//! P1 工具结果瘦身 — 端到端集成验证。
//!
//! 独立测试二进制(独立进程):`tool_offload::init_base` 的 OnceLock 全局态不外泄，
//! 不污染 lib 单测(反之亦然)。这是验证「超阈值 → 落盘句柄 → 可无损读回」全链的唯一安全方式。

use df_ai::context_helpers::{extract_key_info, READ_FILE_OFFLOAD_BYTES};
use df_ai::tool_offload;

fn tmp_base(tag: &str) -> std::path::PathBuf {
    std::env::temp_dir().join(format!("df-ai-ctx-offload-{tag}-{}", std::process::id()))
}

/// 从句柄行里粗取落盘路径(格式:`[...已外置: <path> —— ...]`)。
fn path_of(handle_line: &str) -> String {
    handle_line
        .split("已外置: ")
        .nth(1)
        .and_then(|s| s.split(" ——").next())
        .expect("句柄行应含路径")
        .trim()
        .to_string()
}

#[test]
fn large_read_file_summarized_with_lossless_handle() {
    let base = tmp_base("large");
    let _ = std::fs::remove_dir_all(&base);
    tool_offload::init_base(base.clone());

    // 造一个超阈值的 read_file 结果(代码风格多行文本)
    let body: String = (1..=800)
        .map(|i| format!("line {i}: fn sample_{i}() {{ let x = {i}; }}\n"))
        .collect();
    assert!(body.len() > READ_FILE_OFFLOAD_BYTES, "夹具须超阈值");

    let out = extract_key_info(&body, "read_file");
    assert!(out.len() < body.len(), "超阈值 read_file 应被压缩");
    assert!(out.contains("已外置"), "应追加落盘句柄:\n{out}");
    assert!(out.contains("read_file 读该路径"), "句柄应指引读回方式");

    // 无损性:按句柄路径读回 = 原文逐字节一致
    let line = out.lines().find(|l| l.contains("已外置")).expect("应有句柄行");
    let back = tool_offload::read_offloaded(&path_of(line)).expect("句柄路径应可读回");
    assert_eq!(back, body, "落盘原文须与输入逐字节一致(无损)");

    // 摘要确实变小(瘦身生效)
    let ratio = out.len() as f64 / body.len() as f64;
    assert!(ratio < 0.2, "压缩比应显著(<0.2),实际 {ratio:.3}");

    let _ = std::fs::remove_dir_all(&base);
}

#[test]
fn small_read_file_still_exempt() {
    let base = tmp_base("small");
    tool_offload::init_base(base);
    let small = "line1: fn a() {}\nline2: fn b() {}\n";
    assert_eq!(
        extract_key_info(small, "read_file"),
        small,
        "阈值内 read_file 应原样返回(保 AI 定向读代码语义)"
    );
}

#[test]
fn non_read_file_large_result_also_gets_handle() {
    let base = tmp_base("other");
    let _ = std::fs::remove_dir_all(&base);
    tool_offload::init_base(base.clone());

    // 中性行夹具:不得含 error/panic/.rs: 等错误行信号——错误行保留策略会全量保留
    // 命中行,用信号行做夹具会让「应被压缩」断言先天不成立(测的是普通大结果外置)
    let body: String = (1..=1200).map(|i| format!("match {i}: src/foo.txt:{i}\n")).collect();
    assert!(body.len() >= 8 * 1024, "夹具须 ≥8KB(句柄追加下限)");
    let out = extract_key_info(&body, "grep");
    assert!(out.len() < body.len(), "应被压缩");
    assert!(out.contains("已外置"), "≥8KB 结果应带落盘句柄");

    let line = out.lines().find(|l| l.contains("已外置")).expect("应有句柄行");
    assert_eq!(
        tool_offload::read_offloaded(&path_of(line)).expect("应可读回"),
        body
    );
    let _ = std::fs::remove_dir_all(&base);
}