# coding: utf-8
module Chouette
  class VehicleJourney < Chouette::TridentActiveRecord
    has_metadata
    include ChecksumSupport
    include CustomFieldsSupport
    include VehicleJourneyRestrictions
    include ObjectidSupport
    include StifTransportModeEnumerations

    enum journey_category: { timed: 0, frequency: 1 }

    default_scope { where(journey_category: journey_categories[:timed]) }

    attr_reader :time_table_tokens

    def self.nullable_attributes
      [:transport_mode, :published_journey_name, :vehicle_type_identifier, :published_journey_identifier, :comment]
    end

    belongs_to :company
    belongs_to :route
    belongs_to :journey_pattern
    belongs_to :journey_pattern_only_objectid, -> {select("journey_patterns.objectid")}, class_name: "Chouette::JourneyPattern", foreign_key: :journey_pattern_id
    has_many :stop_areas, through: :journey_pattern

    has_and_belongs_to_many :footnotes, :class_name => 'Chouette::Footnote'
    has_and_belongs_to_many :purchase_windows, :class_name => 'Chouette::PurchaseWindow'
    has_array_of :ignored_routing_contraint_zones, class_name: 'Chouette::RoutingConstraintZone'

    validates_presence_of :route
    validates_presence_of :journey_pattern
    # validates :vehicle_journey_at_stops,
      # Validation temporarily removed for day offsets
      # :vjas_departure_time_must_be_before_next_stop_arrival_time,

      # vehicle_journey_at_stops_are_in_increasing_time_order: false
    validates_presence_of :number

    has_many :vehicle_journey_at_stops, -> { includes(:stop_point).order("stop_points.position") }, :dependent => :destroy
    has_and_belongs_to_many :time_tables, :class_name => 'Chouette::TimeTable', :foreign_key => "vehicle_journey_id", :association_foreign_key => "time_table_id"
    has_many :stop_points, -> { order("stop_points.position") }, :through => :vehicle_journey_at_stops

    before_validation :set_default_values,
      :calculate_vehicle_journey_at_stop_day_offset

    scope :with_stop_area_ids, ->(ids){
      _ids = ids.select(&:present?).map(&:to_i)
      if _ids.present?
        where("array(SELECT stop_points.stop_area_id::integer FROM stop_points INNER JOIN journey_patterns_stop_points ON journey_patterns_stop_points.stop_point_id = stop_points.id WHERE journey_patterns_stop_points.journey_pattern_id = vehicle_journeys.journey_pattern_id) @> array[?]", _ids)
      else
        all
      end
    }

    scope :with_stop_area_id, ->(id){
      if id.present?
        joins(journey_pattern: :stop_points).where('stop_points.stop_area_id = ?', id)
      else
        all
      end
    }

    scope :with_ordered_stop_area_ids, ->(first, second){
      if first.present? && second.present?
        joins(journey_pattern: :stop_points).
          joins('INNER JOIN "journey_patterns" ON "journey_patterns"."id" = "vehicle_journeys"."journey_pattern_id" INNER JOIN "journey_patterns_stop_points" ON "journey_patterns_stop_points"."journey_pattern_id" = "journey_patterns"."id" INNER JOIN "stop_points" as "second_stop_points" ON "second_stop_points"."id" = "journey_patterns_stop_points"."stop_point_id"').
          where('stop_points.stop_area_id = ?', first).
          where('second_stop_points.stop_area_id = ? and stop_points.position < second_stop_points.position', second)
      else
        all
      end
    }

    scope :starting_with, ->(id){
      if id.present?
        joins(journey_pattern: :stop_points).where('stop_points.position = 0 AND stop_points.stop_area_id = ?', id)
      else
        all
      end
    }

    scope :ending_with, ->(id){
      if id.present?
        pattern_ids = all.select(:journey_pattern_id).uniq.map(&:journey_pattern_id)
        pattern_ids = Chouette::JourneyPattern.where(id: pattern_ids).to_a.select{|jp| p "ici: #{jp.stop_points.order(:position).last.stop_area_id}" ; jp.stop_points.order(:position).last.stop_area_id == id.to_i}.map &:id
        where(journey_pattern_id: pattern_ids)
      else
        all
      end
    }

    scope :in_purchase_window, ->(range){
      purchase_windows = Chouette::PurchaseWindow.overlap_dates(range)
      sql = purchase_windows.joins(:vehicle_journeys).select('vehicle_journeys.id').uniq.to_sql
      where("vehicle_journeys.id IN (#{sql})")
    }

    # We need this for the ransack object in the filters
    ransacker :purchase_window_date_gt
    ransacker :stop_area_ids

    # returns VehicleJourneys with at least 1 day in their time_tables
    # included in the given range
    def self.with_matching_timetable date_range
      out = []
      time_tables = Chouette::TimeTable.where(id: self.joins("INNER JOIN time_tables_vehicle_journeys ON vehicle_journeys.id = time_tables_vehicle_journeys.vehicle_journey_id").pluck('time_tables_vehicle_journeys.time_table_id')).overlapping(date_range)
      time_tables = time_tables.select do |time_table|
        range = date_range
        range = date_range & (time_table.start_date-1.day..time_table.end_date+1.day) || [] if time_table.start_date.present? && time_table.end_date.present?
        range.any?{|d| time_table.include_day?(d) }
      end
      out += time_tables.map{|t| t.vehicle_journey_ids}.flatten
      where(id: out)
    end

    # TODO: Remove this validator
    # We've eliminated this validation because it prevented vehicle journeys
    # from being saved with at-stops having a day offset greater than 0,
    # because these would have times that were "earlier" than the previous
    # at-stop. TBD by Luc whether we're deleting this validation altogether or
    # instead rejiggering it to work with day offsets.
    def vjas_departure_time_must_be_before_next_stop_arrival_time
      notice = 'departure time must be before next stop arrival time'
      vehicle_journey_at_stops.each_with_index do |current_stop, index|
        next_stop = vehicle_journey_at_stops[index + 1]

        next unless next_stop && (next_stop[:arrival_time] < current_stop[:departure_time])

        current_stop.errors.add(:departure_time, notice)
        self.errors.add(:vehicle_journey_at_stops, notice)
      end
    end

    def local_id
      "IBOO-#{self.referential.id}-#{self.route.line.get_objectid.local_id}-#{self.id}"
    end

    def checksum_attributes
      [].tap do |attrs|
        attrs << self.published_journey_name
        attrs << self.published_journey_identifier
        attrs << self.try(:company).try(:get_objectid).try(:local_id)
        attrs << self.footnotes.map(&:checksum).sort

        vjas =  self.vehicle_journey_at_stops
        vjas += VehicleJourneyAtStop.where(vehicle_journey_id: self.id) unless self.new_record?
        attrs << vjas.uniq.sort_by { |s| s.stop_point&.position }.map(&:checksum)

        attrs << self.purchase_windows.map(&:checksum).sort if purchase_windows.present?
        attrs << ignored_routing_contraint_zones.map(&:checksum).sort if ignored_routing_contraint_zones.present?
      end
    end

    has_checksum_children VehicleJourneyAtStop

    def set_default_values
      if number.nil?
        self.number = 0
      end
    end

    def sales_start
      purchase_windows.map{|p| p.date_ranges.map &:first}.flatten.min
    end

    def sales_end
      purchase_windows.map{|p| p.date_ranges.map &:last}.flatten.max
    end

    def calculate_vehicle_journey_at_stop_day_offset
      Chouette::VehicleJourneyAtStopsDayOffset.new(
        vehicle_journey_at_stops
      ).update
    end

    scope :without_any_time_table, -> { joins('LEFT JOIN "time_tables_vehicle_journeys" ON "time_tables_vehicle_journeys"."vehicle_journey_id" = "vehicle_journeys"."id" LEFT JOIN "time_tables" ON "time_tables"."id" = "time_tables_vehicle_journeys"."time_table_id"').where(:time_tables => { :id => nil}) }
    scope :without_any_passing_time, -> { joins('LEFT JOIN "vehicle_journey_at_stops" ON "vehicle_journey_at_stops"."vehicle_journey_id" = "vehicle_journeys"."id"').where(vehicle_journey_at_stops: { id: nil }) }

    accepts_nested_attributes_for :vehicle_journey_at_stops, :allow_destroy => true

    def presenter
      @presenter ||= ::VehicleJourneyPresenter.new( self)
    end

    def vehicle_journey_at_stops_matrix
      at_stops = self.vehicle_journey_at_stops.to_a.dup
      active_stop_point_ids = journey_pattern.stop_points.map(&:id)

      (route.stop_points.map(&:id) - at_stops.map(&:stop_point_id)).each do |id|
        vjas = Chouette::VehicleJourneyAtStop.new(stop_point_id: id)
        vjas.dummy = !active_stop_point_ids.include?(id)
        at_stops.insert(route.stop_points.map(&:id).index(id), vjas)
      end
      at_stops
    end

    def create_or_find_vjas_from_state vjas
      return vehicle_journey_at_stops.find(vjas['id']) if vjas['id']
      stop_point = Chouette::StopPoint.find_by(objectid: vjas['stop_point_objectid'])
      stop       = vehicle_journey_at_stops.create(stop_point: stop_point)
      vjas['id'] = stop.id
      vjas['new_record'] = true
      stop
    end

    def update_vjas_from_state state
      state.each do |vjas|
        next if vjas["dummy"]
        stop_point = Chouette::StopPoint.find_by(objectid: vjas['stop_point_objectid'])
        stop_area = stop_point&.stop_area
        tz = stop_area&.time_zone
        tz = tz && ActiveSupport::TimeZone[tz]
        params = {}.tap do |el|
          ['arrival_time', 'departure_time'].each do |field|
            time = "#{vjas[field]['hour']}:#{vjas[field]['minute']}"
            el[field.to_sym] = Time.parse("2000-01-01 #{time}:00 #{tz&.formatted_offset || "UTC"}")
          end
        end
        stop = create_or_find_vjas_from_state(vjas)
        stop.update_attributes(params)
        vjas.delete('errors')
        vjas['errors'] = stop.errors if stop.errors.any?
      end
    end

    def state_update_vjas? vehicle_journey_at_stops
      departure_times = vehicle_journey_at_stops.map do |vjas|
        "#{vjas['departure_time']['hour']}:#{vjas['departure_time']['minute']}"
      end
      times = departure_times.uniq
      (times.count == 1 && times[0] == '00:00') ? false : true
    end

    def update_has_and_belongs_to_many_from_state item
      ['time_tables', 'footnotes', 'purchase_windows'].each do |assos|
        saved = self.send(assos).map(&:id)

        (saved - item[assos].map{|t| t['id']}).each do |id|
          self.send(assos).delete(self.send(assos).find(id))
        end

        item[assos].each do |t|
          klass = "Chouette::#{assos.classify}".constantize
          unless saved.include?(t['id'])
            self.send(assos) << klass.find(t['id'])
          end
        end
      end
    end

    def self.state_update route, state
      objects = []
      transaction do
        state.each do |item|
          item.delete('errors')
          vj = find_by(objectid: item['objectid']) || state_create_instance(route, item)
          next if item['deletable'] && vj.persisted? && vj.destroy
          objects << vj

          if vj.state_update_vjas?(item['vehicle_journey_at_stops'])
            vj.update_vjas_from_state(item['vehicle_journey_at_stops'])
          end

          vj.update_attributes(state_permited_attributes(item))
          vj.update_has_and_belongs_to_many_from_state(item)
          item['errors']   = vj.errors.full_messages.uniq if vj.errors.any?
          item['checksum'] = vj.checksum
        end

        # Delete ids of new object from state if we had to rollback
        if state.any? {|item| item['errors']}
          state.map do |item|
            item.delete('objectid') if item['new_record']
            item['vehicle_journey_at_stops'].map {|vjas| vjas.delete('id') if vjas['new_record'] }
          end
          raise ::ActiveRecord::Rollback
        end
      end

      # Remove new_record flag && deleted item from state if transaction has been saved
      state.map do |item|
        item.delete('new_record')
        item['vehicle_journey_at_stops'].map {|vjas| vjas.delete('new_record') }
      end
      state.delete_if {|item| item['deletable']}
      objects
    end

    def self.state_create_instance route, item
      # Flag new record, so we can unset object_id if transaction rollback
      vj = route.vehicle_journeys.create(state_permited_attributes(item))
      vj.after_commit_objectid
      item['objectid'] = vj.objectid
      item['short_id'] = vj.get_objectid.short_id
      item['new_record'] = true
      vj
    end

    def self.state_permited_attributes item
      attrs = item.slice(
        'published_journey_identifier',
        'published_journey_name',
        'journey_pattern_id',
        'company_id',
        'ignored_routing_contraint_zone_ids'
      ).to_hash

      if item['journey_pattern']
        attrs['journey_pattern_id'] = item['journey_pattern']['id']
      end

      attrs['company_id'] = item['company'] ? item['company']['id'] : nil

      attrs["custom_field_values"] = Hash[
        *(item["custom_fields"] || {})
          .map { |k, v| [k, v["value"]] }
          .flatten
      ]

      attrs
    end

    def missing_stops_in_relation_to_a_journey_pattern(selected_journey_pattern)
      selected_journey_pattern.stop_points - self.stop_points
    end
    def extra_stops_in_relation_to_a_journey_pattern(selected_journey_pattern)
      self.stop_points - selected_journey_pattern.stop_points
    end
    def extra_vjas_in_relation_to_a_journey_pattern(selected_journey_pattern)
      extra_stops = self.extra_stops_in_relation_to_a_journey_pattern(selected_journey_pattern)
      self.vehicle_journey_at_stops.select { |vjas| extra_stops.include?( vjas.stop_point)}
    end
    def time_table_tokens=(ids)
      self.time_table_ids = ids.split(",")
    end
    def bounding_dates
      dates = []

      time_tables.each do |tm|
        dates << tm.start_date if tm.start_date
        dates << tm.end_date if tm.end_date
      end

      dates.empty? ? [] : [dates.min, dates.max]
    end

    def update_journey_pattern( selected_journey_pattern)
      return unless selected_journey_pattern.route_id==self.route_id

      missing_stops_in_relation_to_a_journey_pattern(selected_journey_pattern).each do |sp|
        self.vehicle_journey_at_stops.build( :stop_point => sp)
      end
      extra_vjas_in_relation_to_a_journey_pattern(selected_journey_pattern).each do |vjas|
        vjas._destroy = true
      end
    end

    def fill_passing_times!
      encountered_empty_vjas = []
      previous_stop = nil
      vehicle_journey_at_stops.each do |vjas|
        sp = vjas.stop_point
        if vjas.arrival_time.nil? && vjas.departure_time.nil?
          encountered_empty_vjas << vjas
        else
          if encountered_empty_vjas.any?
            raise "Cannot extrapolate passing times without an initial time" if previous_stop.nil?
            distance_between_known = 0
            distance_from_last_known = 0
            cost = journey_pattern.costs_between previous_stop.stop_point, encountered_empty_vjas.first.stop_point
            raise "MISSING cost between #{previous_stop.stop_point.stop_area.registration_number} AND #{encountered_empty_vjas.first.stop_point.stop_area.registration_number}" unless cost.present?
            distance_between_known += cost[:distance].to_f
            cost = journey_pattern.costs_between encountered_empty_vjas.last.stop_point, sp
            raise "MISSING cost between #{encountered_empty_vjas.last.stop_point.stop_area.registration_number} AND #{sp.stop_area.registration_number}" unless cost.present?
            distance_between_known += cost[:distance].to_f
            distance_between_known += encountered_empty_vjas.each_slice(2).inject(0) do |sum, slice|
              cost = journey_pattern.costs_between slice.first.stop_point, slice.last.stop_point
              raise "MISSING cost between #{slice.first.stop_point.stop_area.registration_number} AND #{slice.last.stop_point.stop_area.registration_number}" unless cost.present?
              sum + cost[:distance].to_f
            end

            previous = previous_stop
            encountered_empty_vjas.each do |empty_vjas|
              cost = journey_pattern.costs_between previous.stop_point, empty_vjas.stop_point
              raise "MISSING cost between #{previous.stop_point.stop_area.registration_number} AND #{empty_vjas.stop_point.stop_area.registration_number}" unless cost.present?
              distance_from_last_known += cost[:distance]

              arrival_time = vjas.arrival_time + (vjas.arrival_day_offset - previous_stop.departure_day_offset)*24.hours
              time = previous_stop.departure_time + distance_from_last_known.to_f / distance_between_known.to_f * (arrival_time - previous_stop.departure_time)
              day_offset = time.day - 1
              time -= day_offset*24.hours

              empty_vjas.update_attribute :arrival_time, time
              empty_vjas.update_attribute :arrival_day_offset, previous_stop.departure_day_offset + day_offset
              empty_vjas.update_attribute :departure_time, time
              empty_vjas.update_attribute :departure_day_offset, previous_stop.departure_day_offset + day_offset
              previous = empty_vjas
            end
            encountered_empty_vjas = []
          end
          previous_stop = vjas
        end
      end
    end

    def self.matrix(vehicle_journeys)
      Hash[*VehicleJourneyAtStop.where(vehicle_journey_id: vehicle_journeys.pluck(:id)).map do |vjas|
        [ "#{vjas.vehicle_journey_id}-#{vjas.stop_point_id}", vjas]
      end.flatten]
    end

    def self.with_stops
      self
        .joins(:journey_pattern)
        .joins('
          LEFT JOIN "vehicle_journey_at_stops"
            ON "vehicle_journey_at_stops"."vehicle_journey_id" =
              "vehicle_journeys"."id"
            AND "vehicle_journey_at_stops"."stop_point_id" =
              "journey_patterns"."departure_stop_point_id"
        ')
        .order('"vehicle_journey_at_stops"."departure_time"')
    end

    # Requires a SELECT DISTINCT and a join with
    # "vehicle_journey_at_stops".
    #
    # Example:
    #   .select('DISTINCT "vehicle_journeys".*')
    #   .joins('
    #     LEFT JOIN "vehicle_journey_at_stops"
    #       ON "vehicle_journey_at_stops"."vehicle_journey_id" =
    #         "vehicle_journeys"."id"
    #   ')
    #   .where_departure_time_between('08:00', '09:45')
    def self.where_departure_time_between(
      start_time,
      end_time,
      allow_empty: false
    )
      self
        .where(
          %Q(
            "vehicle_journey_at_stops"."departure_time" >= ?
            AND "vehicle_journey_at_stops"."departure_time" <= ?
            #{
              if allow_empty
                'OR "vehicle_journey_at_stops"."id" IS NULL'
              end
            }
          ),
          "2000-01-01 #{start_time}:00 UTC",
          "2000-01-01 #{end_time}:00 UTC"
        )
    end

    def self.without_time_tables
      # Joins the VehicleJourney–TimeTable through table to select only those
      # VehicleJourneys that don't have an associated TimeTable.
      self
        .joins('
          LEFT JOIN "time_tables_vehicle_journeys"
            ON "time_tables_vehicle_journeys"."vehicle_journey_id" =
              "vehicle_journeys"."id"
        ')
        .where('"time_tables_vehicle_journeys"."vehicle_journey_id" IS NULL')
    end
  end
end