# frozen_string_literal: true

require 'optparse'

module Synvert
  # Synvert command line interface.
  class CLI
    # Initialize the cli and run.
    #
    # @param args [Array] arguments, default is ARGV.
    # @return [Boolean] true if command runs successfully.
    def self.run(args = ARGV)
      new.run(args)
    end

    # Initialize a CLI.
    def initialize
      @options = { command: 'run', custom_snippet_paths: [], format: 'plain' }
    end

    # Run the CLI.
    # @param args [Array] arguments.
    # @return [Boolean] true if command runs successfully.
    def run(args)
      run_option_parser(args)

      case @options[:command]
      when 'list'
        load_rewriters
        list_available_rewriters
      when 'open'
        open_rewriter
      when 'query'
        load_rewriters
        query_available_rewriters
      when 'show'
        load_rewriters
        show_rewriter
      when 'sync'
        sync_snippets
      when 'generate'
        generate_snippet
      when 'execute'
        execute_snippet
      else
        # run
        load_rewriters
        run_snippet
      end
      true
    rescue SystemExit
      true
    rescue Parser::SyntaxError => e
      puts "Syntax error: #{e.message}"
      puts "file #{e.diagnostic.location.source_buffer.name}"
      puts "line #{e.diagnostic.location.line}"
      false
    rescue Synvert::Core::RewriterNotFound => e
      puts e.message
      false
    end

    private

    # Run OptionParser to parse arguments.
    def run_option_parser(args)
      optparse =
        OptionParser.new do |opts|
          opts.banner = 'Usage: synvert [project_path]'
          opts.on '-d',
                  '--load SNIPPET_PATHS',
                  'load custom snippets, snippet paths can be local file path or remote http url' do |snippet_paths|
            @options[:custom_snippet_paths] = snippet_paths.split(',').map(&:strip)
          end
          opts.on '-l', '--list', 'list all available snippets' do
            @options[:command] = 'list'
          end
          opts.on '-o', '--open SNIPPET_NAME', 'Open a snippet' do |snippet_name|
            @options[:command] = 'open'
            @options[:snippet_name] = snippet_name
          end
          opts.on '-q', '--query QUERY', 'query specified snippets' do |query|
            @options[:command] = 'query'
            @options[:query] = query
          end
          opts.on '--skip FILE_PATTERNS',
                  'skip specified files or directories, separated by comma, e.g. app/models/post.rb,vendor/plugins/**/*.rb' do |file_patterns|
            @options[:skip_file_patterns] = file_patterns.split(',')
          end
          opts.on '-s',
                  '--show SNIPPET_NAME',
                  'show specified snippet description, SNIPPET_NAME is combined by group and name, e.g. ruby/new_hash_syntax' do |snippet_name|
            @options[:command] = 'show'
            @options[:snippet_name] = snippet_name
          end
          opts.on '--sync', 'sync snippets' do
            @options[:command] = 'sync'
          end
          opts.on '--execute', 'execute snippet' do
            @options[:command] = 'execute'
          end
          opts.on '-r', '--run SNIPPET_NAME', 'run specified snippet, e.g. ruby/new_hash_syntax' do |snippet_name|
            @options[:snippet_name] = snippet_name
          end
          opts.on '-g', '--generate NEW_SNIPPET_NAME', 'generate a new snippet' do |name|
            @options[:command] = 'generate'
            @options[:snippet_name] = name
          end
          opts.on '-f', '--format FORMAT', 'output format' do |format|
            @options[:format] = format
          end
          opts.on '-v', '--version', 'show this version' do
            puts "#{VERSION} (with synvert-core #{Core::VERSION} and parser #{Parser::VERSION})"
            exit
          end
        end
      paths = optparse.parse(args)
      Core::Configuration.path = paths.first || Dir.pwd
      if @options[:skip_file_patterns] && !@options[:skip_file_patterns].empty?
        skip_files =
          @options[:skip_file_patterns].map do |file_pattern|
            full_file_pattern = File.join(Core::Configuration.path, file_pattern)
            Dir.glob(full_file_pattern)
          end.flatten
        Core::Configuration.skip_files = skip_files
      end
    end

    # Load all rewriters.
    def load_rewriters
      Dir.glob(File.join(default_snippets_home, 'lib/**/*.rb')).each { |file| require file }

      @options[:custom_snippet_paths].each do |snippet_path|
        if /^http/.match?(snippet_path)
          uri = URI.parse snippet_path
          eval(uri.read)
        else
          require snippet_path
        end
      end
    rescue StandardError
      FileUtils.rm_rf default_snippets_home
      retry
    end

    # List and print all available rewriters.
    def list_available_rewriters
      if Core::Rewriter.availables.empty?
        puts 'There is no snippet under ~/.synvert, please run `synvert --sync` to fetch snippets.'
        return
      end

      if plain_output?
        Core::Rewriter.availables.each do |group, rewriters|
          puts group
          rewriters.each do |name, _rewriter|
            puts '    ' + name
          end
        end
        puts
      elsif json_output?
        output = []
        Core::Rewriter.availables.each do |group, rewriters|
          rewriters.each do |name, rewriter|
            rewriter.process_with_sandbox
            item = {
              group: group,
              name: name,
              description: rewriter.description,
              sub_snippets: rewriter.sub_snippets.map(&:name)
            }
            item[:ruby_version] = rewriter.ruby_version.version if rewriter.ruby_version
            item[:gem_spec] = { name: rewriter.gem_spec.name, version: rewriter.gem_spec.version } if rewriter.gem_spec
            output << item
          end
        end

        puts JSON.generate(output)
      end
    end

    # Open one rewriter.
    def open_rewriter
      editor = [ENV['SYNVERT_EDITOR'], ENV['EDITOR']].find { |e| !e.nil? && !e.empty? }
      return puts 'To open a synvert snippet, set $EDITOR or $SYNVERT_EDITOR' unless editor

      path = File.expand_path(File.join(default_snippets_home, "lib/#{@options[:snippet_name]}.rb"))
      if File.exist? path
        system editor, path
      else
        puts "Can't run #{editor} #{path}"
      end
    end

    # Query and print available rewriters.
    def query_available_rewriters
      Core::Rewriter.availables.each do |group, rewriters|
        if group.include? @options[:query]
          puts group
          rewriters.each do |name, _rewriter|
            puts '    ' + name
          end
        elsif rewriters.keys.any? { |name| name.include? @options[:query] }
          puts group
          rewriters.each do |name, _rewriter|
            puts '    ' + name if name.include?(@options[:query])
          end
        end
      end
      puts
    end

    # Show and print one rewriter.
    def show_rewriter
      path = File.expand_path(File.join(default_snippets_home, "lib/#{@options[:snippet_name]}.rb"))
      if File.exist?(path)
        puts File.read(path)
      else
        puts "snippet #{@options[:snippet_name]} not found"
      end
    end

    # sync snippets
    def sync_snippets
      Snippet.new(default_snippets_home).sync
      puts 'synvert snippets are synced'
      core_version = Snippet.fetch_core_version
      if Gem::Version.new(core_version) > Gem::Version.new(Synvert::Core::VERSION)
        puts "synvert-core is updated, installing synvert-core #{core_version}"
        system('gem install synvert-core')
      end
    end

    # run snippets
    def run_snippet
      snippet_name = @options[:snippet_name]
      if plain_output?
        puts "===== #{snippet_name} started ====="
        group, name = snippet_name.split('/')
        rewriter = Core::Rewriter.call group, name
        rewriter.warnings.each do |warning|
          puts '[Warn] ' + warning.message
        end
        puts rewriter.todo if rewriter.todo
        puts "===== #{snippet_name} done ====="
      elsif json_output?
        group, name = snippet_name.split('/')
        rewriter = Core::Rewriter.call group, name
        output = {
          affected_files: rewriter.affected_files.union(rewriter.sub_snippets.sum([], &:affected_files)).to_a,
          warnings: rewriter.warnings.union(rewriter.sub_snippets.sum([], &:warnings)),
          todo: rewriter.todo
        }
        puts JSON.generate(output)
      end
    end

    # execute snippet
    def execute_snippet
      input = STDIN.read
      if plain_output?
        puts "===== execute started ====="
        rewriter = eval(input)
        rewriter.warnings.each do |warning|
          puts '[Warn] ' + warning.message
        end
        puts rewriter.todo if rewriter.todo
        puts "===== execute done ====="
      elsif json_output?
        rewriter = eval(input)
        output = {
          affected_files: rewriter.affected_files.union(rewriter.sub_snippets.sum([], &:affected_files)).to_a,
          warnings: rewriter.warnings.union(rewriter.sub_snippets.sum([], &:warnings)),
          todo: rewriter.todo
        }
        puts JSON.generate(output)
      end
    end

    # generate a new snippet
    def generate_snippet
      group, name = @options[:snippet_name].split('/')
      FileUtils.mkdir_p("lib/#{group}")
      FileUtils.mkdir_p("spec/#{group}")
      lib_content = <<~EOF
        # frozen_string_literal: true

        Synvert::Rewriter.new '#{group}', '#{name}' do
          description <<~EOS
            It converts Foo to Bar

            ```ruby
            Foo
            ```

            =>

            ```ruby
            Bar
            ```
          EOS

          within_files '**/*.rb' do
            with_node type: 'const', to_source: 'Foo' do
              replace_with 'Bar'
            end
          end
        end
      EOF
      spec_content = <<~EOF
        # frozen_string_literal: true

        require 'spec_helper'

        RSpec.describe 'Convert Foo to Bar' do
          let(:rewriter_name) { '#{group}/#{name}' }
          let(:fake_file_path) { 'foobar.rb' }
          let(:test_content) { 'Foo' }
          let(:test_rewritten_content) { 'Bar' }

          include_examples 'convertable'
        end
      EOF
      File.write("lib/#{group}/#{name}.rb", lib_content)
      File.write("spec/#{group}/#{name}_spec.rb", spec_content)
    end

    def default_snippets_home
      ENV['SYNVERT_SNIPPETS_HOME'] || File.join(ENV['HOME'], '.synvert')
    end

    def plain_output?
      @options[:format] == 'plain'
    end

    def json_output?
      @options[:format] == 'json'
    end
  end
end