import json
import config
import cgi
import os
import sqlite3
import mimetypes
import urllib.parse

import Admin
import utils

def playout(filename, content = "text/html"):
	return ["", [('Content-Type', content if content else "application/octet-stream"), ("X-Accel-Redirect", filename)], None]

def resolve_alias(alias):
	resolved = None
	db = sqlite3.connect(config.database, check_same_thread = False)
	cursor = db.cursor()
	cursor.execute("SELECT user, real, access, storage, display FROM aliases WHERE alias=:alias", {"alias": alias})
	data = cursor.fetchone()
	if data:
		resolved = {"user": data[0], "path": data[1], "access": data[2], "limit": data[3], "display": data[4]}
	else:
		print("Unknown alias " + alias)
	db.close()
	return resolved

def listing(alias):
	listing = {"total": 0, "files": [], "access": alias["access"], "display": alias["display"]}

	if 'r' in alias["access"]:
		directory = utils.target_filename(alias, None)
		listing["files"] = utils.dirlisting(directory, True, False)
		# Calculate total size
		for file in listing["files"]:
			listing["total"] += file["size"]

	return [json.dumps(listing), [('Content-Type','application/json')], "200 OK"]

def upload(alias, post):
	if 'c' not in alias["access"]:
		return ["", [('Content-Type','text/html')], "403 No"]
	if post["file"].filename:
		target = utils.target_filename(alias, utils.sanitize_filename(post["file"].filename))

		while os.path.isfile(target):
			target += "_dup"

		try:
			open(target, 'wb').write(post["file"].file.read())
			print("Uploaded " + target)
			return ["", [('Content-Type','text/html')], "200 OK"]
		except PermissionError as e:
			print("Failed to store " + target + ": " + e.msg)
			return ["", [('Content-Type','text/html')], "500 Error"]
	else:
		print("Upload failed")
		return ["", [('Content-Type','text/html')], "500 Error"]

def route(path, env, post):
	if len(path) == 1 and not path[0]:
		return config.Auth.login(env, post)

	if path[0] == "admin":
		return Admin.route(path, env, post)

	if path[0] == "favicon.ico":
		return playout("/assets/favicon.ico")

	# Get mapped user/path/limits
	alias = resolve_alias(path[0])

	if not alias:
		return utils.redirect(config.homepage)

	# Redirect if no slash after alias
	if len(path) == 1:
		return utils.redirect(path[0] + "/");

	if len(path) > 1 and path[1] == "upload":
		return upload(alias, post)

	if len(path) > 1 and path[1] == "listing":
		return listing(alias)

	if len(path) > 1 and path[1] == "file":
		filename = utils.sanitize_filename(path[2])
		return playout("/data/" + utils.target_filename_internal(alias, filename), mimetypes.guess_type(filename)[0])

	if len(path) > 1 and path[1] == "preview" and alias["display"] == "gallery":
		filename = utils.sanitize_filename(path[2])
		return playout("/data/" + utils.target_filename_internal(alias, "preview/" + filename), mimetypes.guess_type(filename)[0])

	return playout("/interface/listing.htm")

def handle_request(env, response):
	path = env.get('PATH_INFO', '').lstrip('/').split('/')
	post = None
	headers = []

	# Read POST data
	try:
		if env.get('CONTENT_TYPE', '').startswith("multipart/form-data"):
			post = cgi.FieldStorage(environ=env, fp=env['wsgi.input'], keep_blank_values=True)
		else:
			content_length = int(env.get('CONTENT_LENGTH', '0'))
			post_raw = env["wsgi.input"].read(content_length).decode('utf-8')
			post = urllib.parse.parse_qs(post_raw)
	except ValueError as e:
		post = None

	# Route request
	data, addtl_headers, code = route(path, env, post)
	headers.extend(addtl_headers)
	response(code if code else "200 OK", headers)
	return [bytes(data, "utf-8")]