# frozen_string_literal: true

class Seed < ApplicationRecord
  extend FriendlyId
  include PhotoCapable
  include Finishable
  include Ownable
  include Jobbable

  friendly_id :seed_slug, use: %i(slugged finders)

  TRADABLE_TO_VALUES = %w(nowhere locally nationally internationally).freeze
  ORGANIC_VALUES = ['certified organic', 'non-certified organic', 'conventional/non-organic', 'unknown'].freeze
  GMO_VALUES = ['certified GMO-free', 'non-certified GMO-free', 'GMO', 'unknown'].freeze
  HEIRLOOM_VALUES = %w(heirloom hybrid unknown).freeze
  SOURCE_VALUES = ['seed catalogue', 'retail outlet', 'seed bank or similar institution',
                   'traded from another person', 'my own seed saving', 'other/unknown'].freeze
  # A seed packet dated outside this is a typo, not a plan.
  PLANT_BEFORE_YEARS = (1900..2100)

  #
  # Relationships
  belongs_to :crop
  belongs_to :parent_planting, class_name: 'Planting',
                               optional: true, inverse_of: :child_seeds # parent
  has_many :child_plantings, class_name: 'Planting',
                             foreign_key: 'parent_seed_id', dependent: :nullify,
                             inverse_of: :parent_seed # children

  #
  # Validations
  validates :crop, approved: true
  validates :crop, presence: { message: :crop_not_found }
  validates :quantity, allow_nil:    true,
                       numericality: { only_integer: true, greater_than_or_equal_to: 0 }
  validates :days_until_maturity_min, allow_nil:    true,
                                      numericality: { only_integer: true, greater_than_or_equal_to: 0 }
  validates :days_until_maturity_max, allow_nil:    true,
                                      numericality: { only_integer: true, greater_than_or_equal_to: 0 }
  validates :row_spacing, allow_nil:    true,
                          numericality: { only_integer: true, greater_than: 0 }
  validates :variety, :batch_number, length: { maximum: 100 }
  validates :packet_text, length: { maximum: 20_000 }
  validate :plant_before_year_is_a_year
  validates :tradable_to, allow_blank: false,
                          inclusion:   { in: TRADABLE_TO_VALUES, message: :tradable_to_inclusion }
  validates :organic, allow_blank: false,
                      inclusion:   { in: ORGANIC_VALUES, message: :organic_inclusion }
  validates :gmo, allow_blank: false,
                  inclusion:   { in: GMO_VALUES, message: :gmo_inclusion }
  validates :heirloom, allow_blank: false,
                       inclusion:   { in: HEIRLOOM_VALUES, message: :heirloom_inclusion }
  validates :source, allow_blank: true,
                     inclusion:   { in: SOURCE_VALUES, message: :source_inclusion }

  #
  # Photos
  # The photo of one side of the packet, front or back, if there is one. When a
  # side has been photographed again, the newest photo. The older one keeps its
  # label, as it is still a photo of a packet, and not of the crop.
  def packet_photo(side)
    photo_associations.where(label: side).order(:id).last&.photo
  end

  # Which side of the packet a photo of this seed is of, if it is of one. Uses
  # the loaded photo associations, so a page of photos reads them once.
  def label_of(photo)
    photo_associations.find { |association| association.photo_id == photo.id }&.label
  end

  # The packet's front, if there is a photo of it. Otherwise the most liked
  # photo that is not of the back.
  def default_photo
    packet_photo('front') || most_liked_photo
  end

  def most_liked_photo
    photos.merge(PhotoAssociation.where(label: [nil, 'front'])).order(likes_count: :desc, created_at: :desc).first
  end

  #
  # Delegations
  delegate :name, to: :crop, prefix: true
  delegate :location, :latitude, :longitude, to: :owner
  delegate :login_name, :slug, :location, to: :owner, prefix: true

  #
  # Scopes
  default_scope { joins(:owner).merge(Member.kept) } # Ensure owner exists
  scope :tradable, -> { where.not(tradable_to: 'nowhere') }
  scope :interesting, -> { tradable.has_location }
  scope :has_location, -> { joins(:owner).where.not('members.location': nil) }
  scope :recent, -> { order(created_at: :desc) }
  scope :active, -> { where('finished <> true').where('finished_at IS NULL OR finished_at < ?', Time.zone.now) }
  # Where seeds came from, as the filter chips name it.
  SOURCES_BY_KIND = {
    'own'    => ['my own seed saving'],
    'bought' => ['seed catalogue', 'retail outlet', 'seed bank or similar institution'],
    'traded' => ['traded from another person']
  }.freeze
  scope :from_source, ->(kind) { where(source: SOURCES_BY_KIND.fetch(kind)) }
  scope :heirlooms, -> { where(heirloom: 'heirloom') }

  # Seeds of a crop and of its varieties: choosing tomato finds Brandywine
  # tomato seeds too.
  scope :of_crop, ->(crop) { where(crop_id: Crop.where(id: crop.id).or(Crop.where(parent_id: crop.id)).select(:id)) }
  scope :expired, -> { active.where('plant_before < ?', Time.zone.today) }

  # "Plant before" only ever means a season, not a day: seed keeps until the
  # end of the year it is dated to. So members give the year alone, and it is
  # stored as the last day of that year — the column stays a date, and the
  # `expired` scope goes on working unchanged.
  def plant_before_year
    # What was typed, when it was not a year, so the member sees their own
    # input beside the error rather than an emptied field.
    @bad_plant_before_year || plant_before&.year
  end

  def plant_before_year=(year)
    given = year.to_s.strip
    @bad_plant_before_year = nil
    if given.blank?
      self.plant_before = nil
    elsif given.match?(/\A\d{4}\z/) && PLANT_BEFORE_YEARS.cover?(given.to_i)
      self.plant_before = Date.new(given.to_i, 12, 31)
    else
      # Kept so the member sees what they typed, with the error, instead of an
      # emptied field.
      @bad_plant_before_year = given
      self.plant_before = nil
    end
  end

  def tradable
    tradable_to != 'nowhere'
  end

  # Whether the year to sow it by has gone.
  def past_sow_by?
    plant_before.present? && plant_before < Time.zone.today
  end

  # 'heirloom' or 'hybrid', or nil when it isn't known.
  def heirloom_kind
    heirloom unless heirloom == 'unknown'
  end

  def seed_slug
    "#{owner.login_name}-#{crop}".downcase.tr(' ', '-')
  end

  def to_s
    I18n.t('seeds.string', crop: crop.name, owner:)
  end

  def self.homepage_records(limit)
    current.tradable
           .where("plant_before IS NULL OR plant_before < ?", Time.zone.today)
           .order(created_at: :desc)
           .limit(limit)
  end

  private

  def plant_before_year_is_a_year
    return if @bad_plant_before_year.blank?

    errors.add(:plant_before_year,
               "must be a year between #{PLANT_BEFORE_YEARS.first} and #{PLANT_BEFORE_YEARS.last}")
  end
end