main: Set module names as title

[bbhtt]

Choose the "best" title with most module names while making sure it does
not cross 70 characters. The limit is to prevent too much verbosity in
commit messages and PR titles when a large set of modules are getting
updated.

If it crosses 70 characters, start deducting module names and add the
number of remaining updated modules.

[bbhtt]

56 is the max characters Github can hold in the title in a single line. The commit message is probably 70 or 80.

I'd like to keep some form of "backoff" parameter to prevent ugly PR titles.

I convert it to set to avoid duplicate module names see eg. flathub/org.kde.kdenlive#395

[wjt]

Something like this, but preserving the order of changes?

def build_commit_message(changes: t.List[str]) -> str:
    assert len(changes) >= 1

    if len(changes) == 1:
        return changes[0]

    module_names = list({i.split(":", 1)[0] for i in changes})
    for i in reversed(range(2, len(module_names) + 1)):
        print(i)
        xs = module_names[:i - 1]
        y = module_names[i - 1]
        zs = module_names[i:]

        if zs:
            tail = f" and {len(zs)} more"
            xs.append(y)
        else:
            tail = f" and {y}"

        subject = "Update " + ", ".join(xs) + tail
        if len(subject) <= 56:
            return subject

    return f"Update {len(changes)} modules"

[bbhtt]

If you want to preserve the order in the list only there might be some shorter way I'll check soon.

list({i.split(":", 1)[0] for i in changes})

This doesn't preserve order of changes

[bbhtt]

Pushed something that will preserve order. The rest of the formatting I don't have opinions about. But if you can give me it as a patch I can preserve authorship.

[bbhtt]

Also how about adding Update: a, b and n more *modules* ? As these aren't sources necessarily a single module can have multiple sources with checker data associated.

[bbhtt]

But if you can give me it as a patch I can preserve authorship.

@wjt Would you prefer that I finish this?

[wjt]

Sure, I don't mind about authorship!

[bbhtt]

Done

[bbhtt]

I changed the limit to 70 characters to allow more module names in the title.