//! Your task is to implement the `From` trait for `Person` to make creating
//! Persons easier.
//!
//! The From trait is used for value-to-value conversions. When From is
//! implemented for a source type, the Into trait is automatically implemented
//! for the target type. You can read more about it at
//! https://doc.rust-lang.org/std/convert/trait.From.html
//!
//! As a side note, ignore the fact that it makes absolutely no sense that a
//! person has "default values". (This exercise is taken from Rustlings)

#[derive(Debug, PartialEq)]
struct Person {
    name: String,
    age: usize,
}

// We implement the `Default` trait to use it as a fallback when the provided
// string is not convertible into a Person object. Note that this is not good
// practice, one should use a `Result` rather.
impl Default for Person {
    fn default() -> Person {
        Person {
            name: String::from("John"),
            age: 30,
        }
    }
}

// Steps:
// 1. If the length of the provided string is 0, then return the default of
//    Person
// 2. Split the given string on the commas present in it
// 3. Extract the first element from the split operation and use it as the name
// 4. If the name is empty, then return the default of Person
// 5. Extract the other element from the split operation and parse it into a
//    `usize` as the age If while parsing the age, something goes wrong, then
//    return the default of Person Otherwise, then return an instantiated Person
//    object with the results
impl From<&str> for Person {
    // TODO
}

// Do not edit anything below 

#[test]
fn main() {
    // Use the `from` associated function
    let p1 = Person::from("Mark,20");
    // Use the `into` method
    let p2: Person = "Gerald,70".into();

    println!("{:?}", p1);
    println!("{:?}", p2);
}

#[cfg(test)]
mod tests {
    use super::*;
    #[test]
    fn default() {
        // Test that the default person is 30 year old John
        let dp = Person::default();
        assert_eq!(dp.name, "John");
        assert_eq!(dp.age, 30);
    }
    #[test]
    fn empty_convert() {
        // Test that John is returned when an empty string is provided
        let p = Person::from("");
        assert_eq!(p, Person::default());
    }
    #[test]
    fn good_convert() {
        // Test that "Mark,20" works
        let p = Person::from("Mark,20");
        assert_eq!(p.name, "Mark");
        assert_eq!(p.age, 20);
    }
    #[test]
    fn bad_age() {
        // Test that "Mark,twenty" will return the default person due to an
        // error in parsing age
        let p = Person::from("Mark,twenty");
        assert_eq!(p, Person::default());
    }

    #[test]
    fn missing_comma_and_age() {
        let p = Person::from("Mark");
        assert_eq!(p, Person::default());
    }

    #[test]
    fn missing_age() {
        let p = Person::from("Mark,");
        assert_eq!(p, Person::default());
    }

    #[test]
    fn missing_name() {
        let p = Person::from(",1");
        assert_eq!(p, Person::default());
    }

    #[test]
    fn missing_name_and_age() {
        let p = Person::from(",");
        assert_eq!(p, Person::default());
    }

    #[test]
    fn missing_name_and_invalid_age() {
        let p = Person::from(",one");
        assert_eq!(p, Person::default());
    }

    #[test]
    fn trailing_comma() {
        let p = Person::from("Mike,32,");
        assert_eq!(p, Person::default());
    }

    #[test]
    fn trailing_comma_and_some_string() {
        let p = Person::from("Mike,32,man");
        assert_eq!(p, Person::default());
    }
}