# Automate similar pull request creation for multiple repositories with a small python 3.7 script.
# All you have to do:
# 1. Provide your Github credentials in "Globals" section
# 2. Declare repositories and their base branches for which you want to create PR in "repositories_to_base" dictionary
# 3. Complete PR info in "PR constants" section and "create_pr" function
# 4. Implement "execute_changes" function

import os
from os import path
from github import Github

def print_red(text): print("\033[91m {}\033[00m".format(text))
def print_yellow(text): print("\033[93m {}\033[00m".format(text))
def print_green(text): print("\033[92m {}\033[00m".format(text))

# Globals

github_token = "your_github_token"
organization_name = "your_organization"
github = Github(github_token)
organization = github.get_organization(organization_name)

# Repositories to update

repositories_to_base = {
    'first_repo': 'master',
    'second_repo': 'develop',
    'third_repo': 'master'
}

# PR constants

ticket = "ticket_id"
branch = "%s-update-cocoapods"%(ticket)

# Changes to be executed

def execute_changes(repository_name):
    print_yellow("Installing Pods")
    if not path.exists('Podfile'):
        print_red("\nRepository %s does not contain Podfile. Skipping...\n"%(repository_name))
        return False
    os.system('pod install')
    return True

def get_commit_title():
    cocoapods_version = os.popen('pod --version').read()
    return "Update cocoapods to %s"%(cocoapods_version)

# Utility functions

def get_repository(repository_name):
    return organization.get_repo(repository_name)

def get_base_branch(repository_name):
    return repositories_to_base.get(repository_name)

def clone_repository(repository_name):
    print_yellow("Clone repository %s"%(repository_name))
    repository = get_repository(repository_name)
    ssh_url = repository.ssh_url
    os.system("git clone %s"%(ssh_url))

def prepare_branch(repository_name, base_branch, branch):
    print_yellow("Preparing branch %s"%(branch))
    os.system("git add --all; git reset --hard head; git checkout %s; git pull origin %s; git checkout -b %s"%(base_branch, base_branch, branch))

def is_anything_to_commit():
    if os.popen('git diff --exit-code').read():
        return True
    print_red("\nNo changes appeared after execution. Skipping...\n")
    return False

def commit_and_push(branch):
    print_yellow("Commit and push")
    commit_title = get_commit_title()
    os.system('git add --all')
    os.system("git commit -m\"%s\";"%(commit_title))
    os.system("git push origin %s"%(branch))

def create_pr(branch, base_branch):
    print_yellow("Creating PR")
    pr_title = get_commit_title()
    how_to_test = "Run pod install and make sure no changes appeared"
    pr_body = """
    Ticket: %s

    ### What has been done?
    1. %s

    ### How to test?
    1. %s

    """%(ticket, pr_title, how_to_test)

    get_repository(repository_name).create_pull(pr_title, pr_body, base_branch, branch)
    
    # Logs
    print_green('\n\n\nPR successfuly created 🎉')
    print("\nPR title: %s "%(pr_title))
    print("\nPR body: %s "%(pr_body))
    changes = os.popen('git show head').read()
    print("\nPR changes:\n%s\n"%(changes))

def cleanup(repository_name):
    print_yellow("Cleanup")
    os.chdir("..")
    os.system("rm -rf %s"%(repository_name))


# Main :)

for repository_name in repositories_to_base.keys():
    print_yellow("\n\n\n************************* Repository: %s *************************\n\n"%(repository_name))
    base_branch = repositories_to_base.get(repository_name)
    clone_repository(repository_name)
    os.chdir(repository_name)
    prepare_branch(repository_name, base_branch, branch)
    are_changes_executed = execute_changes(repository_name)
    
    if not are_changes_executed:
        cleanup(repository_name)
        continue

    if not is_anything_to_commit():
        cleanup(repository_name)
        continue

    commit_and_push(branch)
    create_pr(branch, base_branch)
    cleanup(repository_name)