# frozen_string_literal: true

require "hashdiff"

module NeetoCompliance
  class JsconfigVerifier < Base
    attr_accessor :diffs

    def initialize
      @diffs = []
    end

    def local_copy
      "app/javascript/jsconfig.json"
    end

    def commons_copy
      NeetoCompliance::NeetoCommons.path.join "common_files", "app", "javascript", "jsconfig.json"
    end

    def local_jsconfig
      @_local_jsconfig ||= read_file local_copy
    end

    def required_jsconfig
      @_required_jsconfig ||= read_file commons_copy
    end

    def read_file(file)
      JSON.parse File.read(file)
    end

    def verify_command
      self.diffs = Hashdiff.best_diff(required_jsconfig, local_jsconfig)
      # diffs is an array of differences and each element is a diff.

      self.diffs.any? { |diff| removed_or_modified?(diff) }
    end

    def removed_or_modified?(diff)
      # A diff is of the format: ['-', 'a.x', 2]
      # A modified key is of the format: ['~', 'a.x', 2, 4]
      # First element is a symbol. '-' indicates removal and `~` indicates modification

      diff[0] == "-" || diff[0] == "~"
    end

    def local_file_exists?
      File.file?(local_copy)
    end

    def newly_added_paths
      self.diffs = Hashdiff.diff(required_jsconfig, local_jsconfig, use_lcs: false)
      capture_addition_into_paths_key = "(?=.*\+)(?=.*compilerOptions.paths)"
      @_newly_added_paths ||= self.diffs.select { |diff| diff.join =~ /#{capture_addition_into_paths_key}.*/ }
    end

    def custom_paths
      paths = Hash.new
      newly_added_paths.each do |path|
        if path[0] == "+"
          key = path[1].split(".").last
          value = path[2]
          paths[key] = value
        end
      end
      @_custom_paths ||= paths
    end

    def modified_paths
      paths = Hash.new
      newly_added_paths.each do |path|
        if path[0] == "~"
          # An unwanted '[0]' character is added at the to all modified diffs by the gem

          paths[path[1].split(".").last.chomp("[0]")] = { common: path[2], local: path[3] }
        end
      end
      @_modified_paths ||= paths
    end

    def add_comments_to_jsconfig_file
      text = File.read(local_copy)
      text['"commons_paths_comment": "",'] = "// don't modify the below paths without consulting with neetoCompliance team"
      text['"custom_paths_comment": ""'] = "// You can add custom project specific paths below this comment"
      File.open(local_copy, "w") { |file| file.puts text }
    end

    def exception_message(paths)
      modified_paths = ""
      paths.each do |key, value|
        modified_paths += "
          path: #{key}
            Common value: [\"#{value[:common]}\"]
            Project's value: [\"#{value[:local]}\"]"
      end
      exception_message = %{
        Could not autofix jsconfig changes. The below path(s) conflict with the one defined in neeto-commons-backend: #{modified_paths}
      }
    end

    def add_place_holders_for_comments
      # Adds placeholders into the entire object to keep track of places where we need to insert comments

      paths_with_comment =
        { "commons_paths_comment": "" }.merge(required_jsconfig["compilerOptions"]["paths"])
      paths_with_comment = paths_with_comment.merge("custom_paths_comment": "")
      paths_with_comment.merge(custom_paths)
    end

    def write_jsconfig_object_to_file
      jsconfig_data = required_jsconfig
      jsconfig_data["compilerOptions"]["paths"] = add_place_holders_for_comments
      File.open(local_copy, "w") do |file|
        file.write(JSON.pretty_generate(jsconfig_data))
      end
    end

    def auto_correct!
      unless valid?
        if !modified_paths.empty?
          raise StandardError.new exception_message(modified_paths)
        end

        write_jsconfig_object_to_file
        add_comments_to_jsconfig_file
      end
    end

    def valid?
      return false unless local_file_exists?

      is_modified_or_removed = verify_command
      !is_modified_or_removed
    end

    def autofix_command
      "cp #{commons_copy} #{local_copy}"
    end

    def neeto_audit_script_command
      "bundle exec neeto-audit -a"
    end

    def upstream_copy
      "https://github.com/bigbinary/neeto-commons-backend/blob/stable/lib/neeto-commons-backend/common_files/app/javascript/jsconfig.json"
    end

    def autofix_suggestion
      base_message = %{
      Your jsconfig.json content doesn't match with the expected neeto-commons content.

      The following is the recommended jsconfig.json content in neeto ecosystem:
      1) View #{upstream_copy}
      2) Or open #{commons_copy}

      This can be fixed automatically by running:
      #{neeto_audit_script_command.yellow}

      To fix manually, start by fully replacing app/javascript/jsconfig.json
      of your app with above mentioned content, by running the following:
      #{autofix_command.yellow}
      }

      # The following is an example diff:
      # [["-", "compilerOptions.moduleResolution", "NodeNext"],
      # ["~", "compilerOptions.module", "ESNext", "ESNex"],
      # ["+", "compilerOptions.paths.neetou", ["../../node_modules/@bigbinary/neetoui/**"]],
      # For the above diff, we only need to get the newly added items marked by "+"
      # and also check whether it's a "path" that has been added.
      if newly_added_paths.empty?
        return base_message
      end

      message = %{
      #{base_message}
      ==================================================
      It seems that you've also added some custom paths in your jsconfig. You can cherry pick and
      append the custom paths to app/javascript/jsconfig.json, if need be, after running above mentioned copy command.
      Refer the comments in #{upstream_copy}
      to see how to add custom paths.
      The following are the custom paths that we have detected in your app/javascript/jsconfig.json:
      #{JSON.pretty_generate(custom_paths).yellow}
      }
    end
  end
end