/**
 * Typed API client for the FastAPI backend.
 */

import { getAccessToken } from "../auth";
import type {
	MediaCounts,
	LibraryCount,
	UserDirectoryResponse,
	UserMessageResponse,
	UserMessageQueueStatus,
	NowPlayingSession,
	MonitoringStatus,
	MonitoringMetrics,
	DiskSpace,
	MediaIndexStatus,
	MediaIndexActionResponse,
	MediaQueryResponse,
	DirectoryListing,
	JobTemplate,
	JobResult,
	ResolvedPath,
} from "../types";

const BASE_URL = import.meta.env.VITE_API_URL || "/api";

function isAbsoluteUrl(value: string): boolean {
	return /^https?:\/\//i.test(value) || value.startsWith("//");
}

function buildUrl(path: string, params?: Record<string, string>): string {
	if (!isAbsoluteUrl(BASE_URL)) {
		const url = new URL(path, window.location.origin);
		if (params) {
			Object.entries(params).forEach(([key, value]) => {
				if (value !== undefined && value !== "")
					url.searchParams.set(key, value);
			});
		}
		return url.toString();
	}

	const url = new URL(path, BASE_URL);
	if (params) {
		Object.entries(params).forEach(([key, value]) => {
			if (value !== undefined && value !== "") url.searchParams.set(key, value);
		});
	}
	return url.toString();
}

async function readErrorDetail(response: Response): Promise<string> {
	const text = await response.text();
	try {
		const parsed = JSON.parse(text) as { detail?: unknown; message?: unknown };
		const detail = parsed.detail ?? parsed.message;
		if (typeof detail === "string" && detail.trim()) {
			return detail;
		}
	} catch {
		// Fall back to the raw response body below.
	}
	return text;
}

function buildHeaders(isJsonBody: boolean): Headers {
	const headers = new Headers();
	const token = getAccessToken();
	if (token) headers.set("Authorization", `Bearer ${token}`);
	if (isJsonBody) headers.set("Content-Type", "application/json");
	return headers;
}

async function get<T>(
	path: string,
	params?: Record<string, string>,
): Promise<T> {
	const response = await fetch(buildUrl(path, params), {
		headers: buildHeaders(false),
	});
	if (!response.ok) {
		throw new Error(`${response.status}: ${await readErrorDetail(response)}`);
	}
	return response.json();
}

async function post<T>(path: string, body?: unknown): Promise<T> {
	const response = await fetch(buildUrl(path), {
		method: "POST",
		headers: buildHeaders(true),
		body: body ? JSON.stringify(body) : undefined,
	});
	if (!response.ok) {
		throw new Error(`${response.status}: ${await readErrorDetail(response)}`);
	}
	return response.json();
}

async function postForm<T>(path: string, body: FormData): Promise<T> {
	const headers = buildHeaders(false);
	const response = await fetch(buildUrl(path), {
		method: "POST",
		headers,
		body,
	});
	if (!response.ok) {
		throw new Error(`${response.status}: ${await readErrorDetail(response)}`);
	}
	return response.json();
}

// Dashboard
export const fetchCounts = () => get<MediaCounts>("/api/dashboard/counts");
export const fetchLibraries = () =>
	get<LibraryCount[]>("/api/dashboard/libraries");
export const fetchActivity = () =>
	get<NowPlayingSession[]>("/api/dashboard/activity");
export const fetchUsers = () => get<UserDirectoryResponse>("/api/users");

// Backward-compatible alias used by older hooks/components.
export const fetchNowPlaying = fetchActivity;

// Monitoring
export const fetchMonitoringStatus = () =>
	get<MonitoringStatus>("/api/monitoring/status");
export const fetchMonitoringMetrics = (
	lastSeconds?: number | null,
	maxLines = 70_000,
) =>
	get<MonitoringMetrics>("/api/monitoring/metrics", {
		...(lastSeconds == null ? {} : { last_seconds: String(lastSeconds) }),
		max_lines: String(maxLines),
	});
export const fetchDiskSpace = () => get<DiskSpace>("/api/monitoring/disk");
export const startCollector = () =>
	post<{ message: string }>("/api/monitoring/start");
export const stopCollector = () =>
	post<{ message: string }>("/api/monitoring/stop");
export const restartCollector = () =>
	post<{ message: string }>("/api/monitoring/restart");

// Media
export const fetchMediaStatus = () =>
	get<MediaIndexStatus>("/api/media/status");
export const buildMediaIndex = () =>
	post<MediaIndexActionResponse>("/api/media/build");
export const stopMediaIndexBuild = () =>
	post<MediaIndexActionResponse>("/api/media/stop");
export const forceStopMediaIndexBuild = () =>
	post<MediaIndexActionResponse>("/api/media/force-stop");
export const queryMedia = (params: {
	libraries?: string;
	types?: string;
	search?: string;
	hdr_filter?: string;
	sort_key?: string;
	sort_order?: string;
	limit?: number;
	offset?: number;
}) =>
	get<MediaQueryResponse>("/api/media/query", {
		libraries: params.libraries || "",
		types: params.types || "Movie,Episode",
		search: params.search || "",
		hdr_filter: params.hdr_filter || "All",
		sort_key: params.sort_key || "title",
		sort_order: params.sort_order || "Ascending",
		limit: String(params.limit || 100),
		offset: String(params.offset || 0),
	});

// Files
export const fetchDirectoryListing = (path: string) =>
	get<DirectoryListing>("/api/files/list", { path });
export const fetchFfprobe = (path: string) =>
	get<Record<string, unknown>>("/api/files/ffprobe", { path });
export const fetchStat = (path: string) =>
	get<{ path: string; output: string }>("/api/files/stat", { path });
export const resolvePath = (path: string) =>
	get<ResolvedPath>("/api/files/resolve-path", { path });

// Jobs
export const fetchJobTemplates = () =>
	get<JobTemplate[]>("/api/jobs/templates");
export const runJob = (jobKey: string, path: string) =>
	post<JobResult>("/api/jobs/run", { job_key: jobKey, path });

export const fetchUserMessageQueueStatus = () =>
	get<UserMessageQueueStatus>("/api/users/message/status");

export const sendUserMessage = (formData: FormData) =>
	postForm<UserMessageResponse>("/api/users/message", formData);