use crate::automaton::AlwaysMatch;
use crate::error::Error;
use crate::raw::{self, Bound, Builder, Fst, Output, Stream};
use crate::stream::Streamer;

const TEXT: &str = include_str!("./../../data/words-100000");

pub fn fst_set<I, S>(ss: I) -> Fst<Vec<u8>>
where
    I: IntoIterator<Item = S>,
    S: AsRef<[u8]>,
{
    let mut bfst = Builder::memory();
    let mut ss: Vec<Vec<u8>> =
        ss.into_iter().map(|s| s.as_ref().to_vec()).collect();
    ss.sort();
    ss.dedup();
    for s in ss.iter() {
        bfst.add(s).unwrap();
    }
    let fst = bfst.into_fst();
    assert_eq!(fst.len(), ss.len());
    fst
}

pub fn fst_map<I, S>(ss: I) -> Fst<Vec<u8>>
where
    I: IntoIterator<Item = (S, u64)>,
    S: AsRef<[u8]>,
{
    let mut bfst = Builder::memory();
    let mut ss: Vec<(Vec<u8>, u64)> =
        ss.into_iter().map(|(s, o)| (s.as_ref().to_vec(), o)).collect();
    ss.sort();
    ss.dedup();
    for (s, o) in ss.into_iter() {
        bfst.insert(s, o).unwrap();
    }
    bfst.into_fst()
}

pub fn fst_inputs<D: AsRef<[u8]>>(fst: &Fst<D>) -> Vec<Vec<u8>> {
    let mut words = vec![];
    let mut rdr = fst.stream();
    while let Some((word, _)) = rdr.next() {
        words.push(word.to_vec());
    }
    words
}

pub fn fst_inputs_outputs<D: AsRef<[u8]>>(
    fst: &Fst<D>,
) -> Vec<(Vec<u8>, u64)> {
    let mut words = vec![];
    let mut rdr = fst.stream();
    while let Some((word, out)) = rdr.next() {
        words.push((word.to_vec(), out.value()));
    }
    words
}

macro_rules! test_set {
    ($name:ident, $($s:expr),+) => {
        #[test]
        fn $name() {
            let mut items = vec![$($s),*];
            let fst = fst_set(&items);
            let mut rdr = fst.stream();
            items.sort_unstable();
            items.dedup();
            for item in &items {
                assert_eq!(rdr.next().unwrap().0, item.as_bytes());
            }
            assert_eq!(rdr.next(), None);
            for item in &items {
                assert!(fst.get(item).is_some());
            }
        }
    }
}

macro_rules! test_set_fail {
    ($name:ident, $($s:expr),+) => {
        #[test]
        #[should_panic]
        fn $name() {
            let mut bfst = Builder::memory();
            $(bfst.add($s).unwrap();)*
        }
    }
}

test_set!(fst_set_only_empty, "");
test_set!(fst_set_one, "a");
test_set!(fst_set_dupe_empty, "", "");
test_set!(fst_set_dupe1, "a", "a");
test_set!(fst_set_dupe2, "a", "b", "b");
test_set!(fst_set_two1, "a", "b");
test_set!(fst_set_two2, "a", "ab");
test_set!(fst_set_jan, "jam", "jbm", "jcm", "jdm", "jem", "jfm", "jgm");

test_set_fail!(fst_set_order1, "b", "a");
test_set_fail!(fst_set_order2, "a", "b", "c", "a");

#[test]
fn fst_set_100000() {
    let words: Vec<Vec<u8>> =
        TEXT.lines().map(|s| s.as_bytes().to_vec()).collect();
    let fst = fst_set(words.clone());
    assert_eq!(words, fst_inputs(&fst));
    for word in &words {
        assert!(
            fst.get(word).is_some(),
            "failed to find word: {}",
            std::str::from_utf8(word).unwrap()
        );
    }
}

macro_rules! test_map {
    ($name:ident, $($s:expr, $o:expr),+) => {
        #[test]
        fn $name() {
            let fst = fst_map(vec![$(($s, $o)),*]);
            let mut rdr = fst.stream();
            $({
                let (s, o) = rdr.next().unwrap();
                assert_eq!((s, o.value()), ($s.as_bytes(), $o));
            })*
            assert_eq!(rdr.next(), None);
            $({
                assert_eq!(fst.get($s.as_bytes()), Some(Output::new($o)));
            })*
        }
    }
}

macro_rules! test_map_fail {
    ($name:ident, $($s:expr, $o:expr),+) => {
        #[test]
        #[should_panic]
        fn $name() {
            let mut bfst = Builder::memory();
            $(bfst.insert($s, $o).unwrap();)*
        }
    }
}

test_map!(fst_map_only_empty1, "", 0);
test_map!(fst_map_only_empty2, "", 100);
test_map!(fst_map_only_empty3, "", 9999999999);
test_map!(fst_map_one1, "a", 0);
test_map!(fst_map_one2, "a", 100);
test_map!(fst_map_one3, "a", 999999999);
test_map!(fst_map_two, "a", 1, "b", 2);
test_map!(fst_map_many1, "a", 34786, "ab", 26);
test_map!(
    fst_map_many2,
    "a",
    34786,
    "ab",
    26,
    "abc",
    58976,
    "abcd",
    25,
    "z",
    58,
    "zabc",
    6798
);
test_map!(fst_map_many3, "a", 1, "ab", 0, "abc", 0);

test_map_fail!(fst_map_dupe_empty, "", 0, "", 0);
test_map_fail!(fst_map_dupe1, "a", 0, "a", 0);
test_map_fail!(fst_map_dupe2, "a", 0, "b", 0, "b", 0);
test_map_fail!(fst_map_order1, "b", 0, "a", 0);
test_map_fail!(fst_map_order2, "a", 0, "b", 0, "c", 0, "a", 0);

#[test]
fn fst_map_100000_increments() {
    let words: Vec<(Vec<u8>, u64)> = TEXT
        .lines()
        .enumerate()
        .map(|(i, s)| (s.as_bytes().to_vec(), i as u64))
        .collect();
    let fst = fst_map(words.clone());
    assert_eq!(words, fst_inputs_outputs(&fst));
    for &(ref word, out) in &words {
        assert_eq!(fst.get(word), Some(Output::new(out)));
    }
}

#[test]
fn fst_map_100000_lengths() {
    let words: Vec<(Vec<u8>, u64)> = TEXT
        .lines()
        .map(|s| (s.as_bytes().to_vec(), s.len() as u64))
        .collect();
    let fst = fst_map(words.clone());
    assert_eq!(words, fst_inputs_outputs(&fst));
    for &(ref word, out) in &words {
        assert_eq!(fst.get(word), Some(Output::new(out)));
    }
}

#[test]
fn invalid_format() {
    match Fst::new(vec![0; 0]) {
        Err(Error::Fst(raw::Error::Format { .. })) => {}
        Err(err) => panic!("expected format error, got {:?}", err),
        Ok(_) => panic!("expected format error, got FST"),
    }
}

#[test]
fn fst_set_zero() {
    let fst = fst_set::<_, String>(vec![]);
    let mut rdr = fst.stream();
    assert_eq!(rdr.next(), None);
}

macro_rules! test_range {
    (
        $name:ident,
        min: $min:expr,
        max: $max:expr,
        imin: $imin:expr,
        imax: $imax:expr,
        $($s:expr),*
    ) => {
        #[test]
        fn $name() {
            let items: Vec<&'static str> = vec![$($s),*];
            let items: Vec<_> = items
                .into_iter()
                .enumerate()
                .map(|(i, k)| (k, i as u64))
                .collect();
            let fst = fst_map(items.clone());
            let mut rdr = Stream::new(fst.as_ref(), AlwaysMatch, $min, $max);
            #[allow(clippy::reversed_empty_ranges)]
            for i in $imin..$imax {
                assert_eq!(
                    rdr.next().unwrap(),
                    (items[i].0.as_bytes(), Output::new(items[i].1)),
                );
            }
            assert_eq!(rdr.next(), None);
        }
    }
}

test_range! {
    fst_range_empty_1,
    min: Bound::Unbounded, max: Bound::Unbounded,
    imin: 0, imax: 0,
}

test_range! {
    fst_range_empty_2,
    min: Bound::Unbounded, max: Bound::Unbounded,
    imin: 0, imax: 1,
    ""
}

test_range! {
    fst_range_empty_3,
    min: Bound::Included(vec![]), max: Bound::Unbounded,
    imin: 0, imax: 1,
    ""
}

test_range! {
    fst_range_empty_4,
    min: Bound::Excluded(vec![]), max: Bound::Unbounded,
    imin: 0, imax: 0,
    ""
}

test_range! {
    fst_range_empty_5,
    min: Bound::Included(vec![]), max: Bound::Unbounded,
    imin: 0, imax: 2,
    "", "a"
}

test_range! {
    fst_range_empty_6,
    min: Bound::Excluded(vec![]), max: Bound::Unbounded,
    imin: 1, imax: 2,
    "", "a"
}

test_range! {
    fst_range_empty_7,
    min: Bound::Unbounded, max: Bound::Unbounded,
    imin: 0, imax: 2,
    "", "a"
}

test_range! {
    fst_range_empty_8,
    min: Bound::Unbounded, max: Bound::Included(vec![]),
    imin: 0, imax: 1,
    ""
}

test_range! {
    fst_range_empty_9,
    min: Bound::Unbounded, max: Bound::Excluded(vec![]),
    imin: 0, imax: 0,
    ""
}

test_range! {
    fst_range_empty_10,
    min: Bound::Unbounded, max: Bound::Included(vec![]),
    imin: 0, imax: 1,
    "", "a"
}

test_range! {
    fst_range_empty_11,
    min: Bound::Included(vec![]), max: Bound::Included(vec![]),
    imin: 0, imax: 1,
    ""
}

test_range! {
    fst_range_1,
    min: Bound::Included(vec![b'a']), max: Bound::Included(vec![b'z']),
    imin: 0, imax: 4,
    "a", "b", "y", "z"
}

test_range! {
    fst_range_2,
    min: Bound::Excluded(vec![b'a']), max: Bound::Included(vec![b'y']),
    imin: 1, imax: 3,
    "a", "b", "y", "z"
}

test_range! {
    fst_range_3,
    min: Bound::Excluded(vec![b'a']), max: Bound::Excluded(vec![b'y']),
    imin: 1, imax: 2,
    "a", "b", "y", "z"
}

test_range! {
    fst_range_4,
    min: Bound::Unbounded, max: Bound::Unbounded,
    imin: 0, imax: 4,
    "a", "b", "y", "z"
}

test_range! {
    fst_range_5,
    min: Bound::Included(b"abd".to_vec()), max: Bound::Unbounded,
    imin: 0, imax: 0,
    "a", "ab", "abc", "abcd", "abcde"
}

test_range! {
    fst_range_6,
    min: Bound::Included(b"abd".to_vec()), max: Bound::Unbounded,
    imin: 5, imax: 6,
    "a", "ab", "abc", "abcd", "abcde", "abe"
}

test_range! {
    fst_range_7,
    min: Bound::Excluded(b"abd".to_vec()), max: Bound::Unbounded,
    imin: 5, imax: 6,
    "a", "ab", "abc", "abcd", "abcde", "abe"
}

test_range! {
    fst_range_8,
    min: Bound::Included(b"abd".to_vec()), max: Bound::Unbounded,
    imin: 5, imax: 6,
    "a", "ab", "abc", "abcd", "abcde", "xyz"
}

test_range! {
    fst_range_9,
    min: Bound::Unbounded, max: Bound::Included(b"abd".to_vec()),
    imin: 0, imax: 5,
    "a", "ab", "abc", "abcd", "abcde", "abe"
}

test_range! {
    fst_range_10,
    min: Bound::Unbounded, max: Bound::Included(b"abd".to_vec()),
    imin: 0, imax: 6,
    "a", "ab", "abc", "abcd", "abcde", "abd"
}

test_range! {
    fst_range_11,
    min: Bound::Unbounded, max: Bound::Included(b"abd".to_vec()),
    imin: 0, imax: 6,
    "a", "ab", "abc", "abcd", "abcde", "abd", "abdx"
}

test_range! {
    fst_range_12,
    min: Bound::Unbounded, max: Bound::Excluded(b"abd".to_vec()),
    imin: 0, imax: 5,
    "a", "ab", "abc", "abcd", "abcde", "abe"
}

test_range! {
    fst_range_13,
    min: Bound::Unbounded, max: Bound::Excluded(b"abd".to_vec()),
    imin: 0, imax: 5,
    "a", "ab", "abc", "abcd", "abcde", "abd"
}

test_range! {
    fst_range_14,
    min: Bound::Unbounded, max: Bound::Excluded(b"abd".to_vec()),
    imin: 0, imax: 5,
    "a", "ab", "abc", "abcd", "abcde", "abd", "abdx"
}

test_range! {
    fst_range_15,
    min: Bound::Included(vec![b'd']), max: Bound::Included(vec![b'c']),
    imin: 0, imax: 0,
    "a", "b", "c", "d", "e", "f"
}

test_range! {
    fst_range_16,
    min: Bound::Included(vec![b'c']), max: Bound::Included(vec![b'c']),
    imin: 2, imax: 3,
    "a", "b", "c", "d", "e", "f"
}

test_range! {
    fst_range_17,
    min: Bound::Excluded(vec![b'c']), max: Bound::Excluded(vec![b'c']),
    imin: 0, imax: 0,
    "a", "b", "c", "d", "e", "f"
}

test_range! {
    fst_range_18,
    min: Bound::Included(vec![b'c']), max: Bound::Excluded(vec![b'c']),
    imin: 0, imax: 0,
    "a", "b", "c", "d", "e", "f"
}

test_range! {
    fst_range_19,
    min: Bound::Included(vec![b'c']), max: Bound::Excluded(vec![b'd']),
    imin: 2, imax: 3,
    "a", "b", "c", "d", "e", "f"
}

#[test]
fn one_vec_multiple_fsts() {
    let mut bfst1 = Builder::memory();
    bfst1.add(b"bar").unwrap();
    bfst1.add(b"baz").unwrap();
    let bytes = bfst1.into_inner().unwrap();
    let fst1_len = bytes.len();

    let mut bfst2 = Builder::new(bytes).unwrap();
    bfst2.add(b"bar").unwrap();
    bfst2.add(b"foo").unwrap();

    let bytes = bfst2.into_inner().unwrap();
    let slice1 = &bytes[0..fst1_len];
    let slice2 = &bytes[fst1_len..bytes.len()];

    let fst1 = Fst::new(slice1).unwrap();
    let fst2 = Fst::new(slice2).unwrap();

    assert_eq!(fst_inputs(&fst1), vec![b"bar".to_vec(), b"baz".to_vec()]);
    assert_eq!(fst_inputs(&fst2), vec![b"bar".to_vec(), b"foo".to_vec()]);
}

#[test]
fn bytes_written() {
    let mut bfst1 = Builder::memory();
    bfst1.add(b"bar").unwrap();
    bfst1.add(b"baz").unwrap();
    let counted_len = bfst1.bytes_written();
    let bytes = bfst1.into_inner().unwrap();
    let fst1_len = bytes.len() as u64;
    let footer_size = 24;
    assert_eq!(counted_len + footer_size, fst1_len);
}

#[test]
fn get_key_simple() {
    let map = fst_map(vec![("abc", 2), ("xyz", 3)]);
    assert_eq!(map.get_key(0), None);
    assert_eq!(map.get_key(1), None);
    assert_eq!(map.get_key(2), Some(b"abc".to_vec()));
    assert_eq!(map.get_key(3), Some(b"xyz".to_vec()));
    assert_eq!(map.get_key(4), None);
}

#[test]
fn get_key_words() {
    let words: Vec<(Vec<u8>, u64)> = TEXT
        .lines()
        .enumerate()
        .map(|(i, line)| (line.as_bytes().to_vec(), i as u64))
        .collect();
    let map = fst_map(words.clone());
    for (key, value) in words {
        assert_eq!(map.get_key(value), Some(key));
    }
}

#[test]
fn get_key_words_discontiguous() {
    let words: Vec<(Vec<u8>, u64)> = TEXT
        .lines()
        .enumerate()
        .map(|(i, line)| (line.as_bytes().to_vec(), i as u64 * 2))
        .collect();
    let map = fst_map(words.clone());
    for (key, value) in words {
        assert_eq!(map.get_key(value), Some(key));
    }
}
