# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
# MIT License. See license.txt

from __future__ import unicode_literals
import frappe
from frappe import _
import frappe.sessions
from frappe.utils import cstr
import mimetypes, json
from werkzeug.wrappers import Response
from werkzeug.routing import Map, Rule, NotFound

from frappe.website.context import get_context
from frappe.website.utils import get_home_page, can_cache, delete_page_cache
from frappe.website.router import clear_sitemap
from frappe.translate import guess_language

class PageNotFoundError(Exception): pass

def render(path=None, http_status_code=None):
	"""render html page"""
	path = resolve_path(path or frappe.local.request.path.strip('/ '))
	data = None

	# if in list of already known 404s, send it
	if can_cache() and frappe.cache().hget('website_404', path):
		data = render_page('404')
		http_status_code = 404

	else:
		try:
			data = render_page_by_language(path)
		except frappe.DoesNotExistError, e:
			doctype, name = get_doctype_from_path(path)
			if doctype and name:
				path = "print"
				frappe.local.form_dict.doctype = doctype
				frappe.local.form_dict.name = name
			elif doctype:
				path = "list"
				frappe.local.form_dict.doctype = doctype
			else:
				# 404s are expensive, cache them!
				frappe.cache().hset('website_404', path, True)
				data = render_page('404')
				http_status_code = 404

			if not data:
				try:
					data = render_page(path)
				except frappe.PermissionError, e:
					data, http_status_code = render_403(e, path)

		except frappe.PermissionError, e:
			data, http_status_code = render_403(e, path)

		except frappe.Redirect, e:
			return build_response(path, "", 301, {
				"Location": frappe.flags.redirect_location or (frappe.local.response or {}).get('location'),
				"Cache-Control": "no-store, no-cache, must-revalidate"
			})

		except Exception:
			path = "error"
			data = render_page(path)
			http_status_code = 500

	data = add_csrf_token(data)

	return build_response(path, data, http_status_code or 200)

def build_response(path, data, http_status_code, headers=None):
	# build response
	response = Response()
	response.data = set_content_type(response, data, path)
	response.status_code = http_status_code
	response.headers[b"X-Page-Name"] = path.encode("utf-8")
	response.headers[b"X-From-Cache"] = frappe.local.response.from_cache or False

	if headers:
		for key, val in headers.iteritems():
			response.headers[bytes(key)] = val.encode("utf-8")

	return response

def render_page_by_language(path):
	translated_languages = frappe.get_hooks("translated_languages_for_website")
	user_lang = guess_language(translated_languages)
	if translated_languages and user_lang in translated_languages:
		try:
			if path and path != "index":
				lang_path = '{0}/{1}'.format(user_lang, path)
			else:
				lang_path = user_lang # index

			return render_page(lang_path)
		except frappe.DoesNotExistError:
			return render_page(path)

	else:
		return render_page(path)

def render_page(path):
	"""get page html"""
	out = None

	if can_cache():
		# return rendered page
		page_cache = frappe.cache().hget("website_page", path)
		if page_cache and frappe.local.lang in page_cache:
			out = page_cache[frappe.local.lang]

	if out:
		frappe.local.response.from_cache = True
		return out

	return build(path)

def build(path):
	if not frappe.db:
		frappe.connect()

	try:
		return build_page(path)
	except frappe.DoesNotExistError:
		hooks = frappe.get_hooks()
		if hooks.website_catch_all:
			path = hooks.website_catch_all[0]
			return build_page(path)
		else:
			raise

def build_page(path):
	if not getattr(frappe.local, "path", None):
		frappe.local.path = path

	context = get_context(path)

	if context.source:
		html = frappe.render_template(context.source, context)
	elif context.template:
		html = frappe.get_template(context.template).render(context)

	# html = frappe.get_template(context.base_template_path).render(context)

	if can_cache(context.no_cache):
		page_cache = frappe.cache().hget("website_page", path) or {}
		page_cache[frappe.local.lang] = html
		frappe.cache().hset("website_page", path, page_cache)

	return html

def resolve_path(path):
	if not path:
		path = "index"

	if path.endswith('.html'):
		path = path[:-5]

	if path == "index":
		path = get_home_page()

	frappe.local.path = path

	if path != "index":
		path = resolve_from_map(path)

	return path

def resolve_from_map(path):
	m = Map([Rule(r["from_route"], endpoint=r["to_route"], defaults=r.get("defaults"))
		for r in frappe.get_hooks("website_route_rules")])
	urls = m.bind_to_environ(frappe.local.request.environ)
	try:
		endpoint, args = urls.match("/" + path)
		path = endpoint
		if args:
			# don't cache when there's a query string!
			frappe.local.no_cache = 1
			frappe.local.form_dict.update(args)

	except NotFound:
		pass

	return path

def set_content_type(response, data, path):
	if isinstance(data, dict):
		response.mimetype = 'application/json'
		response.charset = 'utf-8'
		data = json.dumps(data)
		return data

	response.mimetype = 'text/html'
	response.charset = 'utf-8'

	if "." in path:
		content_type, encoding = mimetypes.guess_type(path)
		if content_type:
			response.mimetype = content_type
			if encoding:
				response.charset = encoding

	return data

def clear_cache(path=None):
	frappe.cache().delete_value("website_generator_routes")
	delete_page_cache(path)
	if not path:
		clear_sitemap()
		frappe.clear_cache("Guest")
		frappe.cache().delete_value("website_404")
		frappe.cache().delete_value("portal_menu_items")
		frappe.cache().delete_value("home_page")

	for method in frappe.get_hooks("website_clear_cache"):
		frappe.get_attr(method)(path)

def render_403(e, pathname):
	path = "message"
	frappe.local.message = """<p><strong>{error}</strong></p>
	<p>
		<a href="/login?redirect-to=/{pathname}" class="btn btn-primary">{login}</a>
	</p>""".format(error=cstr(e.message), login=_("Login"), pathname=frappe.local.path)
	frappe.local.message_title = _("Not Permitted")
	return render_page(path), e.http_status_code

def get_doctype_from_path(path):
	doctypes = frappe.db.sql_list("select name from tabDocType")

	parts = path.split("/")

	doctype = parts[0]
	name = parts[1] if len(parts) > 1 else None

	if doctype in doctypes:
		return doctype, name

	# try scrubbed
	doctype = doctype.replace("_", " ").title()
	if doctype in doctypes:
		return doctype, name

	return None, None

def add_csrf_token(data):
	return data.replace("<!-- csrf_token -->", '<script>frappe.csrf_token = "{0}";</script>'.format(
			frappe.local.session.data.csrf_token))
