chore: reorg

2026-03-22 10:42:42 +00:00 · 2026-03-15 21:07:36 +00:00 · 2026-03-15 21:07:36 +00:00 · 1b5c26bc04
commit 1b5c26bc04
parent e0a023da4f
54 changed files with 411 additions and 227 deletions
--- a/nixcfgs/modules/lib/mergetools.nix
+++ b/nixcfgs/modules/lib/mergetools.nix
@ -0,0 +1,188 @@
+# mergetools.nix — Dual-mode config merge library
+#
+# Supports both Home Manager ("home") and NixOS system-level ("system") modes.
+# All targets are ABSOLUTE paths regardless of mode.
+#
+# Usage (home mode — default):
+#   mergetools = import ../../modules/lib/mergetools.nix { inherit pkgs lib config; };
+#   myConfig = mergetools.mkMergedJson {
+#     name = "my-config";
+#     target = "${config.home.homeDirectory}/.config/app/config.json";
+#     settings = { key = "value"; };
+#   };
+#   # Then:  imports = [ myConfig ];
+#
+# Usage (system mode):
+#   mergetools = import ../../modules/lib/mergetools.nix { inherit pkgs lib config; };
+#   myConfig = mergetools.mkMergedJson {
+#     name = "my-config";
+#     target = "/var/lib/myapp/config.json";
+#     settings = { key = "value"; };
+#     mode = "system";
+#     # owner = "myapp";      # default: "root"
+#     # group = "myapp";      # default: "root"
+#     # permissions = "0640";  # default: "0644"
+#   };
+#   # Then:  imports = [ myConfig ];
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  mkForceVar = force:
+    if force
+    then "true"
+    else "false";
+
+  # Derive a safe relative path for home.file from an absolute target.
+  # Strips the leading $HOME/ to get the relative portion.
+  # e.g., "/home/js0ny/.config/foo" -> ".config/foo"
+  stripHomePrefix = target: let
+    homeDir = config.home.homeDirectory;
+    homeDirSlash = homeDir + "/";
+    len = builtins.stringLength homeDirSlash;
+  in
+    if lib.hasPrefix homeDirSlash target
+    then builtins.substring len (builtins.stringLength target - len) target
+    else builtins.abort "mergetools (home mode): target '${target}' must start with '${homeDirSlash}'";
+
+  # ── Home mode ──────────────────────────────────────────────────────
+
+  mkHomeMerge = {
+    name,
+    target,
+    patchContent,
+    mergeCmdStr,
+    force,
+    emptyInit,
+  }: let
+    relTarget = stripHomePrefix target;
+    patchFile = "${relTarget}.nix-managed";
+  in {
+    home.file."${patchFile}".text = patchContent;
+
+    home.activation."merge-${name}" = lib.hm.dag.entryAfter ["writeBoundary"] ''
+      TARGET="${target}"
+      PATCH="$HOME/${patchFile}"
+      FORCE="${mkForceVar force}"
+
+      if [ -f "$TARGET" ] || [ "$FORCE" = "true" ]; then
+        if [ -f "$PATCH" ]; then
+          verboseEcho "Merging Nix managed config into: $TARGET"
+          run mkdir -p "$(dirname "$TARGET")"
+          if [ ! -f "$TARGET" ]; then
+            echo '${emptyInit}' > "$TARGET"
+          fi
+          run ${mergeCmdStr}
+        fi
+      else
+        verboseEcho "Skipping merge for $TARGET: file missing and force=false"
+      fi
+    '';
+  };
+
+  # ── System mode ────────────────────────────────────────────────────
+
+  mkSystemMerge = {
+    name,
+    target,
+    patchContent,
+    mergeCmdStr,
+    force,
+    emptyInit,
+    owner ? "root",
+    group ? "root",
+    permissions ? "0644",
+  }: let
+    patchFile = pkgs.writeText "${name}.nix-managed" patchContent;
+  in {
+    system.activationScripts."merge-${name}" = lib.stringAfter ["etc"] ''
+      TARGET="${target}"
+      PATCH="${patchFile}"
+      FORCE="${mkForceVar force}"
+
+      if [ -f "$TARGET" ] || [ "$FORCE" = "true" ]; then
+        echo "mergetools: Merging Nix managed config into: $TARGET"
+        mkdir -p "$(dirname "$TARGET")"
+        if [ ! -f "$TARGET" ]; then
+          echo '${emptyInit}' > "$TARGET"
+        fi
+        ${mergeCmdStr}
+        chown ${owner}:${group} "$TARGET"
+        chmod ${permissions} "$TARGET"
+      else
+        echo "mergetools: Skipping merge for $TARGET: file missing and force=false"
+      fi
+    '';
+  };
+
+  # ── Dispatch ───────────────────────────────────────────────────────
+
+  mkMerge = {mode ? "home", ...} @ args: let
+    # Strip mode-irrelevant attrs before passing
+    homeArgs = builtins.removeAttrs args ["mode" "owner" "group" "permissions"];
+    systemArgs = builtins.removeAttrs args ["mode"];
+  in
+    if mode == "home"
+    then mkHomeMerge homeArgs
+    else if mode == "system"
+    then mkSystemMerge systemArgs
+    else builtins.abort "mergetools: unknown mode '${mode}', expected 'home' or 'system'";
+
+  # ── Public API ─────────────────────────────────────────────────────
+
+  mkMergedYaml = {
+    name,
+    target,
+    settings,
+    force ? false,
+    mode ? "home",
+    owner ? "root",
+    group ? "root",
+    permissions ? "0644",
+  }:
+    mkMerge {
+      inherit name target mode force owner group permissions;
+      patchContent = lib.generators.toYAML {} settings;
+      # $TARGET and $PATCH are shell variables set in the activation script
+      mergeCmdStr = ''${pkgs.yq-go}/bin/yq -i -oy -P ". *= load(\"$PATCH\")" "$TARGET"'';
+      emptyInit = "{}";
+    };
+
+  mkMergedJson = {
+    name,
+    target,
+    settings,
+    force ? false,
+    mode ? "home",
+    owner ? "root",
+    group ? "root",
+    permissions ? "0644",
+  }:
+    mkMerge {
+      inherit name target mode force owner group permissions;
+      patchContent = builtins.toJSON settings;
+      mergeCmdStr = ''${pkgs.yq-go}/bin/yq -i -o json -P --indent 2 ". *= load(\"$PATCH\")" "$TARGET"'';
+      emptyInit = "{}";
+    };
+
+  mkMergedIni = {
+    name,
+    target,
+    settings,
+    force ? false,
+    mode ? "home",
+    owner ? "root",
+    group ? "root",
+    permissions ? "0644",
+  }:
+    mkMerge {
+      inherit name target mode force owner group permissions;
+      patchContent = lib.generators.toINI {} settings;
+      mergeCmdStr = ''${pkgs.crudini}/bin/crudini --merge "$TARGET" < "$PATCH"'';
+      emptyInit = "";
+    };
+in {
+  inherit mkMergedYaml mkMergedJson mkMergedIni;
+}