class Prerequisites

# File lib/prerequisites.rb, line 6
def initialize(config)
  @config = config
end

# File lib/prerequisites.rb, line 10
def check
  environment_variables
  executables_in_path
  shell_commands
end

# File lib/prerequisites.rb, line 61
def check_env_var_has_value(var, value)
  unless ENV[var] == value
    raise Prerequisites::EnvironmentVariableError.new(
      "Expected environment variable #{var} to be #{value}"
    )
  end
end

# File lib/prerequisites.rb, line 53
def check_env_var_is_set(env_var)
  unless ENV.key?(env_var)
    raise Prerequisites::EnvironmentVariableError.new(
      "Required environment variable #{env_var} is not set"
    )
  end
end

# File lib/prerequisites.rb, line 69
def check_executable(executable)
  _, _, status = Open3.capture3("which #{executable}")

  unless status.success?
    raise Prerequisites::ExecutableError.new(
      "Required executable #{executable} not found in path"
    )
  end
end

# File lib/prerequisites.rb, line 18
def environment_variables
  config.dig(:environment_variables).to_a.each do |env_var|
    if env_var.is_a?(Hash)
      var, value = env_var.first
      check_env_var_has_value(var, value)
    else
      check_env_var_is_set(env_var)
    end
  end

  true
end

# File lib/prerequisites.rb, line 31
def executables_in_path
  config.dig(:executables_in_path).to_a.each do |executable|
    check_executable(executable)
  end

  true
end

# File lib/prerequisites.rb, line 39
def shell_commands
  config.dig(:shell_commands).to_a.each do |cmd|
    _, _, status = Open3.capture3(cmd)

    unless status.success?
      raise Prerequisites::ShellCommandError.new(
        "Shell command check failed: #{cmd}"
      )
    end
  end

  true
end