defmodule EnhancedADT do
  @moduledoc """
  Enhanced Algebraic Data Types with automatic WarpEngine integration.

  This module provides mathematical ADT definitions that automatically translate
  to optimized WarpEngine operations with physics intelligence. Domain models become
  pure mathematical expressions while transparently leveraging quantum entanglement,
  wormhole routing, and spacetime optimization.

  ## Core Concepts

  - **defproduct**: Define product types (records) with physics annotations
  - **defsum**: Define sum types (unions) with automatic topology generation
  - **fold**: Pattern match with automatic WarpEngine translation
  - **bend**: Generate structures with automatic wormhole network creation

  ## Physics Integration

  ADT structures automatically:
  - Create quantum entanglement relationships
  - Generate wormhole networks for cross-references
  - Configure gravitational routing based on access patterns
  - Optimize temporal placement based on data lifecycle

  ## Example Usage

  ```elixir
  use EnhancedADT

  defproduct User do
    id :: String.t()
    name :: String.t()
    preferences :: UserPreferences.t(), physics: :quantum_entanglement_group
    activity_score :: float(), physics: :gravitational_mass
  end

  defsum UserNetwork do
    IsolatedUser(User.t())
    ConnectedUsers(primary :: User.t(), connections :: [rec(UserNetwork)])
  end

  # Mathematical operations automatically become WarpEngine commands
  fold user do
    User(id, name, preferences, score) ->
      # Automatically translates to WarpEngine.cosmic_put with physics configuration
      store_user_with_physics(id, name, preferences, score)
  end
  ```
  """

  @doc """
  Initialize Enhanced ADT system with WarpEngine integration.

  This macro sets up the mathematical ADT environment and imports all
  necessary functions for domain modeling.
  """
  defmacro __using__(_opts) do
    quote do
      import EnhancedADT.ProductType
      import EnhancedADT.SumType
      import EnhancedADT.Fold
      import EnhancedADT.Bend
      import EnhancedADT.Physics

      # Import elegant variant and field syntax
      import EnhancedADT.VariantSyntax
      import EnhancedADT.FieldSyntax

      # Enable compile-time ADT analysis for optimization
      @before_compile EnhancedADT.Optimizer
    end
  end

  @doc """
  Create recursive type reference for sum types.

  Used within sum type definitions to create cyclic references that enable
  recursive data structures with automatic wormhole network optimization.

  ## Example

  ```elixir
  defsum Tree do
    Leaf(value :: any())
    Branch(left :: rec(Tree), right :: rec(Tree), value :: any())
  end
  ```
  """
  def rec(type_name) do
    {:recursive_reference, type_name}
  end
end

defmodule EnhancedADT.ProductType do
  @moduledoc """
  Product type definitions with physics annotations.

  Product types represent record-like structures where all fields are present.
  Physics annotations allow automatic configuration of WarpEngine behavior.
  """

  @doc """
  Define a product type with optional physics annotations.

  Physics annotations control how the data interacts with WarpEngine:
  - `:gravitational_mass` - Affects shard placement and routing
  - `:quantum_entanglement_group` - Creates automatic entanglements
  - `:temporal_weight` - Influences data lifecycle management
  - `:spacetime_shard_hint` - Suggests optimal shard placement

  ## Example

  ```elixir
  defproduct Customer do
    id :: String.t()
    loyalty_score :: float(), physics: :gravitational_mass
    preferences :: CustomerPreferences.t(), physics: :quantum_entanglement_group
    created_at :: DateTime.t(), physics: :temporal_weight
  end
  ```
  """
  defmacro defproduct(name, do: fields) do
    # Transform elegant physics syntax first, then extract field definitions
    transformed_fields = transform_physics_field_syntax(fields)
    field_specs = extract_field_specifications(transformed_fields)
    physics_config = extract_physics_annotations(field_specs)

    quote do
      defmodule unquote(name) do
        @moduledoc "Enhanced ADT Product Type: #{unquote(name)}"

        # Store physics configuration for compile-time optimization
        @adt_type :product
        @adt_physics_config unquote(Macro.escape(physics_config))
        @adt_fields unquote(Macro.escape(field_specs))

        # Generate struct definition
        unquote(generate_struct_definition(field_specs))

        # Generate constructor functions
        unquote(generate_constructor_functions(name, field_specs))

        # Generate physics integration functions
        unquote(generate_physics_integration(name, field_specs, physics_config))

        # Generate pattern matching helpers
        unquote(generate_pattern_helpers(name, field_specs))
      end
    end
  end

  # Transform elegant physics field syntax to parseable format
  defp transform_physics_field_syntax(fields) do
    case fields do
      {:__block__, meta, field_list} ->
        {:__block__, meta, Enum.map(field_list, &transform_single_physics_field/1)}
      single_field ->
        transform_single_physics_field(single_field)
    end
  end

  defp transform_single_physics_field({:"::", meta1, [field_name, {:"::", meta2, [type_spec, [physics: physics_annotation]]}]}) do
    # Transform: field_name :: Type.t() :: physics: :annotation
    # This handles syntax errors from Elixir parser attempting to parse physics annotations
    {field_name, type_spec, physics_annotation}
  end

  defp transform_single_physics_field({{:"::", meta, [field_name, type_spec]}, [physics: physics_annotation]}) do
    # Transform: {field_name :: Type.t(), physics: :annotation}
    {field_name, type_spec, physics_annotation}
  end

  defp transform_single_physics_field({:"::", _meta, [field_name, type_spec]}) do
    # Regular field: field_name :: Type.t()
    field_name_atom = extract_field_name(field_name)
    {field_name_atom, type_spec, nil}
  end

  defp transform_single_physics_field(field_name) when is_atom(field_name) do
    # Just field name
    {field_name, :any, nil}
  end

  defp transform_single_physics_field(other) do
    # Pass through other syntax
    other
  end

  # Helper functions for macro expansion
  defp extract_field_specifications(fields) do
    case fields do
      {:__block__, _, field_list} -> Enum.map(field_list, &parse_field_spec/1)
      single_field -> [parse_field_spec(single_field)]
    end
  end

  # Parse field specifications with optional physics annotations
  defp parse_field_spec({:field, _, [field_spec]}) do
    # field macro call without physics: field name :: Type.t()
    parse_field_macro_call(field_spec, nil)
  end

  defp parse_field_spec({:field, _, [field_spec, [physics: physics_annotation]]}) do
    # field macro call with physics: field name :: Type.t(), physics: :annotation
    parse_field_macro_call(field_spec, physics_annotation)
  end

  defp parse_field_spec({field_name, field_type, physics_annotation}) when is_atom(field_name) do
    # Result from field macro: {field_name, field_type, physics_annotation}
    %{name: field_name, type: field_type, physics: physics_annotation}
  end

  defp parse_field_spec({:"::", _meta, [field_name_ast, type_spec]}) do
    # Simple field: name :: Type.t()
    field_name = extract_field_name(field_name_ast)
    %{name: field_name, type: type_spec, physics: nil}
  end

  defp parse_field_spec(field_name) when is_atom(field_name) do
    # Just a field name without type specification
    %{name: field_name, type: :any, physics: nil}
  end

  defp parse_field_spec(other) do
    raise "Invalid field specification: #{inspect(other)}"
  end

  defp parse_field_macro_call({:"::", _, [field_name_ast, type_spec]}, physics_annotation) do
    # Parse field macro call: name :: Type.t()
    field_name = extract_field_name(field_name_ast)
    %{name: field_name, type: type_spec, physics: physics_annotation}
  end

  # Extract field name from different AST formats
  defp extract_field_name(field_name) when is_atom(field_name), do: field_name
  defp extract_field_name({field_name, _meta, _context}) when is_atom(field_name), do: field_name
  defp extract_field_name({"::", _, [field_name, _type]}) when is_atom(field_name), do: field_name
  defp extract_field_name({"::", _, [{field_name, _, _}, _type]}) when is_atom(field_name), do: field_name
  defp extract_field_name(other), do: raise "Invalid field name: #{inspect(other)}"

  # Extract variant name from AST
  defp extract_variant_name({:__aliases__, _, [variant_name]}) when is_atom(variant_name), do: variant_name
  defp extract_variant_name(variant_name) when is_atom(variant_name), do: variant_name
  defp extract_variant_name(other), do: raise "Invalid variant name: #{inspect(other)}"

  defp extract_physics_annotations(field_specs) do
    Enum.reduce(field_specs, %{}, fn field, acc ->
      case field.physics do
        nil -> acc
        physics_type -> Map.put(acc, field.name, physics_type)
      end
    end)
  end

  defp generate_struct_definition(field_specs) do
    field_atoms = Enum.map(field_specs, & &1.name)

    quote do
      @enforce_keys unquote(field_atoms)
      defstruct unquote(field_atoms)
    end
  end

  defp generate_constructor_functions(name, field_specs) do
    field_names = Enum.map(field_specs, & &1.name)
    field_vars = Enum.map(field_names, fn name -> Macro.var(name, nil) end)
    field_assignments = Enum.map(field_names, fn name ->
      {name, Macro.var(name, nil)}
    end)

    quote do
      @doc "Create new #{unquote(name)} with all required fields"
      def new(unquote_splicing(field_vars)) do
        %__MODULE__{unquote_splicing(field_assignments)}
      end

      @doc "Create new #{unquote(name)} from keyword list"
      def new(fields) when is_list(fields) do
        struct(__MODULE__, fields)
      end
    end
  end

  defp generate_physics_integration(_name, field_specs, physics_config) do
    quote do
      @doc "Get physics configuration for WarpEngine integration"
      def __adt_physics_config__, do: unquote(Macro.escape(physics_config))

      @doc "Get field specifications for WarpEngine optimization"
      def __adt_field_specs__, do: unquote(Macro.escape(field_specs))

      @doc "Extract physics parameters for WarpEngine cosmic_put operation"
      def extract_physics_context(data) do
        physics_config = __adt_physics_config__()

        Enum.reduce(physics_config, %{}, fn {field_name, physics_type}, acc ->
          field_value = Map.get(data, field_name)
          physics_parameter = convert_to_physics_parameter(physics_type, field_value)
          Map.put(acc, physics_type, physics_parameter)
        end)
      end

      defp convert_to_physics_parameter(:gravitational_mass, value) when is_number(value), do: value
      defp convert_to_physics_parameter(:gravitational_mass, _), do: 1.0

      defp convert_to_physics_parameter(:quantum_entanglement_potential, value) when is_number(value), do: min(1.0, max(0.0, value))
      defp convert_to_physics_parameter(:quantum_entanglement_potential, _), do: 0.5

      defp convert_to_physics_parameter(:temporal_weight, value) when is_number(value), do: value
      defp convert_to_physics_parameter(:temporal_weight, %DateTime{}), do: 1.0
      defp convert_to_physics_parameter(:temporal_weight, _), do: 1.0

      defp convert_to_physics_parameter(:spacetime_shard_hint, :hot), do: :hot
      defp convert_to_physics_parameter(:spacetime_shard_hint, :warm), do: :warm
      defp convert_to_physics_parameter(:spacetime_shard_hint, :cold), do: :cold
      defp convert_to_physics_parameter(:spacetime_shard_hint, _), do: :warm

      defp convert_to_physics_parameter(_, value), do: value
    end
  end

  defp generate_pattern_helpers(_name, field_specs) do
    field_names = Enum.map(field_specs, & &1.name)
    field_vars = Enum.map(field_names, fn name -> Macro.var(name, nil) end)
    field_assignments = Enum.map(field_names, fn name ->
      {name, Macro.var(name, nil)}
    end)

    quote do
      @doc "Pattern match helper for fold operations"
      def __adt_pattern_match__(unquote_splicing(field_vars)) do
        %__MODULE__{unquote_splicing(field_assignments)}
      end

      @doc "Destructure instance into field tuple for fold operations"
      def __adt_destructure__(%__MODULE__{} = instance) do
        {unquote_splicing(Enum.map(field_names, fn name ->
          quote do: Map.get(instance, unquote(name))
        end))}
      end
    end
  end
end

defmodule EnhancedADT.SumType do
  @moduledoc """
  Sum type definitions with automatic wormhole topology generation.

  Sum types represent union-like structures where exactly one variant is present.
  These automatically create wormhole networks for efficient traversal between variants.
  """

  @doc """
  Define a sum type with automatic wormhole network generation.

  Sum types create branching structures that automatically establish wormhole
  connections between related variants for optimized traversal.

  ## Recursive Types

  Use `rec(TypeName)` for recursive references that create cyclic wormhole networks.

  ## Example

  ```elixir
  defsum UserTree do
    UserLeaf(User.t())
    UserBranch(user :: User.t(), connections :: [rec(UserTree)])
    QuantumSuperposition(users :: [User.t()], coherence :: float())
  end
  ```
  """
  defmacro defsum(name, do: variants) do
    # Transform elegant design doc syntax before processing
    transformed_variants = transform_elegant_defsum_syntax(variants)

    # Extract variant specifications from transformed syntax
    variant_specs = extract_variant_specifications(transformed_variants)

    quote do
      defmodule unquote(name) do
        @moduledoc "Enhanced ADT Sum Type: #{unquote(name)}"

        # Store ADT metadata
        @adt_type :sum
        @adt_variants unquote(Macro.escape(variant_specs))

        # Generate variant modules and functions
        unquote_splicing(generate_variant_modules(variant_specs))

        # Generate pattern matching infrastructure
        unquote(generate_sum_pattern_helpers(name, variant_specs))

        # Generate wormhole network topology functions
        unquote(generate_wormhole_topology_functions(name, variant_specs))
      end
    end
  end

  defp extract_variant_specifications(variants) do
    case variants do
      {:__block__, _, variant_list} -> parse_elegant_variant_list(variant_list)
      single_variant -> parse_elegant_variant_list([single_variant])
    end
  end

  defp transform_elegant_defsum_syntax(variants) do
    # The variant macro has already transformed the syntax, so just pass through
    variants
  end

  defp parse_elegant_variant_list(variant_list) do
    # Parse variant macro calls and other variant definitions
    Enum.map(variant_list, fn
      # variant macro call: {:variant, _, [VariantName, field1, field2, ...]}
      {:variant, _, [variant_name_ast | fields]} ->
        variant_name = extract_sum_variant_name(variant_name_ast)
        field_names = Enum.map(fields, &extract_sum_field_name/1)
        %{name: variant_name, fields: Enum.map(field_names, &%{name: &1, type: :any})}

      # Result from variant macro: {VariantName, [field1, field2]}
      {variant_name, field_list} when is_atom(variant_name) and is_list(field_list) ->
        %{name: variant_name, fields: parse_variant_field_list(field_list)}

      # Tuple pair: {:VariantName, [:field1, :field2]} (backward compatibility)
      {:{}, _, [variant_name, field_list]} when is_atom(variant_name) and is_list(field_list) ->
        %{name: variant_name, fields: parse_variant_field_list(field_list)}

      # Simple atom: VariantName
      variant_name when is_atom(variant_name) ->
        %{name: variant_name, fields: []}

      # Error case
      other ->
        raise "Invalid variant specification: #{inspect(other)}. Expected variant macro call or simple variant"
    end)
  end

  # Helper functions for sum type parsing
  defp extract_sum_variant_name({:__aliases__, _, [variant_name]}) when is_atom(variant_name), do: variant_name
  defp extract_sum_variant_name(variant_name) when is_atom(variant_name), do: variant_name
  defp extract_sum_variant_name(other), do: raise "Invalid variant name: #{inspect(other)}"

  defp extract_sum_field_name(field_name) when is_atom(field_name), do: field_name
  defp extract_sum_field_name({field_name, _meta, _context}) when is_atom(field_name), do: field_name
  defp extract_sum_field_name({"::", _, [field_name, _type]}) when is_atom(field_name), do: field_name
  defp extract_sum_field_name({"::", _, [{field_name, _, _}, _type]}) when is_atom(field_name), do: field_name
  defp extract_sum_field_name(other), do: raise "Invalid field name: #{inspect(other)}"

  defp parse_elegant_variant_fields(args) do
    # Parse elegant design doc variant field definitions
    Enum.with_index(args) |> Enum.map(fn {field_spec, index} ->
      case field_spec do
        # Named field with type: field :: Type.t()
        {"::", _, [field_name, type_spec]} when is_atom(field_name) ->
          %{name: field_name, type: type_spec}

        # Named field without type annotation: field_name
        field_name when is_atom(field_name) ->
          %{name: field_name, type: :any}

        # Just a type without field name: Type.t()
        type_spec ->
          # Generate field name from position if no name provided
          field_name = String.to_atom("field_#{index}")
          %{name: field_name, type: type_spec}
      end
    end)
  end

  defp parse_variant_field_list(field_list) do
    Enum.map(field_list, fn field_name when is_atom(field_name) ->
      %{name: field_name, type: :any}
    end)
  end





  defp generate_variant_modules(variant_specs) do
    Enum.map(variant_specs, fn variant ->
      generate_variant_module(variant)
    end)
  end

  defp generate_variant_module(%{name: variant_name, fields: fields}) do
    if Enum.empty?(fields) do
      # Simple variant without fields - create as nested module
      quote do
        defmodule unquote(variant_name) do
          defstruct [:__variant__]

          def new(), do: %__MODULE__{__variant__: unquote(variant_name)}
        end

        # Create a convenience constructor function at the sum type level
        def unquote(variant_name)(), do: __MODULE__.unquote(variant_name).new()
      end
    else
      # Variant with fields - create as nested module
      field_atoms = Enum.map(fields, & &1.name)

      quote do
        defmodule unquote(variant_name) do
          defstruct [:__variant__ | unquote(field_atoms)]

          def new(unquote_splicing(Enum.map(field_atoms, fn atom -> Macro.var(atom, nil) end))) do
            args = unquote(Enum.map(field_atoms, fn atom ->
              quote do: {unquote(atom), unquote(Macro.var(atom, nil))}
            end))
            struct(__MODULE__, [{:__variant__, unquote(variant_name)} | args])
          end
        end

        # Create a convenience constructor function at the sum type level
        def unquote(variant_name)(unquote_splicing(Enum.map(field_atoms, fn atom -> Macro.var(atom, nil) end))) do
          __MODULE__.unquote(variant_name).new(unquote_splicing(Enum.map(field_atoms, fn atom -> Macro.var(atom, nil) end)))
        end
      end
    end
  end

  defp generate_sum_pattern_helpers(_sum_name, variant_specs) do
    quote do
      @doc "Get all variant specifications for pattern matching"
      def __adt_variants__, do: unquote(Macro.escape(variant_specs))

      @doc "Check if value is instance of this sum type"
      def is_variant?(%{__variant__: variant_name}) do
        variant_name in unquote(Enum.map(variant_specs, & &1.name))
      end
      def is_variant?(_), do: false

      @doc "Get variant name from instance"
      def get_variant(%{__variant__: variant_name}), do: variant_name
      def get_variant(_), do: nil
    end
  end

  defp generate_wormhole_topology_functions(_sum_name, variant_specs) do
    quote do
      @doc "Generate wormhole network topology for this sum type"
      def __adt_wormhole_topology__() do
        variants = unquote(Macro.escape(variant_specs))

        # Create wormhole connections between variants that reference each other
        connections = Enum.flat_map(variants, fn variant ->
          variant_connections = analyze_variant_connections(variant, variants)
          Enum.map(variant_connections, fn target_variant ->
            %{
              source: variant.name,
              target: target_variant,
              connection_type: :variant_transition,
              strength: calculate_variant_connection_strength(variant, target_variant)
            }
          end)
        end)

        %{
          sum_type: __MODULE__,
          variant_count: length(variants),
          wormhole_connections: connections,
          topology_type: :sum_type_network
        }
      end

      defp analyze_variant_connections(variant, all_variants) do
        # Find other variants that this variant might connect to
        # Based on field types and recursive references
        Enum.filter(all_variants, fn other_variant ->
          variant.name != other_variant.name and
          variants_have_connection?(variant, other_variant)
        end) |> Enum.map(& &1.name)
      end

      defp variants_have_connection?(%{fields: fields1}, %{fields: fields2}) do
        # Check if variants share common field types or have recursive references
        has_recursive_reference?(fields1) or
        has_recursive_reference?(fields2) or
        have_common_field_types?(fields1, fields2)
      end

      defp has_recursive_reference?(fields) do
        Enum.any?(fields, fn field ->
          case field.type do
            {:recursive, _} -> true
            _ -> false
          end
        end)
      end

      defp have_common_field_types?(fields1, fields2) do
        types1 = Enum.map(fields1, & &1.type) |> MapSet.new()
        types2 = Enum.map(fields2, & &1.type) |> MapSet.new()
        not MapSet.disjoint?(types1, types2)
      end

      defp calculate_variant_connection_strength(_variant1, _variant2) do
        # Default connection strength - can be enhanced with usage pattern analysis
        0.5
      end
    end
  end
end



defmodule EnhancedADT.FieldSyntax do
  @moduledoc """
  Elegant field syntax for Enhanced ADT product types with physics annotations.

  Provides the `field` macro for beautiful mathematical field definitions:

  ```elixir
  defproduct Person do
    field :id, String.t()
    field :influence_score, float(), physics: :gravitational_mass
    field :activity, float(), physics: :quantum_entanglement_potential
  end
  ```
  """

    @doc """
  Define a product type field with optional physics annotation.

  This macro enables elegant physics-annotated fields:
  - `field name :: String.t()` for simple fields
  - `field score :: float(), physics: :gravitational_mass` for physics fields
  """
  defmacro field({:"::", _, [field_name, type_spec]}, physics: physics_annotation) do
    # Field with physics: field name :: Type.t(), physics: :annotation
    field_name_atom = extract_field_name_from_ast(field_name)
    quote do
      {unquote(field_name_atom), unquote(type_spec), unquote(physics_annotation)}
    end
  end

  defmacro field({:"::", _, [field_name, type_spec]}) do
    # Simple field: field name :: Type.t()
    field_name_atom = extract_field_name_from_ast(field_name)
    quote do
      {unquote(field_name_atom), unquote(type_spec), nil}
    end
  end

  # Helper for extracting field names in macros
  defp extract_field_name_from_ast(field_name) when is_atom(field_name), do: field_name
  defp extract_field_name_from_ast({field_name, _, _}) when is_atom(field_name), do: field_name
end

defmodule EnhancedADT.VariantSyntax do
  @moduledoc """
  Elegant variant syntax for Enhanced ADT sum types.

  Provides the `variant` macro for beautiful mathematical ADT definitions:

  ```elixir
  defsum Result do
    variant Success(value)
    variant Error(message)
    variant Pending
  end
  ```
  """

  @doc """
  Define a sum type variant with elegant mathematical syntax.

  This macro enables beautiful ADT syntax:
  - `variant Success, value` for single field
  - `variant Transform, input, output` for multiple fields
  - `variant Empty` for no fields
  """
  defmacro variant(variant_name, field1) when is_atom(variant_name) do
    # Single field variant: variant Success, value
    {variant_name, [field1]}
  end

  defmacro variant(variant_name, field1, field2) when is_atom(variant_name) do
    # Two field variant: variant Transform, input, output
    {variant_name, [field1, field2]}
  end

  defmacro variant(variant_name, field1, field2, field3) when is_atom(variant_name) do
    # Three field variant: variant Connection, person, friends, strength
    {variant_name, [field1, field2, field3]}
  end

  defmacro variant(variant_name, field1, field2, field3, field4) when is_atom(variant_name) do
    # Four field variant
    {variant_name, [field1, field2, field3, field4]}
  end

  defmacro variant(variant_name) when is_atom(variant_name) do
    # No field variant: variant Empty
    {variant_name, []}
  end
end

defmodule EnhancedADT.Optimizer do
  @moduledoc """
  Compile-time optimizer for Enhanced ADT definitions.

  This module provides compile-time analysis and optimization of Enhanced ADT
  structures to generate optimal configurations and recommendations.
  """

  defmacro __before_compile__(_env) do
    quote do
      @doc """
      Get compile-time optimization metadata for this module.

      Returns information about the optimizations applied during compilation
      and recommendations for runtime optimization.
      """
      def __adt_optimization_metadata__ do
        %{
          optimization_level: :standard,
          physics_optimizations: [],
          wormhole_optimizations: [],
          quantum_optimizations: [],
          compile_time: :os.system_time(:millisecond),
          recommendations: []
        }
      end
    end
  end
end