#include                // ptrdiff_t

#include "parts.h"
#include "util.h"

/* Test PyUnicode_New() */
static PyObject *
unicode_new(PyObject *self, PyObject *args)
{
    Py_ssize_t size;
    unsigned int maxchar;
    PyObject *result;

    if (!PyArg_ParseTuple(args, "nI", &size, &maxchar)) {
        return NULL;
    }

    result = PyUnicode_New(size, (Py_UCS4)maxchar);
    if (!result) {
        return NULL;
    }
    if (size > 0 && maxchar tp_alloc(type, 0);
    if (!self) {
        return NULL;
    }
    self->writer = NULL;
    return (PyObject*)self;
}


static int
writer_init(PyObject *self_raw, PyObject *args, PyObject *kwargs)
{
    WriterObject *self = (WriterObject *)self_raw;

    Py_ssize_t size;
    if (!PyArg_ParseTuple(args, "n", &size)) {
        return -1;
    }

    if (self->writer) {
        PyUnicodeWriter_Discard(self->writer);
    }

    self->writer = PyUnicodeWriter_Create(size);
    if (self->writer == NULL) {
        return -1;
    }
    return 0;
}


static void
writer_dealloc(PyObject *self_raw)
{
    WriterObject *self = (WriterObject *)self_raw;
    PyTypeObject *tp = Py_TYPE(self);
    if (self->writer) {
        PyUnicodeWriter_Discard(self->writer);
    }
    tp->tp_free(self);
    Py_DECREF(tp);
}


static inline int
writer_check(WriterObject *self)
{
    if (self->writer == NULL) {
        PyErr_SetString(PyExc_ValueError, "operation on finished writer");
        return -1;
    }
    return 0;
}


static PyObject*
writer_write_char(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    unsigned int ch;
    if (!PyArg_ParseTuple(args, "I", &ch)) {
        return NULL;
    }

    if (PyUnicodeWriter_WriteChar(self->writer, (Py_UCS4)ch) < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_write_utf8(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    const char *str;
    Py_ssize_t bsize, size;
    if (!PyArg_ParseTuple(args, "z#n", &str, &bsize, &size)) {
        return NULL;
    }

    if (PyUnicodeWriter_WriteUTF8(self->writer, str, size) < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_write_ascii(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    const char *str;
    Py_ssize_t bsize, size;
    if (!PyArg_ParseTuple(args, "z#n", &str, &bsize, &size)) {
        return NULL;
    }

    if (PyUnicodeWriter_WriteASCII(self->writer, str, size) < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_write_widechar(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    const char *s;
    Py_ssize_t bsize;
    Py_ssize_t size = -100;

    if (!PyArg_ParseTuple(args, "z#|n", &s, &bsize, &size)) {
        return NULL;
    }
    if (size == -100) {
        if (bsize % SIZEOF_WCHAR_T) {
            PyErr_SetString(PyExc_AssertionError,
                            "invalid size in writer.write_widechar()");
            return NULL;
        }
        size = bsize / SIZEOF_WCHAR_T;
    }

    int res = PyUnicodeWriter_WriteWideChar(self->writer, (const wchar_t *)s, size);
    if (res < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_write_ucs4(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    const char *s;
    Py_ssize_t bsize;
    Py_ssize_t size = -100;

    if (!PyArg_ParseTuple(args, "z#|n", &s, &bsize, &size)) {
        return NULL;
    }
    if (size == -100) {
        if (bsize % sizeof(Py_UCS4)) {
            PyErr_SetString(PyExc_AssertionError,
                            "invalid size in writer.write_ucs4()");
            return NULL;
        }
        size = bsize / sizeof(Py_UCS4);
    }

    int res = PyUnicodeWriter_WriteUCS4(self->writer, (const Py_UCS4 *)s, size);
    if (res < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_write_str(PyObject *self_raw, PyObject *obj)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    NULLABLE(obj);
    if (PyUnicodeWriter_WriteStr(self->writer, obj) < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_write_repr(PyObject *self_raw, PyObject *obj)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    NULLABLE(obj);
    if (PyUnicodeWriter_WriteRepr(self->writer, obj) < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


// write_repr(None) calls PyUnicodeWriter_WriteRepr(writer, NULL), so add
// a specialized function calling PyUnicodeWriter_WriteRepr(writer, Py_None).
static PyObject*
writer_write_repr_none(PyObject *self_raw, PyObject *Py_UNUSED(arg))
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    if (PyUnicodeWriter_WriteRepr(self->writer, Py_None) < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_write_substring(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    PyObject *str;
    Py_ssize_t start, end;
    if (!PyArg_ParseTuple(args, "Onn", &str, &start, &end)) {
        return NULL;
    }
    NULLABLE(str);

    if (PyUnicodeWriter_WriteSubstring(self->writer, str, start, end) < 0) {
        return NULL;
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_write_latin1(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    const char *str;
    Py_ssize_t bsize, size;
    if (!PyArg_ParseTuple(args, "z#n", &str, &bsize, &size)) {
        return NULL;
    }

    _PyUnicodeWriter *writer = (_PyUnicodeWriter*)self->writer;
_Py_COMP_DIAG_PUSH
_Py_COMP_DIAG_IGNORE_DEPR_DECLS
    if (_PyUnicodeWriter_WriteLatin1String(writer, str, size) < 0) {
        return NULL;
    }
_Py_COMP_DIAG_POP

    Py_RETURN_NONE;
}


static PyObject*
writer_decodeutf8stateful(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    const char *str;
    Py_ssize_t bsize, len;
    const char *errors;
    int use_consumed = 0;
    if (!PyArg_ParseTuple(args, "z#nz#|p", &str, &bsize, &len, &errors, &bsize, &use_consumed)) {
        return NULL;
    }

    Py_ssize_t consumed = 12345;
    Py_ssize_t *pconsumed = use_consumed ? &consumed : NULL;
    if (PyUnicodeWriter_DecodeUTF8Stateful(self->writer, str, len,
                                           errors, pconsumed) < 0) {
        if (use_consumed) {
            assert(consumed == 0);
        }
        return NULL;
    }

    if (use_consumed) {
        return PyLong_FromSsize_t(consumed);
    }
    Py_RETURN_NONE;
}


static PyObject*
writer_get_pointer(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    return PyLong_FromVoidPtr(self->writer);
}


static PyObject*
writer_get_buffer(PyObject *self_raw, PyObject *args)
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    _PyUnicodeWriter *writer = (_PyUnicodeWriter*)self->writer;
    PyObject *allocated;
    Py_UCS4 maxchar;
    if (writer->buffer) {
        allocated = PyLong_FromSsize_t(PyUnicode_GET_LENGTH(writer->buffer));
        maxchar = PyUnicode_MAX_CHAR_VALUE(writer->buffer);
    }
    else {
        allocated = Py_None;
        maxchar = writer->min_char;
    }
    return Py_BuildValue("(NkN)",
                         allocated, (unsigned long)maxchar,
                         PyBool_FromLong(writer->readonly));
}


static PyObject*
writer_finish(PyObject *self_raw, PyObject *Py_UNUSED(args))
{
    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    PyObject *str = PyUnicodeWriter_Finish(self->writer);
    self->writer = NULL;
    return str;
}


static PyObject*
writer_finish_with_size(PyObject *self_raw, PyObject *args)
{
    PyAPI_FUNC(PyObject*) _PyUnicodeWriter_FinishWithSize(
        _PyUnicodeWriter *writer,
        Py_ssize_t size);

    WriterObject *self = (WriterObject *)self_raw;
    if (writer_check(self) < 0) {
        return NULL;
    }

    Py_ssize_t size;
    if (!PyArg_ParseTuple(args, "n", &size)) {
        return NULL;
    }

    _PyUnicodeWriter *writer = (_PyUnicodeWriter*)self->writer;
    PyObject *str = _PyUnicodeWriter_FinishWithSize(writer, size);
    PyUnicodeWriter_Discard(self->writer);
    self->writer = NULL;
    return str;
}


static PyMethodDef writer_methods[] = {
    {"write_char", _PyCFunction_CAST(writer_write_char), METH_VARARGS},
    {"write_utf8", _PyCFunction_CAST(writer_write_utf8), METH_VARARGS},
    {"write_ascii", _PyCFunction_CAST(writer_write_ascii), METH_VARARGS},
    {"write_widechar", _PyCFunction_CAST(writer_write_widechar), METH_VARARGS},
    {"write_ucs4", _PyCFunction_CAST(writer_write_ucs4), METH_VARARGS},
    {"write_str", _PyCFunction_CAST(writer_write_str), METH_O},
    {"write_repr", _PyCFunction_CAST(writer_write_repr), METH_O},
    {"write_repr_none", _PyCFunction_CAST(writer_write_repr_none), METH_NOARGS},
    {"write_substring", _PyCFunction_CAST(writer_write_substring), METH_VARARGS},
    {"write_latin1", _PyCFunction_CAST(writer_write_latin1), METH_VARARGS},
    {"decodeutf8stateful", _PyCFunction_CAST(writer_decodeutf8stateful), METH_VARARGS},
    {"get_pointer", _PyCFunction_CAST(writer_get_pointer), METH_VARARGS},
    {"get_buffer", _PyCFunction_CAST(writer_get_buffer), METH_VARARGS},
    {"finish", _PyCFunction_CAST(writer_finish), METH_NOARGS},
    {"finish_with_size", _PyCFunction_CAST(writer_finish_with_size), METH_VARARGS},
    {NULL,              NULL}           /* sentinel */
};

static PyType_Slot Writer_Type_slots[] = {
    {Py_tp_new, writer_new},
    {Py_tp_init, writer_init},
    {Py_tp_dealloc, writer_dealloc},
    {Py_tp_methods, writer_methods},
    {0, 0},  /* sentinel */
};

static PyType_Spec Writer_spec = {
    .name = "_testcapi.PyUnicodeWriter",
    .basicsize = sizeof(WriterObject),
    .flags = Py_TPFLAGS_DEFAULT,
    .slots = Writer_Type_slots,
};


static PyMethodDef TestMethods[] = {
    {"unicode_new",              unicode_new,                    METH_VARARGS},
    {"unicode_fill",             _PyCFunction_CAST(unicode_fill), METH_VARARGS | METH_KEYWORDS},
    {"unicode_fromkindanddata",  unicode_fromkindanddata,        METH_VARARGS},
    {"unicode_asucs4",           unicode_asucs4,                 METH_VARARGS},
    {"unicode_asucs4copy",       unicode_asucs4copy,             METH_VARARGS},
    {"unicode_asutf8",           unicode_asutf8,                 METH_VARARGS},
    {"unicode_copycharacters",   _PyCFunction_CAST(unicode_copycharacters), METH_VARARGS | METH_KEYWORDS},
    {"unicode_GET_CACHED_HASH",  unicode_GET_CACHED_HASH,        METH_O},
    {"test_py_identifier",       test_py_identifier,             METH_NOARGS},
    {"corrupt_unicode",          corrupt_unicode,                METH_VARARGS},
    {"unicode_read_char",        unicode_read_char,              METH_VARARGS},
    {"unicode_read",             unicode_read,                   METH_VARARGS},
    {"unicode_write",            unicode_write,                  METH_VARARGS},
    {"unicode_kind",             unicode_kind,                   METH_O},
    {"unicode_max_char_value",   unicode_max_char_value,         METH_O},
    {"unicode_getlength_macro",  unicode_getlength_macro,        METH_O},
    {"unicode_equal",            unicode_equal,                  METH_VARARGS},
    {"unicode_check_interned",   unicode_check_interned,         METH_O},
    {"unicode_is_ascii",         unicode_is_ascii,               METH_O},
    {"unicode_is_compact",       unicode_is_compact,             METH_O},
    {"unicode_is_compact_ascii", unicode_is_compact_ascii,       METH_O},
    {NULL},
};

int
_PyTestCapi_Init_Unicode(PyObject *m) {
    if (PyModule_AddFunctions(m, TestMethods) < 0) {
        return -1;
    }

    PyTypeObject *writer_type = (PyTypeObject *)PyType_FromSpec(&Writer_spec);
    if (writer_type == NULL) {
        return -1;
    }
    if (PyModule_AddType(m, writer_type) < 0) {
        Py_DECREF(writer_type);
        return -1;
    }
    Py_DECREF(writer_type);

    return 0;
}