/**
 * Shared registration helpers used by both the signup and join pages.
 * Consolidates member creation and welcome email logic.
 */

import { supabaseAdmin } from '$lib/server/supabase';
import { sendTemplatedEmail } from '$lib/server/email';
import type { SupabaseClient } from '@supabase/supabase-js';

// ────────────────────────────────────────────────────────────────
// Types
// ────────────────────────────────────────────────────────────────

export interface RegistrationData {
	userId: string;
	email: string;
	firstName: string;
	lastName: string;
	phone?: string;
	dateOfBirth?: string;
	address?: string;
	nationality?: string[];
}

export interface CreateMemberResult {
	success: boolean;
	error?: string;
	memberId?: string;
}

// ────────────────────────────────────────────────────────────────
// Member Creation
// ────────────────────────────────────────────────────────────────

/**
 * Create a member record in the database after auth user creation.
 *
 * Handles:
 *  - Looking up the default/pending membership status and type
 *  - Generating a sequential MUSA-YYYY-XXXX member ID
 *  - Inserting the member record
 *
 * @param data       Core registration data.
 * @param supabase   The Supabase client to use for DB operations.
 * @param options    Additional options for how the member is created.
 */
export async function createMemberRecord(
	data: RegistrationData,
	supabase: SupabaseClient,
	options?: {
		/** Look up status by name instead of is_default. Defaults to undefined (uses is_default). */
		statusName?: string;
		/** Whether to generate a MUSA-YYYY-XXXX member ID. Defaults to true. */
		generateMemberId?: boolean;
	}
): Promise<CreateMemberResult> {
	const generateMemberId = options?.generateMemberId ?? true;
	const statusName = options?.statusName;

	// Look up the membership status
	let statusQuery;
	if (statusName) {
		statusQuery = supabase
			.from('membership_statuses')
			.select('id')
			.eq('name', statusName)
			.single();
	} else {
		statusQuery = supabase
			.from('membership_statuses')
			.select('id')
			.eq('is_default', true)
			.single();
	}

	const { data: statusData, error: statusError } = await statusQuery;

	if (statusError || !statusData?.id) {
		console.error('No membership status found:', statusError);
		return { success: false, error: 'System configuration error. Please contact support.' };
	}

	// Look up the default membership type
	const { data: typeData, error: typeError } = await supabase
		.from('membership_types')
		.select('id')
		.eq('is_default', true)
		.single();

	if (typeError || !typeData?.id) {
		console.error('No default membership type found:', typeError);
		return { success: false, error: 'System configuration error. Please contact support.' };
	}

	// Generate member ID if requested
	let memberId: string | undefined;
	if (generateMemberId) {
		const year = new Date().getFullYear();
		const { count } = await supabase
			.from('members')
			.select('*', { count: 'exact', head: true });

		const memberNumber = String((count || 0) + 1).padStart(4, '0');
		memberId = `MUSA-${year}-${memberNumber}`;
	}

	// Create the member profile
	const insertPayload: Record<string, unknown> = {
		id: data.userId,
		first_name: data.firstName,
		last_name: data.lastName,
		email: data.email,
		phone: data.phone || null,
		date_of_birth: data.dateOfBirth || null,
		address: data.address || null,
		nationality: data.nationality || [],
		role: 'member',
		membership_status_id: statusData.id,
		membership_type_id: typeData.id
	};

	if (memberId) {
		insertPayload.member_id = memberId;
	}

	const { error: memberError } = await supabase.from('members').insert(insertPayload);

	if (memberError) {
		console.error('Failed to create member profile:', memberError);
		return { success: false, error: 'Failed to create member profile. Please try again or contact support.' };
	}

	return { success: true, memberId };
}

/**
 * Clean up auth user on registration failure.
 * Uses supabaseAdmin to ensure we can always delete the user.
 */
export async function cleanupAuthUser(userId: string): Promise<void> {
	try {
		await supabaseAdmin.auth.admin.deleteUser(userId);
	} catch (deleteError) {
		console.error('Failed to clean up auth user:', deleteError);
	}
}

// ────────────────────────────────────────────────────────────────
// Welcome Email
// ────────────────────────────────────────────────────────────────

/**
 * Send the onboarding welcome email with payment instructions.
 *
 * @param member           Basic member info for the email template.
 * @param paymentSettings  Payment account details from app_settings.
 * @param duesAmount       The annual dues amount.
 * @param paymentDeadline  The payment deadline date.
 */
export async function sendWelcomeEmail(
	member: {
		id: string;
		first_name: string;
		email: string;
		member_id?: string;
	},
	paymentSettings: Record<string, string>,
	duesAmount: number,
	paymentDeadline: Date
): Promise<{ success: boolean; error?: string }> {
	try {
		const result = await sendTemplatedEmail(
			'onboarding_welcome',
			member.email,
			{
				first_name: member.first_name,
				member_id: member.member_id || 'N/A',
				amount: `\u20AC${duesAmount}`,
				payment_deadline: paymentDeadline.toLocaleDateString('en-US', {
					weekday: 'long',
					year: 'numeric',
					month: 'long',
					day: 'numeric'
				}),
				account_holder: paymentSettings.account_holder || 'Monaco USA',
				bank_name: paymentSettings.bank_name || 'Credit Foncier de Monaco',
				iban: paymentSettings.iban || 'Contact for details'
			},
			{
				recipientId: member.id,
				recipientName: member.first_name,
				sentBy: 'system'
			}
		);

		return result;
	} catch (emailError) {
		console.error('Failed to send welcome email:', emailError);
		return { success: false, error: 'Failed to send welcome email' };
	}
}