Module: MilkTea::LSP::Server::ServerCompletion

Included in:

MilkTea::LSP::Server

Defined in:

lib/milk_tea/lsp/server/completion.rb

Constant Summary

MAX_COMPLETION_ITEMS =

200

COMPLETION_KEYWORDS =

%w[
  let var const function async struct enum flags variant union
  type interface opaque if while for match return import public static
  extending external fn event attribute defer break continue pass
  unsafe consuming implements include link foreign proc
  editable in out inout as when inline await static_assert emit
].freeze

TYPE_CONSTRUCTOR_KEYWORDS =

%w[
  ptr ref span array dyn Option Result Task SoA str_buffer const_ptr simd
].freeze

Instance Method Summary

• #attribute_completions(facts, uri, line, char) ⇒ Object
• #completion_data(name) ⇒ Object
• #completion_items_for_type_receiver(facts, receiver_type, prefix) ⇒ Object
• #completion_items_for_value_receiver(facts, receiver_type, prefix) ⇒ Object
• #field_owner_type(receiver_type, facts = nil) ⇒ Object
• #field_type_from_struct_definition(type, facts) ⇒ Object
• #format_string_completions(facts, uri, line, char) ⇒ Object
• #handle_completion(params) ⇒ Object
• #handle_completion_resolve(params) ⇒ Object
• #import_completions(uri, lsp_line, lsp_char) ⇒ Object
• #label_details_for_params(params_str, module_name = nil) ⇒ Object
• #location_matches_reference?(location, ref) ⇒ Boolean
• #method_dispatch_receiver_type_for_completion(receiver_type) ⇒ Object
• #methods_for_receiver_type(facts, receiver_type) ⇒ Object
• #module_dir_contains_mt?(dir) ⇒ Boolean
• #module_member_access_info(tokens, index) ⇒ Object
• #named_argument_completions(facts, uri, line, char) ⇒ Object
• #pointer_type_name?(type) ⇒ Boolean
• #project_field_receiver_type_for_completion(type, facts = nil) ⇒ Object
• #project_method_receiver_type_for_completion(type) ⇒ Object
• #project_receiver_type_for_completion(type) ⇒ Object
• #ref_type_name?(type) ⇒ Boolean
• #resolve_nested_type_binding(facts, name) ⇒ Object
• #resolve_static_type_receiver_method(facts, receiver_name, receiver_path, method_name) ⇒ Object
• #resolve_static_type_reference_target(uri, token, facts) ⇒ Object
• #resolve_type_receiver_info(facts, receiver_name, receiver_path) ⇒ Object
• #same_location?(left, right) ⇒ Boolean
• #snippet_for_callable(label, params) ⇒ Object
• #specialization_completions(facts, _uri, line, char) ⇒ Object
• #static_method_binding_at_token(facts, token) ⇒ Object
• #static_method_binding_for_receiver(facts, receiver_type, method_name) ⇒ Object
• #static_type_method_reference?(ref, target) ⇒ Boolean
• #static_type_method_references(target, include_declaration:) ⇒ Object
• #value_chain_completions(facts, dot_recv_path, lsp_line, lsp_char, prefix) ⇒ Object

Instance Method Details

#attribute_completions(facts, uri, line, char) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 915

def attribute_completions(facts, uri, line, char)
  content = @workspace.get_content(uri)
  return nil unless content
  lines = content.split("\n", -1)
  line_text = lines[line] || ''
  return nil if line_text.empty?

  attr_match = line_text[0...char].match(/@\[(\w*)$/)
  return nil unless attr_match

  prefix = attr_match[1]
  items = []

  %w[packed align deprecated].each do |name|
    next unless prefix.empty? || name.start_with?(prefix)
    items << {
      label:      name,
      kind:       14,
      detail:     "built-in attribute #{name}",
      insertText: name,
      sortText:   "0_#{name}",
      data:       completion_data(name),
    }
  end

  if facts
    facts.attributes&.each do |name, _binding|
      next unless prefix.empty? || name.start_with?(prefix)
      items << {
        label:      name,
        kind:       14,
        detail:     "attribute #{name}",
        insertText: name,
        sortText:   "1_#{name}",
        data:       completion_data(name),
      }
    end
  end

  items.empty? ? nil : items
end

#completion_data(name) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 21

def completion_data(name)
  { uri: @current_completion_uri || '', name: }
end

#completion_items_for_type_receiver(facts, receiver_type, prefix) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 486

def completion_items_for_type_receiver(facts, receiver_type, prefix)
  methods_for_receiver_type(facts, receiver_type).filter_map do |mname, binding|
    next unless binding.ast.is_a?(AST::MethodDef) && binding.ast.kind == :static

    display_name = mname.delete_prefix("static:")
    next unless prefix.empty? || display_name.start_with?(prefix)

    params_str = format_params(binding.type.params)
    item = {
      label:      display_name,
      kind:       6,  # Method
      detail:     "#{display_name}(#{params_str}) -> #{binding.type.return_type}",
      insertText: display_name,
      sortText:   "0_#{display_name}",
      data:       completion_data(display_name),
    }
    if (ld = label_details_for_params(params_str, nil))
      item[:labelDetails] = ld
    end
    if (snippet = snippet_for_callable(display_name, binding.type.params))
      item[:insertText] = snippet
      item[:insertTextFormat] = 2
    end
    item
  end
end

#completion_items_for_value_receiver(facts, receiver_type, prefix) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 672

def completion_items_for_value_receiver(facts, receiver_type, prefix)
  items = []

  field_receiver_type = project_field_receiver_type_for_completion(receiver_type, facts)
  if field_receiver_type.respond_to?(:fields)
    field_receiver_type.fields.each do |fname, ftype|
      next unless prefix.empty? || fname.start_with?(prefix)

      items << {
        label:      fname,
        kind:       8,  # Field
        detail:     "#{fname}: #{ftype}",
        insertText: fname,
        sortText:   "0_#{fname}",
        data:       completion_data(fname),
      }
    end
  end

  method_receiver_type = project_method_receiver_type_for_completion(receiver_type)
  methods = methods_for_receiver_type(facts, method_receiver_type)
  methods.each do |mname, binding|
    next unless prefix.empty? || mname.start_with?(prefix)

    params_str = format_params(binding.type.params)
    item = {
      label:      mname,
      kind:       6,  # Method
      detail:     "#{mname}(#{params_str}) -> #{binding.type.return_type}",
      insertText: mname,
      sortText:   "1_#{mname}",
      data:       completion_data(mname),
    }
    if (ld = label_details_for_params(params_str, nil))
      item[:labelDetails] = ld
    end
    if (snippet = snippet_for_callable(mname, binding.type.params))
      item[:insertText] = snippet
      item[:insertTextFormat] = 2
    end
    items << item
  end

  items
end

#field_owner_type(receiver_type, facts = nil) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 801

def field_owner_type(receiver_type, facts = nil)
  aggregate_type = project_field_receiver_type_for_completion(receiver_type, facts)
  return aggregate_type.definition if aggregate_type.is_a?(Types::StructInstance) || aggregate_type.is_a?(Types::VariantInstance)

  aggregate_type
end

#field_type_from_struct_definition(type, facts) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 782

def field_type_from_struct_definition(type, facts)
  return type unless type.is_a?(Types::GenericInstance)
  return type if ref_type_name?(type) || pointer_type_name?(type)

  struct_def = facts.types[type.name]
  struct_def if struct_def&.respond_to?(:fields)
end

#format_string_completions(facts, uri, line, char) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 957

def format_string_completions(facts, uri, line, char)
  return nil unless facts

  content = @workspace.get_content(uri)
  return nil unless content
  lines = content.split("\n", -1)
  line_text = lines[line] || ''
  return nil if line_text.empty?

  text_before = line_text[0...char]
  open_pos = text_before.rindex('#{')
  return nil unless open_pos

  close_pos = text_before.index('}', open_pos)
  return nil if close_pos && close_pos < char

  prefix = text_before[(open_pos + 2)..] || ''
  items = []

  facts.values.each do |name, binding|
    next unless prefix.empty? || name.start_with?(prefix)
    items << {
      label:      name,
      kind:       13,
      detail:     "#{name}: #{binding.type}",
      insertText: name,
      sortText:   "0_#{name}",
      data:       completion_data(name),
    }
  end

  facts.functions.each do |name, _binding|
    next unless prefix.empty? || name.start_with?(prefix)
    items << {
      label:      name,
      kind:       12,
      detail:     "function #{name}",
      insertText: name,
      sortText:   "1_#{name}",
      data:       completion_data(name),
    }
  end

  frame = enclosing_completion_frame(facts, line + 1)
  if frame
    snapshot = latest_completion_snapshot(frame, line + 1, char + 1)
    if snapshot
      snapshot.bindings.each do |name, binding|
        next unless prefix.empty? || name.start_with?(prefix)
        next unless binding.respond_to?(:name) && binding.respond_to?(:type)
        items << {
          label:      name,
          kind:       13,
          detail:     "#{name}: #{binding.type}",
          insertText: name,
          sortText:   "2_#{name}",
          data:       completion_data(name),
        }
      end
    end
  end

  items.empty? ? nil : items
end

#handle_completion(params) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 40

def handle_completion(params)
  stages = new_perf_stages
  total_start = stages ? monotonic_time : nil
  uri      = params['textDocument']['uri']
  @current_completion_uri = uri
  lsp_line = params['position']['line']
  lsp_char = params['position']['character']
  branch = 'none'
  item_count = 0

  prefix = measure_perf_stage(stages, 'prefix') { current_word_prefix(uri, lsp_line, lsp_char) }

  import_items = measure_perf_stage(stages, 'import_context') { import_completions(uri, lsp_line, lsp_char) }
  if import_items
    branch = 'import'
    item_count = import_items.length
    return { isIncomplete: false, items: import_items }
  end

  facts = measure_perf_stage(stages, 'facts') { @workspace.get_facts(uri) }

  unless facts
    branch = 'no-facts'
    return { isIncomplete: false, items: [] }
  end

  # Attribute context: complete inside @[...]
  attr_items = attribute_completions(facts, uri, lsp_line, lsp_char)
  if attr_items
    branch = 'attribute'
    item_count = attr_items.length
    return { isIncomplete: false, items: attr_items }
  end

  # Format string interpolation: complete inside f"... #{ }
  fmt_items = format_string_completions(facts, uri, lsp_line, lsp_char)
  if fmt_items
    branch = 'format-string'
    item_count = fmt_items.length
    return { isIncomplete: false, items: fmt_items }
  end

  # Named argument completions: inside function/struct call e.g. Point(x: 1, |)
  named_items = named_argument_completions(facts, uri, lsp_line, lsp_char)
  if named_items
    branch = 'named-arg'
    item_count = named_items.length
    return { isIncomplete: false, items: named_items }
  end

  # Specialization context: inside name[...]
  spec_items = specialization_completions(facts, uri, lsp_line, lsp_char)
  if spec_items
    branch = 'specialization'
    item_count = spec_items.length
    return { isIncomplete: false, items: spec_items }
  end

  # When user is typing after '.', return module members or method completions.
  dot_recv = nil
  dot_recv_path = nil
  measure_perf_stage(stages, 'receiver_context') do
    dot_recv = @workspace.find_dot_receiver(uri, lsp_line, lsp_char)
    dot_recv_path = @workspace.find_dot_receiver_path(uri, lsp_line, lsp_char)
  end
  if dot_recv
    # Module member access: rl.init_window, rl.RAYWHITE, etc.
    if (module_binding = facts.imports[dot_recv])
      branch = 'module'
      items = measure_perf_stage(stages, 'build') do
        result = []
        module_binding.functions.each do |fname, binding|
          next unless prefix.empty? || fname.start_with?(prefix)
          params_str = format_params(binding.type.params)
          item = {
            label:      fname,
            kind:       12, # Function
            detail:     "function #{fname}(#{params_str}) -> #{binding.type.return_type}",
            insertText: fname,
            sortText:   "0_#{fname}",
            data:       completion_data(fname),
          }
          if (ld = label_details_for_params(params_str, module_binding.name))
            item[:labelDetails] = ld
          end
          if (snippet = snippet_for_callable(fname, binding.type.params))
            item[:insertText] = snippet
            item[:insertTextFormat] = 2
          end
          result << item
        end
        module_binding.values.each do |vname, binding|
          next unless prefix.empty? || vname.start_with?(prefix)
          result << {
            label:      vname,
            kind:       13, # Variable
            detail:     "#{vname}: #{binding.type}",
            insertText: vname,
            sortText:   "1_#{vname}",
            data:       completion_data(vname),
          }
        end
        module_binding.types.each do |tname, _type|
          next unless prefix.empty? || tname.start_with?(prefix)
          result << {
            label:      tname,
            kind:       5,  # Class
            detail:     "type #{tname}",
            insertText: tname,
            sortText:   "2_#{tname}",
            data:       completion_data(tname),
          }
        end
        result
      end
      item_count = items.length
      return { isIncomplete: false, items: items }
    end
    if (type_receiver = measure_perf_stage(stages, 'type_receiver') { resolve_type_receiver_info(facts, dot_recv, dot_recv_path) })
      receiver_label = type_receiver[:label]
      type = type_receiver[:type]


      # Enum/Flags member access: Color.RED, KeyboardKey.A, etc.
      if type.is_a?(Types::EnumBase)
        branch = 'enum-members'
        items = measure_perf_stage(stages, 'build') do
          type.members.filter_map do |mname|
            next if !prefix.empty? && !mname.start_with?(prefix)
            {
              label:      mname,
              kind:       22, # EnumMember
              detail:     "#{receiver_label}.#{mname}",
              insertText: mname,
              sortText:   "0_#{mname}",
              data:       completion_data(mname),
            }
          end
        end
        item_count = items.length
        return { isIncomplete: false, items: items }
      end

      # Variant arm access: Option.none, Result.success, etc.
      if type.is_a?(Types::Variant)
        branch = 'variant-arms'
        items = measure_perf_stage(stages, 'build') do
          type.arm_names.filter_map do |aname|
            next if !prefix.empty? && !aname.start_with?(prefix)
            {
              label:      aname,
              kind:       22, # EnumMember
              detail:     "#{receiver_label}.#{aname}",
              insertText: aname,
              sortText:   "0_#{aname}",
              data:       completion_data(aname),
            }
          end
        end
        item_count = items.length
        return { isIncomplete: false, items: items }
      end

      # Nested struct type members: ShapeGroup.CircleData, etc.
      if type.is_a?(Types::Struct) && type.respond_to?(:nested_types) && type.nested_types.any?
        branch = 'nested-types'
        items = measure_perf_stage(stages, 'build') do
          type.nested_types.filter_map do |nt_name, _nt_type|
            next if !prefix.empty? && !nt_name.start_with?(prefix)
            {
              label:      nt_name,
              kind:       5,  # Class/type
              detail:     "#{receiver_label}.#{nt_name}",
              insertText: nt_name,
              sortText:   "1_#{nt_name}",
              data:       completion_data(nt_name),
            }
          end
        end
        item_count = items.length
        return { isIncomplete: false, items: items } unless items.empty?
      end

      items = measure_perf_stage(stages, 'build') { completion_items_for_type_receiver(facts, type, prefix) }
      unless items.empty?
        branch = 'type-receiver'
        item_count = items.length
        return { isIncomplete: false, items: items }
      end
    end

    if dot_recv_path && dot_recv_path.include?('.')
      segments = dot_recv_path.split('.', 2)
      mod_alias = segments.first
      value_name = segments[1]
      if mod_alias && value_name && (mod_binding = facts.imports[mod_alias])
        if (val_binding = mod_binding.values[value_name])
          receiver_type = measure_perf_stage(stages, 'imported_value_receiver') { val_binding.type }
          items = measure_perf_stage(stages, 'build') { completion_items_for_value_receiver(facts, receiver_type, prefix) }
          unless items.empty?
            branch = 'imported-value-receiver'
            item_count = items.length
            return { isIncomplete: false, items: items }
          end
        end
      else
        chain_items = measure_perf_stage(stages, 'value_chain') { value_chain_completions(facts, dot_recv_path, lsp_line, lsp_char, prefix) }
        if chain_items
          branch = 'value-chain'
          item_count = chain_items.length
          return { isIncomplete: false, items: chain_items }
        end
      end
    end

    if (receiver_type = measure_perf_stage(stages, 'value_receiver') { resolve_dot_receiver_value_type(facts, dot_recv, lsp_line + 1, lsp_char + 1) })
      items = measure_perf_stage(stages, 'build') { completion_items_for_value_receiver(facts, receiver_type, prefix) }
      unless items.empty?
        branch = 'value-receiver'
        item_count = items.length
        return { isIncomplete: false, items: items }
      end
    end

    # Method completions on a non-module receiver.
    branch = 'method-fallback'
    method_items = measure_perf_stage(stages, 'build') do
      result = []
      facts.methods.each do |_recv_type, methods|
        methods.each do |mname, binding|
          next unless prefix.empty? || mname.start_with?(prefix)

          params_str = format_params(binding.type.params)
          item = {
            label:      mname,
            kind:       6,  # Method
            detail:     "#{mname}(#{params_str}) -> #{binding.type.return_type}",
            insertText: mname,
            sortText:   "0_#{mname}",
            data:       completion_data(mname),
          }
          if (ld = label_details_for_params(params_str, nil))
            item[:labelDetails] = ld
          end
          if (snippet = snippet_for_callable(mname, binding.type.params))
            item[:insertText] = snippet
            item[:insertTextFormat] = 2
          end
          result << item
        end
      end
      result
    end
    item_count = method_items.length
    truncated = item_count > MAX_COMPLETION_ITEMS
    if truncated
      method_items = method_items.first(MAX_COMPLETION_ITEMS)
      item_count = MAX_COMPLETION_ITEMS
    end
    return { isIncomplete: truncated, items: method_items }
  end

  branch = 'global'
  items = measure_perf_stage(stages, 'build') do
    result = []
    function_docs_cache = {}

    # Functions
    facts.functions.each do |name, binding|
      next unless prefix.empty? || name.start_with?(prefix)

      params_str = format_params(binding.type.params)
      entry = {
        label:        name,
        kind:         12, # Function
        detail:       "function #{name}(#{params_str}) -> #{binding.type.return_type}",
        insertText:   name,
        sortText:     "0_#{name}",
        data:         completion_data(name),
      }

      if (ld = label_details_for_params(params_str, nil))
        entry[:labelDetails] = ld
      end

      if (snippet = snippet_for_callable(name, binding.type.params))
        entry[:insertText] = snippet
        entry[:insertTextFormat] = 2
      end

      docs = completion_function_documentation(uri, name, cache: function_docs_cache)
      unless docs.empty?
        entry[:documentation] = {
          kind: 'markdown',
          value: docs,
        }
      end

      result << entry
    end

    # Types
    builtin_names = SemanticAnalyzer::INSTALLABLE_BUILTIN_TYPE_NAMES
    facts.types.each do |name, type|
      next if builtin_names.include?(name)
      next unless prefix.empty? || name.start_with?(prefix)

      kind = case type
              when Types::StructInstance then 22 # Struct
              when Types::EnumBase, Types::Variant then 13 # Enum
              else 7 # Class/type
              end

      result << {
        label:        name,
        kind:         kind,
        detail:       "type #{name}",
        insertText:   name,
        sortText:     "1_#{name}",
        data:         completion_data(name),
      }
    end

    # Imported modules
    facts.imports.each do |name, module_binding|
      next unless prefix.empty? || name.start_with?(prefix)

      result << {
        label:        name,
        kind:         2,  # Module
        detail:       "module #{module_binding.name}",
        insertText:   name,
        sortText:     "2_#{name}",
        data:         completion_data(name),
      }
    end

    # Values
    facts.values.each do |name, binding|
      next unless prefix.empty? || name.start_with?(prefix)

      result << {
        label:        name,
        kind:         13, # Variable
        detail:       "#{name}: #{binding.type}",
        insertText:   name,
        sortText:     "3_#{name}",
        data:         completion_data(name),
      }
    end

    # Locals (variables and parameters visible in current scope)
    frame = enclosing_completion_frame(facts, lsp_line + 1)
    if frame
      snapshot = latest_completion_snapshot(frame, lsp_line + 1, lsp_char + 1)
      if snapshot
        snapshot.bindings.each do |name, binding|
          next unless prefix.empty? || name.start_with?(prefix)
          next unless binding.respond_to?(:name) && binding.respond_to?(:type)

          detail_label = case binding.respond_to?(:kind) && binding.kind
                          when :param then "parameter #{name}: #{binding.type}"
                          when :local then "local #{name}: #{binding.type}"
                          else "#{name}: #{binding.type}"
                          end

          result << {
            label:        name,
            kind:         13, # Variable
            detail:       detail_label,
            insertText:   name,
            sortText:     "3_#{name}",
            data:         completion_data(name),
          }
        end
      end
    end

    TYPE_CONSTRUCTOR_KEYWORDS.each do |tc|
      next unless prefix.empty? || tc.start_with?(prefix)

      result << {
        label:      tc,
        kind:       14, # Keyword
        detail:     "type constructor #{tc}",
        insertText: tc,
        sortText:   "8_#{tc}",
        data:       completion_data(tc),
      }
    end

    COMPLETION_KEYWORDS.each do |kw|
      next unless prefix.empty? || kw.start_with?(prefix)

      result << {
        label:      kw,
        kind:       14, # Keyword
        detail:     "keyword #{kw}",
        insertText: kw,
        sortText:   "9_#{kw}",
        data:       completion_data(kw),
      }
    end

    result
  end

  item_count = items.length
  truncated = item_count > MAX_COMPLETION_ITEMS
  if truncated
    items = items.first(MAX_COMPLETION_ITEMS)
    item_count = MAX_COMPLETION_ITEMS
  end
  { isIncomplete: truncated, items: items }
rescue StandardError => e
  branch = 'error'
  warn "Error in completion handler: #{e.message}"
  { isIncomplete: false, items: [] }
ensure
  log_request_stage_breakdown('textDocument/completion', total_start, uri: uri, stages: stages, summary: "branch=#{branch} items=#{item_count}")
end

#handle_completion_resolve(params) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 816

def handle_completion_resolve(params)
  data = params['data']
  return params unless data.is_a?(Hash)

  name = data['name']
  return params if name.to_s.empty?

  uri = data['uri'] || ''
  definition_entry = @workspace.find_definition_token_global(name, preferred_uri: uri)
  return params unless definition_entry

  doc_comment = @workspace.doc_comment_data_for_definition(definition_entry[:uri], definition_entry[:token])
  docs = signature_help_markdown_for_doc_comment(doc_comment)
  return params if docs.empty?

  params.merge('documentation' => { 'kind' => 'markdown', 'value' => docs })
rescue StandardError => e
  warn "Error in completion resolve handler: #{e.message}"
  params
end

#import_completions(uri, lsp_line, lsp_char) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 837

def import_completions(uri, lsp_line, lsp_char)
  content = @workspace.get_content(uri)
  lines = content.split("\n", -1)
  line = lines[lsp_line] || ''
  stripped = line.lstrip
  return nil unless stripped.start_with?('import ')

  import_kw_pos = line.index('import ')
  after_import = line[(import_kw_pos + 7)..].to_s

  if (as_match = after_import.match(/\s+as\s+/))
    alias_pos = as_match.begin(0)
    cursor_in_import = lsp_char - import_kw_pos - 7
    return nil if cursor_in_import > alias_pos
    after_import = after_import[0...alias_pos]
  end

  cursor_in_import = lsp_char - import_kw_pos - 7
  cursor_in_import = [[cursor_in_import, after_import.length].min, 0].max

  path_typed = after_import[0...cursor_in_import].strip

  segments = path_typed.split('.', -1)
  dir_segments = segments[0...-1]
  filter = segments.last.to_s

  current_path = uri_to_path(uri)
  return nil unless current_path

  roots = MilkTea::ModuleRoots.roots_for_path(current_path)
  fs_dir = dir_segments.join(File::SEPARATOR)

  modules = {}
  filter_lower = filter.downcase

  roots.each do |root|
    search_dir = fs_dir.empty? ? root : File.join(root, fs_dir)
    next unless File.directory?(search_dir)

    Dir.children(search_dir).sort.each do |name|
      next if name.start_with?('.')
      full_path = File.join(search_dir, name)

      if name.end_with?('.mt')
        mod_name = name.delete_suffix('.mt')
        next if mod_name.start_with?('.')
        next if full_path == current_path
        next unless filter.empty? || mod_name.downcase.start_with?(filter_lower)
        modules[mod_name] = mod_name
      elsif File.directory?(full_path) && module_dir_contains_mt?(full_path)
        next unless filter.empty? || name.downcase.start_with?(filter_lower)
        modules[name] = name
      end
    end
  end

  return nil if modules.empty?

  modules.values.sort.map do |mod_name|
    {
      label:      mod_name,
      kind:       2,
      detail:     "module #{mod_name}",
      insertText: mod_name,
      sortText:   "0_#{mod_name}",
      data:       completion_data(mod_name),
    }
  end
end

#label_details_for_params(params_str, module_name = nil) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 33

def label_details_for_params(params_str, module_name = nil)
  result = {}
  result[:detail] = " (#{params_str})" if params_str && !params_str.empty?
  result[:description] = module_name if module_name && !module_name.empty?
  result.empty? ? nil : result
end

#location_matches_reference?(location, ref) ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/milk_tea/lsp/server/completion.rb', line 644

def location_matches_reference?(location, ref)
  return false unless location

  same_location?(location, {
    uri: ref[:uri],
    range: ref[:range]
  })
end

#method_dispatch_receiver_type_for_completion(receiver_type) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 754

def method_dispatch_receiver_type_for_completion(receiver_type)
  return receiver_type.definition if receiver_type.is_a?(Types::StructInstance) || receiver_type.is_a?(Types::VariantInstance)

  if receiver_type.is_a?(Types::Nullable)
    return method_dispatch_receiver_type_for_completion(receiver_type.base)
  end

  return receiver_type unless receiver_type.is_a?(Types::GenericInstance)

  dispatch_receiver_type = Types::Registry.generic_instance(
    receiver_type.name,
    receiver_type.arguments.each_with_index.map do |argument, index|
      argument.is_a?(Types::LiteralTypeArg) ? argument : Types::TypeVar.new("__receiver_arg#{index}")
    end,
  )

  dispatch_receiver_type == receiver_type ? receiver_type : dispatch_receiver_type
end

#methods_for_receiver_type(facts, receiver_type) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 718

def methods_for_receiver_type(facts, receiver_type)
  methods = {}
  return methods unless receiver_type

  receiver_candidates = [receiver_type]
  dispatch_receiver_type = method_dispatch_receiver_type_for_completion(receiver_type)
  receiver_candidates << dispatch_receiver_type if dispatch_receiver_type != receiver_type

  # For GenericInstance or Nullable-wrapped GenericInstance, also try the
  # struct definition from facts.types — method registration keys are
  # always the GenericStructDefinition, not a GenericInstance.
  [dispatch_receiver_type, receiver_type].each do |candidate|
    base = candidate
    base = base.base while base.is_a?(Types::Nullable)
    next unless base.is_a?(Types::GenericInstance)

    definition = facts.types[base.name]
    receiver_candidates << definition if definition && !receiver_candidates.include?(definition)
  end

  receiver_candidates.each do |candidate|
    facts.methods.fetch(candidate, {}).each do |name, binding|
      methods[name] ||= binding
    end
  end

  facts.imports.each_value do |module_binding|
    receiver_candidates.each do |candidate|
      module_binding.methods.fetch(candidate, {}).each do |name, binding|
        methods[name] ||= binding
      end
    end
  end
  methods
end

#module_dir_contains_mt?(dir) ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/milk_tea/lsp/server/completion.rb', line 907

def module_dir_contains_mt?(dir)
  Dir.children(dir).any? do |name|
    next false if name.start_with?('.')
    full = File.join(dir, name)
    name.end_with?('.mt') || (File.directory?(full) && module_dir_contains_mt?(full))
  end
end

#module_member_access_info(tokens, index) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 659

def module_member_access_info(tokens, index)
  dot_index = previous_non_trivia_token_index(tokens, index)
  return nil unless dot_index && tokens[dot_index].type == :dot

  receiver_index = previous_non_trivia_token_index(tokens, dot_index)
  return nil unless receiver_index

  receiver = tokens[receiver_index]
  return nil unless receiver.type == :identifier

  { receiver: receiver.lexeme }
end

#named_argument_completions(facts, uri, line, char) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 1022

def named_argument_completions(facts, uri, line, char)
  return nil unless facts

  content = @workspace.get_content(uri)
  return nil unless content
  lines = content.split("\n", -1)
  line_text = lines[line] || ''
  return nil if line_text.empty?

  text_before = line_text[0...char]

  call_match = text_before.match(/([\w.]+)\s*\(\s*(?:[^)]*,\s*)\s*$/)
  call_match ||= text_before.match(/([\w.]+)\s*\(\s*$/)

  return nil unless call_match

  callable_name = call_match[1]
  prefix_match = text_before.match(/(?:^|[,\s(])(\w*)$/)
  prefix = prefix_match ? prefix_match[1] : ''

  already_provided = text_before.scan(/(\w+)\s*[=:]/).flatten.to_set

  items = []

  if (func_binding = facts.functions[callable_name])
    func_binding.type.params.each do |param|
      next if already_provided.include?(param.name)
      next unless prefix.empty? || param.name.start_with?(prefix)
      items << {
        label:      "#{param.name} = ",
        kind:       14,
        detail:     "#{param.name}: #{param.type}",
        insertText: "#{param.name} = ",
        sortText:   "0_#{param.name}",
        data:       completion_data(param.name),
      }
    end
  end

  resolved_type = facts.types[callable_name]
  if resolved_type.nil? && callable_name.include?('.')
    parts = callable_name.split('.', 2)
    mod_binding = facts.imports[parts[0]]
    resolved_type = mod_binding&.types&.[](parts[1]) if mod_binding
  end

  if resolved_type&.respond_to?(:fields) && !resolved_type.fields.empty?
    resolved_type.fields.each do |fname, ftype|
      next if already_provided.include?(fname)
      next unless prefix.empty? || fname.start_with?(prefix)
      items << {
        label:      "#{fname} = ",
        kind:       8,
        detail:     "#{fname}: #{ftype}",
        insertText: "#{fname} = ",
        sortText:   "0_#{fname}",
        data:       completion_data(fname),
      }
    end
  end

  items.empty? ? nil : items
end

#pointer_type_name?(type) ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/milk_tea/lsp/server/completion.rb', line 812

def pointer_type_name?(type)
  type.is_a?(Types::GenericInstance) && %w[ptr const_ptr].include?(type.name) && type.arguments.length == 1
end

#project_field_receiver_type_for_completion(type, facts = nil) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 773

def project_field_receiver_type_for_completion(type, facts = nil)
  type = type.base while type.is_a?(Types::Nullable)
  type = project_receiver_type_for_completion(type)
  return type.definition if type.is_a?(Types::StructInstance) || type.is_a?(Types::VariantInstance)
  return field_type_from_struct_definition(type, facts) if facts

  type
end

#project_method_receiver_type_for_completion(type) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 790

def project_method_receiver_type_for_completion(type)
  project_receiver_type_for_completion(type)
end

#project_receiver_type_for_completion(type) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 794

def project_receiver_type_for_completion(type)
  return type.arguments.first if ref_type_name?(type)
  return type.arguments.first if pointer_type_name?(type)

  type
end

#ref_type_name?(type) ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/milk_tea/lsp/server/completion.rb', line 808

def ref_type_name?(type)
  type.is_a?(Types::GenericInstance) && type.name == 'ref' && type.arguments.length == 1
end

#resolve_nested_type_binding(facts, name) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 513

def resolve_nested_type_binding(facts, name)
  return { qualified_name: nil, type: nil } unless facts

  facts.types.each_value do |type|
    next unless type.respond_to?(:nested_types)
    if (nested = type.nested_types[name])
      return { qualified_name: "#{type.name}.#{name}", type: nested }
    end
  end
  { qualified_name: nil, type: nil }
end

#resolve_static_type_receiver_method(facts, receiver_name, receiver_path, method_name) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 549

def resolve_static_type_receiver_method(facts, receiver_name, receiver_path, method_name)
  receiver_info = resolve_type_receiver_info(facts, receiver_name, receiver_path)
  return nil unless receiver_info

  binding = static_method_binding_for_receiver(facts, receiver_info[:type], method_name)
  return nil unless binding

  receiver_info.merge(binding:)
end

#resolve_static_type_reference_target(uri, token, facts) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 567

def resolve_static_type_reference_target(uri, token, facts)
  token_end_char = token.column - 1 + token.lexeme.length
  receiver_name = @workspace.find_dot_receiver(uri, token.line - 1, token_end_char)
  receiver_path = @workspace.find_dot_receiver_path(uri, token.line - 1, token_end_char)

  if (target = resolve_static_type_receiver_method(facts, receiver_name, receiver_path, token.lexeme))
    location = module_member_binding_location(uri, target[:module_name], token.lexeme, target[:binding])
    location ||= module_member_definition_location(uri, target[:module_name], token.lexeme)
    return target.merge(location:)
  end

  binding = static_method_binding_at_token(facts, token)
  return nil unless binding

  location = module_member_binding_location(uri, facts.module_name, token.lexeme, binding)
  location ||= module_member_definition_location(uri, facts.module_name, token.lexeme)
  {
    label: token.lexeme,
    type: binding.declared_receiver_type,
    module_name: facts.module_name,
    binding:,
    location:,
  }
end

#resolve_type_receiver_info(facts, receiver_name, receiver_path) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 525

def resolve_type_receiver_info(facts, receiver_name, receiver_path)
  if facts.types.key?(receiver_name)
    type = facts.types.fetch(receiver_name)
    module_name = type.respond_to?(:module_name) ? type.module_name : facts.module_name
    return { label: receiver_name, type:, module_name: }
  end

  nested = resolve_nested_type_binding(facts, receiver_name)
  return { label: nested[:qualified_name], type: nested[:type], module_name: nested[:type].module_name } if nested[:type]

  return nil unless receiver_path&.include?('.')

  module_alias, type_name = receiver_path.split('.', 2)
  return nil unless module_alias && type_name

  module_binding = facts.imports[module_alias]
  return nil unless module_binding

  type = module_binding.types[type_name]
  return nil unless type

  { label: receiver_path, type:, module_name: module_binding.name }
end

#same_location?(left, right) ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/milk_tea/lsp/server/completion.rb', line 653

def same_location?(left, right)
  return false unless left && right

  left[:uri] == right[:uri] && left[:range] == right[:range]
end

#snippet_for_callable(label, params) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 25

def snippet_for_callable(label, params)
  return "#{label}()" if params.empty?
  return nil if params.length > 5

  stops = params.each_with_index.map { |p, i| "${#{i + 1}:#{p.name}}" }
  "#{label}(#{stops.join(', ')})"
end

#specialization_completions(facts, _uri, line, char) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 1086

def specialization_completions(facts, _uri, line, char)
  return nil unless facts

  content = @workspace.get_content(_uri)
  return nil unless content
  lines = content.split("\n", -1)
  line_text = lines[line] || ''
  return nil if line_text.empty?

  text_before = line_text[0...char]
  sp_match = text_before.match(/([\w.]+)\[(.*)$/)
  return nil unless sp_match

  prefix = sp_match[2]
  items = []

  facts.types.each do |name, _type|
    next unless prefix.empty? || name.start_with?(prefix)
    items << {
      label:      name,
      kind:       5,
      detail:     "type #{name}",
      insertText: name,
      sortText:   "0_#{name}",
      data:       completion_data(name),
    }
  end

  items.empty? ? nil : items
end

#static_method_binding_at_token(facts, token) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 592

def static_method_binding_at_token(facts, token)
  binding = method_binding_at_token(facts, token)
  return nil unless binding&.ast.is_a?(AST::MethodDef) && binding.ast.kind == :static

  binding
end

#static_method_binding_for_receiver(facts, receiver_type, method_name) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 559

def static_method_binding_for_receiver(facts, receiver_type, method_name)
  methods = methods_for_receiver_type(facts, receiver_type)
  binding = methods[method_name] || methods["static:#{method_name}"]
  return nil unless binding&.ast.is_a?(AST::MethodDef) && binding.ast.kind == :static

  binding
end

#static_type_method_reference?(ref, target) ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/milk_tea/lsp/server/completion.rb', line 626

def static_type_method_reference?(ref, target)
  token = @workspace.find_token_at(ref[:uri], ref.dig(:range, :start, :line), ref.dig(:range, :start, :character))
  return false unless token&.type == :identifier

  facts = @workspace.get_facts(ref[:uri])
  return false unless facts

  token_end_char = ref.dig(:range, :end, :character)
  receiver_name = @workspace.find_dot_receiver(ref[:uri], ref.dig(:range, :start, :line), token_end_char)
  receiver_path = @workspace.find_dot_receiver_path(ref[:uri], ref.dig(:range, :start, :line), token_end_char)
  candidate = resolve_static_type_receiver_method(facts, receiver_name, receiver_path, token.lexeme)
  return false unless candidate

  candidate_location = module_member_binding_location(ref[:uri], candidate[:module_name], token.lexeme, candidate[:binding])
  candidate_location ||= module_member_definition_location(ref[:uri], candidate[:module_name], token.lexeme)
  same_location?(candidate_location, target[:location])
end

#static_type_method_references(target, include_declaration:) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 599

def static_type_method_references(target, include_declaration:)
  name = target[:binding].name
  target_uri = target[:location][:uri]

  candidate_uris = nil
  if target_uri
    target_facts = @workspace.get_facts(target_uri)
    if target_facts&.module_name
      importing = @workspace.reverse_import_dependents_for(target_facts.module_name)
      candidate_uris = importing.to_a + [target_uri] if importing && !importing.empty?
    end
  end

  refs = if candidate_uris
            @workspace.find_all_references_in(name, candidate_uris)
          else
            @workspace.find_all_references(name)
          end
  refs.filter do |ref|
    if location_matches_reference?(target[:location], ref)
      include_declaration
    else
      static_type_method_reference?(ref, target)
    end
  end
end

#value_chain_completions(facts, dot_recv_path, lsp_line, lsp_char, prefix) ⇒ Object

# File 'lib/milk_tea/lsp/server/completion.rb', line 462

def value_chain_completions(facts, dot_recv_path, lsp_line, lsp_char, prefix)
  return nil unless dot_recv_path&.include?('.')

  chain_segments = dot_recv_path.split('.')
  return nil if chain_segments.length < 2

  first_seg = chain_segments.first
  first_type = resolve_dot_receiver_value_type(facts, first_seg, lsp_line + 1, lsp_char + 1)
  return nil unless first_type

  current_type = first_type
  chain_segments[1..].each do |seg|
    field_owner = project_field_receiver_type_for_completion(current_type, facts)
    if field_owner.respond_to?(:field) && (field_type = field_owner.field(seg))
      current_type = field_type
    else
      return nil
    end
  end

  items = completion_items_for_value_receiver(facts, current_type, prefix)
  items.empty? ? nil : items
end