#!/usr/bin/env python3

import json, psycopg2, re, socket, time

CONFIG_DB_CONNECT = "host=127.0.0.1 port=5432 user=minetest password=PASSWORD dbname=minetest-world"
CONFIG_LISTEN = ("0.0.0.0", 8060)

RECBUF = 1024

p_clen = re.compile("\r?\ncontent-length: *(\d+)\r?\n?", re.IGNORECASE)
p_stmt = re.compile("^(x|y|z)(<|>|=|<=|>=)-?\d{1,5}$")

def send_response(client, code, resp):
	try:
		content_raw = json.dumps(resp).encode()
	except TypeError:
		content_raw = json.dumps({"error": "non_ascii_resp"}).encode()
	mime = "text/json"
	client.sendall(("HTTP/1.1 "+code+"\r\nContent-type: "+mime+"; charset=UTF-8\r\nAccess-Control-Allow-Origin: *\r\nContent-length: "+str(len(content_raw))+"\r\n\r\n").encode()+content_raw)
	client.close()

if __name__ == "__main__":
	conn = psycopg2.connect(CONFIG_DB_CONNECT)
	
	server_addr = CONFIG_LISTEN
	if ":" in server_addr[0]: # IPv6
		sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
	else: # IPv4
		sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
	sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
	sock.settimeout(5)
	sock.bind(server_addr)
	sock.listen(1)
	print("Server started at "+str(server_addr))
	
	while True:
		try:
			client, addr = sock.accept()
		except socket.timeout:
			continue
		
		# Get request
		paquet = b""
		header = b""
		content = b""
		content_len = 0
		resp = {}
		lf = 0
		while True:
			raw = client.recv(RECBUF)
			if raw:
				paquet += raw
				if lf >= 0:
					for c in raw:
						if c == 10:# LF
							lf += 1
						elif c != 13:# CR
							lf = 0
						if lf > 1:
							parts = paquet.split(b"\r\n\r\n")
							header = parts[0]
							content = parts[1]
							try:
								content_len = int(p_clen.search(header.decode()).group(1))
							except (AttributeError, ValueError):
								content_len = 0
							break
					if lf > 1:
						break
			else:
				break
		while len(content) < content_len:
			raw = client.recv(RECBUF)
			paquet += raw
			content += raw
		
		# Get URL
		httpreq = paquet.split(b"\n")
		try:
			url = httpreq[0].split(b" ")[1].decode().split("/")
		except IndexError:
			send_response(client, "400 Bad Request", {"error": "bad_http"})
			continue
		while "" in url:
			url.remove("")
		urll = len(url)
		
		if len(url) > 6:
			send_response(client, "400 Bad Request", {"error": "too_many_statements"})
			continue
		
		if len(url) == 0:
			send_response(client, "400 Bad Request", {"error": "no_statement"})
			continue
		
		stmts = []
		
		bad = False
		for stmt in url:
			if not p_stmt.match(stmt):
				bad = True
				break
			stmts.append("pos"+stmt)
		
		if bad:
			send_response(client, "400 Bad Request", {"error": "bad_statement"})
			continue
		
		req = " AND ".join(stmts)
		
		cur = conn.cursor()
		cur.execute("SELECT * FROM blocks WHERE "+req+" LIMIT 1000;")
		resp["blocks"] = []
		while True:
			block = cur.fetchone()
			if not block:
				break
			resp["blocks"].append([block[0], block[1], block[2], block[3].hex()])
		
		print(req)
		
		# Send response
		send_response(client, "200 OK", resp)
		
		time.sleep(.2)