pub fn add(left: usize, right: usize) -> usize {
    left + right
}

pub fn add_two(a: usize) -> usize {
    a + 2
}

#[cfg(test)]
mod tests {
    use super::*;

    // #[test] indicates this is a test function
    #[test]
    fn exploration() {
        // let result = add(2, 2);
        assert_eq!(add(2, 2), 4);
    }

    // comment this out for now. There is a way to
    // specify which tests are wanted
    // #[test]
    // fn another() {
    //     panic!("Make this test fail!");
    // }

    #[test]
    fn larger_can_hold_smaller() {
        let larger = Rectangle {
            width: 8,
            height: 7,
        };
        let smaller = Rectangle {
            width: 5,
            height: 1,
        };

        assert!(larger.can_hold(&smaller));
    }

    #[test]
    fn smaller_can_hold_larger() {
        let larger = Rectangle {
            width: 8,
            height: 7,
        };
        let smaller = Rectangle {
            width: 5,
            height: 1,
        };

        assert!(!smaller.can_hold(&larger));
    }

    // rust has assert_eq!() and assert_ne!() for
    // testing
    #[test]
    fn it_adds_two() {
        let result = add_two(2);
        assert_eq!(result, 4);
    }

    #[test]
    fn string_contains_name() {
        // any String without Carol will fail here
        let string = String::from("Carol");
        assert!(
            string.contains("Carol"),
            "Greeting did not contain name, value was `{string}`"
        );
    }

    // important to check code handles error conditions properly
    // possible with the should_panic attribute
    #[test]
    #[should_panic]
    fn greater_than_100() {
        Guess::new(200);
    }

    // Test for a should panic with an explicit message
    // Tests to see if the panic message contains the
    // string inside of the expected parameter
    #[test]
    #[should_panic(expected = "less than or equal to 100")]
    fn greater_than_100_precise() {
        Guess::new_precise(200);
    }

    // Can use the Result type in tests
    #[test]
    fn it_works() -> Result<(), String> {
        let result = add(2, 2);

        if result == 4 {
            Ok(())
        } else {
            Err(String::from("two plus two does not equal four"))
        }
    }
}

// pulled from chapter 5
#[derive(Debug)]
struct Rectangle {
    width: u32,
    height: u32,
}

impl Rectangle {
    // purposefully introduce a bug into the code. Swapped the first < with >
    fn can_hold(&self, other: &Rectangle) -> bool {
        self.width > other.width && self.height > other.height
    }
}

pub struct Guess {
    value: i32,
}

impl Guess {
    pub fn new(value: i32) -> Guess {
        // introduce a bug into the code where remove the `|| value > 100`
        // meaning this code will not panic
        if value < 1 || value > 100 {
            panic!("Guess value must be between 1 and 100, got {value}.");
        }

        Guess { value }
    }

    pub fn new_precise(value: i32) -> Guess {
        if value < 1 {
            panic!("Guess value must be greater than or equal to 1, got {value}.");
        } else if value > 100 {
            panic!("Guess value must be less than or equal to 100, got {value}.");
        }

        Guess { value }
    }
}