#![cfg(test)]

use crate::{Error, no_flash, Store, StoreBackend, WriteError};

const SIZE: usize = 1024;
static mut BACKUP_SPACE: [u8; SIZE] = [0; SIZE];

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 backup_space(&self) -> &'static mut [u8] {
        unsafe { &mut BACKUP_SPACE }
    }
}

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_read_str() {
    let mut store = make_store();
    store.write("foo", "bar").unwrap();
    assert_eq!(store.read_str("foo").unwrap().unwrap(), "bar");
}

#[test]
fn write_read_str_utf8() {
    let mut store = make_store();
    store.write("réseau", "point à point").unwrap();
    assert_eq!(store.read_str("réseau").unwrap().unwrap(), "point à point");
}

#[test]
#[cfg(feature = "postcard-values")]
fn write_read_value_str() {
    let mut store = make_store();
    store.write_value("foo", &"bar", [0; 4]).unwrap();
    assert_eq!(store.read_value("foo"), Ok(Some("bar")));
}

#[test]
#[cfg(feature = "postcard-values")]
fn write_read_value_u32() {
    let mut store = make_store();
    store.write_value("foo", &42005u32, [0; 4]).unwrap();
    assert_eq!(store.read_value("foo"), Ok(Some(42005u32)));
}

#[test]
#[cfg(feature = "postcard-values")]
fn write_read_value_i64() {
    let mut store = make_store();
    store.write_value("foo", &-99999999i64, &mut [0; 8]).unwrap();
    assert_eq!(store.read_value("foo"), Ok(Some(-99999999i64)));
}

#[test]
#[cfg(feature = "postcard-values")]
fn write_read_value_f32() {
    let mut store = make_store();
    store.write_value("foo", &3.75e17f32, &mut [0; 4]).unwrap();
    assert_eq!(store.read_value("foo"), Ok(Some(3.75e17f32)));
}

#[test]
#[cfg(feature = "postcard-values")]
fn write_read_value_f64() {
    let mut store = make_store();
    store.write_value("foo", &-1.999e-13f64, [0; 8]).unwrap();
    assert_eq!(store.read_value("foo"), Ok(Some(-1.999e-13f64)));
}

#[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");
}

#[test]
#[cfg(feature = "postcard-values")]
fn write_value_many() {
    let mut store = make_store();
    store.write_value("quux", &(false, 3u8, -42i16), [0; 4]).unwrap();
    for i in 0..1000u32 {
        store.write_value("bar", &i, [0; 4]).unwrap();
        assert_eq!(store.read_value("bar"), Ok(Some(i)));
        store.write_value("foo", &(i % 2 == 0), [0]).unwrap();
        assert_eq!(store.read_value("foo"), Ok(Some(i % 2 == 0)));
    }
    assert_eq!(store.read_value("quux"), Ok(Some((false, 3u8, -42i16))));
}

#[test]
fn no_flash() {
    let mut store = Store::new(no_flash::NoFlash);
    assert_eq!(store.read("foo").unwrap(), None);
    assert_eq!(
        store.write("foo", b"bar"),
        Err(Error::Write(WriteError::Backend(no_flash::NoFlashError)))
    );
}