from stdint import *
import t, c
import stdio
import string
import w32.win32console
import w32.win32memory

# ============================================================
# PointerTest - 测试指针操作、global声明、数组退化、指针算术
# ============================================================

# --- Test 1: global 声明对模块级变量的影响 ---
_g_val: t.CInt = 0
_g_ptr: t.CUInt32T | t.CPtr = None

def test_global_write():
    """测试：缺少 global 声明时，赋值是否修改模块级变量"""
    global _g_val
    _g_val = 42

def test_global_write_no_decl():
    """测试：没有 global 声明时，赋值是否创建局部变量"""
    # 注意：这里故意不声明 global，测试编译器行为
    # 如果 _g_val 在此函数之前被读取过，赋值会修改全局变量
    # 如果 _g_val 在此函数中首次被赋值，会创建局部变量
    _g_val = 99  # 这应该创建一个局部变量

def test_global_ptr():
    global _g_ptr
    buf: t.CUInt32T | t.CPtr = w32.win32memory.VirtualAlloc(None, 256, 0x3000, 0x04)
    if buf:
        string.memset(buf, 0, 256)
        _g_ptr = buf
        p: t.CUInt32T | t.CPtr = _g_ptr
        p[0] = 0xAABBCCDD
        p[1] = 0x11223344

def test_global_ptr_no_decl():
    """测试：没有 global 声明时，指针赋值是否创建局部变量"""
    # _g_ptr 在 test_global_ptr 中已被赋值（有 global）
    # 这里读取 _g_ptr 然后赋值 — 读取会将全局变量加入 Gen.variables
    # 所以后续赋值应该修改全局变量
    old: t.CUInt32T | t.CPtr = _g_ptr  # 读取 -> 加入 Gen.variables
    _g_ptr = None  # 因为之前读取过，这应该修改全局变量


# --- Test 2: 指针算术和数组索引 ---
def test_pointer_arithmetic():
    """测试指针算术：偏移计算是否正确"""
    buf: t.CUInt32T | t.CPtr = w32.win32memory.VirtualAlloc(None, 256, 0x3000, 0x04)
    if not buf:
        stdio.printf("FAIL: VirtualAlloc returned NULL\n")
        return
    string.memset(buf, 0, 256)

    # 写入值
    for i in range(8):
        buf[i] = t.CUInt32T(i * 100)

    # 读取并验证
    ok: t.CInt = 1
    for i in range(8):
        v: t.CUInt32T = buf[i]
        expected: t.CUInt32T = t.CUInt32T(i * 100)
        if v != expected:
            stdio.printf("FAIL: buf[%d] = 0x%x, expected 0x%x\n", i, v, expected)
            ok = 0
    if ok:
        stdio.printf("PASS: pointer arithmetic (buf[i] = i*100)\n")


# --- Test 3: 数组退化为指针 ---
def test_array_decay():
    """测试 list[t.CChar, N] 传递给 t.CConst | str 参数"""
    arr: list[t.CChar, 32]
    string.memset(c.Addr(arr), 0, 32)
    # 手动写入字符串
    src: str = "Hello"
    for i in range(5):
        arr[i] = t.CChar(ord(src[i]))
    arr[5] = 0

    # 传递给 print (接受 t.CConst | str)
    stdio.printf("PASS: array decay -> %s\n", c.Addr(arr))


# --- Test 4: 指针类型转换 (CVoid/CPtr) ---
def test_pointer_cast():
    """测试指针与整数之间的类型转换"""
    buf: t.CUInt32T | t.CPtr = w32.win32memory.VirtualAlloc(None, 256, 0x3000, 0x04)
    if not buf:
        stdio.printf("FAIL: VirtualAlloc returned NULL\n")
        return
    string.memset(buf, 0, 256)

    # 通过 CVoid 指针写入
    raw: t.CVoid | t.CPtr = t.CVoid(t.CUInt64T(buf), t.CPtr)
    # 将 CVoid 指针转回 CUInt32T 指针
    p32: t.CUInt32T | t.CPtr = (t.CUInt32T | t.CPtr)(raw)
    p32[0] = 0xDEADBEEF

    # 通过原始指针读取
    if buf[0] == 0xDEADBEEF:
        stdio.printf("PASS: pointer cast CVoid -> CUInt32T*\n")
    else:
        stdio.printf("FAIL: pointer cast, got 0x%x\n", buf[0])


# --- Test 5: 指针偏移计算 (byte offset vs element offset) ---
def test_pointer_offset():
    """测试指针偏移：CUInt8T* + N 应该偏移 N 字节，CUInt32T* + N 应该偏移 N*4 字节"""
    buf: t.CUInt8T | t.CPtr = w32.win32memory.VirtualAlloc(None, 256, 0x3000, 0x04)
    if not buf:
        stdio.printf("FAIL: VirtualAlloc returned NULL\n")
        return
    string.memset(buf, 0, 256)

    # 写入 4 字节
    buf[0] = 0x41  # 'A'
    buf[1] = 0x42  # 'B'
    buf[2] = 0x43  # 'C'
    buf[3] = 0x44  # 'D'

    # 通过 CUInt32T* 读取（应该读到 0x44434241 on little-endian）
    p32: t.CUInt32T | t.CPtr = (t.CUInt32T | t.CPtr)(t.CVoid(t.CUInt64T(buf), t.CPtr))
    val: t.CUInt32T = p32[0]

    # little-endian: 0x44434241
    if val == 0x44434241:
        stdio.printf("PASS: byte offset vs element offset (0x%x)\n", val)
    else:
        stdio.printf("FAIL: expected 0x44434241, got 0x%x\n", val)


# --- Test 6: 结构体指针访问 ---
class TestStruct():
    a: t.CInt
    b: t.CInt
    c: t.CUInt64T

def test_struct_pointer():
    """测试结构体指针的成员访问"""
    s: TestStruct
    s.a = 10
    s.b = 20
    s.c = 0x123456789ABCDEF0

    p: TestStruct | t.CPtr = c.Addr(s)
    if p.a == 10 and p.b == 20 and p.c == 0x123456789ABCDEF0:
        stdio.printf("PASS: struct pointer access (a=%d b=%d c=0x%llx)\n", p.a, p.b, p.c)
    else:
        stdio.printf("FAIL: struct pointer access (a=%d b=%d c=0x%llx)\n", p.a, p.b, p.c)


# --- Test 7: memcpy/memset 通过指针 ---
def test_memcpy_pointers():
    """测试 memcpy 在指针之间的数据复制"""
    src_buf: t.CUInt32T | t.CPtr = w32.win32memory.VirtualAlloc(None, 64, 0x3000, 0x04)
    dst_buf: t.CUInt32T | t.CPtr = w32.win32memory.VirtualAlloc(None, 64, 0x3000, 0x04)
    if not src_buf or not dst_buf:
        stdio.printf("FAIL: VirtualAlloc returned NULL\n")
        return

    # 初始化 src
    for i in range(8):
        src_buf[i] = t.CUInt32T(i + 1000)

    # 复制
    string.memcpy(t.CVoid(t.CUInt64T(dst_buf), t.CPtr), t.CVoid(t.CUInt64T(src_buf), t.CPtr), 32)

    # 验证
    ok: t.CInt = 1
    for i in range(8):
        if dst_buf[i] != t.CUInt32T(i + 1000):
            stdio.printf("FAIL: dst[%d] = %u, expected %u\n", i, dst_buf[i], i + 1000)
            ok = 0
    if ok:
        stdio.printf("PASS: memcpy between pointers\n")


# --- Test 8: 指针作为函数参数 ---
def fill_array(arr: t.CUInt32T | t.CPtr, count: t.CInt, val: t.CUInt32T):
    for i in range(count):
        arr[i] = val

def test_pointer_param():
    """测试指针作为函数参数传递"""
    buf: t.CUInt32T | t.CPtr = w32.win32memory.VirtualAlloc(None, 64, 0x3000, 0x04)
    if not buf:
        stdio.printf("FAIL: VirtualAlloc returned NULL\n")
        return

    fill_array(buf, 8, 0xCAFEBABE)

    ok: t.CInt = 1
    for i in range(8):
        if buf[i] != 0xCAFEBABE:
            ok = 0
    if ok:
        stdio.printf("PASS: pointer as function parameter\n")
    else:
        stdio.printf("FAIL: pointer as function parameter\n")


def main() -> t.CInt | t.CExport:
    w32.win32console.SetConsoleCP(65001)
    w32.win32console.SetConsoleOutputCP(65001)

    stdio.printf("=== PointerTest: 指针操作基准测试 ===\n\n")

    # Test 1: global 声明
    stdio.printf("--- Test 1: global declaration ---\n")
    _g_val = 0
    test_global_write()
    stdio.printf("After test_global_write(): _g_val = %d (expect 42)\n", _g_val)
    test_global_write_no_decl()
    stdio.printf("After test_global_write_no_decl(): _g_val = %d (expect 42, not 99)\n", _g_val)
    stdio.printf("\n")

    # Test 1b: global pointer
    stdio.printf("--- Test 1b: global pointer ---\n")
    test_global_ptr()
    if _g_ptr:
        p: t.CUInt32T | t.CPtr = _g_ptr
        stdio.printf("_g_ptr[0] = 0x%x (expect 0xAABBCCDD)\n", p[0])
        stdio.printf("_g_ptr[1] = 0x%x (expect 0x11223344)\n", p[1])
    test_global_ptr_no_decl()
    stdio.printf("After test_global_ptr_no_decl(): _g_ptr = %p (expect NULL/0)\n", t.CVoid(t.CUInt64T(_g_ptr), t.CPtr))
    stdio.printf("\n")

    # Test 2: pointer arithmetic
    stdio.printf("--- Test 2: pointer arithmetic ---\n")
    test_pointer_arithmetic()
    stdio.printf("\n")

    # Test 3: array decay
    stdio.printf("--- Test 3: array decay ---\n")
    test_array_decay()
    stdio.printf("\n")

    # Test 4: pointer cast
    stdio.printf("--- Test 4: pointer cast ---\n")
    test_pointer_cast()
    stdio.printf("\n")

    # Test 5: pointer offset
    stdio.printf("--- Test 5: pointer offset (byte vs element) ---\n")
    test_pointer_offset()
    stdio.printf("\n")

    # Test 6: struct pointer
    stdio.printf("--- Test 6: struct pointer access ---\n")
    test_struct_pointer()
    stdio.printf("\n")

    # Test 7: memcpy pointers
    stdio.printf("--- Test 7: memcpy between pointers ---\n")
    test_memcpy_pointers()
    stdio.printf("\n")

    # Test 8: pointer as param
    stdio.printf("--- Test 8: pointer as function parameter ---\n")
    test_pointer_param()
    stdio.printf("\n")

    stdio.printf("=== PointerTest Complete ===\n")
    return 0