use std::path::Path;
use std::process::Command;

use anyhow::{Context, Result, ensure};

pub fn check_public_types(manifest_dir: impl AsRef<Path>, declarations: &[&str]) -> Result<()> {
    let root = manifest_dir.as_ref();
    check_types(root.join("tsconfig.json"))?;
    let directory = tempfile::tempdir()?;
    let mut files = Vec::new();
    for (index, declaration) in declarations.iter().enumerate() {
        let path = directory.path().join(format!("module_{index}.d.ts"));
        std::fs::write(&path, declaration)?;
        files.push(path);
    }
    files.push(root.join("tests/public.ts"));
    let config = directory.path().join("tsconfig.json");
    std::fs::write(
        &config,
        serde_json::to_vec_pretty(&serde_json::json!({
            "extends": root.join("../../lib/ext_build/tsconfig.harness.json"),
            "files": files,
        }))?,
    )?;
    check_types(config)
}

/// Check an extension's tsconfig with the native TypeScript backend.
/// Returns early when AVRIL_TEST_TYPESCRIPT is unset, like the backend test suite.
pub fn check_types(config: impl AsRef<Path>) -> Result<()> {
    let Some(backend) = std::env::var_os("AVRIL_TEST_TYPESCRIPT").filter(|path| !path.is_empty())
    else {
        eprintln!("skipping: AVRIL_TEST_TYPESCRIPT is not set");
        return Ok(());
    };
    let config = config.as_ref();
    let output = Command::new(&backend)
        .arg("--project")
        .arg(config)
        .args(["--noEmit", "--pretty", "false"])
        .output()
        .with_context(|| format!("Type-checking {} with {backend:?}", config.display()))?;
    ensure!(
        output.status.success(),
        "{}:\n{}{}",
        config.display(),
        String::from_utf8_lossy(&output.stdout),
        String::from_utf8_lossy(&output.stderr),
    );
    Ok(())
}