#!/usr/bin/env bash
# Shared flake-introspection helpers for scripts/*.sh. Source alongside
# env.sh:
#   source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/lib/nix-eval.sh"
#
# NIX_EVAL_FLAGS: --no-use-registries so a call here never resolves through
# the user's global flake registry (every call targets this repo's own
# flake, or an explicit github: ref, not a registry alias); --no-accept-flake-config
# so a flake input's own nixConfig (e.g. a dependency's substituters) is
# never honored -- matches accept-flake-config = false already set repo-wide
# (see lib/nix-bootstrap.sh / CLAUDE.md). Reuse this array rather than
# retyping the two flags at each call site.
declare -a NIX_EVAL_FLAGS=(--no-use-registries --no-accept-flake-config)

# list_flake_targets <flake_ref>
# Prints the attribute names under <flake_ref>#nixosConfigurations, one per
# line, e.g.:
#   list_flake_targets .            # from inside the repo
#   list_flake_targets "$repo_root" # from anywhere
list_flake_targets() {
  local flake_ref="$1"
  nix eval --json "${NIX_EVAL_FLAGS[@]}" \
    "${flake_ref}#nixosConfigurations" --apply builtins.attrNames \
  | jq -r '.[]'
}

# flake_target_hostname <flake_ref> <target>
# Prints one nixosConfigurations target's config.networking.hostName.
# Empty (not an error under set -e) if the target doesn't exist or the
# eval otherwise fails -- callers that need to distinguish "empty" from
# "eval failed" should check $? themselves instead of relying on this.
flake_target_hostname() {
  local flake_ref="$1" target="$2"
  nix eval --raw "${NIX_EVAL_FLAGS[@]}" \
    "${flake_ref}#nixosConfigurations.${target}.config.networking.hostName" 2>/dev/null
}

# flake_target_lxc_privileged <flake_ref> <target>
# Prints "true" or "false" for one lxc-* target's config.proxmoxLXC.privileged
# (modules/platforms/lxc.nix is the single source of truth -- e.g.
# lxc-docker sets this true so it can NFS-mount; every other lxc-* host
# stays unprivileged). Only meaningful for lxc-* targets -- the option
# doesn't exist for linode-*/proxmox-* (nixpkgs' proxmox-lxc.nix, which
# declares it, is only ever imported by modules/platforms/lxc.nix). Empty
# (not an error under set -e) if the eval fails.
flake_target_lxc_privileged() {
  local flake_ref="$1" target="$2"
  # Not --raw: the option is a Nix boolean, and --raw can only coerce
  # strings ("cannot coerce a Boolean to a string"). Plain `nix eval`
  # prints a bare `true`/`false` for a boolean, which is exactly the
  # string this needs.
  nix eval "${NIX_EVAL_FLAGS[@]}" \
    "${flake_ref}#nixosConfigurations.${target}.config.proxmoxLXC.privileged" 2>/dev/null
}