#!/usr/bin/env python3

from http.server import SimpleHTTPRequestHandler,HTTPServer
import socket
import csv
import sys
import tempfile
import threading
import os
import gzip
import traceback
import urllib.request
import subprocess
import lzma

def get_local_port(host):
    with socket.socket() as fd:
        fd.bind((host, 0))
        return fd.getsockname()[1]

CLICKHOUSE_HOST = os.environ.get('CLICKHOUSE_HOST', '127.0.0.1')
CLICKHOUSE_PORT_HTTP = os.environ.get('CLICKHOUSE_PORT_HTTP', '8123')

#####################################################################################
# This test starts an HTTP server and serves data to clickhouse url-engine based table.
# The main goal of this test is checking that compress methods are working.
# In order for it to work ip+port of http server (given below) should be
# accessible from clickhouse server.
#####################################################################################

# IP-address of this host accessible from outside world.
HTTP_SERVER_HOST = subprocess.check_output(['hostname', '-i']).decode('utf-8').strip()
HTTP_SERVER_PORT = get_local_port(HTTP_SERVER_HOST)

# IP address and port of the HTTP server started from this script.
HTTP_SERVER_ADDRESS = (HTTP_SERVER_HOST, HTTP_SERVER_PORT)
HTTP_SERVER_URL_STR = 'http://' + ':'.join(str(s) for s in HTTP_SERVER_ADDRESS) + "/"

# Because we need to check content of file.csv we can create this content and avoid reading csv 
CSV_DATA = "Hello, 1\nWorld, 2\nThis, 152\nis, 9283\ntesting, 2313213\ndata, 555\n"


# Choose compression method 
# (Will change during test, need to check standart data sending, to make sure that nothing broke)
COMPRESS_METHOD = 'none'
ADDING_ENDING = ''
ENDINGS = ['.gz', '.xz']
SEND_ENCODING = True

def get_ch_answer(query):
    url = os.environ.get('CLICKHOUSE_URL', 'http://{host}:{port}'.format(host=CLICKHOUSE_HOST, port=CLICKHOUSE_PORT_HTTP))
    return urllib.request.urlopen(url, data=query.encode()).read().decode()

def check_answers(query, answer):
    ch_answer = get_ch_answer(query)
    if ch_answer.strip() != answer.strip():
        print("FAIL on query:", query, file=sys.stderr)
        print("Expected answer:", answer, file=sys.stderr)
        print("Fetched answer :", ch_answer, file=sys.stderr)
        raise Exception("Fail on query")

# Server with head method which is useful for debuging by hands
class HttpProcessor(SimpleHTTPRequestHandler):
    def _set_headers(self):
        self.send_response(200)
        if SEND_ENCODING:
            self.send_header('Content-Encoding', COMPRESS_METHOD)
        if COMPRESS_METHOD == 'none':
            self.send_header('Content-Length', len(CSV_DATA.encode()))
        else:
            self.compress_data()
            self.send_header('Content-Length', len(self.data))
        self.send_header('Content-Type', 'text/csv')
        self.end_headers()

    def do_HEAD(self):
        self._set_headers()
        return

    def compress_data(self):
        if COMPRESS_METHOD == 'gzip':
            self.data = gzip.compress((CSV_DATA).encode())
        elif COMPRESS_METHOD == 'lzma':
            self.data = lzma.compress((CSV_DATA).encode())
        else:
            self.data = 'WRONG CONVERSATION'.encode()


    def do_GET(self):
        self._set_headers()
    
        if COMPRESS_METHOD == 'none':
            self.wfile.write(CSV_DATA.encode())
        else:
            self.wfile.write(self.data)
        return

    def log_message(self, format, *args):
        return

def start_server(requests_amount):
    httpd = HTTPServer(HTTP_SERVER_ADDRESS, HttpProcessor)

    def real_func():
        for i in range(requests_amount):
            httpd.handle_request()

    t = threading.Thread(target=real_func)
    return t

#####################################################################
# Testing area.
#####################################################################

def test_select(dict_name="", schema="word String, counter UInt32", requests=[], answers=[], test_data=""):
    global ADDING_ENDING
    global SEND_ENCODING
    global COMPRESS_METHOD
    for i in range(len(requests)):
        if i > 2:
            ADDING_ENDING = ENDINGS[i-3]
            SEND_ENCODING = False
        
        if dict_name:
            get_ch_answer("drop dictionary if exists {}".format(dict_name))
            get_ch_answer('''CREATE DICTIONARY {} ({})
            PRIMARY KEY word
            SOURCE(HTTP(url '{}' format 'CSV'))
            LAYOUT(complex_key_hashed())
            LIFETIME(0)'''.format(dict_name, schema, HTTP_SERVER_URL_STR+'/test.csv' + ADDING_ENDING))

        COMPRESS_METHOD = requests[i]
        print(i, COMPRESS_METHOD, ADDING_ENDING, SEND_ENCODING)
        check_answers("select * from {}".format(dict_name), answers[i])

def main():
    # first three for encoding, second three for url
    insert_requests = [
            'none',
            'gzip',
            'lzma',
            'gzip',
            'lzma'
    ]

    # This answers got experemently in non compressed mode and they are correct
    answers = ['''This	152\nHello	1\nis	9283\ndata	555\nWorld	2\ntesting	2313213'''] * 5

    t = start_server(len(insert_requests))
    t.start()
    test_select(dict_name="test_table_select", requests=insert_requests, answers=answers)
    t.join()
    print("PASSED")



if __name__ == "__main__":
    try:
        main()
    except Exception as ex:
        exc_type, exc_value, exc_traceback = sys.exc_info()
        traceback.print_tb(exc_traceback, file=sys.stderr)
        print(ex, file=sys.stderr)
        sys.stderr.flush()

        os._exit(1)