# ================================ Customizable Settings ================================
# ================================================================
# Discount by Product
#
# Any matching item will be discounted by the entered amount.
#
# - 'product_selector_match_type' determines whether we look for
# products that do or don't match the entered selectors. Can
# be:
# - ':include' to check if the product does match
# - ':exclude' to make sure the product doesn't match
# - 'product_selector_type' determines how eligible products
# will be identified. Can be either:
# - ':tag' to find products by tag
# - ':type' to find products by type
# - ':vendor' to find products by vendor
# - ':product_id' to find products by ID
# - ':variant_id' to find products by variant ID
# - ':subscription' to find subscription products
# - ':all' for all products
# - 'product_selectors' is a list of identifiers (from above)
# for qualifying products. Product/Variant ID lists should
# only contain numbers (ie. no quotes). If ':all' is used,
# this can also be 'nil'.
# - 'discount_type' is the type of discount to provide. Can be
# either:
# - ':percent'
# - ':dollar'
# - 'discount_amount' is the percentage/dollar discount to
# apply (per item)
# - 'discount_message' is the message to show when a discount
# is applied
# ================================================================
PRODUCT_DISCOUNTS = [
{
product_selector_match_type: :include,
product_selector_type: :tag,
product_selectors: ["your_tag"],
discount_type: :percent,
discount_amount: 10,
discount_message: '10% off tagged products!'
}
]

# ================================ Script Code (do not edit) ================================
# ================================================================
# ProductSelector
#
# Finds matching products by the entered criteria.
# ================================================================
class ProductSelector
def initialize(match_type, selector_type, selectors)
@match_type = match_type
@comparator = match_type == :include ? 'any?' : 'none?'
@selector_type = selector_type
@selectors = selectors
end

def match?(line_item)
if self.respond_to?(@selector_type)
self.send(@selector_type, line_item)
else
raise RuntimeError.new('Invalid product selector type')
end
end

def tag(line_item)
product_tags = line_item.variant.product.tags.map { |tag| tag.downcase.strip }
@selectors = @selectors.map { |selector| selector.downcase.strip }
(@selectors & product_tags).send(@comparator)
end

def type(line_item)
@selectors = @selectors.map { |selector| selector.downcase.strip }
(@match_type == :include) == @selectors.include?(line_item.variant.product.product_type.downcase.strip)
end

def vendor(line_item)
@selectors = @selectors.map { |selector| selector.downcase.strip }
(@match_type == :include) == @selectors.include?(line_item.variant.product.vendor.downcase.strip)
end

def product_id(line_item)
(@match_type == :include) == @selectors.include?(line_item.variant.product.id)
end

def variant_id(line_item)
(@match_type == :include) == @selectors.include?(line_item.variant.id)
end

def subscription(line_item)
!line_item.selling_plan_id.nil?
end

def all(line_item)
true
end
end

# ================================================================
# DiscountApplicator
#
# Applies the entered discount to the supplied line item.
# ================================================================
class DiscountApplicator
def initialize(discount_type, discount_amount, discount_message)
@discount_type = discount_type
@discount_message = discount_message

@discount_amount = if discount_type == :percent
1 - (discount_amount * 0.01)
else
Money.new(cents: 100) * discount_amount
end
end

def apply(line_item)
new_line_price = if @discount_type == :percent
line_item.line_price * @discount_amount
else
[line_item.line_price - (@discount_amount * line_item.quantity), Money.zero].max
end

line_item.change_line_price(new_line_price, message: @discount_message)
end
end

# ================================================================
# ProductDiscountCampaign
#
# Any matching item will be discounted by the entered amount.
# ================================================================
class ProductDiscountCampaign
def initialize(campaigns)
@campaigns = campaigns
end

def run(cart)
@campaigns.each do |campaign|
product_selector = ProductSelector.new(
campaign[:product_selector_match_type],
campaign[:product_selector_type],
campaign[:product_selectors],
)

discount_applicator = DiscountApplicator.new(
campaign[:discount_type],
campaign[:discount_amount],
campaign[:discount_message]
)

cart.line_items.each do |line_item|
next unless product_selector.match?(line_item)
discount_applicator.apply(line_item)
end
end
end
end

CAMPAIGNS = [
ProductDiscountCampaign.new(PRODUCT_DISCOUNTS),
]

CAMPAIGNS.each do |campaign|
campaign.run(Input.cart)
end

Output.cart = Input.cart