// API client for Wotra backend.
// Base URL: /api (relative, works both in dev proxy and production)

const API_BASE = '/api';

function getToken(): string {
	return localStorage.getItem('auth_token') ?? '';
}

export function setToken(token: string) {
	localStorage.setItem('auth_token', token);
}

export function hasToken(): boolean {
	return !!localStorage.getItem('auth_token');
}

async function request<T>(method: string, path: string, body?: unknown): Promise<T> {
	const res = await fetch(`${API_BASE}${path}`, {
		method,
		headers: {
			'Content-Type': 'application/json',
			Authorization: `Bearer ${getToken()}`
		},
		body: body !== undefined ? JSON.stringify(body) : undefined
	});
	if (!res.ok) {
		const err = await res.json().catch(() => ({ error: res.statusText }));
		throw new ApiError(res.status, err.error ?? res.statusText);
	}
	if (res.status === 204) return undefined as T;
	return res.json();
}

export class ApiError extends Error {
	constructor(
		public status: number,
		message: string
	) {
		super(message);
	}
}

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

export interface Entry {
	id: string;
	start_time: number; // unix ms UTC
	end_time: number | null;
	auto_stopped: boolean;
	note: string;
	day_key: string;
	updated_at: number;
}

export interface ClosedDay {
	day_key: string;
	start_time: number | null;
	end_time: number | null;
	worked_ms: number;
	kind: 'work' | 'holiday' | 'vacation' | 'sick';
	closed_at: number;
	updated_at: number;
}

export interface ClosedWeek {
	week_key: string;
	expected_ms: number;
	worked_ms: number;
	delta_ms: number;
	closed_at: number;
	updated_at: number;
}

export interface Settings {
	id: number;
	effective_from: string;
	hours_per_week: number;
	workdays_mask: number;
	timezone: string;
	created_at: number;
}

// ─── Entries ─────────────────────────────────────────────────────────────────

export const entries = {
	start: (note = '') => request<Entry>('POST', '/entries/start', { note }),
	createInterval: (startTime: number, endTime: number, note = '') =>
		request<Entry>('POST', '/entries', { start_time: startTime, end_time: endTime, note }),
	stop: (id: string) => request<Entry>('POST', `/entries/${id}/stop`),
	list: (from?: string, to?: string) => {
		const params = new URLSearchParams();
		if (from) params.set('from', from);
		if (to) params.set('to', to);
		return request<Entry[]>('GET', `/entries?${params}`);
	},
	update: (id: string, body: { start_time?: number; end_time?: number; note?: string }) =>
		request<Entry>('PUT', `/entries/${id}`, body),
	delete: (id: string) => request<void>('DELETE', `/entries/${id}`)
};

// ─── Days ────────────────────────────────────────────────────────────────────

export const days = {
	list: (from?: string, to?: string) => {
		const params = new URLSearchParams();
		if (from) params.set('from', from);
		if (to) params.set('to', to);
		return request<ClosedDay[]>('GET', `/days?${params}`);
	},
	close: (dayKey: string) => request<ClosedDay>('POST', `/days/${dayKey}/close`),
	mark: (dayKey: string, kind: 'holiday' | 'vacation' | 'sick') =>
		request<ClosedDay>('POST', `/days/${dayKey}/mark`, { kind }),
	reopen: (dayKey: string) => request<void>('DELETE', `/days/${dayKey}/close`)
};

// ─── Weeks ───────────────────────────────────────────────────────────────────

export const weeks = {
	list: (from?: string, to?: string) => {
		const params = new URLSearchParams();
		if (from) params.set('from', from);
		if (to) params.set('to', to);
		return request<ClosedWeek[]>('GET', `/weeks?${params}`);
	},
	close: (weekKey: string) => request<ClosedWeek>('POST', `/weeks/${weekKey}/close`),
	reopen: (weekKey: string) => request<void>('DELETE', `/weeks/${weekKey}/close`)
};

// ─── Settings ────────────────────────────────────────────────────────────────

export const settings = {
	current: () => request<Settings>('GET', '/settings'),
	history: () => request<Settings[]>('GET', '/settings/history'),
	upsert: (body: {
		effective_from: string;
		hours_per_week: number;
		workdays_mask: number;
		timezone: string;
	}) => request<Settings>('PUT', '/settings', body)
};

// ─── Health ──────────────────────────────────────────────────────────────────

export const healthz = () =>
	fetch('/healthz').then((r) => r.ok);