import type { SupabaseClient } from '@supabase/supabase-js';
import type { Database } from '$lib/supabase/types';
import { createLogger } from '$lib/utils/logger';

const log = createLogger('api.events');

export interface Event {
	id: string;
	org_id: string;
	name: string;
	slug: string;
	description: string | null;
	status: 'planning' | 'active' | 'completed' | 'archived';
	start_date: string | null;
	end_date: string | null;
	venue_name: string | null;
	venue_address: string | null;
	cover_image_url: string | null;
	color: string | null;
	created_by: string | null;
	created_at: string;
	updated_at: string;
}

export interface EventMember {
	id: string;
	event_id: string;
	user_id: string;
	role: string;
	role_id: string | null;
	notes: string | null;
	assigned_at: string | null;
}

export interface EventRole {
	id: string;
	event_id: string;
	name: string;
	color: string;
	sort_order: number;
	is_default: boolean;
	created_at: string | null;
}

export interface EventDepartment {
	id: string;
	event_id: string;
	name: string;
	color: string;
	description: string | null;
	planned_budget: number;
	sort_order: number;
	created_at: string | null;
}

export interface EventMemberDepartment {
	id: string;
	event_member_id: string;
	department_id: string;
	assigned_at: string | null;
}

export interface EventMemberWithDetails extends EventMember {
	profile?: { id: string; email: string; full_name: string | null; avatar_url: string | null; phone: string | null; discord_handle: string | null; shirt_size: string | null; hoodie_size: string | null };
	event_role?: EventRole;
	departments: EventDepartment[];
}

export interface EventWithCounts extends Event {
	member_count: number;
}

function slugify(text: string): string {
	return text
		.toLowerCase()
		.replace(/[^\w\s-]/g, '')
		.replace(/[\s_]+/g, '-')
		.replace(/-+/g, '-')
		.replace(/^-|-$/g, '')
		.slice(0, 60) || 'event';
}

export async function fetchEvents(
	supabase: SupabaseClient<Database>,
	orgId: string,
	status?: string
): Promise<EventWithCounts[]> {
	let query = supabase
		.from('events')
		.select('*, event_members(count)')
		.eq('org_id', orgId)
		.order('start_date', { ascending: true, nullsFirst: false });

	if (status && status !== 'all') {
		query = query.eq('status', status);
	}

	const { data, error } = await query;

	if (error) {
		log.error('fetchEvents failed', { error, data: { orgId } });
		throw error;
	}

	const events: EventWithCounts[] = (data ?? []).map((e: any) => ({
		...e,
		member_count: e.event_members?.[0]?.count ?? 0,
		event_members: undefined,
	}));

	log.debug('fetchEvents ok', { data: { count: events.length } });
	return events;
}

export async function fetchEvent(
	supabase: SupabaseClient<Database>,
	eventId: string
): Promise<Event | null> {
	const { data, error } = await supabase
		.from('events')
		.select('*')
		.eq('id', eventId)
		.single();

	if (error) {
		if (error.code === 'PGRST116') return null;
		log.error('fetchEvent failed', { error, data: { eventId } });
		throw error;
	}
	return data as unknown as Event;
}

export async function fetchEventBySlug(
	supabase: SupabaseClient<Database>,
	orgId: string,
	eventSlug: string
): Promise<Event | null> {
	const { data, error } = await supabase
		.from('events')
		.select('*')
		.eq('org_id', orgId)
		.eq('slug', eventSlug)
		.single();

	if (error) {
		if (error.code === 'PGRST116') return null;
		log.error('fetchEventBySlug failed', { error, data: { orgId, eventSlug } });
		throw error;
	}
	return data as unknown as Event;
}

export async function createEvent(
	supabase: SupabaseClient<Database>,
	orgId: string,
	userId: string,
	params: {
		name: string;
		description?: string;
		start_date?: string;
		end_date?: string;
		venue_name?: string;
		venue_address?: string;
		color?: string;
	}
): Promise<Event> {
	const baseSlug = slugify(params.name);

	// Ensure unique slug within org
	const { data: existing } = await supabase
		.from('events')
		.select('slug')
		.eq('org_id', orgId)
		.like('slug', `${baseSlug}%`);

	let slug = baseSlug;
	if (existing && existing.length > 0) {
		const existingSlugs = new Set(existing.map((e: any) => e.slug));
		if (existingSlugs.has(slug)) {
			let i = 2;
			while (existingSlugs.has(`${baseSlug}-${i}`)) i++;
			slug = `${baseSlug}-${i}`;
		}
	}

	const { data, error } = await supabase
		.from('events')
		.insert({
			org_id: orgId,
			name: params.name,
			slug,
			description: params.description ?? null,
			start_date: params.start_date ?? null,
			end_date: params.end_date ?? null,
			venue_name: params.venue_name ?? null,
			venue_address: params.venue_address ?? null,
			color: params.color ?? null,
			created_by: userId,
		})
		.select()
		.single();

	if (error) {
		log.error('createEvent failed', { error, data: { orgId, name: params.name } });
		throw error;
	}
	log.info('createEvent ok', { data: { id: data.id, name: params.name, slug } });
	return data as unknown as Event;
}

export async function updateEvent(
	supabase: SupabaseClient<Database>,
	eventId: string,
	params: Partial<Pick<Event, 'name' | 'description' | 'status' | 'start_date' | 'end_date' | 'venue_name' | 'venue_address' | 'cover_image_url' | 'color'>>
): Promise<Event> {
	const { data, error } = await supabase
		.from('events')
		.update({ ...params, updated_at: new Date().toISOString() })
		.eq('id', eventId)
		.select()
		.single();

	if (error) {
		log.error('updateEvent failed', { error, data: { eventId } });
		throw error;
	}
	log.info('updateEvent ok', { data: { id: data.id } });
	return data as unknown as Event;
}

export async function deleteEvent(
	supabase: SupabaseClient<Database>,
	eventId: string
): Promise<void> {
	const { error } = await supabase
		.from('events')
		.delete()
		.eq('id', eventId);

	if (error) {
		log.error('deleteEvent failed', { error, data: { eventId } });
		throw error;
	}
	log.info('deleteEvent ok', { data: { eventId } });
}

export async function fetchEventMembers(
	supabase: SupabaseClient<Database>,
	eventId: string
): Promise<EventMemberWithDetails[]> {
	const { data: members, error } = await supabase
		.from('event_members')
		.select('*')
		.eq('event_id', eventId)
		.order('assigned_at');

	if (error) {
		log.error('fetchEventMembers failed', { error, data: { eventId } });
		throw error;
	}

	if (!members || members.length === 0) return [];

	// Fetch profiles separately (same pattern as org_members)
	const userIds = members.map((m: any) => m.user_id);
	const { data: profiles } = await supabase
		.from('profiles')
		.select('id, email, full_name, avatar_url, phone, discord_handle, shirt_size, hoodie_size')
		.in('id', userIds);

	const profileMap = Object.fromEntries((profiles ?? []).map(p => [p.id, p]));

	// Fetch roles for this event
	const { data: roles } = await supabase
		.from('event_roles')
		.select('*')
		.eq('event_id', eventId);
	const roleMap = Object.fromEntries((roles ?? []).map(r => [r.id, r]));

	// Fetch member-department assignments
	const memberIds = members.map((m: any) => m.id);
	const { data: memberDepts } = await supabase
		.from('event_member_departments')
		.select('*')
		.in('event_member_id', memberIds);

	// Fetch departments for this event
	const { data: departments } = await supabase
		.from('event_departments')
		.select('*')
		.eq('event_id', eventId);
	const deptMap = Object.fromEntries((departments ?? []).map(d => [d.id, d]));

	// Build member-to-departments map
	const memberDeptMap: Record<string, EventDepartment[]> = {};
	for (const md of (memberDepts ?? [])) {
		const dept = deptMap[md.department_id];
		if (dept) {
			if (!memberDeptMap[md.event_member_id]) memberDeptMap[md.event_member_id] = [];
			memberDeptMap[md.event_member_id].push(dept as unknown as EventDepartment);
		}
	}

	return members.map((m: any) => ({
		...m,
		profile: profileMap[m.user_id] ?? undefined,
		event_role: m.role_id ? (roleMap[m.role_id] as unknown as EventRole) ?? undefined : undefined,
		departments: memberDeptMap[m.id] ?? [],
	}));
}

export async function addEventMember(
	supabase: SupabaseClient<Database>,
	eventId: string,
	userId: string,
	params: { role?: 'lead' | 'manager' | 'member'; role_id?: string; notes?: string } = {}
): Promise<EventMember> {
	const { data, error } = await supabase
		.from('event_members')
		.upsert({
			event_id: eventId,
			user_id: userId,
			role: params.role ?? 'member',
			role_id: params.role_id ?? null,
			notes: params.notes ?? null,
		}, { onConflict: 'event_id,user_id' })
		.select()
		.single();

	if (error) {
		log.error('addEventMember failed', { error, data: { eventId, userId } });
		throw error;
	}
	return data as unknown as EventMember;
}

export async function removeEventMember(
	supabase: SupabaseClient<Database>,
	eventId: string,
	userId: string
): Promise<void> {
	const { error } = await supabase
		.from('event_members')
		.delete()
		.eq('event_id', eventId)
		.eq('user_id', userId);

	if (error) {
		log.error('removeEventMember failed', { error, data: { eventId, userId } });
		throw error;
	}
}

// ============================================================
// Event Roles
// ============================================================

export async function fetchEventRoles(
	supabase: SupabaseClient<Database>,
	eventId: string
): Promise<EventRole[]> {
	const { data, error } = await supabase
		.from('event_roles')
		.select('*')
		.eq('event_id', eventId)
		.order('sort_order');

	if (error) {
		log.error('fetchEventRoles failed', { error, data: { eventId } });
		throw error;
	}
	return (data ?? []) as unknown as EventRole[];
}

export async function createEventRole(
	supabase: SupabaseClient<Database>,
	eventId: string,
	params: { name: string; color?: string; sort_order?: number }
): Promise<EventRole> {
	const { data, error } = await supabase
		.from('event_roles')
		.insert({
			event_id: eventId,
			name: params.name,
			color: params.color ?? '#6366f1',
			sort_order: params.sort_order ?? 0,
		})
		.select()
		.single();

	if (error) {
		log.error('createEventRole failed', { error, data: { eventId, name: params.name } });
		throw error;
	}
	return data as unknown as EventRole;
}

export async function updateEventRole(
	supabase: SupabaseClient<Database>,
	roleId: string,
	params: Partial<Pick<EventRole, 'name' | 'color' | 'sort_order' | 'is_default'>>
): Promise<EventRole> {
	const { data, error } = await supabase
		.from('event_roles')
		.update(params)
		.eq('id', roleId)
		.select()
		.single();

	if (error) {
		log.error('updateEventRole failed', { error, data: { roleId } });
		throw error;
	}
	return data as unknown as EventRole;
}

export async function deleteEventRole(
	supabase: SupabaseClient<Database>,
	roleId: string
): Promise<void> {
	const { error } = await supabase
		.from('event_roles')
		.delete()
		.eq('id', roleId);

	if (error) {
		log.error('deleteEventRole failed', { error, data: { roleId } });
		throw error;
	}
}

// ============================================================
// Event Departments
// ============================================================

export async function fetchEventDepartments(
	supabase: SupabaseClient<Database>,
	eventId: string
): Promise<EventDepartment[]> {
	const { data, error } = await supabase
		.from('event_departments')
		.select('*')
		.eq('event_id', eventId)
		.order('sort_order');

	if (error) {
		log.error('fetchEventDepartments failed', { error, data: { eventId } });
		throw error;
	}
	return (data ?? []) as unknown as EventDepartment[];
}

export async function createEventDepartment(
	supabase: SupabaseClient<Database>,
	eventId: string,
	params: { name: string; color?: string; description?: string; sort_order?: number }
): Promise<EventDepartment> {
	const { data, error } = await supabase
		.from('event_departments')
		.insert({
			event_id: eventId,
			name: params.name,
			color: params.color ?? '#00A3E0',
			description: params.description ?? null,
			sort_order: params.sort_order ?? 0,
		})
		.select()
		.single();

	if (error) {
		log.error('createEventDepartment failed', { error, data: { eventId, name: params.name } });
		throw error;
	}
	return data as unknown as EventDepartment;
}

export async function updateEventDepartment(
	supabase: SupabaseClient<Database>,
	deptId: string,
	params: Partial<Pick<EventDepartment, 'name' | 'color' | 'description' | 'sort_order'>>
): Promise<EventDepartment> {
	const { data, error } = await supabase
		.from('event_departments')
		.update(params)
		.eq('id', deptId)
		.select()
		.single();

	if (error) {
		log.error('updateEventDepartment failed', { error, data: { deptId } });
		throw error;
	}
	return data as unknown as EventDepartment;
}

export async function updateDepartmentPlannedBudget(
	supabase: SupabaseClient<Database>,
	deptId: string,
	plannedBudget: number
): Promise<EventDepartment> {
	const { data, error } = await (supabase as any)
		.from('event_departments')
		.update({ planned_budget: plannedBudget })
		.eq('id', deptId)
		.select()
		.single();

	if (error) {
		log.error('updateDepartmentPlannedBudget failed', { error, data: { deptId, plannedBudget } });
		throw error;
	}
	return data as unknown as EventDepartment;
}

export async function deleteEventDepartment(
	supabase: SupabaseClient<Database>,
	deptId: string
): Promise<void> {
	const { error } = await supabase
		.from('event_departments')
		.delete()
		.eq('id', deptId);

	if (error) {
		log.error('deleteEventDepartment failed', { error, data: { deptId } });
		throw error;
	}
}

// ============================================================
// Member-Department Assignments
// ============================================================

export async function assignMemberDepartment(
	supabase: SupabaseClient<Database>,
	eventMemberId: string,
	departmentId: string
): Promise<EventMemberDepartment> {
	const { data, error } = await supabase
		.from('event_member_departments')
		.upsert(
			{ event_member_id: eventMemberId, department_id: departmentId },
			{ onConflict: 'event_member_id,department_id' }
		)
		.select()
		.single();

	if (error) {
		log.error('assignMemberDepartment failed', { error, data: { eventMemberId, departmentId } });
		throw error;
	}
	return data as unknown as EventMemberDepartment;
}

export async function unassignMemberDepartment(
	supabase: SupabaseClient<Database>,
	eventMemberId: string,
	departmentId: string
): Promise<void> {
	const { error } = await supabase
		.from('event_member_departments')
		.delete()
		.eq('event_member_id', eventMemberId)
		.eq('department_id', departmentId);

	if (error) {
		log.error('unassignMemberDepartment failed', { error, data: { eventMemberId, departmentId } });
		throw error;
	}
}