"""Map changed dirs to plan units, preserving the direct trigger directories."""
from __future__ import annotations

from pathlib import Path

from scripts.manifest import ModuleGraphEntry
from scripts.plan_unit import classify_dir, DirKind


def resolve_plan_units(
    repo_root: Path | str,
    changed_dirs: set[str],
    module_graph: dict[str, ModuleGraphEntry],
) -> tuple[dict[str, list[str]], list[str]]:
    """Return (plan_units, orphan_modules).

    plan_units maps plan_dir -> sorted-unique list of changed dirs that triggered it.
    Direct Terragrunt or root-module changes remain in the trigger set so later
    manifest assembly can attach per-plan-unit change context.
    orphan_modules is a list of changed module dirs with zero callsites.
    """
    plan_units: dict[str, set[str]] = {}
    orphans: list[str] = []

    for d in sorted(changed_dirs):
        kind = classify_dir(repo_root, d)
        if kind is DirKind.PLAN_UNIT:
            plan_units.setdefault(d, set()).add(d)
        elif kind is DirKind.MODULE:
            entry = module_graph.get(d)
            callsites = list(entry.callsites) if entry else []
            if not callsites:
                orphans.append(d)
                continue
            for cs in callsites:
                plan_units.setdefault(cs, set()).add(d)

    return (
        {k: sorted(v) for k, v in sorted(plan_units.items())},
        sorted(orphans),
    )