use crate::loader::Loader;
use std::path::{Path, PathBuf};
use tree_sitter::Language;
use std::fs;

lazy_static! {
    static ref ROOT_DIR: PathBuf = [env!("CARGO_MANIFEST_DIR"), ".."].iter().collect();
    static ref FIXTURES_DIR: PathBuf = ROOT_DIR.join("test").join("fixtures");
    static ref HEADER_DIR: PathBuf = ROOT_DIR.join("lib").join("include");
    static ref GRAMMARS_DIR: PathBuf = ROOT_DIR.join("test").join("fixtures").join("grammars");
    static ref SCRATCH_DIR: PathBuf = {
        let result = ROOT_DIR.join("target").join("scratch");
        fs::create_dir_all(&result).unwrap();
        result
    };
    static ref TEST_LOADER: Loader = Loader::new(SCRATCH_DIR.clone());
}

pub fn fixtures_dir<'a>() -> &'static Path {
    &FIXTURES_DIR
}

pub fn get_language(name: &str) -> Language {
    TEST_LOADER
        .load_language_at_path(name, &GRAMMARS_DIR.join(name).join("src"), &HEADER_DIR)
        .unwrap()
}

pub fn get_test_language(name: &str, parser_code: String, path: &Path) -> Language {
    let parser_c_path = SCRATCH_DIR.join(&format!("{}-parser.c", name));
    if !fs::read_to_string(&parser_c_path)
        .map(|content| content == parser_code)
        .unwrap_or(false)
    {
        fs::write(&parser_c_path, parser_code).unwrap();
    }
    let scanner_path = path.join("scanner.c");
    let scanner_path = if scanner_path.exists() {
        Some(scanner_path)
    } else {
        None
    };
    TEST_LOADER
        .load_language_from_sources(
            name,
            &HEADER_DIR,
            &parser_c_path,
            &scanner_path,
        )
        .unwrap()
}