package models

import (
	"time"

	"github.com/google/uuid"
)

// NotificationCategory identifies a kind of in-app notification. The set is
// fixed (mirrors the settings UI); new categories are added here + in the
// preference struct + default merge.
type NotificationCategory string

const (
	NotifInboundReply    NotificationCategory = "inbound_reply"
	NotifInboundOOO      NotificationCategory = "inbound_out_of_office"
	NotifHealthBounce    NotificationCategory = "health_bounce"
	NotifHealthComplaint NotificationCategory = "health_complaint"
	NotifWorkerDowntime  NotificationCategory = "health_worker_downtime"
	NotifSecuritySignIn  NotificationCategory = "security_new_signin"
	NotifBillingAlert    NotificationCategory = "billing_alert"
	NotifTeamActivity    NotificationCategory = "team_activity"
	// NotifCampaignPaused fires when the platform pauses a campaign on its
	// own — today, when an auto-pause guardrail band is breached. Rare and
	// always actionable, so it defaults on with email.
	NotifCampaignPaused NotificationCategory = "campaign_paused"
	// NotifDomainAuth fires when a sending domain starts failing SPF/DMARC.
	// It is the warning shot before the send/warmup gate applies, so it must
	// reach the owner while there is still time to fix the DNS records.
	NotifDomainAuth NotificationCategory = "health_domain_auth"
)

// ChannelPrefs is the per-category delivery toggles: in-app feed, account
// email, a connected Slack workspace, and mobile push (APNs).
type ChannelPrefs struct {
	InApp bool `json:"in_app"`
	Email bool `json:"email"`
	Slack bool `json:"slack"`
	Push  bool `json:"push"`
}

// CategoryPref is the enable flag + channel toggles for one category.
type CategoryPref struct {
	Enabled  bool         `json:"enabled"`
	Channels ChannelPrefs `json:"channels"`
}

// NotificationPreferences is the per-user singleton (jsonb on users). Always
// returned fully populated via DefaultNotificationPreferences merge.
type NotificationPreferences struct {
	InboundReply    CategoryPref `json:"inbound_reply"`
	InboundOOO      CategoryPref `json:"inbound_out_of_office"`
	HealthBounce    CategoryPref `json:"health_bounce"`
	HealthComplaint CategoryPref `json:"health_complaint"`
	WorkerDowntime  CategoryPref `json:"health_worker_downtime"`
	SecuritySignIn  CategoryPref `json:"security_new_signin"`
	BillingAlert    CategoryPref `json:"billing_alert"`
	TeamActivity    CategoryPref `json:"team_activity"`
	CampaignPaused  CategoryPref `json:"campaign_paused"`
	DomainAuth      CategoryPref `json:"health_domain_auth"`

	// EmailDigestMinutes is the email-channel bundling window: pending
	// notification emails hold this long, then flush as one email. Bounded
	// by config.NotificationEmailWindow* (30 min floor, 24h ceiling).
	// Security sign-in alerts always go out immediately.
	EmailDigestMinutes int `json:"email_digest_minutes"`
}

// DefaultNotificationPreferences is the merge base. Health categories default ON
// (operationally important + low volume); inbound categories default OFF (a big
// campaign would otherwise flood the feed with a notification per recipient).
// Push defaults on: it only fires for devices the user explicitly registered by
// granting the OS notification permission, and enabled categories should reach
// those devices without a second opt-in.
func DefaultNotificationPreferences() NotificationPreferences {
	on := CategoryPref{Enabled: true, Channels: ChannelPrefs{InApp: true, Push: true}}
	off := CategoryPref{Enabled: false, Channels: ChannelPrefs{InApp: true, Push: true}}
	// Billing defaults to email on: rare, and a paused workspace must reach
	// whoever can fix it even when nobody is watching the dashboard.
	billing := CategoryPref{Enabled: true, Channels: ChannelPrefs{InApp: true, Push: true, Email: true}}
	// A campaign the platform stopped by itself has to reach whoever can
	// restart it, so this one emails by default too.
	campaignPaused := CategoryPref{Enabled: true, Channels: ChannelPrefs{InApp: true, Push: true, Email: true}}
	// A domain the platform will eventually stop sending from has to reach
	// whoever can edit the DNS, so this one emails by default too.
	domainAuth := CategoryPref{Enabled: true, Channels: ChannelPrefs{InApp: true, Push: true, Email: true}}
	return NotificationPreferences{
		InboundReply:       off,
		InboundOOO:         off,
		HealthBounce:       on,
		HealthComplaint:    on,
		WorkerDowntime:     on,
		SecuritySignIn:     on,
		BillingAlert:       billing,
		TeamActivity:       on,
		CampaignPaused:     campaignPaused,
		DomainAuth:         domainAuth,
		EmailDigestMinutes: 30,
	}
}

// CategoryPref returns the preference for a category (zero value if unknown).
func (p NotificationPreferences) CategoryPref(c NotificationCategory) CategoryPref {
	switch c {
	case NotifInboundReply:
		return p.InboundReply
	case NotifInboundOOO:
		return p.InboundOOO
	case NotifHealthBounce:
		return p.HealthBounce
	case NotifHealthComplaint:
		return p.HealthComplaint
	case NotifWorkerDowntime:
		return p.WorkerDowntime
	case NotifSecuritySignIn:
		return p.SecuritySignIn
	case NotifBillingAlert:
		return p.BillingAlert
	case NotifTeamActivity:
		return p.TeamActivity
	case NotifCampaignPaused:
		return p.CampaignPaused
	case NotifDomainAuth:
		return p.DomainAuth
	default:
		return CategoryPref{}
	}
}

// Notification is one row in the in-app feed.
type Notification struct {
	ID             uuid.UUID            `json:"id"`
	UserID         uuid.UUID            `json:"user_id"`
	OrganizationID *uuid.UUID           `json:"organization_id,omitempty"`
	Category       NotificationCategory `json:"category"`
	Title          string               `json:"title"`
	Body           string               `json:"body,omitempty"`
	Link           string               `json:"link,omitempty"`
	Metadata       map[string]any       `json:"metadata,omitempty"`
	ReadAt         *time.Time           `json:"read_at,omitempty"`
	CreatedAt      time.Time            `json:"created_at"`

	// Email-channel digest bookkeeping — internal, never serialized to
	// clients. GroupKey ties the same org event across users so the flush
	// loop can coalesce it into one email with every recipient in To.
	GroupKey      string     `json:"-"`
	EmailState    string     `json:"-"`
	EmailDueAt    *time.Time `json:"-"`
	EmailAttempts int        `json:"-"`
	// PreRead inserts the row already read: used when the user has the
	// in-app channel off but email on, so the feed stays the delivery
	// record without ringing the bell.
	PreRead bool `json:"-"`
}

// UpdateNotificationPreferencesRequest is the PUT payload.
type UpdateNotificationPreferencesRequest struct {
	Preferences NotificationPreferences `json:"preferences"`
}

// DeviceToken is one push-capable device registration (APNs).
type DeviceToken struct {
	ID          uuid.UUID `json:"id"`
	UserID      uuid.UUID `json:"user_id"`
	Platform    string    `json:"platform"`
	Token       string    `json:"token"`
	Environment string    `json:"environment"`
	CreatedAt   time.Time `json:"created_at"`
	LastSeenAt  time.Time `json:"last_seen_at"`
}

// RegisterDeviceTokenRequest is the POST payload from the mobile app.
type RegisterDeviceTokenRequest struct {
	Token       string `json:"token" binding:"required"`
	Platform    string `json:"platform"`
	Environment string `json:"environment"`
}