notificationService.ts

Purpose

This module configures the global Expo notification handler and exposes functions for requesting notification permissions and sending heatstroke risk alerts. Unlike notifications.ts, alert content is determined by a normalized risk level value rather than a raw core temperature.

Its responsibilities include:

• Installing the global setNotificationHandler at module load time
• Requesting foreground notification permissions from the user
• Scheduling an immediate local notification with a risk-level-appropriate message
• Mapping a normalized risk level to one of three message strings

Invariants

Handler Installed at Import Time

Notifications.setNotificationHandler is called as a module-level side effect.

The handler always allows banner display, sound, and list display. Badge setting is always disabled.

Immediate Trigger

All notifications use trigger: null, delivering alerts immediately.

Risk Level Thresholds

Exports

requestNotificationPermissions()

async function requestNotificationPermissions(): Promise<boolean>

Requests notification permissions. Returns true if granted.

sendHeatstrokeAlert(...)

async function sendHeatstrokeAlert(riskLevel: number): Promise<void>

Schedules an immediate local notification with a message appropriate to the given normalized risk level.

Parameters