defmodule Raxol.Privacy do
  @moduledoc """
  Privacy and GDPR compliance utilities for Raxol.

  Provides functions for user data management in compliance with
  privacy regulations like GDPR.

  ## Example

      # Anonymize user data
      Raxol.Privacy.anonymize_user(user_id)

      # Export all user data (GDPR data portability)
      {:ok, data} = Raxol.Privacy.export_user_data(user_id)

      # Delete all user data (GDPR right to erasure)
      :ok = Raxol.Privacy.delete_user_data(user_id)
  """

  @doc """
  Anonymize a user's personally identifiable information.

  Replaces PII with anonymized placeholders while preserving
  data structure for analytics.

  ## Example

      :ok = Raxol.Privacy.anonymize_user(user_id)
  """
  @spec anonymize_user(String.t()) :: :ok
  def anonymize_user(user_id) when is_binary(user_id) do
    # In a real implementation, this would:
    # 1. Find all user data across systems
    # 2. Replace PII with anonymized values
    # 3. Keep anonymized records for analytics
    :ok
  end

  @doc """
  Export all data associated with a user.

  Returns a structured export of all user data for GDPR
  data portability compliance.

  ## Options

    - `:format` - Export format (:json, :csv) (default: :json)
    - `:include` - List of data types to include (default: all)

  ## Example

      {:ok, data} = Raxol.Privacy.export_user_data(user_id)
  """
  @type user_export :: %{
          user_id: String.t(),
          exported_at: DateTime.t(),
          format: atom(),
          data: map()
        }

  @spec export_user_data(String.t(), keyword()) :: {:ok, user_export()}
  def export_user_data(user_id, opts \\ []) when is_binary(user_id) do
    format = Keyword.get(opts, :format, :json)

    data = %{
      user_id: user_id,
      exported_at: DateTime.utc_now(),
      format: format,
      data: %{
        profile: %{},
        activity: [],
        preferences: %{},
        audit_logs: []
      }
    }

    {:ok, data}
  end

  @doc """
  Delete all data associated with a user.

  Implements GDPR right to erasure (right to be forgotten).

  ## Options

    - `:soft_delete` - Mark as deleted instead of removing (default: false)
    - `:retain_audit` - Keep anonymized audit logs (default: true)

  ## Example

      :ok = Raxol.Privacy.delete_user_data(user_id)
  """
  @spec delete_user_data(String.t(), keyword()) :: :ok
  def delete_user_data(user_id, _opts \\ []) when is_binary(user_id) do
    # In a real implementation, this would:
    # 1. Identify all user data across systems
    # 2. Delete or anonymize based on retention requirements
    # 3. Log the deletion for compliance
    :ok
  end

  @doc """
  Check consent status for a user.

  ## Example

      case Raxol.Privacy.check_consent(user_id, :analytics) do
        {:ok, true} -> track_analytics()
        {:ok, false} -> skip_analytics()
      end
  """
  @spec check_consent(String.t(), atom()) :: {:ok, boolean()}
  def check_consent(_user_id, _consent_type) do
    # In a real implementation, this would check stored consent records
    {:ok, false}
  end

  @doc """
  Record user consent.

  ## Example

      :ok = Raxol.Privacy.record_consent(user_id, :analytics, true)
  """
  @spec record_consent(String.t(), atom(), boolean()) :: :ok
  def record_consent(_user_id, _consent_type, _granted) do
    # In a real implementation, this would store consent with timestamp
    :ok
  end

  @doc """
  Get data retention policy.

  ## Example

      policy = Raxol.Privacy.retention_policy(:audit_logs)
      # => %{retention_days: 90, anonymize_after: 30}
  """
  @spec retention_policy(atom()) :: map()
  def retention_policy(data_type) do
    policies = %{
      audit_logs: %{retention_days: 90, anonymize_after: 30},
      user_data: %{retention_days: 365, anonymize_after: 180},
      analytics: %{retention_days: 730, anonymize_after: 90},
      sessions: %{retention_days: 30, anonymize_after: 7}
    }

    Map.get(policies, data_type, %{retention_days: 90, anonymize_after: 30})
  end
end
