import t
import stdio
import string
import c
import testcheck

# ============================================================
# Test 1: 字符串指针迭代 - 逐字符直到\0
# ============================================================
def test_string_ptr_iter():
    testcheck.section("Test 1: string pointer iteration")
    s: t.CChar | t.CPtr = "Hello"
    p: t.CChar | t.CPtr = s
    count: t.CInt = 0
    while c.Deref(p) != 0:
        count += 1
        p += 1
    testcheck.check(count == 5, "ptr iter (count=5)", "ptr iter (count expect 5)")

# ============================================================
# Test 2: 字符串指针求和ASCII值
# ============================================================
def test_string_ascii_sum():
    testcheck.section("Test 2: string ASCII sum")
    s: t.CChar | t.CPtr = "ABC"
    p: t.CChar | t.CPtr = s
    total: t.CInt = 0
    while c.Deref(p) != 0:
        total += t.CInt(c.Deref(p))
        p += 1
    # A=65, B=66, C=67 => 198
    testcheck.check(total == 198, "ASCII sum (total=198)", "ASCII sum (total expect 198)")

# ============================================================
# Test 3: 手动strcpy - 指针复制
# ============================================================
def test_manual_strcpy():
    testcheck.section("Test 3: manual strcpy via pointers")
    src: t.CChar | t.CPtr = "Test"
    dst: list[t.CChar, 32] = [0]
    sp: t.CChar | t.CPtr = src
    dp: t.CChar | t.CPtr = c.Addr(dst)
    while c.Deref(sp) != 0:
        c.Set(c.Deref(dp), c.Deref(sp))
        sp += 1
        dp += 1
    c.Set(c.Deref(dp), 0)
    testcheck.check(dst[0] == 84 and dst[1] == 101 and dst[2] == 115 and dst[3] == 116, "manual strcpy (T=84 e=101 s=115 t=116)", "manual strcpy (expect T=84 e=101 s=115 t=116)")

# ============================================================
# Test 4: 指针比较和偏移
# ============================================================
def test_ptr_offset_compare():
    testcheck.section("Test 4: pointer offset and compare")
    arr: list[t.CInt, 5] = [0]
    for i in range(5):
        arr[i] = i * 10
    p: t.CInt | t.CPtr = c.Addr(arr)
    start: t.CInt | t.CPtr = p
    total: t.CInt = 0
    while p != start + 5:
        total += c.Deref(p)
        p += 1
    testcheck.check(total == 100, "ptr offset (total=100)", "ptr offset (total expect 100)")

# ============================================================
# Test 5: 字符串长度手动计算
# ============================================================
def test_manual_strlen():
    testcheck.section("Test 5: manual strlen")
    s: t.CChar | t.CPtr = "Hello World!"
    p: t.CChar | t.CPtr = s
    length: t.CSizeT = 0
    while c.Deref(p) != 0:
        length += 1
        p += 1
    testcheck.check(length == 12, "manual strlen (len=12)", "manual strlen (len expect 12)")

# ============================================================
# Test 6: 指针反向遍历字符串
# ============================================================
def test_reverse_string_ptr():
    testcheck.section("Test 6: reverse string via pointer")
    src: t.CChar | t.CPtr = "abcd"
    dst: list[t.CChar, 32] = [0]
    # Find end of src
    p: t.CChar | t.CPtr = src
    length: t.CInt = 0
    while c.Deref(p) != 0:
        length += 1
        p += 1
    # Copy in reverse
    dp: t.CChar | t.CPtr = c.Addr(dst)
    p = src + length - 1
    while p >= src:
        c.Set(c.Deref(dp), c.Deref(p))
        dp += 1
        p -= 1
    c.Set(c.Deref(dp), 0)
    # "abcd" reversed = "dcba" = 100,99,98,97
    testcheck.check(dst[0] == 100 and dst[1] == 99 and dst[2] == 98 and dst[3] == 97, "reverse string (d=100 c=99 b=98 a=97)", "reverse string (expect d=100 c=99 b=98 a=97)")

# ============================================================
# Test 7: 多级指针 - 指向指针的指针
# ============================================================
def test_double_pointer():
    testcheck.section("Test 7: double pointer")
    x: t.CInt = 42
    px: t.CInt | t.CPtr = c.Addr(x)
    ppx: t.CInt | t.CPtr | t.CPtr = c.Addr(px)
    # Read through double pointer
    val: t.CInt = c.Deref(c.Deref(ppx))
    testcheck.check(val == 42, "double pointer (val=42)", "double pointer (val expect 42)")

# ============================================================
# Test 8: 指针算术 - 数组元素访问
# ============================================================
def test_ptr_arithmetic():
    testcheck.section("Test 8: pointer arithmetic")
    arr: list[t.CInt, 8] = [0]
    for i in range(8):
        arr[i] = (i + 1) * (i + 1)
    p: t.CInt | t.CPtr = c.Addr(arr)
    # Access arr[3] via pointer: p + 3
    val: t.CInt = c.Deref(p + 3)
    # arr[3] = 4*4 = 16
    testcheck.check(val == 16, "ptr arithmetic (arr[3]=16)", "ptr arithmetic (arr[3] expect 16)")

# ============================================================
# Test 9: 字符串比较 - 逐字符指针
# ============================================================
def test_manual_strcmp():
    testcheck.section("Test 9: manual strcmp via pointers")
    s1: t.CChar | t.CPtr = "Hello"
    s2: t.CChar | t.CPtr = "Hello"
    p1: t.CChar | t.CPtr = s1
    p2: t.CChar | t.CPtr = s2
    equal: t.CInt = 1
    while c.Deref(p1) != 0 and c.Deref(p2) != 0:
        if c.Deref(p1) != c.Deref(p2):
            equal = 0
            break
        p1 += 1
        p2 += 1
    if c.Deref(p1) != c.Deref(p2):
        equal = 0
    testcheck.check(equal == 1, "manual strcmp (equal=1)", "manual strcmp (equal expect 1)")

# ============================================================
# Test 10: 结构体指针访问
# ============================================================
class Vec2:
    x: t.CInt
    y: t.CInt

def test_struct_ptr_access():
    testcheck.section("Test 10: struct pointer access")
    v: Vec2 = Vec2()
    v.x = 10
    v.y = 20
    p: Vec2 | t.CPtr = c.Addr(v)
    # Modify through pointer
    c.Deref(p).x = 100
    c.Deref(p).y = 200
    testcheck.check(v.x == 100 and v.y == 200, "struct ptr (x=100 y=200)", "struct ptr (x y expect 100 200)")

def main() -> t.CInt:
    testcheck.begin("StringIterTest: String/Pointer Iteration Tests")
    test_string_ptr_iter()
    test_string_ascii_sum()
    test_manual_strcpy()
    test_ptr_offset_compare()
    test_manual_strlen()
    test_reverse_string_ptr()
    test_double_pointer()
    test_ptr_arithmetic()
    test_manual_strcmp()
    test_struct_ptr_access()
    return testcheck.end()
