package models

import (
	"net/http"
)

// NotificationFilter handles users filtering their notification list by category. It is populated
// from front-end checkboxes and translates to SQL filters for PaginateNotifications.
type NotificationFilter struct {
	Likes         bool `json:"likes"` // form field name
	Comments      bool `json:"comments"`
	NewPhotos     bool `json:"photos"`
	AlsoCommented bool `json:"replies"` // also_comment and also_posted
	PrivatePhoto  bool `json:"private"`
	Misc          bool `json:"misc"` // friendship_approved, cert_approved, cert_rejected, inner_circle, custom
}

var defaultNotificationFilter = NotificationFilter{
	Likes:         true,
	Comments:      true,
	NewPhotos:     true,
	AlsoCommented: true,
	PrivatePhoto:  true,
	Misc:          true,
}

// NewNotificationFilterFromForm creates a NotificationFilter struct parsed from an HTTP form.
func NewNotificationFilterFromForm(r *http.Request) NotificationFilter {
	// Are these boxes checked in a frontend post?
	var (
		nf = NotificationFilter{
			Likes:         r.FormValue("likes") == "true",
			Comments:      r.FormValue("comments") == "true",
			NewPhotos:     r.FormValue("photos") == "true",
			AlsoCommented: r.FormValue("replies") == "true",
			PrivatePhoto:  r.FormValue("private") == "true",
			Misc:          r.FormValue("misc") == "true",
		}
	)

	// Default view or when no checkboxes were sent, all are true.
	if nf.IsZero() {
		return defaultNotificationFilter
	}
	return nf
}

// IsZero checks for an empty filter.
func (nf NotificationFilter) IsZero() bool {
	return nf == NotificationFilter{}
}

// IsAll checks if all filters are checked.
func (nf NotificationFilter) IsAll() bool {
	return nf == defaultNotificationFilter
}

// Query returns the SQL "WHERE" clause that applies the filters to the Notifications query.
//
// If no filters should be added, ok returns false.
func (nf NotificationFilter) Query() (where string, placeholders []interface{}, ok bool) {
	if nf.IsAll() {
		return "", nil, false
	}

	var (
		// Notification types to include.
		types = []interface{}{}
	)

	// Translate
	if nf.Likes {
		types = append(types, NotificationLike)
	}
	if nf.Comments {
		types = append(types, NotificationComment)
	}
	if nf.NewPhotos {
		types = append(types, NotificationNewPhoto)
	}
	if nf.AlsoCommented {
		types = append(types, NotificationAlsoCommented, NotificationAlsoPosted)
	}
	if nf.PrivatePhoto {
		types = append(types, NotificationPrivatePhoto)
	}
	if nf.Misc {
		types = append(types, NotificationFriendApproved, NotificationCertApproved, NotificationCertRejected, NotificationCustom)
	}

	return "type IN ?", types, true
}