defmodule Automata.CollectiveIntelligence.KnowledgeSynthesis.MultilevelKnowledgeStore do
  @moduledoc """
  Implements a multi-level knowledge store for managing hierarchical knowledge.
  
  This module provides a storage system for managing knowledge at multiple levels
  of abstraction, from raw data to high-level concepts, with efficient querying,
  traversal, and maintenance operations.
  """
  
  use GenServer
  
  alias Automata.CollectiveIntelligence.KnowledgeSynthesis.KnowledgeRepresentation
  alias Automata.CollectiveIntelligence.KnowledgeSynthesis.KnowledgeSynthesis
  
  alias KnowledgeRepresentation.KnowledgeAtom
  alias KnowledgeRepresentation.KnowledgeTriple
  alias KnowledgeRepresentation.KnowledgeFrame
  alias KnowledgeRepresentation.KnowledgeGraph
  alias KnowledgeRepresentation.HierarchicalConcept
  
  alias KnowledgeSynthesis.ConflictResolution
  alias KnowledgeSynthesis.AbstractionSynthesis
  alias KnowledgeSynthesis.IntegrationSynthesis
  alias KnowledgeSynthesis.ConsistencyVerification
  
  # Client API
  
  @doc """
  Starts the multilevel knowledge store.
  """
  def start_link(opts \\ []) do
    name = Keyword.get(opts, :name, __MODULE__)
    GenServer.start_link(__MODULE__, opts, name: name)
  end
  
  @doc """
  Adds a knowledge atom to the store.
  """
  def add_atom(store \\ __MODULE__, atom) do
    GenServer.call(store, {:add_atom, atom})
  end
  
  @doc """
  Adds a knowledge triple to the store.
  """
  def add_triple(store \\ __MODULE__, triple) do
    GenServer.call(store, {:add_triple, triple})
  end
  
  @doc """
  Adds a knowledge frame to the store.
  """
  def add_frame(store \\ __MODULE__, frame) do
    GenServer.call(store, {:add_frame, frame})
  end
  
  @doc """
  Adds a knowledge graph to the store.
  """
  def add_graph(store \\ __MODULE__, graph) do
    GenServer.call(store, {:add_graph, graph})
  end
  
  @doc """
  Adds a hierarchical concept to the store.
  """
  def add_concept(store \\ __MODULE__, concept) do
    GenServer.call(store, {:add_concept, concept})
  end
  
  @doc """
  Retrieves a knowledge atom by ID.
  """
  def get_atom(store \\ __MODULE__, atom_id) do
    GenServer.call(store, {:get_atom, atom_id})
  end
  
  @doc """
  Retrieves a knowledge triple by ID.
  """
  def get_triple(store \\ __MODULE__, triple_id) do
    GenServer.call(store, {:get_triple, triple_id})
  end
  
  @doc """
  Retrieves a knowledge frame by ID.
  """
  def get_frame(store \\ __MODULE__, frame_id) do
    GenServer.call(store, {:get_frame, frame_id})
  end
  
  @doc """
  Retrieves a knowledge graph by ID.
  """
  def get_graph(store \\ __MODULE__, graph_id) do
    GenServer.call(store, {:get_graph, graph_id})
  end
  
  @doc """
  Retrieves a hierarchical concept by ID.
  """
  def get_concept(store \\ __MODULE__, concept_id) do
    GenServer.call(store, {:get_concept, concept_id})
  end
  
  @doc """
  Queries the store for knowledge atoms matching criteria.
  """
  def query_atoms(store \\ __MODULE__, criteria) do
    GenServer.call(store, {:query_atoms, criteria})
  end
  
  @doc """
  Queries the store for knowledge triples matching criteria.
  """
  def query_triples(store \\ __MODULE__, criteria) do
    GenServer.call(store, {:query_triples, criteria})
  end
  
  @doc """
  Performs a graph pattern match query.
  """
  def graph_pattern_match(store \\ __MODULE__, pattern) do
    GenServer.call(store, {:graph_pattern_match, pattern})
  end
  
  @doc """
  Traverses concept hierarchy from a starting concept.
  """
  def traverse_concept_hierarchy(store \\ __MODULE__, starting_concept_id, direction \\ :down, max_depth \\ 3) do
    GenServer.call(store, {:traverse_concept_hierarchy, starting_concept_id, direction, max_depth})
  end
  
  @doc """
  Synthesizes higher-level knowledge based on current store content.
  """
  def synthesize(store \\ __MODULE__, level \\ :all, options \\ []) do
    GenServer.call(store, {:synthesize, level, options})
  end
  
  @doc """
  Verifies the consistency of the knowledge store.
  """
  def verify_consistency(store \\ __MODULE__, level \\ :all) do
    GenServer.call(store, {:verify_consistency, level})
  end
  
  # Server callbacks
  
  @impl true
  def init(opts) do
    # Initialize empty stores for different knowledge types
    atoms = %{}
    triples = %{}
    frames = %{}
    graphs = %{}
    concepts = %{}
    
    # Index structures for efficient querying
    atom_content_index = %{}
    triple_subject_index = %{}
    triple_predicate_index = %{}
    triple_object_index = %{}
    frame_slot_index = %{}
    concept_name_index = %{}
    
    # Initialize with options
    auto_synthesis = Keyword.get(opts, :auto_synthesis, false)
    auto_consistency = Keyword.get(opts, :auto_consistency, true)
    synthesis_threshold = Keyword.get(opts, :synthesis_threshold, 10)
    
    state = %{
      atoms: atoms,
      triples: triples,
      frames: frames,
      graphs: graphs,
      concepts: concepts,
      atom_content_index: atom_content_index,
      triple_subject_index: triple_subject_index,
      triple_predicate_index: triple_predicate_index,
      triple_object_index: triple_object_index,
      frame_slot_index: frame_slot_index,
      concept_name_index: concept_name_index,
      auto_synthesis: auto_synthesis,
      auto_consistency: auto_consistency,
      synthesis_threshold: synthesis_threshold,
      last_synthesis: nil,
      pending_synthesis: MapSet.new([:atom, :triple, :frame, :graph, :concept]),
      change_count: 0
    }
    
    {:ok, state}
  end
  
  @impl true
  def handle_call({:add_atom, atom}, _from, state) do
    # Add to atoms store
    updated_atoms = Map.put(state.atoms, atom.id, atom)
    
    # Update content index
    updated_content_index = update_atom_content_index(state.atom_content_index, atom)
    
    # Check if auto consistency verification is enabled
    consistency_result = if state.auto_consistency do
      case ConsistencyVerification.verify_atom_consistency([atom]) do
        {:ok, _} -> :consistent
        {:inconsistent, issues} -> {:inconsistent, issues}
      end
    else
      :not_checked
    end
    
    # Update state
    updated_state = %{state | 
      atoms: updated_atoms,
      atom_content_index: updated_content_index,
      change_count: state.change_count + 1,
      pending_synthesis: MapSet.put(state.pending_synthesis, :atom)
    }
    
    # Check if should auto-synthesize
    final_state = if state.auto_synthesis && state.change_count >= state.synthesis_threshold do
      {synth_result, new_state} = do_synthesize(updated_state, :all, [])
      %{new_state | change_count: 0}
    else
      updated_state
    end
    
    {:reply, {:ok, atom.id, consistency_result}, final_state}
  end
  
  @impl true
  def handle_call({:add_triple, triple}, _from, state) do
    # Add to triples store
    updated_triples = Map.put(state.triples, triple.id, triple)
    
    # Update indices
    updated_subject_index = update_triple_subject_index(state.triple_subject_index, triple)
    updated_predicate_index = update_triple_predicate_index(state.triple_predicate_index, triple)
    updated_object_index = update_triple_object_index(state.triple_object_index, triple)
    
    # Check if auto consistency verification is enabled
    consistency_result = if state.auto_consistency do
      case ConsistencyVerification.verify_triple_consistency([triple]) do
        {:ok, _} -> :consistent
        {:inconsistent, issues} -> {:inconsistent, issues}
      end
    else
      :not_checked
    end
    
    # Update state
    updated_state = %{state | 
      triples: updated_triples,
      triple_subject_index: updated_subject_index,
      triple_predicate_index: updated_predicate_index,
      triple_object_index: updated_object_index,
      change_count: state.change_count + 1,
      pending_synthesis: MapSet.put(state.pending_synthesis, :triple)
    }
    
    # Check if should auto-synthesize
    final_state = if state.auto_synthesis && state.change_count >= state.synthesis_threshold do
      {synth_result, new_state} = do_synthesize(updated_state, :all, [])
      %{new_state | change_count: 0}
    else
      updated_state
    end
    
    {:reply, {:ok, triple.id, consistency_result}, final_state}
  end
  
  @impl true
  def handle_call({:add_frame, frame}, _from, state) do
    # Add to frames store
    updated_frames = Map.put(state.frames, frame.id, frame)
    
    # Update slot index
    updated_slot_index = update_frame_slot_index(state.frame_slot_index, frame)
    
    # Update state
    updated_state = %{state | 
      frames: updated_frames,
      frame_slot_index: updated_slot_index,
      change_count: state.change_count + 1,
      pending_synthesis: MapSet.put(state.pending_synthesis, :frame)
    }
    
    # Check if should auto-synthesize
    final_state = if state.auto_synthesis && state.change_count >= state.synthesis_threshold do
      {synth_result, new_state} = do_synthesize(updated_state, :all, [])
      %{new_state | change_count: 0}
    else
      updated_state
    end
    
    {:reply, {:ok, frame.id}, final_state}
  end
  
  @impl true
  def handle_call({:add_graph, graph}, _from, state) do
    # Add to graphs store
    updated_graphs = Map.put(state.graphs, graph.id, graph)
    
    # Check if auto consistency verification is enabled
    consistency_result = if state.auto_consistency do
      case ConsistencyVerification.verify_graph_consistency(graph) do
        {:ok, _} -> :consistent
        {:inconsistent, issues} -> {:inconsistent, issues}
      end
    else
      :not_checked
    end
    
    # Update state
    updated_state = %{state | 
      graphs: updated_graphs,
      change_count: state.change_count + 1,
      pending_synthesis: MapSet.put(state.pending_synthesis, :graph)
    }
    
    # Check if should auto-synthesize
    final_state = if state.auto_synthesis && state.change_count >= state.synthesis_threshold do
      {synth_result, new_state} = do_synthesize(updated_state, :all, [])
      %{new_state | change_count: 0}
    else
      updated_state
    end
    
    {:reply, {:ok, graph.id, consistency_result}, final_state}
  end
  
  @impl true
  def handle_call({:add_concept, concept}, _from, state) do
    # Add to concepts store
    updated_concepts = Map.put(state.concepts, concept.id, concept)
    
    # Update name index
    updated_name_index = update_concept_name_index(state.concept_name_index, concept)
    
    # Update state
    updated_state = %{state | 
      concepts: updated_concepts,
      concept_name_index: updated_name_index,
      change_count: state.change_count + 1,
      pending_synthesis: MapSet.put(state.pending_synthesis, :concept)
    }
    
    # Check if should auto-synthesize
    final_state = if state.auto_synthesis && state.change_count >= state.synthesis_threshold do
      {synth_result, new_state} = do_synthesize(updated_state, :all, [])
      %{new_state | change_count: 0}
    else
      updated_state
    end
    
    {:reply, {:ok, concept.id}, final_state}
  end
  
  @impl true
  def handle_call({:get_atom, atom_id}, _from, state) do
    case Map.fetch(state.atoms, atom_id) do
      {:ok, atom} -> {:reply, {:ok, atom}, state}
      :error -> {:reply, {:error, :not_found}, state}
    end
  end
  
  @impl true
  def handle_call({:get_triple, triple_id}, _from, state) do
    case Map.fetch(state.triples, triple_id) do
      {:ok, triple} -> {:reply, {:ok, triple}, state}
      :error -> {:reply, {:error, :not_found}, state}
    end
  end
  
  @impl true
  def handle_call({:get_frame, frame_id}, _from, state) do
    case Map.fetch(state.frames, frame_id) do
      {:ok, frame} -> {:reply, {:ok, frame}, state}
      :error -> {:reply, {:error, :not_found}, state}
    end
  end
  
  @impl true
  def handle_call({:get_graph, graph_id}, _from, state) do
    case Map.fetch(state.graphs, graph_id) do
      {:ok, graph} -> {:reply, {:ok, graph}, state}
      :error -> {:reply, {:error, :not_found}, state}
    end
  end
  
  @impl true
  def handle_call({:get_concept, concept_id}, _from, state) do
    case Map.fetch(state.concepts, concept_id) do
      {:ok, concept} -> {:reply, {:ok, concept}, state}
      :error -> {:reply, {:error, :not_found}, state}
    end
  end
  
  @impl true
  def handle_call({:query_atoms, criteria}, _from, state) do
    # Perform query on atoms
    results = query_atoms_store(state, criteria)
    {:reply, {:ok, results}, state}
  end
  
  @impl true
  def handle_call({:query_triples, criteria}, _from, state) do
    # Perform query on triples
    results = query_triples_store(state, criteria)
    {:reply, {:ok, results}, state}
  end
  
  @impl true
  def handle_call({:graph_pattern_match, pattern}, _from, state) do
    # Perform pattern matching on graphs
    results = match_graph_pattern(state, pattern)
    {:reply, {:ok, results}, state}
  end
  
  @impl true
  def handle_call({:traverse_concept_hierarchy, concept_id, direction, max_depth}, _from, state) do
    # Traverse concept hierarchy
    case traverse_hierarchy(state, concept_id, direction, max_depth) do
      {:ok, hierarchy} -> {:reply, {:ok, hierarchy}, state}
      {:error, reason} -> {:reply, {:error, reason}, state}
    end
  end
  
  @impl true
  def handle_call({:synthesize, level, options}, _from, state) do
    # Perform knowledge synthesis
    {result, new_state} = do_synthesize(state, level, options)
    {:reply, result, new_state}
  end
  
  @impl true
  def handle_call({:verify_consistency, level}, _from, state) do
    # Verify knowledge consistency
    result = do_verify_consistency(state, level)
    {:reply, result, state}
  end
  
  # Private functions for index management
  
  defp update_atom_content_index(index, atom) do
    # Convert content to string for indexing
    content_key = get_content_key(atom.content)
    
    # Update index
    Map.update(index, content_key, [atom.id], fn ids -> [atom.id | ids] end)
  end
  
  defp update_triple_subject_index(index, triple) do
    # Convert subject to string for indexing
    subject_key = get_content_key(triple.subject)
    
    # Update index
    Map.update(index, subject_key, [triple.id], fn ids -> [triple.id | ids] end)
  end
  
  defp update_triple_predicate_index(index, triple) do
    # Convert predicate to string for indexing
    predicate_key = get_content_key(triple.predicate)
    
    # Update index
    Map.update(index, predicate_key, [triple.id], fn ids -> [triple.id | ids] end)
  end
  
  defp update_triple_object_index(index, triple) do
    # Convert object to string for indexing
    object_key = get_content_key(triple.object)
    
    # Update index
    Map.update(index, object_key, [triple.id], fn ids -> [triple.id | ids] end)
  end
  
  defp update_frame_slot_index(index, frame) do
    # Update index for each slot in the frame
    Enum.reduce(Map.keys(frame.slots), index, fn slot_name, acc ->
      slot_key = get_content_key(slot_name)
      
      # Update index for this slot
      Map.update(acc, slot_key, [frame.id], fn ids -> [frame.id | ids] end)
    end)
  end
  
  defp update_concept_name_index(index, concept) do
    # Create normalized name for indexing
    name_key = normalize_name(concept.name)
    
    # Update index
    Map.update(index, name_key, [concept.id], fn ids -> [concept.id | ids] end)
  end
  
  defp get_content_key(content) do
    cond do
      is_binary(content) -> content
      is_atom(content) -> Atom.to_string(content)
      is_number(content) -> to_string(content)
      true -> inspect(content)
    end
  end
  
  defp normalize_name(name) do
    name
    |> String.downcase()
    |> String.replace(~r/[^a-z0-9]/, "")
  end
  
  # Private functions for querying
  
  defp query_atoms_store(state, criteria) do
    # Filter atoms based on criteria
    Enum.filter(state.atoms, fn {_id, atom} ->
      matches_atom_criteria?(atom, criteria)
    end)
    |> Enum.map(fn {_id, atom} -> atom end)
  end
  
  defp matches_atom_criteria?(atom, criteria) do
    Enum.all?(criteria, fn {key, value} ->
      case key do
        :content ->
          atom.content == value
          
        :content_regex when is_binary(atom.content) ->
          Regex.match?(value, atom.content)
          
        :confidence_min ->
          atom.confidence >= value
          
        :confidence_max ->
          atom.confidence <= value
          
        :source ->
          atom.source == value
          
        :timestamp_after ->
          DateTime.compare(atom.timestamp, value) == :gt
          
        :timestamp_before ->
          DateTime.compare(atom.timestamp, value) == :lt
          
        :metadata_contains ->
          Enum.all?(value, fn {meta_key, meta_value} ->
            Map.get(atom.metadata, meta_key) == meta_value
          end)
          
        _ ->
          # Unknown criterion, assume match
          true
      end
    end)
  end
  
  defp query_triples_store(state, criteria) do
    # Use indices for efficient querying when possible
    potential_ids = if Keyword.has_key?(criteria, :subject) do
      # Use subject index
      subject_key = get_content_key(criteria[:subject])
      Map.get(state.triple_subject_index, subject_key, [])
    else
      if Keyword.has_key?(criteria, :predicate) do
        # Use predicate index
        predicate_key = get_content_key(criteria[:predicate])
        Map.get(state.triple_predicate_index, predicate_key, [])
      else
        if Keyword.has_key?(criteria, :object) do
          # Use object index
          object_key = get_content_key(criteria[:object])
          Map.get(state.triple_object_index, object_key, [])
        else
          # No efficient index, check all triples
          Map.keys(state.triples)
        end
      end
    end
    
    # Filter triples based on criteria
    Enum.filter(potential_ids, fn id ->
      triple = Map.get(state.triples, id)
      matches_triple_criteria?(triple, criteria)
    end)
    |> Enum.map(fn id -> Map.get(state.triples, id) end)
  end
  
  defp matches_triple_criteria?(triple, criteria) do
    Enum.all?(criteria, fn {key, value} ->
      case key do
        :subject ->
          triple.subject == value
          
        :predicate ->
          triple.predicate == value
          
        :object ->
          triple.object == value
          
        :confidence_min ->
          triple.confidence >= value
          
        :confidence_max ->
          triple.confidence <= value
          
        :source ->
          triple.source == value
          
        :timestamp_after ->
          DateTime.compare(triple.timestamp, value) == :gt
          
        :timestamp_before ->
          DateTime.compare(triple.timestamp, value) == :lt
          
        _ ->
          # Unknown criterion, assume match
          true
      end
    end)
  end
  
  defp match_graph_pattern(state, pattern) do
    # This is a simplified implementation that only works with basic patterns
    # A full implementation would use subgraph isomorphism algorithms
    
    # Extract pattern structure
    pattern_triples = pattern[:triples] || []
    pattern_constraints = pattern[:constraints] || []
    
    # Get candidate triples for the first pattern triple
    if Enum.empty?(pattern_triples) do
      []
    else
      first_pattern = hd(pattern_triples)
      
      # Get candidate triples for first pattern
      candidates = query_triples_store(state, [
        subject: first_pattern[:subject],
        predicate: first_pattern[:predicate],
        object: first_pattern[:object]
      ])
      
      # Find all matches for the full pattern
      matching_bindings = find_pattern_matches(state, candidates, tl(pattern_triples), %{})
      
      # Apply constraints
      Enum.filter(matching_bindings, fn binding ->
        satisfies_constraints?(binding, pattern_constraints)
      end)
    end
  end
  
  defp find_pattern_matches(_state, _candidates, [], bindings) do
    # Base case: no more patterns to match
    [bindings]
  end
  
  defp find_pattern_matches(_state, [], _remaining_patterns, _bindings) do
    # No candidates for current pattern
    []
  end
  
  defp find_pattern_matches(state, candidates, remaining_patterns, bindings) do
    # For each candidate, try to match the rest of the pattern
    Enum.flat_map(candidates, fn triple ->
      # Update bindings with this candidate
      updated_bindings = update_bindings(bindings, hd(remaining_patterns), triple)
      
      # Find candidates for next pattern
      next_pattern = hd(remaining_patterns)
      next_candidates = query_triples_store(state, [
        subject: apply_binding(next_pattern[:subject], updated_bindings),
        predicate: apply_binding(next_pattern[:predicate], updated_bindings),
        object: apply_binding(next_pattern[:object], updated_bindings)
      ])
      
      # Continue matching with next pattern
      find_pattern_matches(state, next_candidates, tl(remaining_patterns), updated_bindings)
    end)
  end
  
  defp update_bindings(bindings, pattern, triple) do
    # Update variable bindings based on triple match
    updated = bindings
    
    updated = if is_variable(pattern[:subject]) do
      Map.put(updated, pattern[:subject], triple.subject)
    else
      updated
    end
    
    updated = if is_variable(pattern[:predicate]) do
      Map.put(updated, pattern[:predicate], triple.predicate)
    else
      updated
    end
    
    updated = if is_variable(pattern[:object]) do
      Map.put(updated, pattern[:object], triple.object)
    else
      updated
    end
    
    updated
  end
  
  defp is_variable(term) do
    is_binary(term) && String.starts_with?(term, "?")
  end
  
  defp apply_binding(term, bindings) do
    if is_variable(term) && Map.has_key?(bindings, term) do
      Map.get(bindings, term)
    else
      term
    end
  end
  
  defp satisfies_constraints?(bindings, constraints) do
    # Check if bindings satisfy all constraints
    Enum.all?(constraints, fn constraint ->
      case constraint do
        {:equals, var1, var2} ->
          Map.get(bindings, var1) == Map.get(bindings, var2)
          
        {:not_equals, var1, var2} ->
          Map.get(bindings, var1) != Map.get(bindings, var2)
          
        _ ->
          # Unknown constraint, assume satisfied
          true
      end
    end)
  end
  
  defp traverse_hierarchy(state, concept_id, direction, max_depth) do
    # Check if concept exists
    case Map.fetch(state.concepts, concept_id) do
      {:ok, concept} ->
        # Start hierarchy with root concept
        hierarchy = %{
          concept: concept,
          depth: 0,
          children: []
        }
        
        # Traverse based on direction
        case direction do
          :down ->
            # Traverse down to children
            {:ok, traverse_down(state, hierarchy, max_depth)}
            
          :up ->
            # Traverse up to parents
            {:ok, traverse_up(state, hierarchy, max_depth)}
            
          :both ->
            # Traverse both directions
            down_hierarchy = traverse_down(state, hierarchy, max_depth)
            up_hierarchy = traverse_up(state, hierarchy, max_depth)
            
            # Combine results
            {:ok, %{
              concept: concept,
              depth: 0,
              children: down_hierarchy.children,
              parents: up_hierarchy.parents
            }}
        end
        
      :error ->
        {:error, :concept_not_found}
    end
  end
  
  defp traverse_down(state, hierarchy, max_depth) do
    concept = hierarchy.concept
    depth = hierarchy.depth
    
    if depth >= max_depth do
      # Reached maximum depth
      hierarchy
    else
      # Find all children
      child_ids = concept.children_ids
      
      # Get child concepts
      children = Enum.map(child_ids, fn child_id ->
        child_concept = Map.get(state.concepts, child_id)
        
        if child_concept do
          # Recursively traverse child's children
          child_hierarchy = %{
            concept: child_concept,
            depth: depth + 1,
            children: []
          }
          
          traverse_down(state, child_hierarchy, max_depth)
        else
          nil
        end
      end)
      |> Enum.reject(&is_nil/1)
      
      # Update hierarchy with children
      %{hierarchy | children: children}
    end
  end
  
  defp traverse_up(state, hierarchy, max_depth) do
    concept = hierarchy.concept
    depth = hierarchy.depth
    
    if depth >= max_depth do
      # Reached maximum depth
      hierarchy
    else
      # Get parent concept
      parent_id = concept.parent_id
      
      if parent_id do
        parent_concept = Map.get(state.concepts, parent_id)
        
        if parent_concept do
          # Recursively traverse parent's parent
          parent_hierarchy = %{
            concept: parent_concept,
            depth: depth + 1,
            parents: []
          }
          
          parent_result = traverse_up(state, parent_hierarchy, max_depth)
          
          # Update hierarchy with parent
          Map.put(hierarchy, :parents, [parent_result])
        else
          hierarchy
        end
      else
        hierarchy
      end
    end
  end
  
  # Knowledge synthesis implementation
  
  defp do_synthesize(state, level, options) do
    # Determine which levels to synthesize
    levels_to_synthesize = case level do
      :all -> [:atom, :triple, :frame, :graph, :concept]
      levels when is_list(levels) -> levels
      level when level in [:atom, :triple, :frame, :graph, :concept] -> [level]
      _ -> []
    end
    
    # Intersect with pending synthesis
    effective_levels = levels_to_synthesize
    |> Enum.filter(fn level -> MapSet.member?(state.pending_synthesis, level) end)
    
    # Apply synthesis for each level
    {synthesis_results, new_state} = Enum.reduce(effective_levels, {%{}, state}, fn level, {results, current_state} ->
      {level_result, updated_state} = synthesize_level(current_state, level, options)
      {Map.put(results, level, level_result), updated_state}
    end)
    
    # Clear pending synthesis for processed levels
    cleared_pending = Enum.reduce(effective_levels, state.pending_synthesis, fn level, acc ->
      MapSet.delete(acc, level)
    end)
    
    # Return results and update state
    final_state = %{new_state | 
      pending_synthesis: cleared_pending,
      last_synthesis: DateTime.utc_now()
    }
    
    {{:ok, synthesis_results}, final_state}
  end
  
  defp synthesize_level(state, :atom, options) do
    # Synthesize atom level - resolve conflicts and integrate atoms
    atoms = Map.values(state.atoms)
    
    if length(atoms) > 1 do
      # Integrate atoms
      case IntegrationSynthesis.integrate_atoms(atoms) do
        {:ok, integrated_atoms} ->
          # Update state with integrated atoms
          new_state = add_integrated_atoms(state, integrated_atoms)
          {{:integrated, length(integrated_atoms)}, new_state}
          
        {:error, reason} ->
          {{:error, reason}, state}
      end
    else
      # Not enough atoms for synthesis
      {{:no_change, :insufficient_atoms}, state}
    end
  end
  
  defp synthesize_level(state, :triple, options) do
    # Synthesize triple level - resolve conflicts and integrate triples
    triples = Map.values(state.triples)
    
    if length(triples) > 1 do
      # Integrate triples
      case IntegrationSynthesis.integrate_triples(triples) do
        {:ok, integrated_triples} when is_list(integrated_triples) ->
          # Update state with integrated triples
          new_state = add_integrated_triples(state, integrated_triples)
          {{:integrated, length(integrated_triples)}, new_state}
          
        {:ok, graph} when is_map(graph) ->
          # Generated a knowledge graph, add it
          new_state = %{state | 
            graphs: Map.put(state.graphs, graph.id, graph)
          }
          
          {{:synthesized_graph, graph.id}, new_state}
          
        {:error, reason} ->
          {{:error, reason}, state}
      end
    else
      # Not enough triples for synthesis
      {{:no_change, :insufficient_triples}, state}
    end
  end
  
  defp synthesize_level(state, :frame, options) do
    # Synthesize frame level - integrate frames and create templates
    frames = Map.values(state.frames)
    
    if length(frames) > 1 do
      # Attempt to create frame template
      case AbstractionSynthesis.frame_template_from_instances(
        frames,
        "Template_" <> DateTime.to_string(DateTime.utc_now())
      ) do
        {:ok, template} ->
          # Add template to frames
          new_state = %{state | 
            frames: Map.put(state.frames, template.id, template)
          }
          
          {{:created_template, template.id}, new_state}
          
        _ ->
          # Try integration instead
          case IntegrationSynthesis.integrate_frames(frames) do
            {:ok, integrated_frame} ->
              # Add integrated frame
              new_state = %{state | 
                frames: Map.put(state.frames, integrated_frame.id, integrated_frame)
              }
              
              {{:integrated, integrated_frame.id}, new_state}
              
            {:error, reason} ->
              {{:error, reason}, state}
          end
      end
    else
      # Not enough frames for synthesis
      {{:no_change, :insufficient_frames}, state}
    end
  end
  
  defp synthesize_level(state, :graph, options) do
    # Synthesize graph level - find patterns in graphs
    graphs = Map.values(state.graphs)
    
    if length(graphs) > 1 do
      # Attempt to extract graph patterns
      case AbstractionSynthesis.graph_pattern_from_instances(
        graphs,
        "Pattern_" <> DateTime.to_string(DateTime.utc_now())
      ) do
        {:ok, pattern_graph} ->
          # Add pattern to graphs
          new_state = %{state | 
            graphs: Map.put(state.graphs, pattern_graph.id, pattern_graph)
          }
          
          {{:discovered_pattern, pattern_graph.id}, new_state}
          
        _ ->
          # Try integration instead
          case IntegrationSynthesis.integrate_graphs(graphs) do
            {:ok, integrated_graph} ->
              # Add integrated graph
              new_state = %{state | 
                graphs: Map.put(state.graphs, integrated_graph.id, integrated_graph)
              }
              
              {{:integrated, integrated_graph.id}, new_state}
              
            {:error, reason} ->
              {{:error, reason}, state}
          end
      end
    else
      # Not enough graphs for synthesis
      {{:no_change, :insufficient_graphs}, state}
    end
  end
  
  defp synthesize_level(state, :concept, options) do
    # Synthesize concept level - create abstractions and hierarchies
    concepts = Map.values(state.concepts)
    
    if length(concepts) > 1 do
      # Group concepts by similarity to find candidates for abstraction
      similar_concepts = find_similar_concepts(concepts, 0.7)
      
      if Enum.empty?(similar_concepts) do
        # No similar concepts found
        {{:no_change, :no_similar_concepts}, state}
      else
        # Take first group of similar concepts
        group = hd(similar_concepts)
        
        # Create abstract concept
        abstract_name = "Abstract_" <> hd(group).name
        abstract_description = "Abstract concept derived from #{length(group)} similar concepts"
        
        case AbstractionSynthesis.abstract_concept_from_instances(
          group,
          abstract_name,
          abstract_description
        ) do
          {:ok, abstract_concept, updated_instances} ->
            # Update state with new abstract concept and updated instances
            new_concepts = Enum.reduce(updated_instances, state.concepts, fn instance, acc ->
              Map.put(acc, instance.id, instance)
            end)
            |> Map.put(abstract_concept.id, abstract_concept)
            
            new_state = %{state | concepts: new_concepts}
            
            {{:created_abstraction, abstract_concept.id}, new_state}
            
          {:error, reason} ->
            {{:error, reason}, state}
        end
      end
    else
      # Not enough concepts for synthesis
      {{:no_change, :insufficient_concepts}, state}
    end
  end
  
  defp add_integrated_atoms(state, integrated_atoms) do
    # Add integrated atoms to state
    new_atoms = Enum.reduce(integrated_atoms, state.atoms, fn atom, acc ->
      Map.put(acc, atom.id, atom)
    end)
    
    # Update content index
    new_content_index = Enum.reduce(integrated_atoms, state.atom_content_index, fn atom, acc ->
      update_atom_content_index(acc, atom)
    end)
    
    # Update state
    %{state | 
      atoms: new_atoms,
      atom_content_index: new_content_index
    }
  end
  
  defp add_integrated_triples(state, integrated_triples) do
    # Add integrated triples to state
    new_triples = Enum.reduce(integrated_triples, state.triples, fn triple, acc ->
      Map.put(acc, triple.id, triple)
    end)
    
    # Update indices
    {new_subject_index, new_predicate_index, new_object_index} = 
      Enum.reduce(integrated_triples, {state.triple_subject_index, state.triple_predicate_index, state.triple_object_index}, 
        fn triple, {subj_idx, pred_idx, obj_idx} ->
          new_subj = update_triple_subject_index(subj_idx, triple)
          new_pred = update_triple_predicate_index(pred_idx, triple)
          new_obj = update_triple_object_index(obj_idx, triple)
          
          {new_subj, new_pred, new_obj}
        end)
    
    # Update state
    %{state | 
      triples: new_triples,
      triple_subject_index: new_subject_index,
      triple_predicate_index: new_predicate_index,
      triple_object_index: new_object_index
    }
  end
  
  defp find_similar_concepts(concepts, threshold) do
    # Group concepts by similarity
    initial_groups = Enum.map(concepts, fn concept -> [concept] end)
    
    # Merge similar groups
    merge_similar_concept_groups(initial_groups, threshold)
  end
  
  defp merge_similar_concept_groups(groups, threshold) do
    # Try to merge any pair of groups
    {new_groups, merged} = merge_similar_groups(groups, &concept_similarity/2, threshold)
    
    # If no merges made, we're done
    if merged do
      # Continue merging
      merge_similar_concept_groups(new_groups, threshold)
    else
      # Stable grouping achieved
      new_groups
    end
  end
  
  defp merge_similar_groups(groups, similarity_fn, threshold) do
    # Check all pairs of groups
    group_pairs = for i <- 0..(length(groups) - 1),
                      j <- (i + 1)..(length(groups) - 1),
                      do: {Enum.at(groups, i), Enum.at(groups, j)}
    
    # Try to find a pair to merge
    case Enum.find(group_pairs, fn {group1, group2} ->
      # Calculate average similarity between all pairs of items
      pairs = for item1 <- group1, item2 <- group2, do: {item1, item2}
      
      if Enum.empty?(pairs) do
        false
      else
        total_similarity = Enum.reduce(pairs, 0, fn {item1, item2}, acc ->
          acc + similarity_fn.(item1, item2)
        end)
        
        avg_similarity = total_similarity / length(pairs)
        avg_similarity >= threshold
      end
    end) do
      nil ->
        # No pair found, grouping is stable
        {groups, false}
        
      {group1, group2} ->
        # Merge the groups
        merged_group = group1 ++ group2
        remaining_groups = groups -- [group1, group2]
        
        {[merged_group | remaining_groups], true}
    end
  end
  
  defp concept_similarity(concept1, concept2) do
    # Calculate similarity based on attributes, relations, and name
    
    # Name similarity
    name_sim = string_similarity(concept1.name, concept2.name)
    
    # Attribute similarity
    attr_sim = map_similarity(concept1.attributes, concept2.attributes)
    
    # Relations similarity
    rel_sim = map_similarity(concept1.relations, concept2.relations)
    
    # Weighted average
    name_sim * 0.3 + attr_sim * 0.4 + rel_sim * 0.3
  end
  
  defp string_similarity(str1, str2) do
    # Simple string similarity based on character overlap
    # In a real implementation, use a proper string distance function
    
    chars1 = String.graphemes(str1) |> MapSet.new()
    chars2 = String.graphemes(str2) |> MapSet.new()
    
    intersection = MapSet.intersection(chars1, chars2) |> MapSet.size()
    union = MapSet.union(chars1, chars2) |> MapSet.size()
    
    if union == 0, do: 1.0, else: intersection / union
  end
  
  defp map_similarity(map1, map2) do
    # Calculate similarity between two maps
    keys1 = Map.keys(map1) |> MapSet.new()
    keys2 = Map.keys(map2) |> MapSet.new()
    
    # Calculate Jaccard similarity of keys
    key_intersection = MapSet.intersection(keys1, keys2)
    key_union = MapSet.union(keys1, keys2)
    
    if MapSet.size(key_union) == 0 do
      0.0
    else
      MapSet.size(key_intersection) / MapSet.size(key_union)
    end
  end
  
  # Consistency verification implementation
  
  defp do_verify_consistency(state, level) do
    # Determine which levels to verify
    levels_to_verify = case level do
      :all -> [:atom, :triple, :graph]
      levels when is_list(levels) -> levels
      level when level in [:atom, :triple, :graph] -> [level]
      _ -> []
    end
    
    # Apply verification for each level
    results = Enum.map(levels_to_verify, fn level ->
      {level, verify_level_consistency(state, level)}
    end)
    |> Enum.into(%{})
    
    # Check overall consistency
    if Enum.any?(results, fn {_level, result} -> elem(result, 0) == :inconsistent end) do
      {:inconsistent, results}
    else
      {:ok, results}
    end
  end
  
  defp verify_level_consistency(state, :atom) do
    # Verify atom consistency
    atoms = Map.values(state.atoms)
    ConsistencyVerification.verify_atom_consistency(atoms)
  end
  
  defp verify_level_consistency(state, :triple) do
    # Verify triple consistency
    triples = Map.values(state.triples)
    ConsistencyVerification.verify_triple_consistency(triples)
  end
  
  defp verify_level_consistency(state, :graph) do
    # Verify graph consistency
    graphs = Map.values(state.graphs)
    
    # Check each graph
    results = Enum.map(graphs, fn graph ->
      {graph.id, ConsistencyVerification.verify_graph_consistency(graph)}
    end)
    |> Enum.into(%{})
    
    # Check if any graphs are inconsistent
    if Enum.any?(results, fn {_id, result} -> elem(result, 0) == :inconsistent end) do
      inconsistent_graphs = Enum.filter(results, fn {_id, result} -> elem(result, 0) == :inconsistent end)
      |> Enum.map(fn {id, {_, issues}} -> {id, issues} end)
      |> Enum.into(%{})
      
      {:inconsistent, inconsistent_graphs}
    else
      {:ok, results}
    end
  end
end