defmodule ExIceberg.Table.SnapshotsTable do
  @moduledoc """
  SnapshotsTable provides access to table snapshot information.

  This module allows you to inspect table snapshots, which represent
  the state of a table at a specific point in time.

  Similar to iceberg-rust's SnapshotsTable functionality.
  """

  defstruct [:table_metadata]

  @type t :: %__MODULE__{
          table_metadata: map()
        }

  @doc """
  Creates a new SnapshotsTable from table metadata.

  This is typically called by MetadataTable.snapshots/1.
  """
  def new(table_metadata) do
    %__MODULE__{table_metadata: table_metadata}
  end

  @doc """
  Returns the schema of the snapshots table.

  This describes the structure of snapshot metadata that would be
  returned by scan operations.

  ## Examples

      schema = ExIceberg.Table.SnapshotsTable.schema(snapshots_table)
      # Returns schema information about snapshot fields
  """
  def schema(%__MODULE__{}) do
    # For now, return a basic schema description
    # In the future, this could call into Rust to get the actual schema
    %{
      "fields" => [
        %{"name" => "committed_at", "type" => "timestamp", "required" => true},
        %{"name" => "snapshot_id", "type" => "long", "required" => true},
        %{"name" => "parent_id", "type" => "long", "required" => false},
        %{"name" => "operation", "type" => "string", "required" => false},
        %{"name" => "manifest_list", "type" => "string", "required" => true},
        %{"name" => "summary", "type" => "map<string,string>", "required" => false}
      ]
    }
  end

  @doc """
  Returns basic information about available snapshots.

  Note: This is a placeholder implementation. Full scan functionality
  would require additional Rust NIF functions to iterate through snapshots.

  ## Examples

      info = ExIceberg.Table.SnapshotsTable.info(snapshots_table)
  """
  def info(%__MODULE__{}) do
    %{
      "description" => "Snapshots table for inspecting table history",
      "note" => "Full scan functionality requires additional implementation"
    }
  end
end
