# frozen_string_literal: true

require "liquid/c/version"
require "liquid"
require "liquid_c"
require "liquid/c/compile_ext"

Liquid::C::BlockBody.class_eval do
  def render(context)
    render_to_output_buffer(context, +"")
  end
end

module Liquid
  BlockBody.class_eval do
    def self.c_rescue_render_node(context, output, line_number, exc, blank_tag)
      # There seems to be a MRI ruby bug with how the rb_rescue C function,
      # where $! gets set for its rescue callback, but it doesn't stay set
      # after a nested exception is raised and handled as is the case in
      # Liquid::Context#internal_error. This isn't a problem for plain ruby code,
      # so use a ruby rescue block to have setup $! properly.
      raise(exc)
    rescue => exc
      rescue_render_node(context, output, line_number, exc, blank_tag)
    end
  end
end

module Liquid
  module C
    # Placeholder for variables in the Liquid::C::BlockBody#nodelist.
    class VariablePlaceholder
      class << self
        private :new
      end
    end

    class Tokenizer
      MAX_SOURCE_BYTE_SIZE = (1 << 24) - 1
    end
  end
end

Liquid::Raw.class_eval do
  alias_method :ruby_parse, :parse

  def parse(tokenizer)
    if parse_context.liquid_c_nodes_disabled?
      ruby_parse(tokenizer)
    else
      c_parse(tokenizer)
    end
  end
end

Liquid::ParseContext.class_eval do
  class << self
    attr_accessor :liquid_c_nodes_disabled
  end
  self.liquid_c_nodes_disabled = false

  alias_method :ruby_new_block_body, :new_block_body

  def new_block_body
    if liquid_c_nodes_disabled?
      ruby_new_block_body
    else
      Liquid::C::BlockBody.new(self)
    end
  end

  alias_method :ruby_new_tokenizer, :new_tokenizer
  def new_tokenizer(source, start_line_number: nil, for_liquid_tag: false)
    unless liquid_c_nodes_disabled?
      source = source.to_s.to_str
      if source.bytesize <= Liquid::C::Tokenizer::MAX_SOURCE_BYTE_SIZE
        source = source.encode(Encoding::UTF_8)
        return Liquid::C::Tokenizer.new(source, start_line_number || 0, for_liquid_tag)
      else
        @liquid_c_nodes_disabled = true
      end
    end

    ruby_new_tokenizer(source, start_line_number: start_line_number, for_liquid_tag: for_liquid_tag)
  end

  def parse_expression(markup)
    if liquid_c_nodes_disabled?
      Liquid::Expression.ruby_parse(markup)
    else
      Liquid::C::Expression.lax_parse(markup)
    end
  end

  # @api private
  def liquid_c_nodes_disabled?
    # Liquid::Profiler exposes the internal parse tree that we don't want to build when
    # parsing with liquid-c, so consider liquid-c to be disabled when using it.
    # Also, some templates are parsed before the profiler is running, on which case we
    # provide the `disable_liquid_c_nodes` option to enable the Ruby AST to be produced
    # so the profiler can use it on future runs.
    return @liquid_c_nodes_disabled if defined?(@liquid_c_nodes_disabled)
    @liquid_c_nodes_disabled = !Liquid::C.enabled || @template_options[:profile] ||
      @template_options[:disable_liquid_c_nodes] || self.class.liquid_c_nodes_disabled
  end
end

module Liquid
  module C
    module DocumentClassPatch
      def parse(tokenizer, parse_context)
        if tokenizer.is_a?(Liquid::C::Tokenizer)
          if parse_context[:bug_compatible_whitespace_trimming]
            # Temporary to test rollout of the fix for this bug
            tokenizer.bug_compatible_whitespace_trimming!
          end

          begin
            parse_context.start_liquid_c_parsing
            super
          ensure
            parse_context.cleanup_liquid_c_parsing
          end
        else
          super
        end
      end
    end
    Liquid::Document.singleton_class.prepend(DocumentClassPatch)
  end
end

Liquid::Variable.class_eval do
  class << self
    # @api private
    def call_variable_fallback_stats_callback(parse_context)
      callbacks = parse_context[:stats_callbacks]
      callbacks[:variable_fallback]&.call if callbacks
    end

    private

    # helper method for C code
    def rescue_strict_parse_syntax_error(error, markup, parse_context)
      error.line_number = parse_context.line_number
      error.markup_context = "in \"{{#{markup}}}\""
      case parse_context.error_mode
      when :strict
        raise
      when :warn
        parse_context.warnings << error
      end
      call_variable_fallback_stats_callback(parse_context)
      lax_parse(markup, parse_context) # Avoid redundant strict parse
    end

    def lax_parse(markup, parse_context)
      old_error_mode = parse_context.error_mode
      begin
        set_error_mode(parse_context, :lax)
        new(markup, parse_context)
      ensure
        set_error_mode(parse_context, old_error_mode)
      end
    end

    def set_error_mode(parse_context, mode)
      parse_context.instance_variable_set(:@error_mode, mode)
    end
  end

  alias_method :ruby_strict_parse, :strict_parse

  def strict_parse(markup)
    if parse_context.liquid_c_nodes_disabled?
      ruby_strict_parse(markup)
    else
      c_strict_parse(markup)
    end
  end
end

Liquid::StrainerTemplate.class_eval do
  class << self
    private

    def filter_methods_hash
      @filter_methods_hash ||= {}.tap do |hash|
        filter_methods.each do |method_name|
          hash[method_name.to_sym] = true
        end
      end
    end

    # Convert wrong number of argument error into a liquid exception to
    # treat it as an error in the template, not an internal error.
    def arg_exc_to_liquid_exc(argument_error)
      raise Liquid::ArgumentError, argument_error.message, argument_error.backtrace
    rescue Liquid::ArgumentError => liquid_exc
      liquid_exc
    end
  end
end

Liquid::C::Expression.class_eval do
  class << self
    def lax_parse(markup)
      strict_parse(markup)
    rescue Liquid::SyntaxError
      Liquid::Expression.ruby_parse(markup)
    end
  end
end

Liquid::Expression.class_eval do
  class << self
    alias_method :ruby_parse, :parse

    def c_parse(markup)
      Liquid::C::Expression.lax_parse(markup)
    end
  end
end

Liquid::Context.class_eval do
  alias_method :ruby_evaluate, :evaluate
  alias_method :ruby_find_variable, :find_variable
  alias_method :ruby_strict_variables=, :strict_variables=

  # This isn't entered often by Ruby (most calls stay in C via VariableLookup#evaluate)
  # so the wrapper method isn't costly.
  def c_find_variable_kwarg(key, raise_on_not_found: true)
    c_find_variable(key, raise_on_not_found)
  end
end

Liquid::ResourceLimits.class_eval do
  def self.new(limits)
    if Liquid::C.enabled
      Liquid::C::ResourceLimits.new(
        limits[:render_length_limit],
        limits[:render_score_limit],
        limits[:assign_score_limit]
      )
    else
      super
    end
  end
end

module Liquid
  module C
    class << self
      attr_reader :enabled

      def enabled=(value)
        @enabled = value
        if value
          Liquid::Context.send(:alias_method, :evaluate, :c_evaluate)
          Liquid::Context.send(:alias_method, :find_variable, :c_find_variable_kwarg)
          Liquid::Context.send(:alias_method, :strict_variables=, :c_strict_variables=)
          Liquid::Expression.singleton_class.send(:alias_method, :parse, :c_parse)
        else
          Liquid::Context.send(:alias_method, :evaluate, :ruby_evaluate)
          Liquid::Context.send(:alias_method, :find_variable, :ruby_find_variable)
          Liquid::Context.send(:alias_method, :strict_variables=, :ruby_strict_variables=)
          Liquid::Expression.singleton_class.send(:alias_method, :parse, :ruby_parse)
        end
      end
    end

    self.enabled = true
  end
end