette.routing import Route

formatter = None

async def startup_task():
    get_lexer_for_filename('x.txt')
    global formatter
    formatter = HtmlFormatter(style='pastie', nobackground=True)

async def run_highlight(request):
    data = await request.body()
    try:
        lexer = get_lexer_for_filename(request.query_params['filename'], data)
    except ClassNotFound:
        lexer = TextLexer()
    return HTMLResponse(''.join([
        f'<!-- Pygments {pygments.__version__}: {lexer.name} ({lexer.__class__.__name__}) -->',
        '<style>', formatter.get_style_defs('.highlight'), '</style>',
        pygments.highlight(data, lexer, formatter)
    ]))

app = Starlette(
        routes=[
            Route('/highlight', run_highlight, methods=["POST"]),
            ],
        on_startup=[startup_task],
        )