use std::fs;
use std::path::PathBuf;

use mlua::{Function, Lua, Table};

fn fixture_path(name: &str) -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("tests")
        .join("fixtures")
        .join(name)
}

fn load_fixture(name: &str) -> (Lua, Table) {
    let lua = Lua::new();
    let src = fs::read_to_string(fixture_path(name)).unwrap();
    let table: Table = lua.load(&src).set_name(name).eval().unwrap();
    (lua, table)
}

#[test]
fn lua_line_framer_fixture_splits_crlf_and_lf() {
    let (lua, table) = load_fixture("lua_line_framer.lua");
    let feed: Function = table.get("feed").unwrap();

    let input = lua.create_string(b"hello\r\nworld\n").unwrap();
    let frames: Vec<String> = feed.call(input).unwrap();
    assert_eq!(frames, vec!["hello", "world"]);
}

#[test]
fn lua_line_framer_fixture_handles_split_chunks_and_flush() {
    let (lua, table) = load_fixture("lua_line_framer.lua");
    let feed: Function = table.get("feed").unwrap();
    let flush: Function = table.get("flush").unwrap();
    let pending_len: Function = table.get("pending_len").unwrap();
    let reset: Function = table.get("reset").unwrap();

    let frames: Vec<String> = feed.call(lua.create_string(b"par").unwrap()).unwrap();
    assert!(frames.is_empty());
    assert_eq!(pending_len.call::<usize>(()).unwrap(), 3);

    let frames: Vec<String> = feed.call(lua.create_string(b"tial\n").unwrap()).unwrap();
    assert_eq!(frames, vec!["partial"]);

    let flushed: Option<String> = flush.call(()).unwrap();
    assert_eq!(flushed.as_deref(), None);

    reset.call::<()>(()).unwrap();
    assert_eq!(pending_len.call::<usize>(()).unwrap(), 0);
}

#[test]
fn lua_text_decoder_fixture_decodes_text_and_rejects_empty() {
    let (lua, table) = load_fixture("lua_text_decoder.lua");
    let decode: Function = table.get("decode").unwrap();

    let decoded: Option<Table> = decode.call(lua.create_string(b"abc").unwrap()).unwrap();
    let decoded = decoded.expect("non-empty frame should decode");
    let kind: String = decoded.get("kind").unwrap();
    let data: String = decoded.get("data").unwrap();
    assert_eq!(kind, "text");
    assert_eq!(data, "abc");

    let empty: Option<Table> = decode.call(lua.create_string(b"").unwrap()).unwrap();
    assert!(empty.is_none(), "empty frame should be rejected");
}