// Package events passes events between the parts of JobSearch that cause
// them, such as the fetcher, and the parts that react to them, such as the
// WebSocket hub, so neither depends on the other. It holds the event types
// and their payloads.
package events

import "git.avsdev.uk/Go/job-search/internal/types"

// Event types: an Event's Type, which says what its Payload is.
const (
	// OpportunitiesUpdated is published when a save stores new
	// opportunities or new releases of stored ones. Its payload is an
	// OpportunitiesUpdatedPayload.
	OpportunitiesUpdated = "OpportunitiesUpdated"
	// OpportunityMarksUpdated is published when an opportunity's marks are
	// changed over the API. Its payload is the opportunity's
	// types.OpportunityMarks after the change, which include its UUID.
	OpportunityMarksUpdated = "OpportunityMarksUpdated"
	// ClassificationsUpdated is published when a save brings classification
	// codes into use (some opportunity has them) or takes them out of use.
	// Its payload is a ClassificationsUpdatedPayload.
	ClassificationsUpdated = "ClassificationsUpdated"
)

// ---------- OpportunitiesUpdated ----------

// MaxListedOpportunities is the most opportunities an
// OpportunitiesUpdatedPayload lists by UUID; more make it Large.
const MaxListedOpportunities = 50

// OpportunitiesUpdatedPayload lists the opportunities a save changed by UUID:
// New were stored for the first time, and Updated were already stored and
// gained at least one new release. Summary counts them.
//
// When there are more than MaxListedOpportunities, Large is true and New and
// Updated are empty, to keep the event small; Summary still counts them.
// Neither is ever null.
//
// Batch is the hash of the store's change batch recording them. A client
// gets them, with any later changes, from GET /api/opportunities with
// changed_after set to the last batch it has seen.
type OpportunitiesUpdatedPayload struct {
	New     []string             `json:"new"`
	Updated []string             `json:"updated"`
	Large   bool                 `json:"large"`
	Summary OpportunitiesSummary `json:"summary"`
	Batch   string               `json:"batch"`
}

// OpportunitiesSummary counts the opportunities in an
// OpportunitiesUpdatedPayload.
type OpportunitiesSummary struct {
	New     int `json:"new"`
	Updated int `json:"updated"`
}

// ---------- ClassificationsUpdated ----------

// ClassificationsUpdatedPayload is how the classification codes in use
// changed, so a client's list of them can be kept up to date without asking
// for it again: Added are the codes now in use, in full, and Removed the ids
// of those no longer in use. Neither is ever null.
type ClassificationsUpdatedPayload struct {
	Added   []types.ClassificationCode `json:"added"`
	Removed []int64                    `json:"removed"`
}