use std::io::Write;
use std::path::PathBuf;
use std::process::{Command, Stdio};
use std::sync::atomic::{AtomicUsize, Ordering};

static NEXT_FILE: AtomicUsize = AtomicUsize::new(0);

struct SourceFile(PathBuf);

impl SourceFile {
    fn new(content: &[u8]) -> Self {
        let path = std::env::temp_dir().join(format!(
            "aster-parse-{}-{}.endor",
            std::process::id(),
            NEXT_FILE.fetch_add(1, Ordering::Relaxed)
        ));
        std::fs::write(&path, content).unwrap();
        Self(path)
    }
}

impl Drop for SourceFile {
    fn drop(&mut self) {
        let _ = std::fs::remove_file(&self.0);
    }
}

#[test]
fn parse_command_prints_ast_without_executing_source() {
    let source = SourceFile::new("function 表示(): String { return 未定義() }".as_bytes());
    let output = Command::new(env!("CARGO_BIN_EXE_lyra"))
        .arg("parse")
        .arg(&source.0)
        .output()
        .unwrap();
    assert!(
        output.status.success(),
        "{}",
        String::from_utf8_lossy(&output.stderr)
    );
    let stdout = String::from_utf8(output.stdout).unwrap();
    assert!(stdout.contains("表示"));
    assert!(stdout.contains("未定義"));
    assert!(stdout.contains("Call"));
}

#[test]
fn parse_command_reports_source_locations_and_rejects_invalid_utf8() {
    let source = SourceFile::new(b"function f(): Number {\n  return )\n}");
    let output = Command::new(env!("CARGO_BIN_EXE_lyra"))
        .arg("parse")
        .arg(&source.0)
        .output()
        .unwrap();
    assert!(!output.status.success());
    assert!(output.stdout.is_empty());
    let stderr = String::from_utf8(output.stderr).unwrap();
    assert!(stderr.contains(":2:10:"), "{stderr}");
    assert!(stderr.contains("expected"));
    let source = SourceFile::new(&[0xff]);
    let output = Command::new(env!("CARGO_BIN_EXE_lyra"))
        .arg("parse")
        .arg(&source.0)
        .output()
        .unwrap();
    assert!(!output.status.success());
    assert!(output.stdout.is_empty());
}

fn parse_stdin(source: &[u8]) -> std::process::Output {
    let mut child = Command::new(env!("CARGO_BIN_EXE_lyra"))
        .args(["parse", "-"])
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .spawn()
        .unwrap();
    let mut stdin = child.stdin.take().unwrap();
    stdin.write_all(source).unwrap();
    drop(stdin);
    child.wait_with_output().unwrap()
}

#[test]
fn parse_command_reads_stdin_to_eof_and_reports_its_origin() {
    let output = parse_stdin("function 表示(): String { return \"日\" }".as_bytes());
    assert!(
        output.status.success(),
        "{}",
        String::from_utf8_lossy(&output.stderr)
    );
    assert!(String::from_utf8(output.stdout).unwrap().contains("表示"));
    let output = parse_stdin(b"function f(): Number {\n  return )\n}");
    assert!(!output.status.success());
    assert!(
        String::from_utf8(output.stderr)
            .unwrap()
            .contains("<stdin>:2:10:")
    );
    let output = parse_stdin(&[0xff]);
    assert!(!output.status.success());
    assert!(
        String::from_utf8(output.stderr)
            .unwrap()
            .contains("<stdin>: invalid UTF-8 at byte 0")
    );
}

#[test]
fn parse_command_exports_versioned_json_for_expression_and_interactive_inputs() {
    for (mode, source) in [("expression", "f(\"日\")"), ("interactive", "let x = 1")] {
        let source = SourceFile::new(source.as_bytes());
        let output = Command::new(env!("CARGO_BIN_EXE_lyra"))
            .args(["parse", "--json", "--mode", mode])
            .arg(&source.0)
            .output()
            .unwrap();
        assert!(
            output.status.success(),
            "{}",
            String::from_utf8_lossy(&output.stderr)
        );
        let document =
            frontend::ast::AstDocument::from_json(std::str::from_utf8(&output.stdout).unwrap())
                .unwrap();
        assert_eq!(document.schema, frontend::ast::AST_SCHEMA_ID);
        match (mode, document.root) {
            ("expression", frontend::ast::AstRoot::Expression(_))
            | ("interactive", frontend::ast::AstRoot::Interactive(_)) => {}
            _ => panic!("incorrect parse mode"),
        }
    }
    let output = Command::new(env!("CARGO_BIN_EXE_lyra"))
        .args(["parse", "--mode", "unknown", "-"])
        .output()
        .unwrap();
    assert!(!output.status.success());
    assert!(output.stdout.is_empty());
}