#![cfg(test)]

use crate::{Store, StoreBackend};

const SIZE: usize = 1024;

pub struct TestBackend {
    data: [u8; SIZE],
}

impl TestBackend {
    pub fn new() -> Self {
        TestBackend {
            data: [!0; SIZE],
        }
    }
}

impl StoreBackend for TestBackend {
    type Data = [u8; SIZE];

    fn data(&self) -> &Self::Data {
        &self.data
    }

    type Error = ();
    fn erase(&mut self) -> Result<(), Self::Error> {
        for b in &mut self.data {
            *b = !0;
        }
        Ok(())
    }

    fn program(&mut self, offset: usize, payload: &[u8]) -> Result<(), Self::Error> {
        let end = offset + payload.len();
        if end > self.len() {
            return Err(());
        }
        self.data[offset..end].copy_from_slice(payload);
        Ok(())
    }
}

fn make_store() -> Store<TestBackend> {
    let backend = TestBackend::new();
    Store::new(backend)
}

#[test]
fn empty_read_not_found() {
    let store = make_store();
    assert_eq!(store.read("foo").unwrap(), None)
}

    
#[test]
fn write_read() {
    let mut store = make_store();
    store.write("foo", b"bar").unwrap();
    assert_eq!(store.read("foo").unwrap().unwrap(), b"bar");
}
    
#[test]
fn write_int_read_str() {
    let mut store = make_store();
    store.write_int("foo", 42).unwrap();
    assert_eq!(store.read_str("foo").unwrap().unwrap(), "42");
}

#[test]
fn write_many() {
    let mut store = make_store();
    store.write("foo", b"do not compact away").unwrap();
    for _ in 0..10000 {
        store.write("bar", b"SPAM").unwrap();
    }
    assert_eq!(store.read("foo").unwrap().unwrap(), b"do not compact away");
    assert_eq!(store.read("bar").unwrap().unwrap(), b"SPAM");
}