use std::{
    env,
    fs::read_to_string,
    io::{self, Write},
    path::{Path, PathBuf},
    sync::{Arc, RwLock},
};

use swc_common::comments::SingleThreadedComments;
use swc_ecma_ast::EsVersion;
use swc_ecma_codegen::{self, text_writer::WriteJs, Emitter};
use swc_ecma_parser::{lexer::Lexer, Parser, Syntax};
use testing::NormalizedOutput;

const IGNORED_PASS_TESTS: &[&str] = &[
    // Temporally ignored
    "431ecef8c85d4d24.js",
    "8386fbff927a9e0e.js",
    "5654d4106d7025c2.js",
    // Stack size (Stupid parens)
    "6b5e7e125097d439.js",
    "714be6d28082eaa7.js",
    "882910de7dd1aef9.js",
    "dd3c63403db5c06e.js",
    // Wrong tests (variable name or value is different)
    "0339fa95c78c11bd.js",
    "0426f15dac46e92d.js",
    "0b4d61559ccce0f9.js",
    "0f88c334715d2489.js",
    "1093d98f5fc0758d.js",
    "15d9592709b947a0.js",
    "2179895ec5cc6276.js",
    "247a3a57e8176ebd.js",
    "441a92357939904a.js",
    "47f974d6fc52e3e4.js",
    "4e1a0da46ca45afe.js",
    "5829d742ab805866.js",
    "589dc8ad3b9aa28f.js",
    "598a5cedba92154d.js",
    "72d79750e81ef03d.js",
    "7788d3c1e1247da9.js",
    "7b72d7b43bedc895.js",
    "7dab6e55461806c9.js",
    "82c827ccaecbe22b.js",
    "87a9b0d1d80812cc.js",
    "8c80f7ee04352eba.js",
    "96f5d93be9a54573.js",
    "988e362ed9ddcac5.js",
    "9bcae7c7f00b4e3c.js",
    "a8a03a88237c4e8f.js",
    "ad06370e34811a6a.js",
    "b0fdc038ee292aba.js",
    "b62c6dd890bef675.js",
    "cb211fadccb029c7.js",
    "ce968fcdf3a1987c.js",
    "db3c01738aaf0b92.js",
    "e1387fe892984e2b.js",
    "e71c1d5f0b6b833c.js",
    "e8ea384458526db0.js",
    // We don't implement Annex B fully.
    "1c1e2a43fe5515b6.js",
    "3dabeca76119d501.js",
    "52aeec7b8da212a2.js",
    "59ae0289778b80cd.js",
    "a4d62a651f69d815.js",
    "c06df922631aeabc.js",
];

#[testing::fixture("../swc_ecma_parser/tests/test262-parser/pass/*.js")]
fn identity(input: PathBuf) {
    if !cfg!(target_os = "windows") {
        do_test(&input, true);
    }
    do_test(&input, false);
}

fn do_test(entry: &Path, minify: bool) {
    let ref_dir = Path::new(env!("CARGO_MANIFEST_DIR"))
        .join("tests")
        .join(if minify { "test262-min" } else { "test262" });

    let file_name = entry
        .file_name()
        .unwrap()
        .to_str()
        .expect("to_str() failed")
        .to_string();

    let input = read_to_string(entry).unwrap();

    let ignore = IGNORED_PASS_TESTS.contains(&&*file_name);

    if ignore {
        return;
    }

    let module = file_name.contains("module");

    let ref_dir = ref_dir;

    let msg = format!(
        "\n\n========== Running codegen test {}\nSource:\n{}\n",
        file_name, input
    );
    let mut wr = Buf(Arc::new(RwLock::new(vec![])));

    ::testing::run_test(false, |cm, handler| {
        let src = cm.load_file(entry).expect("failed to load file");
        eprintln!(
            "{}\nPos: {:?} ~ {:?} (L{})",
            msg,
            src.start_pos,
            src.end_pos,
            src.count_lines()
        );

        let comments = SingleThreadedComments::default();
        let lexer = Lexer::new(
            Syntax::default(),
            Default::default(),
            (&*src).into(),
            Some(&comments),
        );
        let mut parser: Parser<Lexer> = Parser::new_from(lexer);

        {
            let mut wr = Box::new(swc_ecma_codegen::text_writer::JsWriter::new(
                cm.clone(),
                "\n",
                &mut wr,
                None,
            )) as Box<dyn WriteJs>;

            if minify {
                wr = Box::new(swc_ecma_codegen::text_writer::omit_trailing_semi(wr));
            }

            let mut emitter = Emitter {
                cfg: swc_ecma_codegen::Config {
                    minify,
                    target: EsVersion::Es5,
                    ..Default::default()
                },
                cm,
                wr,
                comments: if minify { None } else { Some(&comments) },
            };

            // Parse source
            if module {
                emitter
                    .emit_module(
                        &parser
                            .parse_module()
                            .map_err(|e| e.into_diagnostic(handler).emit())?,
                    )
                    .unwrap();
            } else {
                emitter
                    .emit_script(
                        &parser
                            .parse_script()
                            .map_err(|e| e.into_diagnostic(handler).emit())?,
                    )
                    .unwrap();
            }
        }
        let ref_file = format!("{}", ref_dir.join(&file_name).display());

        let code_output = wr.0.read().unwrap();
        let with_srcmap =
            NormalizedOutput::from(String::from_utf8_lossy(&code_output).into_owned());
        with_srcmap.compare_to_file(ref_file).unwrap();
        Ok(())
    })
    .expect("failed to run test");
}

#[derive(Debug, Clone)]
struct Buf(Arc<RwLock<Vec<u8>>>);
impl Write for Buf {
    fn write(&mut self, data: &[u8]) -> io::Result<usize> {
        self.0.write().unwrap().write(data)
    }

    fn flush(&mut self) -> io::Result<()> {
        self.0.write().unwrap().flush()
    }
}