/* statement.c - the statement type
 *
 * Copyright (C) 2005-2010 Gerhard Häring <gh@ghaering.de>
 *
 * This file is part of pysqlite.
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */

#include "statement.h"
#include "cursor.h"
#include "connection.h"
#include "microprotocols.h"
#include "prepare_protocol.h"
#include "util.h"

/* prototypes */
static int pysqlite_check_remaining_sql(const char* tail);

typedef enum {
 LINECOMMENT_1,
 IN_LINECOMMENT,
 COMMENTSTART_1,
 IN_COMMENT,
 COMMENTEND_1,
 NORMAL
} parse_remaining_sql_state;

typedef enum {
 TYPE_LONG,
 TYPE_FLOAT,
 TYPE_UNICODE,
 TYPE_BUFFER,
 TYPE_UNKNOWN
} parameter_type;

int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* connection, PyObject* sql)
{
 const char* tail;
 int rc;
 const char* sql_cstr;
 Py_ssize_t sql_cstr_len;
 const char* p;

 self->st = NULL;
 self->in_use = 0;

 sql_cstr = PyUnicode_AsUTF8AndSize(sql, &sql_cstr_len);
 if (sql_cstr == NULL) {
 rc = PYSQLITE_SQL_WRONG_TYPE;
 return rc;
 }
 if (strlen(sql_cstr) != (size_t)sql_cstr_len) {
 PyErr_SetString(PyExc_ValueError, "the query contains a null character");
 return PYSQLITE_SQL_WRONG_TYPE;
 }

 self->in_weakreflist = NULL;
 Py_INCREF(sql);
 self->sql = sql;

 /* Determine if the statement is a DML statement.
 SELECT is the only exception. See #9924. */
 self->is_dml = 0;
 for (p = sql_cstr; *p != 0; p++) {
 switch (*p) {
 case ' ':
 case '\r':
 case '\n':
 case '\t':
 continue;
 }

 self->is_dml = (PyOS_strnicmp(p, "insert", 6) == 0)
 || (PyOS_strnicmp(p, "update", 6) == 0)
 || (PyOS_strnicmp(p, "delete", 6) == 0)
 || (PyOS_strnicmp(p, "replace", 7) == 0);
 break;
 }

 Py_BEGIN_ALLOW_THREADS
 rc = sqlite3_prepare_v2(connection->db,
 sql_cstr,
 -1,
 &self->st,
 &tail);
 Py_END_ALLOW_THREADS

 self->db = connection->db;

 if (rc == SQLITE_OK && pysqlite_check_remaining_sql(tail)) {
 (void)sqlite3_finalize(self->st);
 self->st = NULL;
 rc = PYSQLITE_TOO_MUCH_SQL;
 }

 return rc;
}

int pysqlite_statement_bind_parameter(pysqlite_Statement* self, int pos, PyObject* parameter)
{
 int rc = SQLITE_OK;
 const char *string;
 Py_ssize_t buflen;
 parameter_type paramtype;

 if (parameter == Py_None) {
 rc = sqlite3_bind_null(self->st, pos);
 goto final;
 }

 if (PyLong_CheckExact(parameter)) {
 paramtype = TYPE_LONG;
 } else if (PyFloat_CheckExact(parameter)) {
 paramtype = TYPE_FLOAT;
 } else if (PyUnicode_CheckExact(parameter)) {
 paramtype = TYPE_UNICODE;
 } else if (PyLong_Check(parameter)) {
 paramtype = TYPE_LONG;
 } else if (PyFloat_Check(parameter)) {
 paramtype = TYPE_FLOAT;
 } else if (PyUnicode_Check(parameter)) {
 paramtype = TYPE_UNICODE;
 } else if (PyObject_CheckBuffer(parameter)) {
 paramtype = TYPE_BUFFER;
 } else {
 paramtype = TYPE_UNKNOWN;
 }

 switch (paramtype) {
 case TYPE_LONG: {
 sqlite_int64 value = _pysqlite_long_as_int64(parameter);
 if (value == -1 && PyErr_Occurred())
 rc = -1;
 else
 rc = sqlite3_bind_int64(self->st, pos, value);
 break;
 }
 case TYPE_FLOAT:
 rc = sqlite3_bind_double(self->st, pos, PyFloat_AsDouble(parameter));
 break;
 case TYPE_UNICODE:
 string = PyUnicode_AsUTF8AndSize(parameter, &buflen);
 if (string == NULL)
 return -1;
 if (buflen > INT_MAX) {
 PyErr_SetString(PyExc_OverflowError,
 "string longer than INT_MAX bytes");
 return -1;
 }
 rc = sqlite3_bind_text(self->st, pos, string, (int)buflen, SQLITE_TRANSIENT);
 break;
 case TYPE_BUFFER: {
 Py_buffer view;
 if (PyObject_GetBuffer(parameter, &view, PyBUF_SIMPLE) != 0) {
 PyErr_SetString(PyExc_ValueError, "could not convert BLOB to buffer");
 return -1;
 }
 if (view.len > INT_MAX) {
 PyErr_SetString(PyExc_OverflowError,
 "BLOB longer than INT_MAX bytes");
 PyBuffer_Release(&view);
 return -1;
 }
 rc = sqlite3_bind_blob(self->st, pos, view.buf, (int)view.len, SQLITE_TRANSIENT);
 PyBuffer_Release(&view);
 break;
 }
 case TYPE_UNKNOWN:
 rc = -1;
 }

final:
 return rc;
}

/* returns 0 if the object is one of Python's internal ones that don't need to be adapted */
static int _need_adapt(PyObject* obj)
{
 if (pysqlite_BaseTypeAdapted) {
 return 1;
 }

 if (PyLong_CheckExact(obj) || PyFloat_CheckExact(obj)
 || PyUnicode_CheckExact(obj) || PyByteArray_CheckExact(obj)) {
 return 0;
 } else {
 return 1;
 }
}

void pysqlite_statement_bind_parameters(pysqlite_Statement* self, PyObject* parameters)
{
 PyObject* current_param;
 PyObject* adapted;
 const char* binding_name;
 int i;
 int rc;
 int num_params_needed;
 Py_ssize_t num_params;

 Py_BEGIN_ALLOW_THREADS
 num_params_needed = sqlite3_bind_parameter_count(self->st);
 Py_END_ALLOW_THREADS

 if (PyTuple_CheckExact(parameters) || PyList_CheckExact(parameters) || (!PyDict_Check(parameters) && PySequence_Check(parameters))) {
 /* parameters passed as sequence */
 if (PyTuple_CheckExact(parameters)) {
 num_params = PyTuple_GET_SIZE(parameters);
 } else if (PyList_CheckExact(parameters)) {
 num_params = PyList_GET_SIZE(parameters);
 } else {
 num_params = PySequence_Size(parameters);
 }
 if (num_params != num_params_needed) {
 PyErr_Format(pysqlite_ProgrammingError,
 "Incorrect number of bindings supplied. The current "
 "statement uses %d, and there are %zd supplied.",
 num_params_needed, num_params);
 return;
 }
 for (i = 0; i < num_params; i++) {
 if (PyTuple_CheckExact(parameters)) {
 current_param = PyTuple_GET_ITEM(parameters, i);
 Py_XINCREF(current_param);
 } else if (PyList_CheckExact(parameters)) {
 current_param = PyList_GET_ITEM(parameters, i);
 Py_XINCREF(current_param);
 } else {
 current_param = PySequence_GetItem(parameters, i);
 }
 if (!current_param) {
 return;
 }

 if (!_need_adapt(current_param)) {
 adapted = current_param;
 } else {
 adapted = pysqlite_microprotocols_adapt(current_param, (PyObject*)&pysqlite_PrepareProtocolType, NULL);
 if (adapted) {
 Py_DECREF(current_param);
 } else {
 PyErr_Clear();
 adapted = current_param;
 }
 }

 rc = pysqlite_statement_bind_parameter(self, i + 1, adapted);
 Py_DECREF(adapted);

 if (rc != SQLITE_OK) {
 if (!PyErr_Occurred()) {
 PyErr_Format(pysqlite_InterfaceError, "Error binding parameter %d - probably unsupported type.", i);
 }
 return;
 }
 }
 } else if (PyDict_Check(parameters)) {
 /* parameters passed as dictionary */
 for (i = 1; i <= num_params_needed; i++) {
 Py_BEGIN_ALLOW_THREADS
 binding_name = sqlite3_bind_parameter_name(self->st, i);
 Py_END_ALLOW_THREADS
 if (!binding_name) {
 PyErr_Format(pysqlite_ProgrammingError, "Binding %d has no name, but you supplied a dictionary (which has only names).", i);
 return;
 }

 binding_name++; /* skip first char (the colon) */
 if (PyDict_CheckExact(parameters)) {
 current_param = PyDict_GetItemString(parameters, binding_name);
 Py_XINCREF(current_param);
 } else {
 current_param = PyMapping_GetItemString(parameters, binding_name);
 }
 if (!current_param) {
 PyErr_Format(pysqlite_ProgrammingError, "You did not supply a value for binding %d.", i);
 return;
 }

 if (!_need_adapt(current_param)) {
 adapted = current_param;
 } else {
 adapted = pysqlite_microprotocols_adapt(current_param, (PyObject*)&pysqlite_PrepareProtocolType, NULL);
 if (adapted) {
 Py_DECREF(current_param);
 } else {
 PyErr_Clear();
 adapted = current_param;
 }
 }

 rc = pysqlite_statement_bind_parameter(self, i, adapted);
 Py_DECREF(adapted);

 if (rc != SQLITE_OK) {
 if (!PyErr_Occurred()) {
 PyErr_Format(pysqlite_InterfaceError, "Error binding parameter :%s - probably unsupported type.", binding_name);
 }
 return;
 }
 }
 } else {
 PyErr_SetString(PyExc_ValueError, "parameters are of unsupported type");
 }
}

int pysqlite_statement_finalize(pysqlite_Statement* self)
{
 int rc;

 rc = SQLITE_OK;
 if (self->st) {
 Py_BEGIN_ALLOW_THREADS
 rc = sqlite3_finalize(self->st);
 Py_END_ALLOW_THREADS
 self->st = NULL;
 }

 self->in_use = 0;

 return rc;
}

int pysqlite_statement_reset(pysqlite_Statement* self)
{
 int rc;

 rc = SQLITE_OK;

 if (self->in_use && self->st) {
 Py_BEGIN_ALLOW_THREADS
 rc = sqlite3_reset(self->st);
 Py_END_ALLOW_THREADS

 if (rc == SQLITE_OK) {
 self->in_use = 0;
 }
 }

 return rc;
}

void pysqlite_statement_mark_dirty(pysqlite_Statement* self)
{
 self->in_use = 1;
}

void pysqlite_statement_dealloc(pysqlite_Statement* self)
{
 if (self->st) {
 Py_BEGIN_ALLOW_THREADS
 sqlite3_finalize(self->st);
 Py_END_ALLOW_THREADS
 }

 self->st = NULL;

 Py_XDECREF(self->sql);

 if (self->in_weakreflist != NULL) {
 PyObject_ClearWeakRefs((PyObject*)self);
 }

 Py_TYPE(self)->tp_free((PyObject*)self);
}

/*
 * Checks if there is anything left in an SQL string after SQLite compiled it.
 * This is used to check if somebody tried to execute more than one SQL command
 * with one execute()/executemany() command, which the DB-API and we don't
 * allow.
 *
 * Returns 1 if there is more left than should be. 0 if ok.
 */
static int pysqlite_check_remaining_sql(const char* tail)
{
 const char* pos = tail;

 parse_remaining_sql_state state = NORMAL;

 for (;;) {
 switch (*pos) {
 case 0:
 return 0;
 case '-':
 if (state == NORMAL) {
 state = LINECOMMENT_1;
 } else if (state == LINECOMMENT_1) {
 state = IN_LINECOMMENT;
 }
 break;
 case ' ':
 case '\t':
 break;
 case '\n':
 case 13:
 if (state == IN_LINECOMMENT) {
 state = NORMAL;
 }
 break;
 case '/':
 if (state == NORMAL) {
 state = COMMENTSTART_1;
 } else if (state == COMMENTEND_1) {
 state = NORMAL;
 } else if (state == COMMENTSTART_1) {
 return 1;
 }
 break;
 case '*':
 if (state == NORMAL) {
 return 1;
 } else if (state == LINECOMMENT_1) {
 return 1;
 } else if (state == COMMENTSTART_1) {
 state = IN_COMMENT;
 } else if (state == IN_COMMENT) {
 state = COMMENTEND_1;
 }
 break;
 default:
 if (state == COMMENTEND_1) {
 state = IN_COMMENT;
 } else if (state == IN_LINECOMMENT) {
 } else if (state == IN_COMMENT) {
 } else {
 return 1;
 }
 }

 pos++;
 }

 return 0;
}

PyTypeObject pysqlite_StatementType = {
 PyVarObject_HEAD_INIT(NULL, 0)
 MODULE_NAME ".Statement", /* tp_name */
 sizeof(pysqlite_Statement), /* tp_basicsize */
 0, /* tp_itemsize */
 (destructor)pysqlite_statement_dealloc, /* tp_dealloc */
 0, /* tp_print */
 0, /* tp_getattr */
 0, /* tp_setattr */
 0, /* tp_reserved */
 0, /* tp_repr */
 0, /* tp_as_number */
 0, /* tp_as_sequence */
 0, /* tp_as_mapping */
 0, /* tp_hash */
 0, /* tp_call */
 0, /* tp_str */
 0, /* tp_getattro */
 0, /* tp_setattro */
 0, /* tp_as_buffer */
 Py_TPFLAGS_DEFAULT, /* tp_flags */
 0, /* tp_doc */
 0, /* tp_traverse */
 0, /* tp_clear */
 0, /* tp_richcompare */
 offsetof(pysqlite_Statement, in_weakreflist), /* tp_weaklistoffset */
 0, /* tp_iter */
 0, /* tp_iternext */
 0, /* tp_methods */
 0, /* tp_members */
 0, /* tp_getset */
 0, /* tp_base */
 0, /* tp_dict */
 0, /* tp_descr_get */
 0, /* tp_descr_set */
 0, /* tp_dictoffset */
 (initproc)0, /* tp_init */
 0, /* tp_alloc */
 0, /* tp_new */
 0 /* tp_free */
};

extern int pysqlite_statement_setup_types(void)
{
 pysqlite_StatementType.tp_new = PyType_GenericNew;
 return PyType_Ready(&pysqlite_StatementType);
}