Initial parametric Feather case generator

lib/feather_case_wizard/toolchain.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+module FeatherCaseWizard
+  class ToolError < StandardError; end
+
+  class Toolchain
+    attr_reader :openscad, :blender
+
+    def initialize(env: ENV)
+      @env = env
+      @openscad = discover("OPENSCAD", "openscad")
+      @blender = discover("BLENDER", "blender")
+    end
+
+    def check!
+      missing = []
+      missing << "OpenSCAD (`sudo apt-get install openscad` or set OPENSCAD)" unless openscad
+      missing << "Blender (`sudo apt-get install blender` or set BLENDER)" unless blender
+      return self if missing.empty?
+
+      raise ToolError, "Missing required tools:\n  - #{missing.join("\n  - ")}"
+    end
+
+    def run!(*command, chdir: nil, env: {})
+      options = chdir ? {chdir: chdir} : {}
+      stdout, stderr, status = Open3.capture3(env, *command, **options)
+      return [stdout, stderr] if status.success?
+
+      detail = [stdout, stderr].reject(&:empty?).join("\n").strip
+      result = status.exitstatus || "signal #{status.termsig}"
+      raise ToolError, "Command failed (#{result}): #{command.first}\n#{detail}"
+    rescue Errno::ENOENT => e
+      raise ToolError, "Cannot run #{command.first}: #{e.message}"
+    end
+
+    private
+
+    def discover(env_name, command)
+      override = @env[env_name]
+      return File.expand_path(override) if override && File.executable?(override)
+
+      @env.fetch("PATH", "").split(File::PATH_SEPARATOR).each do |directory|
+        candidate = File.join(directory, command)
+        return candidate if File.file?(candidate) && File.executable?(candidate)
+      end
+      nil
+    end
+  end
+end