document.addEventListener("DOMContentLoaded", function() {
	const input = document.getElementById("command-input");
	if (!input) return;
	let commandHistory = JSON.parse(sessionStorage.getItem("commandHistory")) || [];
	let historyIndex = commandHistory.length;
	let tabIndex = -1;
	let tabMatches = [];

	document.querySelector("form").addEventListener("submit", function(event) {
		const command = input.value.trim();
		if (command) {
			commandHistory.push(command);
			sessionStorage.setItem("commandHistory", JSON.stringify(commandHistory));
			historyIndex = commandHistory.length;
		}
	});

	window.addEventListener("keydown", function(event) {
		if (document.activeElement !== input) return;

		const cursorPos = input.selectionStart;
		const textLength = input.value.length;

		// Prevent default behavior for specific Ctrl+Key shortcuts
		if (event.ctrlKey && ["w", "n", "p", "h", "e", "a", "k", "u", "d", "r", "t"].includes(event.key.toLowerCase())) {
			event.preventDefault();
			event.stopPropagation();
		}

		// Ctrl+A: Move cursor to the beginning
		if (event.ctrlKey && event.key === "a") {
			input.setSelectionRange(0, 0);
		}

		// Ctrl+E: Move cursor to the end
		else if (event.ctrlKey && event.key === "e") {
			input.setSelectionRange(textLength, textLength);
		}

		// Ctrl+U: Clear the input field
		else if (event.ctrlKey && event.key === "u") {
			input.value = "";
		}

		// Ctrl+K: Delete everything after the cursor
		else if (event.ctrlKey && event.key === "k") {
			input.value = input.value.substring(0, cursorPos);
		}

		// Ctrl+W: Delete the previous word
		else if (event.ctrlKey && event.key === "w") {
			const beforeCursor = input.value.substring(0, cursorPos);
			const afterCursor = input.value.substring(cursorPos);
			const newBeforeCursor = beforeCursor.replace(/\S+\s*$/, ""); // Delete last word
			input.value = newBeforeCursor + afterCursor;
			input.setSelectionRange(newBeforeCursor.length, newBeforeCursor.length);
		}

		// Ctrl+H: Delete the previous character (Backspace)
		else if (event.ctrlKey && event.key === "h") {
			if (cursorPos > 0) {
				input.value = input.value.substring(0, cursorPos - 1) + input.value.substring(cursorPos);
				input.setSelectionRange(cursorPos - 1, cursorPos - 1);
			}
		}

		// Ctrl+D: Delete character under cursor (or clear input if empty)
		else if (event.ctrlKey && event.key === "d") {
			if (textLength === 0) {
				console.log("Ctrl+D: No input, simulating EOF");
			} else if (cursorPos < textLength) {
				input.value = input.value.substring(0, cursorPos) + input.value.substring(cursorPos + 1);
				input.setSelectionRange(cursorPos, cursorPos);
			}
		}

		// Ctrl+P: Previous command (up)
		else if (event.ctrlKey && event.key === "p") {
			if (historyIndex > 0) {
				historyIndex--;
				input.value = commandHistory[historyIndex];
			} else if (historyIndex === 0) {
				input.value = commandHistory[0];
			}
		}

		// Ctrl+N: Next command (down)
		else if (event.ctrlKey && event.key === "n") {
			if (historyIndex < commandHistory.length - 1) {
				historyIndex++;
				input.value = commandHistory[historyIndex];
			} else {
				historyIndex = commandHistory.length;
				input.value = "";
			}
		}

		// Ctrl+R: Prevent page reload (for future reverse search)
		else if (event.ctrlKey && event.key === "r") {
			console.log("Reverse search triggered (not yet implemented)");
		}

		// Tab Completion
		else if (event.key === "Tab") {
			event.preventDefault();
			const currentText = input.value.trim();

			if (currentText === "") return;

			// Find all matching commands from history
			if (tabIndex === -1) {
				tabMatches = commandHistory.filter(cmd => cmd.startsWith(currentText));
				if (tabMatches.length === 0) return;
			}

			// Cycle through matches
			if (event.shiftKey) {
				tabIndex = tabIndex > 0 ? tabIndex - 1 : tabMatches.length - 1; // Shift+Tab goes backward
			} else {
				tabIndex = (tabIndex + 1) % tabMatches.length;
			}

			input.value = tabMatches[tabIndex];
		}

		// Allow Enter key to submit form
		if (event.key === "Enter") {
			tabIndex = -1; // Reset tab completion cycle
			return;
		}
	}, true);
});