module Skr

    class SoLine < Skr::Model

        acts_as_uom
        is_sku_loc_line parent: 'sales_order'

        belongs_to :sales_order
        belongs_to :sku_loc, export: true
        has_one :sku, :through => :sku_loc, export: true
        has_one :location, :through => :sales_order
        has_many :pt_lines,  :before_add=>:setup_new_pt_line, :inverse_of=>:so_line,
                 extend: Concerns::PT::Lines, :listen=>{save:'update_qty_picking'}

        # has_many :inv_lines, :before_add=>:setup_new_inv_line, :inverse_of=>:so_line

        validates :sales_order, :sku_loc,  set: true

        validates :price, :qty, :numericality=>true
        validates :qty_allocated, :numericality=>{ :greater_than_or_equal_to=>0 }
        validate  :ensure_allocation_is_correct
        validate  :ensure_so_is_open, on: :create

        has_additional_events :qty_change

        before_validation   :set_defaults_from_associations
        before_create  :allocate_max_available
        before_destroy :ensure_deleteable

        scope :open, ->{
            joins(:sales_order).merge(SalesOrder.open).where( arel_table[:qty].gt( arel_table[:qty_invoiced] ) )
        }
        scope :allocated,   ->{ where( arel_table[:qty_allocated].gt( 0 ) ) }
        scope :unallocated, ->{
            t = table_name; where( "#{t}.qty_allocated < #{t}.qty - #{t}.qty_invoiced - #{t}.qty_canceled" )
        }
        scope :unshipped, lambda {|unused=nil|
            t = table_name; where( "#{t}.qty > #{t}.qty_invoiced + #{t}.qty_canceled" )
        }
        scope :pickable,    ->{ where( arel_table[:qty_allocated].gt( arel_table[:qty_picking] ) ) }

        def location=(location)
            self.cancel!
            self.sku_loc = self.sku.sku_locs.find_or_create_for( location )
            self.allocate_max_available
            self.save!
            self
        end

        # allocate the maximum available qty to the line
        def allocate_max_available
            self.qty_allocated = [ 0, [ sku_loc.qty_available+qty_allocated, qty ].min ].max if self.sku.does_track_inventory?
            self
        end

        # A line is fully allocated if the qty_allocated is less than the qty ordered - the qty invoiced - the qty canceled
        # @return [Boolean]
        def is_fully_allocated?
            self.qty_allocated >= qty - qty_invoiced - qty_canceled
        end

        # The pickable qty is the qty allocated - the qty already on pick tickets
        # @return [Fixnum]
        def pickable_qty
            qty_allocated - qty_picking
        end

        def cancel!
            self.update_attributes :qty_allocated => 0, :qty_picking=> 0
            pt_lines.picking.each{ |ptl| ptl.cancel! }
        end

        private

        def update_qty_shipped
            inv_qty = self.inv_lines.sum(:qty)
            update_attributes( :qty_invoiced=> inv_qty, :qty_allocated => [ qty_allocated - inv_qty, 0 ].max )
        end
        def update_qty_picking( pt=nil )
            update_attributes( :qty_picking=> pt_lines.ea_picking_qty/uom_size )
        end


        def fire_after_save_events
            %w{ allocated picking invoiced canceled }.each do | event |
                if changes[ "qty_#{event}" ]
                    fire_event( :qty_change )
                    break
                end
            end
            super
        end

        def set_defaults_from_associations
            self.uom         = sku.uoms.default if self.uom_code.blank?
            self.description = sku.description if self.description.blank?
            self.sku_code    = sku.code        if self.sku_code.blank?
            if !price && sales_order && sales_order.customer && sku_loc && uom.present?
                self.price = Skr.config.pricing_provider.price(sku_loc:sku_loc, customer:sales_order.customer, uom:uom, qty:qty)
            end
            true
        end

        def setup_new_inv_line( line )
            line.qty = self.sku.is_other_charge? ? self.qty : self.qty_allocated
            setup_new_line(line)
        end
        def setup_new_pt_line( line )
            line.qty = self.sku.is_other_charge? ? self.qty : self.pickable_qty
            setup_new_line(line)
        end

        def setup_new_line(line)
            line.price    = self.price
            line.sku_loc  = self.sku_loc
            line.uom      = self.uom
            true
        end

        def ensure_allocation_is_correct
            return true unless qty_allocated_changed?
            diff = qty_allocated - qty_allocated_was
            if qty_allocated > qty
                errors.add(:qty_allocated, "must be less than qty ordered (#{qty})")
            end
            if diff > 0 && sku_loc && diff > sku_loc.qty_available
                errors.add(:qty_allocated, "new allocation (#{qty_allocated}) - old allocation (#{qty_allocated_was}) can't be more than qty available (#{ sku_loc.qty_available })")
                return false
            end
            true
        end


        def ensure_so_is_open
            unless self.sales_order.open?
                errors.add(:base,"Cannot add item #{self.sku_code} to non-open Sales Order")
                return false
            end
            true
        end

        def ensure_deleteable
            if qty_allocated > 0
                errors.add(:base,'Cannot delete line when allocated')
                return false
            end
            if qty_invoiced > 0
                errors.add(:base,"Cannot delete line after it's shipped")
                return false
            end
            true
        end



    end


end # Skr module