import { useEffect, useRef, useState } from "react";
import { useLocation } from "wouter";
import { ChevronRight, Download, File, Folder, FolderPlus, FolderOpen, Home, MoreVertical, Pencil, Trash2, Upload, FolderInput } from "lucide-react";
import { useFiles } from "@/store/files";
import { client } from "@/jmap/client";
import type { FileNode } from "@/jmap/types";
import { formatSize, formatListDate } from "@/lib/format";
import { Empty, Spinner } from "@/ui/misc";
import { MenuItem, MenuSep, Popover, useMenu } from "@/ui/popover";
import { confirmDialog, promptDialog, Dialog } from "@/ui/dialog";
import { toast } from "@/ui/toast";

export function FilesView({ nodeId }: { nodeId?: string }) {
  const [, navigate] = useLocation();
  const files = useFiles();
  const parentId = nodeId ?? null;
  const [dropping, setDropping] = useState(false);
  const [selected, setSelected] = useState<string | null>(null);
  const menu = useMenu();
  const [menuNode, setMenuNode] = useState<FileNode | null>(null);
  const [moveNode, setMoveNode] = useState<FileNode | null>(null);
  const inputRef = useRef<HTMLInputElement>(null);

  useEffect(() => {
    if (files.available) void files.loadChildren(parentId);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [files.available, parentId]);

  // Ensure ancestors are loaded for breadcrumbs
  useEffect(() => {
    if (!files.available || !parentId) return;
    const n = files.nodes[parentId];
    if (!n) {
      void client.call<{ list: FileNode[] }>("FileNode/get", { accountId: files.accountId, ids: [parentId], fetchParents: true }).then((r) => {
        useFiles.setState((s) => {
          const nodes = { ...s.nodes };
          for (const x of r.list) nodes[x.id] = x;
          return { nodes };
        });
      }).catch(() => undefined);
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [parentId, files.available]);

  if (!files.available) return <div className="p-16"><Empty icon={<FolderOpen size={40} />} title="File storage is not available">This account does not have the JMAP file storage capability.</Empty></div>;

  const ids = files.children[parentId ?? "root"] ?? [];
  const nodes = ids.map((id) => files.nodes[id]).filter((n): n is FileNode => Boolean(n));
  const path = files.pathTo(parentId);

  const onDrop = (e: React.DragEvent) => {
    e.preventDefault();
    setDropping(false);
    const list = Array.from(e.dataTransfer.files);
    if (list.length) void files.upload(parentId, list);
  };

  const download = (n: FileNode) => {
    if (!n.blobId) return;
    const a = document.createElement("a");
    a.href = client.downloadUrl(files.accountId!, n.blobId, n.name, n.type ?? "application/octet-stream");
    a.download = n.name;
    a.click();
  };

  return (
    <div className={`files-layout ${dropping ? "dropping" : ""}`} onDragOver={(e) => { if (e.dataTransfer.types.includes("Files")) { e.preventDefault(); setDropping(true); } }} onDragLeave={() => setDropping(false)} onDrop={onDrop}>
      <div className="files-toolbar">
        <div className="breadcrumb">
          <button className={path.length ? "" : "current"} onClick={() => navigate("/files")}><Home size={16} /></button>
          {path.map((n, i) => (
            <span key={n.id} className="row gap-4">
              <ChevronRight size={14} className="faint" />
              <button className={i === path.length - 1 ? "current" : ""} onClick={() => navigate(`/files/${n.id}`)}>{n.name}</button>
            </span>
          ))}
        </div>
        <button className="btn btn-sm" onClick={() => inputRef.current?.click()}><Upload size={16} /> Upload</button>
        <input ref={inputRef} type="file" multiple hidden onChange={(e) => { const l = Array.from(e.target.files ?? []); if (l.length) void files.upload(parentId, l); e.target.value = ""; }} />
        <button className="btn btn-sm" onClick={async () => { const n = await promptDialog({ title: "New folder", placeholder: "Folder name" }); if (n?.trim()) { try { await files.mkdir(parentId, n.trim()); } catch (err) { toast.error((err as Error).message); } } }}><FolderPlus size={16} /> New folder</button>
      </div>
      {files.uploads.length > 0 && (
        <div className="list-hint" style={{ flexDirection: "column", alignItems: "stretch", gap: 4 }}>
          {files.uploads.map((u) => <div key={u.id} className="row"><span className="truncate grow">{u.name}</span>{u.error ? <span style={{ color: "var(--danger)" }}>{u.error}</span> : <span>{u.progress}%</span>}</div>)}
        </div>
      )}
      {files.error && <div className="error-box" style={{ margin: 12 }}>{files.error}</div>}
      <div className="files-scroll">
        {files.loading && !nodes.length ? <Spinner /> : !nodes.length ? (
          <Empty icon={<FolderOpen size={40} />} title="This folder is empty">Drag files here or use Upload.</Empty>
        ) : (
          <table className="files-table">
            <thead><tr><th>Name</th><th className="hide-mobile">Size</th><th className="hide-mobile">Modified</th><th /></tr></thead>
            <tbody>
              {nodes.map((n) => (
                <tr key={n.id} className={selected === n.id ? "selected" : ""} onClick={() => setSelected(n.id)} onDoubleClick={() => (n.nodeType === "directory" ? navigate(`/files/${n.id}`) : download(n))} onContextMenu={(e) => { e.preventDefault(); setMenuNode(n); menu.openAt(e.clientX, e.clientY); }}>
                  <td><div className="f-name">{n.nodeType === "directory" ? <Folder size={18} /> : <File size={18} />}<span onClick={(e) => { if (n.nodeType === "directory") { e.stopPropagation(); navigate(`/files/${n.id}`); } }} style={n.nodeType === "directory" ? { cursor: "pointer" } : undefined}>{n.name}</span></div></td>
                  <td className="hide-mobile muted">{n.nodeType === "directory" ? "—" : formatSize(n.size)}</td>
                  <td className="hide-mobile muted">{formatListDate(n.modified ?? n.created)}</td>
                  <td style={{ textAlign: "right" }}><button className="icon-btn sm" onClick={(e) => { e.stopPropagation(); setMenuNode(n); menu.open(e); }} aria-label="Options"><MoreVertical size={16} /></button></td>
                </tr>
              ))}
            </tbody>
          </table>
        )}
      </div>
      <Popover anchor={menu.anchor} onClose={menu.close} width={200}>
        {menuNode && (
          <>
            {menuNode.nodeType === "directory" ? <MenuItem icon={<FolderOpen size={16} />} label="Open" onClick={() => navigate(`/files/${menuNode.id}`)} /> : <MenuItem icon={<Download size={16} />} label="Download" onClick={() => download(menuNode)} />}
            <MenuItem icon={<Pencil size={16} />} label="Rename" disabled={!menuNode.myRights?.mayRename} onClick={async () => { const n = await promptDialog({ title: "Rename", defaultValue: menuNode.name }); if (n?.trim() && n !== menuNode.name) { try { await files.rename(menuNode.id, n.trim()); } catch (err) { toast.error((err as Error).message); } } }} />
            <MenuItem icon={<FolderInput size={16} />} label="Move to…" onClick={() => setMoveNode(menuNode)} />
            <MenuSep />
            <MenuItem danger icon={<Trash2 size={16} />} label="Delete" disabled={!menuNode.myRights?.mayDelete} onClick={async () => { if (await confirmDialog({ title: `Delete “${menuNode.name}”?`, confirmLabel: "Delete", danger: true })) { try { await files.destroy([menuNode.id]); toast.success("Deleted"); } catch (err) { toast.error((err as Error).message); } } }} />
          </>
        )}
      </Popover>
      {moveNode && <MoveDialog node={moveNode} onClose={() => setMoveNode(null)} />}
    </div>
  );
}

function MoveDialog({ node, onClose }: { node: FileNode; onClose: () => void }) {
  const files = useFiles();
  const [cur, setCur] = useState<string | null>(null);
  useEffect(() => {
    void files.loadChildren(cur);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [cur]);
  const dirs = (files.children[cur ?? "root"] ?? []).map((id) => files.nodes[id]).filter((n): n is FileNode => Boolean(n && n.nodeType === "directory" && n.id !== node.id));
  const path = files.pathTo(cur);
  return (
    <Dialog open onClose={onClose} title={`Move “${node.name}”`} size="sm" footer={<><button className="btn" onClick={onClose}>Cancel</button><button className="btn btn-primary" disabled={cur === (node.parentId ?? null)} onClick={async () => { try { await files.move(node.id, cur); toast.success("Moved"); onClose(); } catch (err) { toast.error((err as Error).message); } }}>Move here</button></>}>
      <div className="breadcrumb mb-8">
        <button onClick={() => setCur(null)}><Home size={14} /></button>
        {path.map((n) => <span key={n.id} className="row gap-4"><ChevronRight size={12} /><button onClick={() => setCur(n.id)}>{n.name}</button></span>)}
      </div>
      {dirs.map((d) => <button key={d.id} className="menu-item" onClick={() => setCur(d.id)}><Folder size={16} /><span className="grow">{d.name}</span><ChevronRight size={14} /></button>)}
      {!dirs.length && <p className="hint">No subfolders here.</p>}
    </Dialog>
  );
}