# The skill-build check: drives fixture skills through the content tier so
# `nix flake check` covers every discovery shape and the collision hard-error.
{
  pkgs,
  mkSkill,
  discoverSkills,
}:
let
  inherit (pkgs) lib;

  # A valid tree covering every discovery shape at once: two top-level skills
  # (alpha, delta), a skill nested under a cosmetic container (beta, which also
  # owns an asset subfolder whose own SKILL.md must NOT become a skill), and a
  # skill several containers deep (gamma).
  discovered = discoverSkills ./fixtures/valid;
  built = map (skill: mkSkill { inherit pkgs; inherit (skill) name src; }) discovered;

  # Discovery of a tree with two skills resolving to the same name must throw at
  # eval.
  # tryEval catches the throw, so the check can assert discovery failed rather
  # than silently clobbering.
  collision = builtins.tryEval (discoverSkills ./fixtures/collision);

  discoveredNames = lib.sort (a: b: a < b) (map (skill: skill.name) discovered);
in
pkgs.runCommandLocal "skill-build-check"
  {
    # Referencing every built skill forces each one to build before this
    # derivation — that is the "build every auto-discovered skill" coverage.
    # Each entry is "name=storepath" so the assertions can read each $out root
    # without re-deriving anything, and confirm the name passthru round-trips.
    pairs = lib.concatStringsSep " " (map (skill: "${skill.skillName}=${skill}") built);
    collisionSucceeded = if collision.success then "yes" else "no";
    expectedNames = lib.concatStringsSep " " discoveredNames;
  }
  ''
    fail() { echo "FAIL: $1" >&2; exit 1; }

    echo "content tier: the name-collision fixture must fail discovery at eval"
    [ "$collisionSucceeded" = no ] \
      || fail "a two-skills-one-name tree was discovered without error"

    echo "content tier: discovery finds every skill regardless of nesting depth,"
    echo "              and stops at a skill rather than descending into its assets"
    [ "$expectedNames" = "alpha beta delta gamma" ] \
      || fail "discovered names were [$expectedNames], expected [alpha beta delta gamma]"

    echo "content tier: each built skill has SKILL.md at its \$out root"
    beta_path=
    for pair in $pairs; do
      name="''${pair%%=*}"
      path="''${pair#*=}"
      test -f "$path/SKILL.md" || fail "$name has no SKILL.md at its \$out root"
      [ "$name" = beta ] && beta_path="$path"
    done

    echo "content tier: a skill's asset subfolder rides along in \$out and is"
    echo "              not split off into its own skill"
    [ -n "$beta_path" ] || fail "beta was not discovered"
    test -f "$beta_path/tools/SKILL.md" \
      || fail "beta's asset subfolder did not ride along into \$out"

    touch "$out"
  ''