#[path = "../../../os-pci-discovery/src/capabilities.rs"]
mod pci_capabilities;

use pci_capabilities::{Capability, ConfigReader, Error, Store, walk};

struct Config {
    words: [u32; 64],
    reads: usize,
    fail_at: Option<u8>,
}

impl Config {
    fn two_nodes() -> Self {
        let mut words = [0; 64];
        words[0x40 / 4] = 1 | (0x50 << 8);
        words[0x50 / 4] = 5;
        Self {words, reads: 0, fail_at: None}
    }
}

impl ConfigReader for Config {
    fn read_dword(&mut self, offset: u8) -> Result<u32, Error> {
        self.reads += 1;
        if self.fail_at == Some(offset) { return Err(Error::ReadFailed); }
        Ok(self.words[usize::from(offset) / 4])
    }
}

#[test]
fn os_pci_discovery_capabilities_positive() {
    let mut config = Config::two_nodes();
    let mut store = Store::<3>::new();
    let chain = store.discover(&mut config, 0x40).unwrap();
    assert_eq!(chain.len, 2);
    assert_eq!(chain.entries, [
        Some(Capability {offset: 0x40, id: 1, next: 0x50}),
        Some(Capability {offset: 0x50, id: 5, next: 0}), None]);
    assert_eq!(config.reads, 2);
    assert_eq!(store.snapshot().chain, Some(chain));
    assert_eq!(store.snapshot().published_count, 2);
    let empty = walk::<3>(&mut config, 0).unwrap();
    assert_eq!(empty.len, 0);
    assert_eq!(config.reads, 2);
}

#[test]
fn os_pci_discovery_capabilities_negative() {
    let mut config = Config::two_nodes();
    let mut store = Store::<2>::new();
    store.discover(&mut config, 0x40).unwrap();
    let before = store.snapshot();
    config.words[0x40 / 4] = 1 | (0x40 << 8);
    assert_eq!(store.discover(&mut config, 0x40), Err(Error::Cycle));
    assert_eq!(store.snapshot(), before);
    assert_eq!(store.discover(&mut config, 0x41), Err(Error::InvalidPointer));
    assert_eq!(store.discover(&mut config, 0x3c), Err(Error::InvalidPointer));
    assert_eq!(store.snapshot(), before);
    config.words[0x40 / 4] = 1 | (0x50 << 8);
    config.words[0x50 / 4] = 5 | (0x60 << 8);
    assert_eq!(store.discover(&mut config, 0x40), Err(Error::Full));
    assert_eq!(store.snapshot(), before);
    config.words[0x50 / 4] = 5;
    config.fail_at = Some(0x50);
    assert_eq!(store.discover(&mut config, 0x40), Err(Error::ReadFailed));
    assert_eq!(store.snapshot(), before);
}