# frozen_string_literal: true

require 'securerandom'
module ForemanAnsible
  # Service to list an inventory to be passed to the ansible-playbook binary
  class InventoryCreator
    attr_reader :hosts

    def initialize(hosts, template_invocation = nil)
      @hosts = hosts
      @template_invocation = template_invocation
    end

    # It returns a hash in a format that Ansible understands.
    # See http://docs.ansible.com/ansible/developing_inventory.html
    # for more details.
    # For now, we don't group the hosts based on different paramters
    # (use https://github.com/theforeman/foreman_ansible_inventory for
    # more advanced cases). Therefore we have only the 'all' group
    # with all hosts.
    def to_hash
      hosts = @hosts.map(&:name)

      { 'all' => { 'hosts' => hosts,
                   'vars' => template_inputs(@template_invocation) },
        '_meta' => { 'hostvars' => hosts_vars } }
    end

    def hosts_vars
      hosts.reduce({}) do |hash, host|
        hash.update(
          host.name => host_vars(host)
        )
      end
    end

    def host_vars(host)
      {
        'foreman' => reduced_host_info(host).fetch('parameters', {}),
        'foreman_ansible_roles' => host_roles(host)
      }.merge(connection_params(host)).
        merge(host_params(host)).
        merge(ansible_params(host))
    end

    def connection_params(host)
      # Preference order is:
      # 1st option: host parameters.
      #   - If they're set to 'ansible_whatever' we use that over anything else
      # 2nd option: REX options.
      #   - both settings, ssh password, effective_user can be used
      # 3rd option:
      #   - other settings

      return {} unless @template_invocation
      ansible_settings.
        merge(remote_execution_options(host)).
        merge(ansible_extra_options(host))
    end

    def host_roles(host)
      host.all_ansible_roles.map(&:name)
    end

    def ansible_params(host)
      ForemanAnsible::AnsibleInfo.new(host).ansible_params
    end

    def reduced_host_info(host)
      HostInfo.providers.each_with_object({}) do |provider_class, memo|
        next memo if [HostInfoProviders::HostParamsInfo, ForemanAnsible::AnsibleInfo].include? provider_class
        provider = provider_class.new(host)
        info = provider.host_info
        memo.deep_merge! info if info
        memo
      end
    end

    def host_params(host)
      host.host_params
    end

    def ansible_settings
      Hash[
        %w[connection ssh_private_key_file
           winrm_server_cert_validation].map do |setting|
          ["ansible_#{setting}", Setting["ansible_#{setting}"]]
        end
      ]
    end

    def ansible_extra_options(host)
      host.host_params.select do |key, _|
        /ansible_/.match(key) || Setting[key]
      end
    end

    def remote_execution_options(host)
      params = {
        'ansible_user' => host_setting(host, 'remote_execution_ssh_user'),
        'ansible_become_method' => host_setting(host, 'remote_execution_effective_user_method'),
        'ansible_ssh_private_key_file' => ansible_or_rex_ssh_private_key(host),
        'ansible_port' => host_setting(host, 'remote_execution_ssh_port'),
        'ansible_host' => AnsibleProvider.find_ip_or_hostname(host)
      }
      if @template_invocation.effective_user.present?
        params['ansible_become_user'] = @template_invocation.effective_user
        params['ansible_become'] = true
      end
      # Backward compatibility for Ansible 1.x
      params['ansible_ssh_port'] = params['ansible_port']
      params['ansible_ssh_user'] = params['ansible_user']
      params
    end

    def template_inputs(template_invocation)
      return {} unless template_invocation&.input_values
      input_values = template_invocation.input_values
      result = input_values.each_with_object({}) do |input, vars_hash|
        vars_hash[input.template_input.name] = input.value
      end
      result
    end

    def ansible_or_rex_ssh_private_key(host)
      ansible_private_file = host_setting(host, 'ansible_ssh_private_key_file')
      if !ansible_private_file.empty?
        ansible_private_file
      else
        ForemanRemoteExecutionCore.settings[:ssh_identity_key_file]
      end
    end

    private

    def host_setting(host, setting)
      host.params[setting.to_s] || Setting[setting]
    end
  end
end