// File browser page behavior: uploading via the "Upload files"/"Upload
// folder" buttons and via drag & drop onto the listing, both re-using the
// same upload() call. Folder uploads (button or drop) recreate their
// directory structure server-side by encoding the relative path in each
// uploaded file's name (see FormData.append's third argument below).
(function initFileBrowser(): void {
	const dropZone = document.getElementById("file-drop-zone") as HTMLDivElement | null;
	const filesInput = document.getElementById("upload-files-input") as HTMLInputElement | null;
	const folderInput = document.getElementById("upload-folder-input") as HTMLInputElement | null;
	const newFolderButton = document.getElementById("new-folder-button") as HTMLButtonElement | null;
	const sortSelect = document.getElementById("sort-select") as HTMLSelectElement | null;
	const status = document.getElementById("upload-status") as HTMLParagraphElement | null;
	if (!dropZone) {
		return;
	}

	const uploadUrl = dropZone.dataset.uploadUrl || window.location.pathname;

	function setStatus(msg: string): void {
		if (status) {
			status.textContent = msg;
		}
	}

	async function upload(files: File[]): Promise<void> {
		if (files.length === 0) {
			return;
		}
		const formData = new FormData();
		for (const file of files) {
			const relPath = (file as File & { webkitRelativePath?: string }).webkitRelativePath || file.name;
			formData.append("files", file, file.name);
			formData.append("paths", relPath);
		}

		setStatus(`Uploading ${files.length} file(s)…`);
		try {
			const resp = await fetch(uploadUrl, { method: "POST", body: formData });
			if (!resp.ok) {
				const text = await resp.text();
				setStatus(`Upload failed: ${text}`);
				return;
			}
			window.location.reload();
		} catch (err) {
			setStatus(`Upload failed: ${String(err)}`);
		}
	}

	filesInput?.addEventListener("change", () => {
		void upload(Array.from(filesInput.files || []));
		filesInput.value = "";
	});

	folderInput?.addEventListener("change", () => {
		void upload(Array.from(folderInput.files || []));
		folderInput.value = "";
	});

	const folderNameRe = /^[a-zA-Z0-9._-]{1,64}$/;

	newFolderButton?.addEventListener("click", async () => {
		const name = window.prompt("New folder name:");
		if (!name) {
			return;
		}
		if (!folderNameRe.test(name)) {
			setStatus("Folder name must be 1-64 letters, digits, '-' or '_'.");
			return;
		}
		setStatus(`Creating folder "${name}"…`);
		try {
			const resp = await fetch(`${uploadUrl}?mkdir=1`, {
				method: "POST",
				headers: { "Content-Type": "application/x-www-form-urlencoded" },
				body: new URLSearchParams({ name }),
			});
			if (!resp.ok) {
				const text = await resp.text();
				setStatus(`Could not create folder: ${text}`);
				return;
			}
			window.location.reload();
		} catch (err) {
			setStatus(`Could not create folder: ${String(err)}`);
		}
	});

	document.querySelectorAll<HTMLButtonElement>(".delete-entry-button").forEach((button) => {
		button.addEventListener("click", async () => {
			const relPath = button.dataset.path || "";
			const name = button.dataset.name || relPath;
			if (!window.confirm(`Delete "${name}"? This cannot be undone.`)) {
				return;
			}
			setStatus(`Deleting "${name}"…`);
			try {
				const resp = await fetch(`/web/files/${relPath}`, { method: "DELETE" });
				if (!resp.ok) {
					const text = await resp.text();
					setStatus(`Could not delete "${name}": ${text}`);
					return;
				}
				window.location.reload();
			} catch (err) {
				setStatus(`Could not delete "${name}": ${String(err)}`);
			}
		});
	});

	if (sortSelect) {
		sortSelect.addEventListener("change", () => {
			const value = sortSelect.value;
			let sortBy = "name";
			let sortDir = "asc";
			if (value === "name_asc") {
				sortBy = "name";
				sortDir = "asc";
			} else if (value === "name_desc") {
				sortBy = "name";
				sortDir = "desc";
			}
			window.location.href = `${uploadUrl}?sort_by=${sortBy}&sort_dir=${sortDir}`;
		});
	}

	function readEntry(entry: FileSystemEntry): Promise<File[]> {
		return new Promise((resolve) => {
			if (entry.isFile) {
				(entry as FileSystemFileEntry).file((file) => {
					Object.defineProperty(file, "webkitRelativePath", {
						value: entry.fullPath.replace(/^\//, ""),
					});
					resolve([file]);
				}, () => resolve([]));
				return;
			}
			if (entry.isDirectory) {
				const reader = (entry as FileSystemDirectoryEntry).createReader();
				const allEntries: FileSystemEntry[] = [];
				const readBatch = (): void => {
					reader.readEntries(async (batch) => {
						if (batch.length === 0) {
							const nested = await Promise.all(allEntries.map(readEntry));
							resolve(nested.flat());
							return;
						}
						allEntries.push(...batch);
						readBatch();
					}, () => resolve([]));
				};
				readBatch();
				return;
			}
			resolve([]);
		});
	}

	dropZone.addEventListener("dragover", (e) => {
		e.preventDefault();
		dropZone.classList.add("border-indigo-400", "bg-indigo-50");
	});
	dropZone.addEventListener("dragleave", () => {
		dropZone.classList.remove("border-indigo-400", "bg-indigo-50");
	});
	dropZone.addEventListener("drop", (e) => {
		e.preventDefault();
		dropZone.classList.remove("border-indigo-400", "bg-indigo-50");
		const items = e.dataTransfer?.items;
		if (!items) {
			return;
		}
		const entries: FileSystemEntry[] = [];
		for (const item of Array.from(items)) {
			const entry = item.webkitGetAsEntry?.();
			if (entry) {
				entries.push(entry);
			}
		}
		if (entries.length === 0) {
			void upload(Array.from(e.dataTransfer?.files || []));
			return;
		}
		void Promise.all(entries.map(readEntry)).then((groups) => upload(groups.flat()));
	});
})();