//! test262 harness 内嵌注册表与前缀拼接/缓存：`HarnessSources`（21 处 `include_str!`）、`HARNESS`、黑名单、
//! 前缀拼接与缓存。全部 `include_str!` 路径相对上 3 级到仓库根，依赖本文件平铺 `src/` 一级，禁子目录。

use crate::meta::TestMeta;
use std::collections::HashMap;
use std::sync::{Arc, OnceLock, RwLock};

/// 内嵌的 test262 harness 辅助脚本注册表（编译期 include_str! 打包）。
pub(crate) struct HarnessSources {
    sources: HashMap<&'static str, &'static str>,
}

/// harness 前缀缓存键：由测试 `includes` 列表唯一确定。
pub(crate) type HarnessPrefixCache = HashMap<Vec<String>, String>;

impl HarnessSources {
    /// 构建 harness 源注册表（键为文件名，值为编译期内嵌源码）。
    pub(crate) fn new() -> Self {
        let mut sources = HashMap::new();
        sources.insert("sta.js", include_str!("../../../tests/test262/harness/sta.js"));
        sources.insert("assert.js", include_str!("../../../tests/test262/harness/assert.js"));
        sources.insert("propertyHelper.js", include_str!("../../../tests/test262/harness/propertyHelper.js"));
        sources.insert("compareArray.js", include_str!("../../../tests/test262/harness/compareArray.js"));
        sources.insert("fnGlobalObject.js", include_str!("../../../tests/test262/harness/fnGlobalObject.js"));
        sources.insert("nans.js", include_str!("../../../tests/test262/harness/nans.js"));
        sources.insert("dateConstants.js", include_str!("../../../tests/test262/harness/dateConstants.js"));
        sources.insert(
            "decimalToHexString.js",
            include_str!("../../../tests/test262/harness/decimalToHexString.js"),
        );
        sources.insert("isConstructor.js", include_str!("../../../tests/test262/harness/isConstructor.js"));
        sources.insert("nativeErrors.js", include_str!("../../../tests/test262/harness/nativeErrors.js"));
        sources.insert(
            "nativeFunctionMatcher.js",
            include_str!("../../../tests/test262/harness/nativeFunctionMatcher.js"),
        );
        sources.insert("regExpUtils.js", include_str!("../../../tests/test262/harness/regExpUtils.js"));
        sources.insert(
            "assertRelativeDateMs.js",
            include_str!("../../../tests/test262/harness/assertRelativeDateMs.js"),
        );
        sources.insert(
            "wellKnownIntrinsicObjects.js",
            include_str!("../../../tests/test262/harness/wellKnownIntrinsicObjects.js"),
        );
        sources.insert("typeCoercion.js", include_str!("../../../tests/test262/harness/typeCoercion.js"));
        sources.insert("deepEqual.js", include_str!("../../../tests/test262/harness/deepEqual.js"));
        sources.insert("testTypedArray.js", include_str!("../../../tests/test262/harness/testTypedArray.js"));
        sources.insert("temporalHelpers.js", include_str!("../../../tests/test262/harness/temporalHelpers.js"));
        sources.insert("asyncHelpers.js", include_str!("../../../tests/test262/harness/asyncHelpers.js"));
        sources.insert("doneprintHandle.js", include_str!("../../../tests/test262/harness/doneprintHandle.js"));
        sources.insert("promiseHelper.js", include_str!("../../../tests/test262/harness/promiseHelper.js"));
        Self { sources }
    }

    /// 按文件名取 harness 源码。
    pub(crate) fn get(&self, name: &str) -> Option<&'static str> {
        self.sources.get(name).copied()
    }
}

pub(crate) static HARNESS: OnceLock<HarnessSources> = OnceLock::new();

/// 判断 harness 文件是否在支持范围之外（依赖 Proxy/Intl/async 等未实现特性）。
fn is_blacklisted_harness(name: &str) -> bool {
    matches!(
        name,
        "testIntl.js"
            | "testAtomics.js"
            | "atomicsHelper.js"
            | "proxyTrapsHelper.js"
            | "tcoHelper.js"
            | "detachArrayBuffer.js"
            | "resizableArrayBufferUtils.js"
            | "byteConversionValues.js"
            | "compareIterator.js"
            | "iteratorZipUtils.js"
    )
}

/// 生成 `Test262Error` 的 JS prelude（供测试脚本 `assert` 失败时抛出）。
/// 向拼接源码追加一段带注释标记的 harness 代码块。
pub(crate) fn append_source_chunk(out: &mut String, name: &str, source: &str) {
    out.push_str("\n// ---- test262 harness: ");
    out.push_str(name);
    out.push_str(" ----\n");
    out.push_str(source);
    out.push('\n');
}

/// 取测试元数据的 harness 缓存键（即其 `includes` 列表）。
fn harness_key(meta: &TestMeta) -> Vec<String> {
    let mut key = meta.includes.clone();
    if meta.flags.iter().any(|f| f == "onlyStrict") {
        key.push("__onlyStrict__".into());
    }
    key
}

/// 按测试元数据拼接完整的 harness 前缀源码（prelude + sta/assert + 各 include）。
fn build_harness_source(meta: &TestMeta, harness: &HarnessSources) -> Result<String, String> {
    let mut source = String::new();
    // onlyStrict 测试在严格模式下运行：指令必须位于脚本最前（harness 之前）。
    if meta.flags.iter().any(|f| f == "onlyStrict") {
        append_source_chunk(&mut source, "use strict", "\"use strict\";");
    }
    // Test262Error 由 sta.js 提供；此处不再重复定义（重复函数声明会引发
    // 引擎 prototype 语义错乱，导致 assert.throws 的 constructor 比对失败）。
    append_source_chunk(
        &mut source,
        "sta.js",
        harness.get("sta.js").ok_or_else(|| String::from("unknown harness: sta.js"))?,
    );
    append_source_chunk(
        &mut source,
        "assert.js",
        harness
            .get("assert.js")
            .ok_or_else(|| String::from("unknown harness: assert.js"))?,
    );
    for include in &meta.includes {
        if is_blacklisted_harness(include) {
            return Err(format!("out-of-scope harness: {include}"));
        }
        let include_source = harness.get(include).ok_or_else(|| format!("unknown harness: {include}"))?;
        append_source_chunk(&mut source, include, include_source);
    }
    Ok(source)
}

/// 取得（并缓存）测试所需的 harness 前缀源码；缓存键为 includes 组合。
pub(crate) fn get_harness_prefix(
    meta: &TestMeta, harness: &HarnessSources, cache: &Arc<RwLock<HarnessPrefixCache>>,
) -> Result<String, String> {
    let key = harness_key(meta);
    {
        let guard = cache.read().unwrap();
        if let Some(prefix) = guard.get(&key) {
            return Ok(prefix.clone());
        }
    }

    let source = build_harness_source(meta, harness)?;
    cache.write().unwrap().insert(key, source.clone());
    Ok(source)
}