#!python3

"""
Download all Reids commands from https://redis.io/commands.
Output to csv format.
"""
import sys
import csv

from lxml import etree
import requests

stdout_writer = csv.writer(sys.stdout)


def eprint(*args, **kwargs):
    print(*args, file=sys.stderr, **kwargs)


eprint("Download https://redis.io/commands page...")
page = requests.get("https://redis.io/commands").text
eprint("Download finished!")

eprint("Start prase page...")
html = etree.HTML(page)
commands = html.xpath("//div[@class='container']/ul/li")
stdout_writer.writerow(["Group", "Command", "Args", "Summary", "Redis.io link"])
command_rows = []
# parse page
for command in commands:
    group = command.attrib["data-group"]
    command_name = command.xpath("./a/span[@class='command']/text()")[0].strip()
    command_args = command.xpath(
        "./a/span[@class='command']/span[@class='args']/text()"
    )[0].strip()
    command_summary = command.xpath("./a/span[@class='summary']/text()")[0].strip()
    command_link = "https://redis.io" + command.xpath("./a/@href")[0].strip()
    command_rows.append(
        [
            group,
            command_name,
            " ".join(command_args.split()),
            command_summary,
            command_link,
        ]
    )
# write to stdout
for row in sorted(command_rows):
    stdout_writer.writerow(row)
eprint("Down.")