use std::error::Error;

fn main() -> Result<(), Box<dyn Error>> {

    //// 000_println.rs
    println!("Printed text.");
    print!("No new line.");

    //// 010_add_distract_math_literal_operator.rs
    //https://doc.rust-lang.org/rust-by-example/primitives/literals.html
    println!("1 + 2 = {}", 1u32 + 2);
    println!("1 + 2 = {}", 32 + 2);

    println!("1 - 2 = {}", 1i32 - 2);
    //println!("1 - 2 = {}", 1u32 - 2); // panic because of overflow, program halts !!

    // Short-circuiting boolean logic
    println!("true AND false is {}", true && false);
    println!("true OR false is {}", true || false);
    println!("NOT true is {}", !true);

    // Bitwise operations
    println!("0011 AND 0101 is {:04b}", 0b0011u32 & 0b0101);
    println!("0011 OR 0101 is {:04b}", 0b0011u32 | 0b0101);
    println!("0011 XOR 0101 is {:04b}", 0b0011u32 ^ 0b0101);
    println!("1 << 5 is {}", 1u32 << 5);
    println!("0x80 >> 2 is 0x{:x}", 0x80u32 >> 2);

    // Use underscores to improve readability!
    println!("One million is written as {}", 1_000_000u32);

    reverse((1,true));
    tuplez();

    // HTTP example
    let body = reqwest::blocking::get("https://api.coindesk.com/v1/bpi/currentprice.json")?.text()?;
    println!("body = {:?}", body);
    Ok(())
}


//// 020_tuples.rs
// https://doc.rust-lang.org/rust-by-example/primitives/tuples.html

// Tuples can be used as function arguments and as return values
fn reverse(pair: (i32, bool)) -> (bool, i32) {
    // `let` can be used to bind the members of a tuple to variables
    let (integer, boolean) = pair;

    (boolean, integer)
}

// The following struct is for the activity.
#[derive(Debug)]
struct Matrix(f32, f32, f32, f32);

fn tuplez() {

    // ---------- //

    // A tuple with a bunch of different types
    let long_tuple = (1u8, 2u16, 3u32, 4u64,
                      -1i8, -2i16, -3i32, -4i64,
                      0.1f32, 0.2f64,
                      'a', true);

    // Values can be extracted from the tuple using tuple indexing
    println!("long tuple first value: {}", long_tuple.0);
    println!("long tuple second value: {}", long_tuple.1);

    // ---------- //

    // Tuples can be tuple members
    let tuple_of_tuples = ((1u8, 2u16, 2u32), (4u64, -1i8), -2i16);

    // Tuples are printable
    println!("tuple of tuples: {:?}", tuple_of_tuples); // !! {:?} is useful also for debugging
    
    // But long Tuples cannot be printed !!
    // let too_long_tuple = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13);
    // println!("too long tuple: {:?}", too_long_tuple);
    // TODO ^ Uncomment the above 2 lines to see the compiler error

    let pair = (1, true);
    println!("pair is {:?}", pair);

    println!("the reversed pair is {:?}", reverse(pair));

    // To create one element tuples, the comma is required to tell them apart
    // from a literal surrounded by parentheses
    println!("one element tuple: {:?}", (5u32,));
    println!("just an integer: {:?}", (5u32));

    //tuples can be destructured to create bindings
    let tuple = (1, "hello", 4.5, true);

    let (a, b, c, d) = tuple;
    println!("{:?}, {:?}, {:?}, {:?}", a, b, c, d);

    let matrix = Matrix(1.1, 1.2, 2.1, 2.2);
    println!("{:?}", matrix);

}