use std::io::Write;
use std::process::{Command, Stdio};
use std::str;

static PROGNAME: &'static str = "./nl";

fn run(args: &[&'static str]) -> String {
    let po = Command::new(PROGNAME)
        .args(args)
        .output()
        .unwrap_or_else(|e| panic!("{}", e));

    str::from_utf8(&po.stdout).unwrap().to_string()
}

fn run_with_stdin(input: &str, args: &[&'static str]) -> String {
    let mut process = Command::new(PROGNAME)
        .args(args)
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .spawn()
        .unwrap_or_else(|e| panic!("{}", e));

    process.stdin
        .take()
        .unwrap_or_else(|| panic!("Could not take child process stdin"))
        .write_all(input.as_bytes())
        .unwrap_or_else(|e| panic!("{}", e));

    let po = process.wait_with_output().unwrap_or_else(|e| panic!("{}", e));
    str::from_utf8(&po.stdout).unwrap().to_string()
}

#[test]
fn test_stdin_nonewline() {
    let out = run_with_stdin("No Newline", &[]);
    assert_eq!(&out, "     1\tNo Newline\n");
}
#[test]
fn test_stdin_newline() {
    let out = run_with_stdin("Line One\nLine Two\n", &["-s", "-", "-w", "1"]);
    assert_eq!(&out, "1-Line One\n2-Line Two\n");
}

#[test]
fn test_padding_without_overflow() {
    let out = run(&["-i", "1000", "-s", "x", "-n", "rz", "simple.txt"]);
    assert_eq!(&out, "000001xL1\n001001xL2\n002001xL3\n003001xL4\n004001xL5\n005001xL6\n006001xL7\n007001xL8\n008001xL9\n009001xL10\n010001xL11\n011001xL12\n012001xL13\n013001xL14\n014001xL15\n");
}

#[test]
fn test_padding_with_overflow() {
    let out = run(&["-i", "1000", "-s", "x", "-n", "rz", "-w", "4", "simple.txt"]);
    assert_eq!(&out, "0001xL1\n1001xL2\n2001xL3\n3001xL4\n4001xL5\n5001xL6\n6001xL7\n7001xL8\n8001xL9\n9001xL10\n10001xL11\n11001xL12\n12001xL13\n13001xL14\n14001xL15\n");
}

#[test]
fn test_sections_and_styles() {
    for &(fixture, output) in [
        (
            "section.txt", 
            "\nHEADER1\nHEADER2\n\n1  |BODY1\n2  |BODY2\n\nFOOTER1\nFOOTER2\n\nNEXTHEADER1\nNEXTHEADER2\n\n1  |NEXTBODY1\n2  |NEXTBODY2\n\nNEXTFOOTER1\nNEXTFOOTER2\n"
        ),
        (
            "joinblanklines.txt",
            "1  |Nonempty\n2  |Nonempty\n3  |Followed by 10x empty\n\n\n\n\n4  |\n\n\n\n\n5  |\n6  |Followed by 5x empty\n\n\n\n\n7  |\n8  |Followed by 4x empty\n\n\n\n\n9  |Nonempty\n10 |Nonempty\n11 |Nonempty.\n"
        ),
    ].iter() {
        let out = run(&["-s", "|", "-n", "ln", "-w", "3", "-b", "a", "-l", "5", fixture]);
        assert_eq!(&out, output);
    }
}