#![warn(clippy::manual_unwrap_or_default)]
#![allow(clippy::unnecessary_literal_unwrap)]

fn main() {
    let x: Option<Vec<String>> = None;
    x.unwrap_or_default();

    let x: Option<Vec<String>> = None;
    x.unwrap_or_default();

    let x: Option<String> = None;
    x.unwrap_or_default();

    let x: Option<Vec<String>> = None;
    x.unwrap_or_default();

    let x: Option<Vec<String>> = None;
    x.unwrap_or_default();

    // Issue #12564
    // No error as &Vec<_> doesn't implement std::default::Default
    let mut map = std::collections::HashMap::from([(0, vec![0; 3]), (1, vec![1; 3]), (2, vec![2])]);
    let x: &[_] = if let Some(x) = map.get(&0) { x } else { &[] };
    // Same code as above written using match.
    let x: &[_] = match map.get(&0) {
        Some(x) => x,
        None => &[],
    };

    let x: Result<String, i64> = Ok(String::new());
    x.unwrap_or_default();

    let x: Result<String, i64> = Ok(String::new());
    x.unwrap_or_default();

    // edge case
    // because the `Some(bizarro)` pattern is not actually reachable,
    // changing this match to `unwrap_or_default` would have side effects
    let bizarro = Some(String::new());
    match bizarro {
        _ => String::new(),
        Some(bizarro) => bizarro,
    };
}

// Issue #12531
unsafe fn no_deref_ptr(a: Option<i32>, b: *const Option<i32>) -> i32 {
    unsafe {
        match a {
            // `*b` being correct depends on `a == Some(_)`
            Some(_) => (*b).unwrap_or_default(),
            _ => 0,
        }
    }
}

const fn issue_12568(opt: Option<bool>) -> bool {
    match opt {
        Some(s) => s,
        None => false,
    }
}

fn issue_12569() {
    let match_none_se = match 1u32.checked_div(0) {
        Some(v) => v,
        None => {
            println!("important");
            0
        },
    };
    let match_some_se = match 1u32.checked_div(0) {
        Some(v) => {
            println!("important");
            v
        },
        None => 0,
    };
    let iflet_else_se = if let Some(v) = 1u32.checked_div(0) {
        v
    } else {
        println!("important");
        0
    };
    let iflet_then_se = if let Some(v) = 1u32.checked_div(0) {
        println!("important");
        v
    } else {
        0
    };
}

// Should not warn!
fn issue_12928() {
    let x = Some((1, 2));
    let y = if let Some((a, _)) = x { a } else { 0 };
    let y = if let Some((a, ..)) = x { a } else { 0 };
    let x = Some([1, 2]);
    let y = if let Some([a, _]) = x { a } else { 0 };
    let y = if let Some([a, ..]) = x { a } else { 0 };

    struct X {
        a: u8,
        b: u8,
    }
    let x = Some(X { a: 0, b: 0 });
    let y = if let Some(X { a, .. }) = x { a } else { 0 };
    struct Y(u8, u8);
    let x = Some(Y(0, 0));
    let y = if let Some(Y(a, _)) = x { a } else { 0 };
    let y = if let Some(Y(a, ..)) = x { a } else { 0 };
}

// For symmetry with `manual_unwrap_or` test
fn allowed_manual_unwrap_or_zero() -> u32 {
    Some(42).unwrap_or_default()
}

mod issue14716 {
    struct Foo {
        name: Option<String>,
    }

    fn bar(project: &Foo) {
        let _name = match project.name {
            Some(ref x) => x,
            None => "",
        };
    }
}

fn issue_15807() {
    let uncopyable_res: Result<usize, String> = Ok(1);
    let _ = if let Ok(v) = uncopyable_res { v } else { 0 };

    let x = uncopyable_res;
    let _ = x.unwrap_or_default();
    //~^ manual_unwrap_or_default

    let copyable_res: Result<usize, ()> = Ok(1);
    let _ = copyable_res.unwrap_or_default();
    //~^ manual_unwrap_or_default
    let _ = copyable_res;
}
