require 'pathname'
require 'json'

module KPM
  class PluginsManager

    def initialize(plugins_dir, logger)
      @plugins_dir = Pathname.new(plugins_dir)
      @logger = logger
    end

    def set_active(plugin_name_or_path, plugin_version=nil)
      if plugin_name_or_path.nil?
        @logger.warn('Unable to mark a plugin as active: no name or path specified')
        return
      end

      if plugin_version.nil?
        # Full path specified, with version
        link = Pathname.new(plugin_name_or_path).join('../SET_DEFAULT')
        FileUtils.rm_f(link)
        FileUtils.ln_s(plugin_name_or_path, link, :force => true)
      else
        # Plugin name (fs directory) specified
        plugin_dir_glob = @plugins_dir.join('*').join(plugin_name_or_path)
        # Only one should match (java or ruby plugin)
        Dir.glob(plugin_dir_glob).each do |plugin_dir_path|
          plugin_dir = Pathname.new(plugin_dir_path)
          link = plugin_dir.join('SET_DEFAULT')
          FileUtils.rm_f(link)
          FileUtils.ln_s(plugin_dir.join(plugin_version), link, :force => true)
        end
      end

      update_fs(plugin_name_or_path, plugin_version) do |tmp_dir|
        FileUtils.rm_f(tmp_dir.join('disabled.txt'))
        FileUtils.rm_f(tmp_dir.join('restart.txt'))
      end
    end

    def uninstall(plugin_name_or_path, plugin_version=nil)
      update_fs(plugin_name_or_path, plugin_version) do |tmp_dir|
        FileUtils.rm_f(tmp_dir.join('restart.txt'))
        # Be safe, keep the code, just never start it
        FileUtils.touch(tmp_dir.join('disabled.txt'))
      end
    end

    def restart(plugin_name_or_path, plugin_version=nil)
      update_fs(plugin_name_or_path, plugin_version) do |tmp_dir|
        # Remove disabled.txt so that the plugin is started if it was stopped
        FileUtils.rm_f(tmp_dir.join('disabled.txt'))
        FileUtils.touch(tmp_dir.join('restart.txt'))
      end
    end

    def validate_plugin_identifier_key(plugin_key, coordinate_map)
      identifiers = read_plugin_identifiers
      entry = identifiers[plugin_key]
      if entry
        coordinate_map.each_pair do |key, value|
          return false if !validate_plugin_identifier_key_value(plugin_key, key, entry[key.to_s], value)
        end
      end
      true
    end

    def add_plugin_identifier_key(plugin_key, plugin_name, language, coordinate_map)

      identifiers = read_plugin_identifiers
      # If key does not already exists or if the version in the json is not the one we are currently installing we update the entry, if not nothing to do
      if !identifiers.has_key?(plugin_key) ||
         (coordinate_map && identifiers[plugin_key]['version'] != coordinate_map[:version])

        entry = {'plugin_name' => plugin_name}
        entry['language'] = language
        if coordinate_map
          entry['group_id'] = coordinate_map[:group_id]
          entry['artifact_id'] = coordinate_map[:artifact_id]
          entry['packaging'] = coordinate_map[:packaging]
          entry['classifier'] = coordinate_map[:classifier]
          entry['version'] = coordinate_map[:version]
        end
        identifiers[plugin_key] = entry
        write_plugin_identifiers(identifiers)
      end

      identifiers
    end

    def remove_plugin_identifier_key(plugin_key)
      identifiers = read_plugin_identifiers
      # If key does not already exists we update it, if not nothing to do.
      if identifiers.has_key?(plugin_key)
        identifiers.delete(plugin_key)
        write_plugin_identifiers(identifiers)
      end

      identifiers
    end

    def get_plugin_key_and_name(plugin_name_or_key)
      identifiers = read_plugin_identifiers
      if identifiers.has_key?(plugin_name_or_key)
        # It's a plugin key
        [plugin_name_or_key, identifiers[plugin_name_or_key]['plugin_name']]
      else
        # Check it's already a plugin name
        identifiers.each { |plugin_key, entry| return [plugin_key, plugin_name_or_key] if entry['plugin_name'] == plugin_name_or_key }
        nil
      end
    end

    def get_identifier_key_and_entry(plugin_name_or_key)
      identifiers = read_plugin_identifiers
      identifiers.each_pair do |key, value|
        return [key, value] if key == plugin_name_or_key || value['plugin_name'] == plugin_name_or_key
      end
      nil
    end

    def guess_plugin_name(artifact_id)
      return nil if artifact_id.nil?
      captures = artifact_id.scan(/(.*)-plugin/)
      if captures.empty? || captures.first.nil? || captures.first.first.nil?
        short_name = artifact_id
      else
        # 'analytics-plugin' or 'stripe-plugin' passed
        short_name = captures.first.first
      end
      Dir.glob(@plugins_dir.join('*').join('*')).each do |plugin_path|
        plugin_name = File.basename(plugin_path)
        if plugin_name == short_name ||
            plugin_name == artifact_id ||
            !plugin_name.scan(/-#{short_name}/).empty? ||
            !plugin_name.scan(/#{short_name}-/).empty?
          return plugin_name
        end
      end
      nil
    end

    def read_plugin_identifiers
      path = Pathname.new(@plugins_dir).join('plugin_identifiers.json')
      identifiers = {}
      begin
        identifiers = File.open(path, 'r') do |f|
          JSON.parse(f.read)
        end
      rescue Errno::ENOENT
      end
      identifiers
    end

    private

    def validate_plugin_identifier_key_value(plugin_key, value_type, entry_value, coordinate_value)
      # The json does not contain the coordinates (case when installed from install_plugin_from_fs)
      return true if entry_value.nil?

      if entry_value != coordinate_value
        @logger.warn("Entry in plugin_identifiers.json for key #{plugin_key} does not match for coordinate #{value_type}: got #{coordinate_value} instead of #{entry_value}")
        return false
      end
      true
    end

    def write_plugin_identifiers(identifiers)

      path = Pathname.new(@plugins_dir).join('plugin_identifiers.json')
      Dir.mktmpdir do |tmp_dir|
        tmp_path = Pathname.new(tmp_dir).join('plugin_identifiers.json')
        File.open(tmp_path, 'w') do |f|
          f.write(identifiers.to_json)
        end

        FileUtils.mv(tmp_path, path)
      end
    end

    # Note: the plugin name here is the directory name on the filesystem
    def update_fs(plugin_name_or_path, plugin_version=nil, &block)
      if plugin_name_or_path.nil?
        @logger.warn('Unable to update the filesystem: no name or path specified')
        return
      end

      p = plugin_version.nil? ? plugin_name_or_path : @plugins_dir.join('*').join(plugin_name_or_path).join(plugin_version == :all ? '*' : plugin_version)

      modified = []
      Dir.glob(p).each do |plugin_dir_path|
        plugin_dir = Pathname.new(plugin_dir_path)
        tmp_dir = plugin_dir.join('tmp')
        FileUtils.mkdir_p(tmp_dir)

        yield(tmp_dir) if block_given?

        modified << plugin_dir
      end

      if modified.empty?
        if plugin_version.nil?
          @logger.warn("No plugin found with name #{plugin_name_or_path}. Installed plugins: #{Dir.glob(@plugins_dir.join('*').join('*'))}")
        else
          @logger.warn("No plugin found with name #{plugin_name_or_path} and version #{plugin_version}. Installed plugins: #{Dir.glob(@plugins_dir.join('*').join('*').join('*'))}")
        end
      end

      modified
    end
  end
end