//! The native sink (extensions/native-sink.md): the committed corpus
//! `live-conformance/native-sink/vectors.json` regenerates byte for byte from its fixed seeds and
//! is the only file there besides its README; every call in it gets the answer it states; every
//! reason §8 names is reached by a vector; and the C ABI (`ffi_sink`) gives the answers the Rust
//! module gives, through the symbols a C host links.
#![cfg(feature = "native_sink")]

use std::ffi::CString;
use std::path::PathBuf;

use serde_json::{json, Value};
use wai::ffi::{wai_buffer_free, WaiBuffer, WAI_OK};
use wai::ffi_sink::*;
use wai::native_sink::corpus;

fn wai_dir() -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("..")
}

fn committed() -> Vec<u8> {
    std::fs::read(wai_dir().join("live-conformance/native-sink/vectors.json")).unwrap()
}

#[test]
fn the_committed_corpus_regenerates_from_its_seeds() {
    assert!(committed() == corpus::bytes(&corpus::generate()), "live-conformance/native-sink/vectors.json differs from `wai_native_sink_vectors gen`");
    let mut files: Vec<String> = std::fs::read_dir(wai_dir().join("live-conformance/native-sink")).unwrap().flatten().map(|e| e.file_name().to_string_lossy().into_owned()).collect();
    files.sort();
    assert_eq!(files, ["README.md", "vectors.json"]);
}

#[test]
fn every_call_gets_its_stated_answer() {
    let doc: Value = serde_json::from_slice(&committed()).unwrap();
    corpus::verify(&doc).unwrap();
}

/// Every reason of §8 is reached by a vector, and the extension's table lists exactly those.
#[test]
fn every_reason_refuses_a_vector() {
    let doc: Value = serde_json::from_slice(&committed()).unwrap();
    let text = std::fs::read_to_string(wai_dir().join("extensions/native-sink.md")).unwrap();
    let mut reached = std::collections::BTreeSet::new();
    for c in doc["cases"].as_array().unwrap() {
        for call in c["calls"].as_array().unwrap() {
            for k in ["refused", "error"] {
                if let Some(r) = call["answer"][k].as_str() {
                    reached.insert(r.to_string());
                }
            }
        }
    }
    for c in doc["configs"].as_array().unwrap() {
        reached.insert(c["refused"].as_str().unwrap().to_string());
    }
    let table: std::collections::BTreeSet<String> = text
        .split("## 8. Reasons")
        .nth(1)
        .unwrap()
        .split("\n## ")
        .next()
        .unwrap()
        .lines()
        .filter_map(|l| l.strip_prefix("| `").and_then(|r| r.split('`').next()).map(str::to_string))
        .collect();
    assert_eq!(reached, table, "the reasons the corpus reaches and §8's table");
}

fn take(b: WaiBuffer) -> Vec<u8> {
    let v = unsafe { std::slice::from_raw_parts(b.data, b.len) }.to_vec();
    unsafe { wai_buffer_free(b) };
    v
}

fn empty() -> WaiBuffer {
    WaiBuffer { data: std::ptr::null_mut(), len: 0, cap: 0 }
}

/// Every case, run through the C ABI, gets the answers the corpus states for it.
#[test]
fn the_c_abi_gives_the_corpus_answers() {
    assert_eq!(wai_sink_abi_version(), WAI_SINK_ABI_VERSION);
    let doc: Value = serde_json::from_slice(&committed()).unwrap();
    let obj = |n: &Value| -> Vec<u8> { n.as_str().map(|n| wai::stream_audit::unhex(doc["objects"][n].as_str().unwrap()).unwrap()).unwrap_or_default() };
    for case in doc["cases"].as_array().unwrap() {
        let cfg = CString::new(case["config"].to_string()).unwrap();
        let seed = wai::stream_audit::unhex(case["seed"].as_str().unwrap()).unwrap();
        let mut s: *mut WaiSink = std::ptr::null_mut();
        assert_eq!(unsafe { wai_sink_open(cfg.as_ptr(), seed.as_ptr(), 32, case["start_us"].as_u64().unwrap(), &mut s) }, WAI_OK);
        for call in case["calls"].as_array().unwrap() {
            let d = &call["do"];
            let want = &call["answer"];
            let mut out = empty();
            let got: Value = match d["call"].as_str().unwrap() {
                "playlist" => {
                    let url = CString::new(d["url"].as_str().unwrap()).unwrap();
                    let b = obj(&d["body"]);
                    let r = obj(&d["receipt"]);
                    let rp = if d["receipt"].is_null() { std::ptr::null() } else { r.as_ptr() };
                    let st = unsafe { wai_sink_playlist(s, url.as_ptr(), b.as_ptr(), b.len(), rp, r.len(), &mut out) };
                    if st == WAI_OK { serde_json::from_slice(&take(out)).unwrap() } else { json!({"error": last_reason()}) }
                }
                "parent" => {
                    let url = CString::new(d["url"].as_str().unwrap()).unwrap();
                    let name = CString::new(d["name"].as_str().unwrap()).unwrap();
                    let b = obj(&d["body"]);
                    let bp = if d["body"].is_null() { std::ptr::null() } else { b.as_ptr() };
                    let st = unsafe { wai_sink_playlist_parent(s, url.as_ptr(), name.as_ptr(), bp, b.len()) };
                    if st == WAI_OK { json!({"ok": true}) } else { json!({"error": last_reason()}) }
                }
                "object" => {
                    let meta = CString::new(d["meta"].to_string()).unwrap();
                    let b = obj(&d["body"]);
                    let st = unsafe { wai_sink_object(s, meta.as_ptr(), b.as_ptr(), b.len(), &mut out) };
                    if st == WAI_OK { serde_json::from_slice(&take(out)).unwrap() } else { json!({"error": last_reason()}) }
                }
                "event" => {
                    let n = CString::new(d["name"].as_str().unwrap()).unwrap();
                    let st = unsafe { wai_sink_event(s, n.as_ptr(), d["t_us"].as_u64().unwrap()) };
                    if st == WAI_OK { json!({"ok": true}) } else { json!({"error": last_reason()}) }
                }
                "observe" => {
                    let o = CString::new(d["obs"].to_string()).unwrap();
                    let st = unsafe { wai_sink_observe(s, o.as_ptr(), &mut out) };
                    if st == WAI_OK { serde_json::from_slice(&take(out)).unwrap() } else { json!({"error": last_reason()}) }
                }
                "energy" => {
                    let e = CString::new(d["entry"].to_string()).unwrap();
                    let st = unsafe { wai_sink_energy(s, e.as_ptr()) };
                    if st == WAI_OK { json!({"ok": true}) } else { json!({"error": last_reason()}) }
                }
                "attach" => {
                    let n = CString::new(d["name"].as_str().unwrap()).unwrap();
                    let b = obj(&d["body"]);
                    let st = unsafe { wai_sink_attach(s, n.as_ptr(), b.as_ptr(), b.len()) };
                    if st == WAI_OK { json!({"ok": true}) } else { json!({"error": last_reason()}) }
                }
                "cmcd" => {
                    let st = unsafe { wai_sink_take_cmcd(s, &mut out) };
                    if st == WAI_OK { json!({"cmcd": String::from_utf8(take(out)).unwrap()}) } else { json!({"error": last_reason()}) }
                }
                "end" => {
                    let n = CString::new(d["ended"].as_str().unwrap()).unwrap();
                    let st = unsafe { wai_sink_end(s, n.as_ptr(), d["t_us"].as_u64().unwrap(), &mut out) };
                    if st == WAI_OK { json!({"bundle": String::from_utf8(take(out)).unwrap()}) } else { json!({"error": last_reason()}) }
                }
                other => panic!("{other}"),
            };
            assert_eq!(&got, want, "{}: {d}", case["name"]);
        }
        unsafe { wai_sink_free(s) };
    }
}

fn last_reason() -> String {
    let p = wai::ffi::wai_last_error();
    let s = unsafe { std::ffi::CStr::from_ptr(p) }.to_string_lossy().into_owned();
    s.split(':').next().unwrap().to_string()
}

/// A session with no seed has a fresh key: two sessions never share one (stream-audit §3.2).
#[test]
fn a_session_without_a_seed_has_a_fresh_key() {
    let cfg = CString::new(json!({"channel": "film-library", "owner": "00".repeat(32)}).to_string()).unwrap();
    let mut players = std::collections::BTreeSet::new();
    for _ in 0..8 {
        let mut s: *mut WaiSink = std::ptr::null_mut();
        assert_eq!(unsafe { wai_sink_open(cfg.as_ptr(), std::ptr::null(), 0, 1, &mut s) }, WAI_OK);
        let mut out = empty();
        assert_eq!(unsafe { wai_sink_info(s, &mut out) }, WAI_OK);
        let info: Value = serde_json::from_slice(&take(out)).unwrap();
        players.insert(info["player"].as_str().unwrap().to_string());
        unsafe { wai_sink_free(s) };
    }
    assert_eq!(players.len(), 8);
}

/// Bad inputs return the sink's status codes, never a panic across the boundary.
#[test]
fn the_c_abi_refuses_bad_inputs_with_its_codes() {
    let mut s: *mut WaiSink = std::ptr::null_mut();
    let bad = CString::new("{\"channel\": 1}").unwrap();
    assert_eq!(unsafe { wai_sink_open(bad.as_ptr(), std::ptr::null(), 0, 1, &mut s) }, WAI_ERR_SINK_INPUT);
    assert!(s.is_null());
    let not_json = CString::new("{").unwrap();
    assert_eq!(unsafe { wai_sink_open(not_json.as_ptr(), std::ptr::null(), 0, 1, &mut s) }, WAI_ERR_SINK_INPUT);
    let cfg = CString::new(json!({"channel": "film-library", "owner": "00".repeat(32)}).to_string()).unwrap();
    assert_eq!(unsafe { wai_sink_open(cfg.as_ptr(), [1u8; 31].as_ptr(), 31, 1, &mut s) }, wai::ffi::WAI_ERR_INVALID_ARG);
    assert_eq!(unsafe { wai_sink_open(cfg.as_ptr(), std::ptr::null(), 0, 1, &mut s) }, WAI_OK);
    let mut out = empty();
    let e = CString::new("ended").unwrap();
    assert_eq!(unsafe { wai_sink_end(std::ptr::null(), e.as_ptr(), 2, &mut out) }, wai::ffi::WAI_ERR_INVALID_ARG);
    let u = CString::new("https://a.example/x").unwrap();
    assert_eq!(unsafe { wai_sink_playlist(s, u.as_ptr(), std::ptr::null(), 4, std::ptr::null(), 0, &mut out) }, wai::ffi::WAI_ERR_INVALID_ARG);
    let meta = CString::new(json!({"url": "https://a.example/x", "t_us": 2}).to_string()).unwrap();
    assert_eq!(unsafe { wai_sink_object(s, meta.as_ptr(), b"x".as_ptr(), 1, &mut out) }, WAI_OK);
    unsafe { wai_buffer_free(out) };
    let mut out = empty();
    assert_eq!(unsafe { wai_sink_end(s, e.as_ptr(), 3, &mut out) }, WAI_OK);
    unsafe { wai_buffer_free(out) };
    let mut out = empty();
    assert_eq!(unsafe { wai_sink_end(s, e.as_ptr(), 4, &mut out) }, WAI_ERR_SINK_ENDED);
    assert!(out.data.is_null());
    unsafe { wai_sink_free(s) };
}