-- Notification deliveries table (tracks per-device delivery attempts)
CREATE TABLE notification_deliveries (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    notification_receiver_id UUID NOT NULL REFERENCES notification_receivers(id) ON DELETE CASCADE,
    user_device_id UUID NOT NULL REFERENCES user_devices(id) ON DELETE CASCADE,
    channel VARCHAR(50) NOT NULL DEFAULT 'push' CHECK (channel IN ('push', 'websocket', 'email')),
    delivery_status VARCHAR(50) NOT NULL DEFAULT 'pending' CHECK (delivery_status IN ('pending', 'sent', 'delivered', 'failed')),
    provider VARCHAR(50) CHECK (provider IN ('firebase', 'onesignal')),
    provider_message_id VARCHAR(255),
    sent_at TIMESTAMP WITH TIME ZONE,
    delivered_at TIMESTAMP WITH TIME ZONE,
    failed_at TIMESTAMP WITH TIME ZONE,
    failure_reason TEXT,
    retry_count INT NOT NULL DEFAULT 0,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

-- Indexes
CREATE INDEX idx_notification_deliveries_receiver_id ON notification_deliveries(notification_receiver_id);
CREATE INDEX idx_notification_deliveries_device_id ON notification_deliveries(user_device_id);
CREATE INDEX idx_notification_deliveries_status ON notification_deliveries(delivery_status);
CREATE INDEX idx_notification_deliveries_provider ON notification_deliveries(provider);