from collections.abc import Iterable


def merge_activity(
    github: dict[str, int],
    gitea: dict[str, int],
    dates: Iterable[str] | None = None,
) -> dict[str, dict[str, int]]:
    keys = set(github) | set(gitea)
    if dates is not None:
        keys |= set(dates)

    merged: dict[str, dict[str, int]] = {}
    for date_key in sorted(keys):
        gh = int(github.get(date_key, 0))
        gt = int(gitea.get(date_key, 0))
        merged[date_key] = {
            "github": gh,
            "gitea": gt,
            "total": gh + gt,
        }
    return merged


def filter_activity_source(
    merged: dict[str, dict[str, int]],
    source: str,
) -> dict[str, dict[str, int]]:
    if source == "all":
        return merged

    filtered: dict[str, dict[str, int]] = {}
    for day, counts in merged.items():
        github = counts.get("github", 0)
        gitea = counts.get("gitea", 0)
        if source == "github":
            filtered[day] = {"github": github, "gitea": 0, "total": github}
        elif source == "gitea":
            filtered[day] = {"github": 0, "gitea": gitea, "total": gitea}
        else:
            filtered[day] = counts
    return filtered