// components/utilities/files/api.ts
export type FsEntry = {
    name: string;
    path: string;          // absolute or from root, e.g. "/public" or "/public/readme.txt"
    isDir: boolean;
    size?: number | null;  // bytes
    modified?: string | null; // ISO date string
    mime?: string | null;  // server-provided mime, optional
};

export type ListResponse = {
    cwd: string;           // normalized path we listed
    entries: FsEntry[];    // unsorted list
};

export type SortKey = "name" | "size" | "modified" | "type";
export type SortDir = "asc" | "desc";

export async function list(path: string): Promise<ListResponse> {
    const u = new URL("/api/files/list", location.origin);
    if (path) u.searchParams.set("path", path);
    const res = await fetch(u.toString(), { credentials: "include", cache: "no-store" });
    if (!res.ok) throw new Error(`list ${path}: ${res.status}`);
    return res.json();
}

export function rawUrl(path: string): string {
    const u = new URL("/api/files/raw", location.origin);
    u.searchParams.set("path", path);
    return u.toString();
}

export async function download(path: string): Promise<void> {
    // try direct browser download via a hidden <a download>
    const u = new URL("/api/files/download", location.origin);
    u.searchParams.set("path", path);
    const a = document.createElement("a");
    a.href = u.toString();
    a.rel = "noopener";
    a.download = ""; // hint to save-as
    document.body.appendChild(a);
    a.click();
    a.remove();
}

export function parentDir(p: string): string {
    if (!p || p === "/") return "/";
    const segs = p.replace(/\\/g, "/").split("/").filter(Boolean);
    segs.pop();
    return "/" + segs.join("/");
}

export function nicelyFormatBytes(n?: number | null): string {
    if (!Number.isFinite(n as number) || (n as number) < 0) return "—";
    const b = n as number;
    if (b < 1024) return `${b} B`;
    const units = ["KB","MB","GB","TB"];
    let v = b / 1024, i = 0;
    while (v >= 1024 && i < units.length - 1) { v /= 1024; i++; }
    return `${v.toFixed(v >= 100 ? 0 : v >= 10 ? 1 : 2)} ${units[i]}`;
}

export function extFromName(name: string): string {
    const m = /\.([^.]+)$/.exec(name || "");
    return m ? m[1].toLowerCase() : "";
}

export function isPreviewableImage(mime?: string | null, name?: string): boolean {
    const ext = extFromName(name || "");
    return /^image\//.test(mime || "") || ["png","jpg","jpeg","gif","webp","bmp","svg"].includes(ext);
}

export function isPreviewableText(mime?: string | null, name?: string): boolean {
    const ext = extFromName(name || "");
    return /^text\//.test(mime || "") || ["txt","csv","md","json","log"].includes(ext);
}

export function isPreviewablePdf(mime?: string | null, name?: string): boolean {
    const ext = extFromName(name || "");
    return (mime || "").includes("pdf") || ext === "pdf";
}