//ww:run
package main;

import os;
import fmt;
import io;
import temp;

fn fresh() i32 = {
	let fd: i32 = -1;
	let path: str;
	match (temp.named(&fd, &path, "/tmp", temp.mode.RDWR, 0o600: i32)) {
	case void => void;
	case let e: os.oserror => return -1;
	};
	if (os.remove(path) != 0) { os.close(fd); return -1; };
	return fd;
};

fn expect(fd: i32, nw: size, want: str) bool = {
	if (os.lseek(fd, 0i64, os.whence.SET) != 0i64) {
		os.close(fd);
		return false;
	};
	let buf: [16]u8;
	let n: i64 = os.read(fd, &buf[0], 16u64);
	let closed: i32 = os.close(fd);
	if (closed != 0 || n != want.len: i64 || nw != want.len: size) {
		return false;
	};
	let i: i32 = 0;
	for (i < want.len) {
		if (buf[i] != want[i]) { return false; };
		i += 1;
	};
	return true;
};

export fn main() i32 = {
	let fd: i32 = fresh();
	if (fd < 0) { return 1; };
	match (fmt.fprintf(fd: io.file, "{:5}", 42i64)) {
	case let n: size => { if (!expect(fd, n, "   42")) { return 2; }; };
	case io.error => { os.close(fd); return 3; };
	};

	fd = fresh();
	if (fd < 0) { return 4; };
	match (fmt.fprintf(fd: io.file, "{:.3}", "hello")) {
	case let n: size => { if (!expect(fd, n, "hel")) { return 5; }; };
	case io.error => { os.close(fd); return 6; };
	};

	fd = fresh();
	if (fd < 0) { return 7; };
	match (fmt.fprintf(fd: io.file, "{:x}", 255i64)) {
	case let n: size => { if (!expect(fd, n, "ff")) { return 8; }; };
	case io.error => { os.close(fd); return 9; };
	};

	fd = fresh();
	if (fd < 0) { return 10; };
	match (fmt.fprintf(fd: io.file, "{:+}", 7i64)) {
	case let n: size => { if (!expect(fd, n, "+7")) { return 11; }; };
	case io.error => { os.close(fd); return 12; };
	};

	fd = fresh();
	if (fd < 0) { return 13; };
	match (fmt.fprintf(fd: io.file, "{:_05}", 42i64)) {
	case let n: size => { if (!expect(fd, n, "00042")) { return 14; }; };
	case io.error => { os.close(fd); return 15; };
	};
	return 0;
};