/* Internet Archive directory listing searcher */

if(document.location.pathname.search("/download/") == 0) /* if directory listing viewed */ {
	var listing = document.getElementsByClassName("download-directory-listing")[0];

	// create search bar in memory before inserting
	var search_bar = document.createElement("input");
	search_bar.placeholder="search files";
	search_bar.onkeyup=search_list;
	search_bar.style.marginRight="0.5em";

	// create clear button and search result counter in memory before inserting
	var search_clear_button = document.createElement("button");
	search_clear_button.style.marginRight="1em";
	search_clear_button.innerHTML="clear";
	search_clear_button.onclick=clear_search;
	
	// create "inverted" check box in memory
	var inverted_checkbox = document.createElement("input");
	inverted_checkbox.type = "checkbox";
	inverted_checkbox.onclick = search_list; // repeat search after changing mode
	inverted_checkbox.style.marginRight="0.5em";
		// create checkbox label
		var inverted_checkbox_label = document.createElement("label");
		inverted_checkbox_label.appendChild(inverted_checkbox);
		var span = document.createElement("span");
		inverted_checkbox_label.appendChild(span);
		inverted_checkbox_label.lastChild.innerHTML="invert results";
		inverted_checkbox_label.style.marginRight="1em";
	
	// create "case-sensitive" check box in memory
	var case_sensitive_checkbox = document.createElement("input");
	case_sensitive_checkbox.type = "checkbox";
	case_sensitive_checkbox.onclick = search_list; // repeat search after changing mode
	case_sensitive_checkbox.style.marginRight="0.5em";
		// create checkbox label
		var case_sensitive_checkbox_label = document.createElement("label");
		case_sensitive_checkbox_label.appendChild(case_sensitive_checkbox);
		var span = document.createElement("span");
		case_sensitive_checkbox_label.appendChild(span);
		case_sensitive_checkbox_label.lastChild.innerHTML="case-sensitive";
		case_sensitive_checkbox_label.style.marginRight="1em";
	
	
	// create result counter field in memory
	var result_counter = document.createElement("span");

	var listing_hr = listing.getElementsByTagName("hr")[0];
	listing.insertBefore(search_bar, listing_hr); // insert search bar into page
	listing.insertBefore(search_clear_button, listing_hr); // insert "clear" button into page
	listing.insertBefore(inverted_checkbox_label, listing_hr); // insert "invert results" checkbox
	listing.insertBefore(case_sensitive_checkbox_label, listing_hr); // insert "case-sensitive" checkbox
	listing.insertBefore(result_counter, listing_hr); // insert result counter into page
	search_bar.focus(); // actuate search bar without clicking or tapping on it

	var list_items = listing.getElementsByTagName("tr");
	var count = 0; // initialize counter for "for" loops
	var result_count = 0; // initialize result counter

}

function search_list() {
	result_count = 0; // reset result counter
	search_bar.setAttribute("value",search_bar.value); // compatibility
	var search_input = search_bar.value;
	var searched_content = ""; // initialize to eliminate JSHint error
		
	if (! case_sensitive_checkbox.checked) {
		// convert to case-insensitive
		search_input = search_input.toLowerCase();
	}
	
	// The inverted checkbox status is not checked inside the "for" loop for efficiency. A pice of code that needs to be run many times should be a short as possible for improving performance.
	if (! inverted_checkbox.checked) /* meaning unchecked */ {
		for (count=2 /* skip "go to parent directory" */; count < list_items.length; count++) {		
			// perform search
			searched_content=list_items[count].innerHTML;
			if (! case_sensitive_checkbox.checked) {
				// convert to case-insensitive if checkbox not check
				searched_content = searched_content.toLowerCase();
			}
			if (searched_content.search(search_input)<0) /* if no match */ {
				list_items[count].style.display="none"; // hide 
			} else {
				list_items[count].style.display=""; // fall back to original CSS by resetting to undefined
				result_count++; // count results
				}
		}
	} else {
		for (count=2 /* skip "go to parent directory" */; count < list_items.length; count++) {		
			// perform inverted search
			searched_content=list_items[count].innerHTML;
			if (! case_sensitive_checkbox.checked) {
				// convert to case-insensitive if checkbox not check
				searched_content = searched_content.toLowerCase();
			}
			if (searched_content.search(search_input)>-1) /* if match */ {
				list_items[count].style.display="none"; // hide 
			} else {
				list_items[count].style.display=""; // fall back to original CSS by resetting to undefined
				result_count++; // count results
				}
		}
	}
		
	result_counter.innerHTML = result_count;
	if (result_count == 1) result_counter.innerHTML += " result"; // singular
		else result_counter.innerHTML += " results"; // plural
}



function clear_search() {
	search_bar.value="";
	search_list();
}