# Trusted host construction only. Authored Workers cannot choose the caller,
# reserved identities, engine directory or sandbox executable.
{
  pkgs,
  sandbox,
  authorityUser ? "quixos-graph",
  engineDirectory ? "/run/quixos-restricted-engines",
  firstUid ? 610000,
  identityCount ? 64,
}:
assert builtins.match "[a-z][a-z0-9_-]{0,63}" authorityUser != null;
assert builtins.match "/run/[a-zA-Z0-9_/-]+" engineDirectory != null;
assert !(pkgs.lib.hasInfix ".." engineDirectory);
assert !(pkgs.lib.hasSuffix "/" engineDirectory);
assert builtins.stringLength engineDirectory < 80;
assert builtins.isInt firstUid && builtins.isInt identityCount;
assert firstUid >= 610000 && firstUid + identityCount <= 2147483647;
assert identityCount >= 1 && identityCount <= 64;
pkgs.runCommand "quixos-restricted-identity-launcher" { nativeBuildInputs = [ pkgs.stdenv.cc ]; } ''
  mkdir -p "$out/bin"
  $CC -O2 -Wall -Wextra -Werror ${./identity-launcher.c} \
    -DSANDBOX_EXECUTABLE='"${sandbox}/bin/quixos-restricted-sandbox"' \
    -DAUTHORITY_USER='"${authorityUser}"' \
    -DENGINE_DIRECTORY='"${engineDirectory}"' \
    -DENGINE_FIRST_UID=${toString firstUid} \
    -DENGINE_IDENTITY_COUNT=${toString identityCount} \
    -o "$out/bin/quixos-restricted-engine"
''