from flask import Flask
from flask import render_template
from flask import request
from diagrams import Generators,Generator,Example
import os
from flask.helpers import send_from_directory
import argparse
import sys

scriptdir=os.path.dirname(os.path.abspath(__file__))
app = Flask(__name__,static_url_path='',static_folder=scriptdir+'/../web', template_folder=scriptdir+'/../templates')

@app.route('/')
def home():
		return index()

def index(err=None,gen='dot',source="",message="",genResult=None):
		""" render index page with the given parameters"""
		return render_template('index.html',gen=gen,gens=Generators.generators(),err=err, message=message, source=source,genResult=genResult)

@app.route('/example/<generator>')
def example(generator):
		""" get the given example generator """
		txt=Example.get(generator)
		return txt

@app.route('/check/<generator>')
def check(generator):
		gen=Generators.get(generator)
		if gen is not None:
				return gen.getHtmlInfo()
		else:
				return "%s is not a valid generator" % generator

@app.route('/render/<outputType>/<crc32>', methods=['GET'])
def render(outputType,crc32):
		# allow extension ending for direct rendering e.g. in wikis
		ext="."+outputType
		if crc32.endswith(ext):
				crc32=crc32[:-len(ext)]
		outputDirectory=Generator.getOutputDirectory()
		filename="%s.%s" % (crc32,outputType)
		#print ("outputDirectory %s\nfilename %s" % (outputDirectory, filename), file=sys.stderr)
		return send_from_directory(outputDirectory, filename)

@app.route('/render', methods=['POST'])
def renderForWikiExtension():
		""" endpoint for diagrams extension"""
		source=request.form.get('source')
		renderer=request.form.get('renderer')
		types=request.form.get('types')
		ip=request.remote_addr
		generator=request.form.get('generator')
		gen=Generators.get(generator)
		#print ("generator %s\nsource %s\nrenderer %s\ntypes %s" % (generator, source, renderer, types), file=sys.stderr)
		result=gen.generate(generator,source,'png',renderer)
		json=result.asJson(request.base_url)
		return json


@app.route('/diagrams', methods=['GET', 'POST']) #allow both GET and POST requests
def form_example():
		err=None
		genResult=None
		message=""
		source=None
		gen=None
		if request.method == 'POST':
				try:
						source = request.form.get('source')
						alias=request.form.get('generator')
						generatorId=Generators.generatorIdForAlias(alias)
						outputType=request.form.get(generatorId+'-output')
						gen=Generators.get(generatorId)
						if gen is None:
								raise Exception("invalid generator %s",generatorId)
						genResult=gen.generate(alias,source,outputType,useCached=True)
						if not genResult.isValid():
								raise Exception("could not generate %s for %s",outputType,generatorId)
				except Exception as ex:
						err=ex
		return index(err=err, message=message,source=source,gen=gen,genResult=genResult)

if __name__ == '__main__':
		parser = argparse.ArgumentParser(description="Diagrams rendering webservice")
		parser.add_argument('--debug',
																 action='store_true',
																 help="run in debug mode")
		parser.add_argument('--port',
																 type=int,
																 default=5003,
																 help="the port to use")
		parser.add_argument('--host',
																 default="0.0.0.0",
																 help="the host to serve for")
		args=parser.parse_args(sys.argv[1:])
		app.run(debug=args.debug,port=args.port,host=args.host)