use std::sync::Arc;

use proptest::{prop_assert, prop_assert_eq, proptest};

use smol_str::SmolStr;

#[test]
#[cfg(target_pointer_width = "64")]
fn smol_str_is_smol() {
    assert_eq!(
        ::std::mem::size_of::<SmolStr>(),
        ::std::mem::size_of::<String>(),
    );
}

#[test]
fn assert_traits() {
    fn f<T: Send + Sync + ::std::fmt::Debug + Clone>() {}
    f::<SmolStr>();
}

#[test]
fn conversions() {
    let s: SmolStr = "Hello, World!".into();
    let s: String = s.into();
    assert_eq!(s, "Hello, World!");

    let s: SmolStr = Arc::<str>::from("Hello, World!").into();
    let s: Arc<str> = s.into();
    assert_eq!(s.as_ref(), "Hello, World!");
}

#[test]
fn const_fn_ctor() {
    const EMPTY: SmolStr = SmolStr::new_inline("");
    const A: SmolStr = SmolStr::new_inline("A");
    const HELLO: SmolStr = SmolStr::new_inline("HELLO");
    const LONG: SmolStr = SmolStr::new_inline("ABCDEFGHIZKLMNOPQRSTUVW");

    assert_eq!(EMPTY, SmolStr::from(""));
    assert_eq!(A, SmolStr::from("A"));
    assert_eq!(HELLO, SmolStr::from("HELLO"));
    assert_eq!(LONG, SmolStr::from("ABCDEFGHIZKLMNOPQRSTUVW"));
}

#[allow(deprecated)]
#[test]
fn old_const_fn_ctor() {
    const EMPTY: SmolStr = SmolStr::new_inline_from_ascii(0, b"");
    const A: SmolStr = SmolStr::new_inline_from_ascii(1, b"A");
    const HELLO: SmolStr = SmolStr::new_inline_from_ascii(5, b"HELLO");
    const LONG: SmolStr = SmolStr::new_inline_from_ascii(23, b"ABCDEFGHIZKLMNOPQRSTUVW");

    assert_eq!(EMPTY, SmolStr::from(""));
    assert_eq!(A, SmolStr::from("A"));
    assert_eq!(HELLO, SmolStr::from("HELLO"));
    assert_eq!(LONG, SmolStr::from("ABCDEFGHIZKLMNOPQRSTUVW"));
}

fn check_props(std_str: &str, smol: SmolStr) -> Result<(), proptest::test_runner::TestCaseError> {
    prop_assert_eq!(smol.as_str(), std_str);
    prop_assert_eq!(smol.len(), std_str.len());
    prop_assert_eq!(smol.is_empty(), std_str.is_empty());
    if smol.len() <= 23 {
        prop_assert!(!smol.is_heap_allocated());
    }
    Ok(())
}

proptest! {
    #[test]
    fn roundtrip(s: String) {
        check_props(s.as_str(), SmolStr::new(s.clone()))?;
    }

    #[test]
    fn roundtrip_spaces(s in r"( )*") {
        check_props(s.as_str(), SmolStr::new(s.clone()))?;
    }

    #[test]
    fn roundtrip_newlines(s in r"\n*") {
        check_props(s.as_str(), SmolStr::new(s.clone()))?;
    }

    #[test]
    fn roundtrip_ws(s in r"( |\n)*") {
        check_props(s.as_str(), SmolStr::new(s.clone()))?;
    }

    #[test]
    fn from_string_iter(slices in proptest::collection::vec(".*", 1..100)) {
        let string: String = slices.iter().map(|x| x.as_str()).collect();
        let smol: SmolStr = slices.into_iter().collect();
        check_props(string.as_str(), smol)?;
    }

    #[test]
    fn from_str_iter(slices in proptest::collection::vec(".*", 1..100)) {
        let string: String = slices.iter().map(|x| x.as_str()).collect();
        let smol: SmolStr = slices.iter().collect();
        check_props(string.as_str(), smol)?;
    }
}

#[cfg(feature = "serde")]
mod serde_tests {
    use super::*;
    use serde::{Deserialize, Serialize};
    use std::collections::HashMap;

    #[derive(Serialize, Deserialize)]
    struct SmolStrStruct {
        pub(crate) s: SmolStr,
        pub(crate) vec: Vec<SmolStr>,
        pub(crate) map: HashMap<SmolStr, SmolStr>,
    }

    #[test]
    fn test_serde() {
        let s = SmolStr::new("Hello, World");
        let s = serde_json::to_string(&s).unwrap();
        assert_eq!(s, "\"Hello, World\"");
        let s: SmolStr = serde_json::from_str(&s).unwrap();
        assert_eq!(s, "Hello, World");
    }

    #[test]
    fn test_serde_reader() {
        let s = SmolStr::new("Hello, World");
        let s = serde_json::to_string(&s).unwrap();
        assert_eq!(s, "\"Hello, World\"");
        let s: SmolStr = serde_json::from_reader(std::io::Cursor::new(s)).unwrap();
        assert_eq!(s, "Hello, World");
    }

    #[test]
    fn test_serde_struct() {
        let mut map = HashMap::new();
        map.insert(SmolStr::new("a"), SmolStr::new("ohno"));
        let struct_ = SmolStrStruct {
            s: SmolStr::new("Hello, World"),
            vec: vec![SmolStr::new("Hello, World"), SmolStr::new("Hello, World")],
            map,
        };
        let s = serde_json::to_string(&struct_).unwrap();
        let _new_struct: SmolStrStruct = serde_json::from_str(&s).unwrap();
    }

    #[test]
    fn test_serde_struct_reader() {
        let mut map = HashMap::new();
        map.insert(SmolStr::new("a"), SmolStr::new("ohno"));
        let struct_ = SmolStrStruct {
            s: SmolStr::new("Hello, World"),
            vec: vec![SmolStr::new("Hello, World"), SmolStr::new("Hello, World")],
            map,
        };
        let s = serde_json::to_string(&struct_).unwrap();
        let _new_struct: SmolStrStruct = serde_json::from_reader(std::io::Cursor::new(s)).unwrap();
    }

    #[test]
    fn test_serde_hashmap() {
        let mut map = HashMap::new();
        map.insert(SmolStr::new("a"), SmolStr::new("ohno"));
        let s = serde_json::to_string(&map).unwrap();
        let _s: HashMap<SmolStr, SmolStr> = serde_json::from_str(&s).unwrap();
    }

    #[test]
    fn test_serde_hashmap_reader() {
        let mut map = HashMap::new();
        map.insert(SmolStr::new("a"), SmolStr::new("ohno"));
        let s = serde_json::to_string(&map).unwrap();
        let _s: HashMap<SmolStr, SmolStr> =
            serde_json::from_reader(std::io::Cursor::new(s)).unwrap();
    }

    #[test]
    fn test_serde_vec() {
        let vec = vec![SmolStr::new(""), SmolStr::new("b")];
        let s = serde_json::to_string(&vec).unwrap();
        let _s: Vec<SmolStr> = serde_json::from_str(&s).unwrap();
    }

    #[test]
    fn test_serde_vec_reader() {
        let vec = vec![SmolStr::new(""), SmolStr::new("b")];
        let s = serde_json::to_string(&vec).unwrap();
        let _s: Vec<SmolStr> = serde_json::from_reader(std::io::Cursor::new(s)).unwrap();
    }
}

#[test]
fn test_search_in_hashmap() {
    let mut m = ::std::collections::HashMap::<SmolStr, i32>::new();
    m.insert("aaa".into(), 17);
    assert_eq!(17, *m.get("aaa").unwrap());
}

#[test]
fn test_from_char_iterator() {
    let examples = [
        // Simple keyword-like strings
        ("if", false),
        ("for", false),
        ("impl", false),
        // Strings containing two-byte characters
        ("パーティーへ行かないか", true),
        ("パーティーへ行か", true),
        ("パーティーへ行_", false),
        ("和製漢語", false),
        ("部落格", false),
        ("사회과학원 어학연구소", true),
        // String containing diverse characters
        ("表ポあA鷗ŒéＢ逍Üßªąñ丂㐀𠀀", true),
    ];
    for (raw, is_heap) in &examples {
        let s: SmolStr = raw.chars().collect();
        assert_eq!(s.as_str(), *raw);
        assert_eq!(s.is_heap_allocated(), *is_heap);
    }
    // String which has too many characters to even consider inlining: Chars::size_hint uses
    // (`len` + 3) / 4. With `len` = 89, this results in 23, so `from_iter` will immediately
    // heap allocate
    let raw: String = std::iter::repeat('a').take(23 * 4 + 1).collect();
    let s: SmolStr = raw.chars().collect();
    assert_eq!(s.as_str(), raw);
    assert!(s.is_heap_allocated());
}

#[test]
fn test_bad_size_hint_char_iter() {
    struct BadSizeHint<I>(I);

    impl<T, I: Iterator<Item = T>> Iterator for BadSizeHint<I> {
        type Item = T;

        fn next(&mut self) -> Option<Self::Item> {
            self.0.next()
        }

        fn size_hint(&self) -> (usize, Option<usize>) {
            (1024, None)
        }
    }

    let data = "testing";
    let collected: SmolStr = BadSizeHint(data.chars()).collect();
    let new = SmolStr::new(data);

    // Because of the bad size hint, `collected` will be heap allocated, but `new` will be inline

    // If we try to use the type of the string (inline/heap) to quickly test for equality, we need to ensure
    // `collected` is inline allocated instead
    assert!(collected.is_heap_allocated());
    assert!(!new.is_heap_allocated());
    assert_eq!(new, collected);
}

#[test]
fn test_to_smolstr() {
    use smol_str::ToSmolStr;

    for i in 0..26 {
        let a = &"abcdefghijklmnopqrstuvwxyz"[i..];

        assert_eq!(a, a.to_smolstr());
        assert_eq!(a, smol_str::format_smolstr!("{}", a));
    }
}