# frozen_string_literal: true

require "shellwords"

module Homebrew
  # Helper module for running RuboCop.
  #
  # @api private
  module Style
    module_function

    # Checks style for a list of files, printing simple RuboCop output.
    # Returns true if violations were found, false otherwise.
    def check_style_and_print(files, **options)
      check_style_impl(files, :print, **options)
    end

    # Checks style for a list of files, returning results as a RubocopResults
    # object parsed from its JSON output.
    def check_style_json(files, **options)
      check_style_impl(files, :json, **options)
    end

    def check_style_impl(files, output_type,
                         fix: false,
                         except_cops: nil, only_cops: nil,
                         display_cop_names: false,
                         debug: false, verbose: false)
      raise ArgumentError, "Invalid output type: #{output_type.inspect}" unless [:print, :json].include?(output_type)

      shell_files, ruby_files =
        Array(files).map(&method(:Pathname))
                    .partition { |f| f.realpath == HOMEBREW_BREW_FILE.realpath || f.extname == ".sh" }

      rubocop_result = if shell_files.any? && ruby_files.none?
        output_type == :json ? [] : true
      else
        run_rubocop(ruby_files, output_type,
                    fix: fix,
                    except_cops: except_cops, only_cops: only_cops,
                    display_cop_names: display_cop_names,
                    debug: debug, verbose: verbose)
      end

      shellcheck_result = if ruby_files.any? && shell_files.none?
        output_type == :json ? [] : true
      else
        run_shellcheck(shell_files, output_type)
      end

      if output_type == :json
        RubocopResults.new(rubocop_result + shellcheck_result)
      else
        rubocop_result && shellcheck_result
      end
    end

    def run_rubocop(files, output_type,
                    fix: false, except_cops: nil, only_cops: nil, display_cop_names: false,
                    debug: false, verbose: false)
      Homebrew.install_bundler_gems!
      require "rubocop"
      require "rubocops"

      args = %w[
        --force-exclusion
      ]
      args << if fix
        "--auto-correct"
      else
        "--parallel"
      end

      args += ["--extra-details"] if verbose
      args += ["--display-cop-names"] if display_cop_names || verbose

      if except_cops
        except_cops.map! { |cop| RuboCop::Cop::Cop.registry.qualified_cop_name(cop.to_s, "") }
        cops_to_exclude = except_cops.select do |cop|
          RuboCop::Cop::Cop.registry.names.include?(cop) ||
            RuboCop::Cop::Cop.registry.departments.include?(cop.to_sym)
        end

        args << "--except" << cops_to_exclude.join(",") unless cops_to_exclude.empty?
      elsif only_cops
        only_cops.map! { |cop| RuboCop::Cop::Cop.registry.qualified_cop_name(cop.to_s, "") }
        cops_to_include = only_cops.select do |cop|
          RuboCop::Cop::Cop.registry.names.include?(cop) ||
            RuboCop::Cop::Cop.registry.departments.include?(cop.to_sym)
        end

        odie "RuboCops #{only_cops.join(",")} were not found" if cops_to_include.empty?

        args << "--only" << cops_to_include.join(",")
      end

      has_non_formula = files.any? do |file|
        File.expand_path(file).start_with? HOMEBREW_LIBRARY_PATH
      end

      if files.any? && !has_non_formula
        config = if files.first && File.exist?("#{files.first}/spec")
          HOMEBREW_LIBRARY/".rubocop_rspec.yml"
        else
          HOMEBREW_LIBRARY/".rubocop.yml"
        end
        args << "--config" << config
      end

      if files.blank?
        args << HOMEBREW_LIBRARY_PATH
      else
        args += files
      end

      cache_env = { "XDG_CACHE_HOME" => "#{HOMEBREW_CACHE}/style" }

      case output_type
      when :print
        args << "--debug" if debug
        args << "--format" << "simple" if files.present?

        system cache_env, "rubocop", *args
        $CHILD_STATUS.success?
      when :json
        result = system_command "rubocop", args: ["--format", "json", *args], env: cache_env
        json = json_result!(result)
        json["files"]
      end
    end

    def run_shellcheck(files, output_type)
      shellcheck   = which("shellcheck")
      shellcheck ||= which("shellcheck", ENV["HOMEBREW_PATH"])
      shellcheck ||= begin
        ohai "Installing `shellcheck` for shell style checks..."
        safe_system HOMEBREW_BREW_FILE, "install", "shellcheck"
        which("shellcheck") || which("shellcheck", ENV["HOMEBREW_PATH"])
      end

      if files.empty?
        files = [
          HOMEBREW_BREW_FILE,
          # TODO: HOMEBREW_REPOSITORY/"completions/bash/brew",
          *Pathname.glob("#{HOMEBREW_LIBRARY}/Homebrew/*.sh"),
          *Pathname.glob("#{HOMEBREW_LIBRARY}/Homebrew/cmd/*.sh"),
          *Pathname.glob("#{HOMEBREW_LIBRARY}/Homebrew/utils/*.sh"),
        ]
      end

      args = ["--shell=bash", "--", *files] # TODO: Add `--enable=all` to check for more problems.

      case output_type
      when :print
        system shellcheck, "--format=tty", *args
        $CHILD_STATUS.success?
      when :json
        result = system_command shellcheck, args: ["--format=json1", *args]
        json = json_result!(result)

        # Convert to same format as RuboCop offenses.
        json["comments"].group_by { |v| v["file"] }
                        .map do |k, v|
          {
            "path"     => k,
            "offenses" => v.map do |o|
              o.delete("file")

              o["cop_name"] = "SC#{o.delete("code")}"

              level = o.delete("level")
              o["severity"] = { "style" => "refactor", "info" => "convention" }.fetch(level, level)

              line = o.delete("line")
              column = o.delete("column")

              o["corrected"] = false
              o["correctable"] = o.delete("fix").present?

              o["location"] = {
                "start_line"   => line,
                "start_column" => column,
                "last_line"    => o.delete("endLine"),
                "last_column"  => o.delete("endColumn"),
                "line"         => line,
                "column"       => column,
              }

              o
            end,
          }
        end
      end
    end

    def json_result!(result)
      # An exit status of 1 just means violations were found; other numbers mean
      # execution errors.
      # JSON needs to be at least 2 characters.
      result.assert_success! if !(0..1).cover?(result.status.exitstatus) || result.stdout.length < 2

      JSON.parse(result.stdout)
    end

    # Result of a RuboCop run.
    class RubocopResults
      def initialize(files)
        @file_offenses = {}
        files.each do |f|
          next if f["offenses"].empty?

          file = File.realpath(f["path"])
          @file_offenses[file] = f["offenses"].map { |x| RubocopOffense.new(x) }
        end
      end

      def file_offenses(path)
        @file_offenses.fetch(path.to_s, [])
      end
    end

    # A RuboCop offense.
    class RubocopOffense
      attr_reader :severity, :message, :corrected, :location, :cop_name

      def initialize(json)
        @severity = json["severity"]
        @message = json["message"]
        @cop_name = json["cop_name"]
        @corrected = json["corrected"]
        @location = RubocopLineLocation.new(json["location"])
      end

      def severity_code
        @severity[0].upcase
      end

      def corrected?
        @corrected
      end

      def correction_status
        "[Corrected] " if corrected?
      end

      def to_s(display_cop_name: false)
        if display_cop_name
          "#{severity_code}: #{location.to_short_s}: #{cop_name}: " \
          "#{Tty.green}#{correction_status}#{Tty.reset}#{message}"
        else
          "#{severity_code}: #{location.to_short_s}: #{Tty.green}#{correction_status}#{Tty.reset}#{message}"
        end
      end
    end

    # Source location of a RuboCop offense.
    class RubocopLineLocation
      attr_reader :line, :column, :length

      def initialize(json)
        @line = json["line"]
        @column = json["column"]
        @length = json["length"]
      end

      def to_s
        "#{line}: col #{column} (#{length} chars)"
      end

      def to_short_s
        "#{line}: col #{column}"
      end
    end
  end
end