=begin

Generalizes the hybrid storage manager to be more declarative in 
syntax. Matches are executed in order of appearance so the first
matching manager is returned. You should always add at least one
manager with no constraints as a default case.

### Example

  StorageManager::Match.new do |matcher|
    matcher.add_manager(type: :crop) do
      StorageManager::SFTP.new("raikou3.donmai.us", base_url: "https://raikou3.donmai.us", hierarchical: true, base_dir: "/var/www/raikou3")
    end

    matcher.add_manager(id: 1..850_000) do
      StorageManager::SFTP.new("raikou1.donmai.us", base_url: "https://raikou1.donmai.us", hierarchical: true, base_dir: "/var/www/raikou1")
    end

    matcher.add_manager(id: 850_001..2_000_000) do
      StorageManager::SFTP.new("raikou2.donmai.us", base_url: "https://raikou2.donmai.us", hierarchical: true, base_dir: "/var/www/raikou2")
    end

    matcher.add_manager(id: 1..3_000_000, type: [:large, :original]) do
      StorageManager::SFTP.new(*Danbooru.config.all_server_hosts, base_url: "https://hijiribe.donmai.us/data")
    end

    matcher.add_manager({}) do
      StorageManager::SFTP.new(*Danbooru.config.all_server_hosts, base_url: "#{CurrentUser.root_url}/data")
    end
  end

=end

class StorageManager::Match < StorageManager
  def initialize
    @managers = []

    yield self if block_given?
  end

  def add_manager(constraints)
    manager = yield
    @managers << [constraints, manager]
  end

  def find(params)
    @managers.each do |constraints, manager|
      match = true

      if params[:id] && constraints[:id] && !constraints[:id].include?(params[:id].to_i)
        match = false
      end

      if constraints[:id] && !params[:id]
        match = false
      end

      if params[:type] && constraints[:type]
        if constraints[:type].respond_to?(:include?) 
          if !constraints[:type].include?(params[:type])
            match = false
          end
        elsif constraints[:type] != params[:type]
          match = false
        end
      end

      if constraints[:type] && !params[:type]
        match = false
      end

      if match
        if block_given?
          return yield(manager)
        else
          return manager
        end
      end
    end
  end

  def store_file(io, post, type)
    find(id: post.id, type: type) do |manager|
      manager.store_file(io, post, type)
    end
  end

  def delete_file(post_id, md5, file_ext, type)
    find(id: post_id, type: type) do |manager|
      manager.delete_file(post_id, md5, file_ext, type)
    end
  end

  def open_file(post, type)
    find(id: post.id, type: type) do |manager|
      manager.open_file(post, type)
    end
  end

  def file_url(post, type, **options)
    find(id: post.id, type: type) do |manager|
      manager.file_url(post, type, **options)
    end
  end

  def file_path(post, file_ext, type, **options)
    find(id: post.id, type: type) do |manager|
      manager.file_path(post, file_ext, type, **options)
    end
  end
end