use super::*;

fn parse(x: &[u8]) -> Ast<PreExpansion> {
    do_parse(x)
        .map_err(|(err, rest)| (err, String::from_utf8_lossy(&rest)))
        .unwrap()
}

const TIMEOUT_MS: u64 = 100;

macro_rules! parse_test {
    ($l:expr, $r:expr $(,)?) => {{
        let (tx, rx) = std::sync::mpsc::channel();

        std::thread::spawn(move || {
            #[allow(unreachable_code, unused_variables)]
            let result = std::panic::catch_unwind(|| {
                let l = $l;
                let r = $r;
                if l != r {
                    let mut left = Vec::new();
                    l.cdisplay(&mut left).unwrap();
                    let mut right = Vec::new();
                    r.cdisplay(&mut right).unwrap();
                    let left = String::from_utf8_lossy(&left);
                    let right = String::from_utf8_lossy(&right);
                    if left != right {
                        panic!("parse equality error\nleft:  {left}\nright: {right}")
                    }
                }
            });
            let _ = tx.send(result);
        });

        match rx.recv_timeout(std::time::Duration::from_millis(TIMEOUT_MS)) {
            Ok(Ok(())) => (),
            Ok(Err(e)) => std::panic::resume_unwind(e),
            Err(_) => panic!("test timed out after {TIMEOUT_MS} ms"),
        }
    }};
}

#[test]
fn command_interp() {
    parse_test!(
        parse(br#""$(echo echo)""#),
        pipes([cmd([str([cmdp(pipes([cmd([
            estr(b"echo"),
            estr(b"echo"),
        ])]))])])]),
    )
}

#[test]
fn string_concat() {
    parse_test!(
        parse(br#"  foo'bar'"baz"  "#),
        pipes([cmd([estr(b"foobarbaz")])]),
    );
}

#[test]
fn simple_string() {
    parse_test!(parse(b"foo"), pipes([cmd([estr(b"foo")])]));
}

#[test]
fn simple_var() {
    parse_test!(parse(b"$foo"), pipes([cmd([str([var(b"foo")])])]));
}

#[test]
fn ls_pipe_cat() {
    parse_test!(
        parse(b"ls | cat"),
        pipes([cmd([estr(b"ls")]), cmd([estr(b"cat")])]),
    );
}

#[test]
fn ls_pipe_cat_nospace() {
    parse_test!(
        parse(b"ls|cat"),
        pipes([cmd([estr(b"ls")]), cmd([estr(b"cat")])]),
    );
}

#[test]
fn unclosed_single_quote() {
    assert!(do_parse(b"x'").is_err())
}

#[test]
fn unclosed_double_quote() {
    assert!(do_parse(b"x\"").is_err())
}

#[test]
fn tilde() {
    parse_test!(
        parse(b"echo ~"),
        pipes([cmd([estr(b"echo"), str([var(b"HOME")])])]),
    );
}

#[test]
fn tilde2() {
    parse_test!(
        parse(b"echo ~/foo/bar"),
        pipes([cmd([
            estr(b"echo"),
            str([var(b"HOME"), plain(b"/foo/bar")]),
        ])]),
    );
}

#[test]
fn tilde3() {
    parse_test!(
        parse(b"echo ~ "),
        pipes([cmd([estr(b"echo"), str([var(b"HOME")])])]),
    );
}

#[test]
fn tilde4() {
    parse_test!(
        parse(b"echo ~'x'"),
        pipes([cmd([estr(b"echo"), estr(b"~x")])]),
    );
}

#[test]
fn tilde5() {
    parse_test!(
        parse(b"echo ~$FOO"),
        pipes([cmd([estr(b"echo"), str([plain(b"~"), var(b"FOO")])])]),
    );
}

#[test]
fn tilde6() {
    parse_test!(
        parse(b"git rebase -i HEAD~10"),
        pipes([cmd([
            estr(b"git"),
            estr(b"rebase"),
            estr(b"-i"),
            estr(b"HEAD~10"),
        ])]),
    );
}

#[test]
fn set_variable_in_fun() {
    parse_test!(
        parse(b"fun setter { set x = 1 }"),
        decl(estr(b"setter"), block([assign(estr(b"x"), estr(b"1"))])),
    );
}

#[test]
fn variable_with_defaults() {
    parse_test!(
        parse(b"${x:-y}"),
        pipes([cmd([str([var_default(b"x", estr(b"y"))])])]),
    );
}

#[test]
fn escape_newline() {
    parse_test!(parse(b"\"\\n\""), pipes([cmd([estr(b"\n")])]));
}

#[test]
fn escape_carriage_return() {
    parse_test!(parse(b"\"\\r\""), pipes([cmd([estr(b"\r")])]));
}

#[test]
fn escape_tab() {
    parse_test!(parse(b"\"\\t\""), pipes([cmd([estr(b"\t")])]));
}

#[test]
fn escape_hex_1() {
    parse_test!(parse(b"\\x41"), pipes([cmd([estr(b"A")])]));
}

#[test]
fn escape_hex_2() {
    parse_test!(parse(b"\\x0a"), pipes([cmd([estr(b"\n")])]));
}

#[test]
fn pipe_on_new_line() {
    parse_test!(
        parse(b"cat file \n | cat"),
        pipes([cmd([estr(b"cat"), estr(b"file")]), cmd([estr(b"cat")])]),
    );
}

#[test]
fn semicolon() {
    parse_test!(
        parse(b"fun f { x ; y }"),
        decl(
            estr(b"f"),
            block([pipes([cmd([estr(b"x")])]), pipes([cmd([estr(b"y")])])]),
        ),
    );
}

#[test]
fn newline_separates_commands() {
    parse_test!(
        parse(b"fun f { x \n y }"),
        decl(
            estr(b"f"),
            block([pipes([cmd([estr(b"x")])]), pipes([cmd([estr(b"y")])])]),
        ),
    );
}

#[test]
fn newline_does_not_separate_pipes() {
    parse_test!(
        parse(b"fun f { x \n| y }"),
        decl(
            estr(b"f"),
            block([pipes([cmd([estr(b"x")]), cmd([estr(b"y")])])]),
        ),
    );
}

#[test]
fn simple_if() {
    parse_test!(
        parse(b"if cond { x }"),
        cond(
            pipes([cmd([estr(b"cond")]),]),
            block([pipes([cmd([estr(b"x")]),])]),
            block([])
        )
    );
}

#[test]
fn if_else() {
    parse_test!(
        parse(b"if cond { x } else { y }"),
        cond(
            pipes([cmd([estr(b"cond")]),]),
            block([pipes([cmd([estr(b"x")]),])]),
            block([pipes([cmd([estr(b"y")]),])])
        )
    );
}

#[test]
fn simple_while() {
    parse_test!(parse(b"while cond { x }"), todo!());
}

#[test]
fn multiline_string_1() {
    parse_test!(
        parse(
            br#"echo """
hello
world""""#
        ),
        pipes([cmd([estr(b"echo"), estr(b"hello\nworld")]),])
    );
}

#[test]
fn multiline_string_2() {
    parse_test!(
        parse(
            br#"echo """
line 1
$var
line 3
""""#
        ),
        pipes([cmd([
            estr(b"echo"),
            str([plain(b"line 1\n"), var(b"var"), plain(b"\nline 3\n")])
        ]),])
    );
}

#[test]
fn multiline_string_3() {
    parse_test!(
        parse(
            br#"echo '''
line 1
$var
line 3
'''"#
        ),
        pipes([cmd([estr(b"echo"), estr(b"line 1\n$var\nline 3\n")]),])
    );
}

#[test]
fn multiline_string_4() {
    parse_test!(
        parse(
            br#"echo foo"""
text
"""
more text
"""foo
"#
        ),
        pipes([cmd([estr(b"echo"), estr(b"text\n\"\"\"\nmore text\n")]),])
    );
}

#[test]
fn exit_code() {
    parse_test!(
        parse(b"echo $?"),
        pipes([cmd([estr(b"echo"), str([var(b"?")])])])
    )
}

#[test]
fn exit_code_2() {
    parse_test!(
        parse(b"echo \"$?\""),
        pipes([cmd([estr(b"echo"), str([var(b"?")])])])
    )
}

#[test]
fn dollar_non_var() {
    parse_test!(
        parse(b"echo $_"),
        pipes([cmd([estr(b"echo"), estr(b"$_")]),])
    )
}

#[test]
fn backslash_eof() {
    assert_eq!(do_parse(b"echo \\").unwrap_err().0, ParseError::Eof);
}

#[test]
fn backslash_joins_lines() {
    parse_test!(
        parse(b"echo foo\\\nbar"),
        pipes([cmd([estr(b"echo"), estr(b"foobar")]),])
    )
}

fn combinations(choices: &[&[u8]], n: usize) -> impl Iterator<Item = Vec<u8>> {
    struct CombinationGenerator<'a> {
        choices: &'a [&'a [u8]],
        indices: Vec<usize>,
        done: bool,
    }

    impl<'a> Iterator for CombinationGenerator<'a> {
        type Item = Vec<u8>;

        fn next(&mut self) -> Option<Self::Item> {
            if self.done {
                return None;
            }

            // Build current combination
            let mut out = Vec::new();
            for &i in &self.indices {
                out.extend_from_slice(self.choices[i]);
            }

            // Increment like a base-N counter
            for pos in (0..self.indices.len()).rev() {
                if self.indices[pos] + 1 < self.choices.len() {
                    self.indices[pos] += 1;
                    for j in pos + 1..self.indices.len() {
                        self.indices[j] = 0;
                    }
                    return Some(out);
                }
            }

            // Last combination reached
            self.done = true;
            Some(out)
        }
    }

    CombinationGenerator {
        choices,
        indices: vec![0; n],
        done: n == 0 && choices.is_empty(),
    }
}

fn coerce<T>(t: T) -> T {
    t
}

#[test]
fn test_escape_bruteforce() {
    let words = [
        coerce::<&'static [u8]>(b"\""),
        b"'",
        b"x",
        b"y",
        b"z",
        b"\\",
        b"|",
        b"$",
        b"{",
        b"}",
        b"'''",
        b"\"\"\"",
    ];

    let quotes = [
        StringDelimiter::None,
        StringDelimiter::Interp,
        StringDelimiter::Strict,
        StringDelimiter::InterpCustom(b"x".into()),
        StringDelimiter::StrictCustom(b"x".into()),
    ];

    for quote in quotes {
        for phrase in combinations(&words[..], 5) {
            let mut x = Vec::new();
            quote.write_opening_delimiter(&mut x);
            quote.escape(&phrase, &mut x);
            quote.write_closing_delimiter(&mut x);
            let s = ExpString::parse(&mut Cursor::new(&x, ParseMode::Command))
                .map_err(|e| format!("{quote:?} escape {} failed: {e:?}", x.escape_ascii()))
                .unwrap();
            assert_eq!(s.parts.len(), 1, "{}", x.escape_ascii());
            let s = s.parts[0].clone();
            let s = s.unwrap_boring();

            let x = String::from_utf8(x).unwrap();
            let s = String::from_utf8(s).unwrap();
            let phrase = String::from_utf8(phrase).unwrap();
            assert_eq!(
                phrase, s,
                "escape/parse roundtrip in StringDelimiter::{quote:?} failed: {phrase} -> {x} -> {s}"
            );
        }
    }
}