Milestones depend on delivery promise configuration

Milestones are calculated based on delivery configuration operations.
Operations taken into account are always_at_start, before_shipping and from_destination. Operations of type after_shipping are not taken into account.
Milestones are precalculated and stored in Endpoint Delivery Promises under the object cutoffs.

Milestone names are auto-generated and match delivery configuration’s operation names. 

Endpoint Delivery Promise (EDP) Cutoff Example

{
    "_id" : ObjectId("618225724bbd51a42c47ce10"),
    "cutoffs" : {
        "prep_time_sfs" : 1636030800,
        "carrier_pickup" : 1636030800,
        "without_always_at_start" : 1636027200,
        "purchase_cutoff" : 1636027200
    },
    "delivery_method" : "STD",
    "delivery_route_id" : "GB_GB_DPD_Standard",
    "eta_end" : 1636232400,
    "eta_start" : 1636117201,
    "expired" : false,
    "pickup_day" : 1635984000,
    "sales_channel_id" : "web",
    "version" : 0,
    "endpoint_ids" : [ 
        "190", 
        "157"
    ],
    "public_id" : "5279a9cc-3c6b-11ec-bf59-02420a0001f3",
    "unavailable_endpoint_ids" : []
}

To exploit milestones during orders treatment, milestones must configured in the worklflow. This allows to set milestones - considered that it has been reached - and set alerts if not reached in time.

Workflow

1. set_milestone : Initiate milestones for line item groups

   1. To make use of milestones, they must be stored for the order at each of its line_item_groups claimed transition. To do so, the action set_milestone has to be set in the claim transition of the line_item_groups.

2. set_milestone_alert : Schedule alerts to be triggered at milestones cutoffs (plus a delay)

   1. Notifications can be scheduled to be triggerd at the time of milestones cutoffs (plus a certain delay). When triggered, a validity check will be performed to ensure the specified milestone has not yet been reached/acheived. If already reached, notifications won't be triggered.

      A special notification named "recompute_cutoffs_sets" can be called to recompute the cutoffs for each milestones.

    placed:
      transitions:
        claimed: # De placed à claimed (VI)
          conditions:
          actions_after:
          - type: set_milestone
          - type: set_milestone_alert
            parameters:
              milestone: packed
              notifications:
              - name: send_mail
                delay: -300
                params:
                  to: "tbaudon@onestock-retail.com"
    claimed:
      transitions:
        packed: # De claimed à packed (VI)
          conditions:
          actions_after:
          - type: set_milestone
            parameters:
              milestone : preparation #name depends on DP config
    packed:
      transitions:
        dispatched: # De packed à dispatched (VI)
          conditions:
          actions_after:
          - type: set_milestone
            parameters:
              milestone : carrier_pickup

Recovering milestones' information (not sure where to place it)

Milestone information can be retrieved by calling the OMSv2 route GET v2/orders/:order_id/delivery_promise/details

type DPDetails []DPDetailsForIndexes // List of DPDetails by index ranges

type IndexRanges struct {
  from int
  to int
}
type DPDetailsForIndexes struct {
  index_ranges     IndexRanges              
  endpoint_id      string                           
  milestones       map[string]IndexRanges 
  notification_key string                           
  cutoffs_sets     CutoffsSets // cutoffs sets from best to worst (depending of the context)
}

type CutoffsSets []CutoffsSet
type Carrier struct {
  name string
  option name
}
type CutoffsSet struct { // each index of milestones_cutoffs and eta_ends correspond to one possible scenario
  carrier             *Carrier
  milestones_cutoffs  map[string][]*int64 // for each milestone, the list of cutoffs
  eta_ends            []*int64            // the list of eta ends
}