module Sequel::Plugins::ValidationClassMethods::ClassMethods

def extract_options!(array)
  array.last.is_a?(Hash) ? array.pop : OPTS
end

def freeze
  @validations.freeze.each_value(&:freeze)
  @validation_reflections.freeze.each_value do |vs|
    vs.freeze.each do |v|
      v.freeze
      v.last.freeze
    end
  end
  super
end

def has_validations?
  !validations.empty?
end

def reflect_validation(type, opts, atts)
  atts.each do |att|
    (validation_reflections[att] ||= []) << [type, opts]
  end
end

def skip_superclass_validations
  superclass.validations.each do |att, procs|
    if @validations[att]
      @validations[att] -= procs
    end
  end
  @skip_superclass_validations = true
end

def skip_superclass_validations?
  @skip_superclass_validations
end

def validate(o)
  validations.each do |att, procs|
    v = case att
    when Array
      att.map{|a| o.get_column_value(a)}
    else
      o.get_column_value(att)
    end
    procs.each {|tag, p| p.call(o, att, v)}
  end
end

def validates(&block)
  Generator.new(self, &block)
end

def validates_acceptance_of(*atts)
  opts = {
    :message => 'is not accepted',
    :allow_nil => true,
    :accept => '1',
    :tag => :acceptance,
  }.merge!(extract_options!(atts))
  reflect_validation(:acceptance, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    o.errors.add(a, opts[:message]) unless v == opts[:accept]
  end
end

def validates_confirmation_of(*atts)
  opts = {
    :message => 'is not confirmed',
    :tag => :confirmation,
  }.merge!(extract_options!(atts))
  reflect_validation(:confirmation, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    o.errors.add(a, opts[:message]) unless v == o.get_column_value(:"#{a}_confirmation")
  end
end

def validates_each(*atts, &block)
  opts = extract_options!(atts)
  blank_meth = db.method(:blank_object?).to_proc
  i = opts[:if]
  am = opts[:allow_missing]
  an = opts[:allow_nil]
  ab = opts[:allow_blank]
  blk = if i || am || an || ab
    if i.is_a?(Proc)
      i = Plugins.def_sequel_method(self, "validation_class_methods_if", 0, &i)
    end
    proc do |o,a,v|
      next if i && !validation_if_proc(o, i)
      next if an && Array(v).all?(&:nil?)
      next if ab && Array(v).all?(&blank_meth)
      next if am && Array(a).all?{|x| !o.values.has_key?(x)}
      yield(o, a, v)
    end
  else
    block
  end
  tag = opts[:tag]
  atts.each do |a| 
    a_vals = Sequel.synchronize{validations[a] ||= []}
    if tag && (old = a_vals.find{|x| x[0] == tag})
      old[1] = blk
    else
      a_vals << [tag, blk]
    end
  end
end

def validates_format_of(*atts)
  opts = {
    :message => 'is invalid',
    :tag => :format,
  }.merge!(extract_options!(atts))
  
  unless opts[:with].is_a?(Regexp)
    raise ArgumentError, "A regular expression must be supplied as the :with option of the options hash"
  end
  
  reflect_validation(:format, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    o.errors.add(a, opts[:message]) unless v.to_s =~ opts[:with]
  end
end

def validates_inclusion_of(*atts)
  opts = extract_options!(atts)
  n = opts[:in]
  unless n && (n.respond_to?(:cover?) || n.respond_to?(:include?))
    raise ArgumentError, "The :in parameter is required, and must respond to cover? or include?"
  end
  opts[:message] ||= "is not in range or set: #{n.inspect}"
  reflect_validation(:inclusion, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    o.errors.add(a, opts[:message]) unless n.public_send(n.respond_to?(:cover?) ? :cover? : :include?, v)
  end
end

def validates_length_of(*atts)
  opts = {
    :nil_message  => 'is not present',
    :too_long     => 'is too long',
    :too_short    => 'is too short',
    :wrong_length => 'is the wrong length'
  }.merge!(extract_options!(atts))
  
  opts[:tag] ||= ([:length] + [:maximum, :minimum, :is, :within].reject{|x| !opts.include?(x)}).join('-').to_sym
  reflect_validation(:length, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    if m = opts[:maximum]
      o.errors.add(a, opts[:message] || (v ? opts[:too_long] : opts[:nil_message])) unless v && v.size <= m
    end
    if m = opts[:minimum]
      o.errors.add(a, opts[:message] || opts[:too_short]) unless v && v.size >= m
    end
    if i = opts[:is]
      o.errors.add(a, opts[:message] || opts[:wrong_length]) unless v && v.size == i
    end
    if w = opts[:within]
      o.errors.add(a, opts[:message] || opts[:wrong_length]) unless v && w.public_send(w.respond_to?(:cover?) ? :cover? : :include?, v.size)
    end
  end
end

def validates_numericality_of(*atts)
  opts = {
    :message => 'is not a number',
    :tag => :numericality,
  }.merge!(extract_options!(atts))
  reflect_validation(:numericality, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    begin
      if opts[:only_integer]
        Kernel.Integer(v.to_s)
      else
        Kernel.Float(v.to_s)
      end
    rescue
      o.errors.add(a, opts[:message])
    end
  end
end

def validates_presence_of(*atts)
  opts = {
    :message => 'is not present',
    :tag => :presence,
  }.merge!(extract_options!(atts))
  reflect_validation(:presence, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    o.errors.add(a, opts[:message]) if db.send(:blank_object?, v) && v != false
  end
end

def validates_schema_type(*atts)
  opts = {
    :tag => :schema_type,
  }.merge!(extract_options!(atts))
  reflect_validation(:schema_type, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    next if v.nil? || (klass = o.send(:schema_type_class, a)).nil?
    if klass.is_a?(Array) ? !klass.any?{|kls| v.is_a?(kls)} : !v.is_a?(klass)
      message = opts[:message] || "is not a valid #{Array(klass).join(" or ").downcase}"
      o.errors.add(a, message)
    end
  end
end

def validates_uniqueness_of(*atts)
  opts = {
    :message => 'is already taken',
    :tag => :uniqueness,
  }.merge!(extract_options!(atts))
  reflect_validation(:uniqueness, opts, atts)
  atts << opts
  validates_each(*atts) do |o, a, v|
    error_field = a
    a = Array(a)
    v = Array(v)
    next if v.empty? || !v.all?
    ds = o.class.where(a.zip(v))
    num_dups = ds.count
    allow = if num_dups == 0
      # No unique value in the database
      true
    elsif num_dups > 1
      # Multiple "unique" values in the database!!
      # Someone didn't add a unique index
      false
    elsif o.new?
      # New record, but unique value already exists in the database
      false
    elsif ds.first === o
      # Unique value exists in database, but for the same record, so the update won't cause a duplicate record
      true
    else
      false
    end
    o.errors.add(error_field, opts[:message]) unless allow
  end
end

def validation_if_proc(o, i)
  case i
  when Symbol
    o.get_column_value(i)
  else
    raise(::Sequel::Error, "invalid value for :if validation option")
  end
end