"""gcov 覆盖率采集全链路测试

测试内容:
  1. cobc --coverage 编译含 IF 分支的简单 COBOL 程序
  2. 运行生成 .gcda 文件
  3. collect_gcov() 解析 line_rate > 0
  4. 清理中间产物
"""

import sys, os, subprocess, tempfile
from pathlib import Path

sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))

import pytest
from hina.gcov_collector import collect_gcov


HAVE_COBC = None


def _check_cobc() -> bool:
    """检查 cobc 是否在 PATH 且支持 --coverage"""
    global HAVE_COBC
    if HAVE_COBC is not None:
        return HAVE_COBC
    try:
        r = subprocess.run(["cobc", "--version"], capture_output=True, text=True, timeout=15)
        HAVE_COBC = r.returncode == 0
    except FileNotFoundError:
        HAVE_COBC = False
    return HAVE_COBC


# ── 嵌入一个简单的 COBOL 程序 (IF 分支) ──

SAMPLE_COBOL = """\
       IDENTIFICATION DIVISION.
       PROGRAM-ID. test-gcov.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 WS-X PIC 9(2) VALUE 0.
       01 WS-Y PIC 9(2) VALUE 0.
       PROCEDURE DIVISION.
           MOVE 10 TO WS-X.
           IF WS-X > 5 THEN
               MOVE 1 TO WS-Y
           ELSE
               MOVE 2 TO WS-Y
           END-IF.
           DISPLAY "Y=" WS-Y.
           STOP RUN.
"""


# ── 夹具: 创建临时目录存放 COBOL 源和编译产物 ──


@pytest.fixture
def work_dir() -> Path:
    """创建临时工作目录"""
    with tempfile.TemporaryDirectory(prefix="gcov_test_") as tmp:
        yield Path(tmp)


# ── 辅助函数 ──


def _compile_with_coverage(src_path: Path, out_dir: Path) -> bool:
    """用 cobc --coverage 编译, 返回是否成功"""
    r = subprocess.run(
        ["cobc", "-x", "--coverage", str(src_path), "-o", str(out_dir / "test-gcov.exe")],
        capture_output=True, text=True, timeout=30,
        cwd=str(out_dir),
    )
    if r.returncode != 0:
        print(f"[compile] stderr: {r.stderr[:300]}")
    return r.returncode == 0


def _run_executable(exe_path: Path, run_dir: Path) -> bool:
    """运行可执行文件, 返回是否成功"""
    r = subprocess.run(
        [str(exe_path)],
        capture_output=True, text=True, timeout=15,
        cwd=str(run_dir),
    )
    if r.returncode != 0:
        print(f"[run] stderr: {r.stderr[:300]}")
    print(f"[run] stdout: {r.stdout.strip()}")
    return r.returncode == 0


# ── 测试用例 ──


@pytest.mark.skipif(not _check_cobc(), reason="cobc 未安装或不在 PATH 中")
def test_gcov_basic_collect(work_dir: Path) -> None:
    """全链路: 编译 → 运行 → collect_gcov → 验证 line_rate"""

    # 1. 写入 COBOL 源文件
    src = work_dir / "test-gcov.cbl"
    src.write_text(SAMPLE_COBOL, encoding="utf-8")

    # 2. 编译 (--coverage)
    assert _compile_with_coverage(src, work_dir), "cobc --coverage 编译失败"

    # 3. 确认 .gcno 已生成
    gcno_files = list(work_dir.glob("*.gcno"))
    assert len(gcno_files) > 0, "编译后未生成 .gcno 文件"

    # 4. 运行程序 (生成 .gcda)
    exe = work_dir / "test-gcov.exe"
    assert _run_executable(exe, work_dir), "程序运行失败"

    # 5. 确认 .gcda 已生成
    gcda_files = list(work_dir.glob("*.gcda"))
    assert len(gcda_files) > 0, "运行后未生成 .gcda 文件"

    # 6. 调用 collect_gcov() 采集覆盖率
    result = collect_gcov(cobol_src=src, work_dir=work_dir)
    print(f"[gcov] collect_gcov returned: {result}")

    # 7. 验证结果
    assert result["available"] is True, f"覆盖率采集失败: {result.get('reason', 'unknown')}"
    assert result["line_rate"] > 0, f"line_rate 应为正值, 实际: {result['line_rate']}"
    assert result["total_lines"] > 0, f"total_lines 应为正值, 实际: {result['total_lines']}"
    assert result["executed_lines"] > 0, f"executed_lines 应为正值, 实际: {result['executed_lines']}"

    # 8. 验证分支覆盖 (IF 的两路应至少覆盖了一路)
    assert result["line_rate"] <= 1.0, f"line_rate 不应超过 1.0"
    print(f"[gcov] ✅ line_rate={result['line_rate']} ({result['executed_lines']}/{result['total_lines']})")


@pytest.mark.skipif(not _check_cobc(), reason="cobc 未安装或不在 PATH 中")
def test_gcov_no_gcda_graceful(work_dir: Path) -> None:
    """无 .gcda 文件时 collect_gcov 应优雅降级"""

    src = work_dir / "test-gcov.cbl"
    src.write_text(SAMPLE_COBOL, encoding="utf-8")

    # 编译但不运行, 所以没有 .gcda
    subprocess.run(
        ["cobc", "-x", "--coverage", str(src), "-o", str(work_dir / "test-gcov.exe")],
        capture_output=True, text=True, timeout=30,
        cwd=str(work_dir),
    )

    result = collect_gcov(cobol_src=src, work_dir=work_dir)
    # 没有 .gcda 时应 graceful 返回 {available: False}
    assert result["available"] is False
    print(f"[gcov] 无 .gcda 降级正常: {result}")