#!/bin/python3
"""
Small utility to upgrade all packages in a requirements.txt file in the current directory to the latest version as determined by a CLI call to `pip show {package}`.
"""

import sys
import re
import subprocess

filename = 'requirements.txt'

try:
    requirement_file = open(filename, 'r')
except:
    print(f"No '{filename}' found here.")
    sys.exit(1)

requirements = dict()
for line in requirement_file.readlines():
    parts = line.split("==")
    requirements[parts[0].strip()] = parts[
        1].strip() if len(parts) > 1 else None

requirements_fixed = dict()
print("Collecting newest pip package versions...")
for package, version in requirements.items():
    process = subprocess.Popen(
        ["pip", "show", package],
        stdin=subprocess.PIPE,
        stdout=subprocess.PIPE,
        stderr=sys.stderr)
    output = str(process.stdout.read())
    pattern = r'Name: (.*)\\nVersion: ([0-9a-zA-Z.]+)'
    groups = re.search(pattern, output).groups()
    requirements_fixed[groups[0]] = groups[1]
    print(f"{groups[0]}=={groups[1]}")

assert len(requirements) == len(requirements_fixed)

handle = open(filename, 'w')
handle.writelines([f"{p}=={v}\n" for p, v in requirements_fixed.items()])
print(f"Updated {len(requirements_fixed)} packages in {filename}")