/*
 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#include "config.h"
#include "SQLiteStatement.h"

#include "Logging.h"
#include "SQLValue.h"
#include <sqlite3.h>
#include <wtf/Assertions.h>
#include <wtf/text/StringImpl.h>

namespace WebCore {

#if SQLITE_VERSION_NUMBER < 3003009

// FIXME: This overload helps us compile with older versions of SQLite 3, but things like quotas will not work.
static inline int sqlite3_prepare16_v2(sqlite3* db, const void* zSql, int nBytes, sqlite3_stmt** ppStmt, const void** pzTail)
{
    return sqlite3_prepare16(db, zSql, nBytes, ppStmt, pzTail);
}

#endif

SQLiteStatement::SQLiteStatement(SQLiteDatabase& db, const String& sql)
    : m_database(db)
    , m_query(sql)
    , m_statement(0)
#ifndef NDEBUG
    , m_isPrepared(false)
#endif
{
}

SQLiteStatement::~SQLiteStatement()
{
    finalize();
}

int SQLiteStatement::prepare()
{
    ASSERT(!m_isPrepared);

    MutexLocker databaseLock(m_database.databaseMutex());
    if (m_database.isInterrupted())
        return SQLITE_INTERRUPT;

    const void* tail = 0;
    LOG(SQLDatabase, "SQL - prepare - %s", m_query.ascii().data());
    String strippedQuery = m_query.stripWhiteSpace();
    const UChar* nullTermed = strippedQuery.deprecatedCharactersWithNullTermination();
    int error = sqlite3_prepare16_v2(m_database.sqlite3Handle(), nullTermed, -1, &m_statement, &tail);

    // Starting with version 3.6.16, sqlite has a patch (http://www.sqlite.org/src/ci/256ec3c6af)
    // that should make sure sqlite3_prepare16_v2 doesn't return a SQLITE_SCHEMA error.
    // If we're using an older sqlite version, try to emulate the patch.
    if (error == SQLITE_SCHEMA) {
      sqlite3_finalize(m_statement);
      error = sqlite3_prepare16_v2(m_database.sqlite3Handle(), m_query.deprecatedCharactersWithNullTermination(), -1, &m_statement, &tail);
    }

    if (error != SQLITE_OK)
        LOG(SQLDatabase, "sqlite3_prepare16 failed (%i)\n%s\n%s", error, m_query.ascii().data(), sqlite3_errmsg(m_database.sqlite3Handle()));
    const UChar* ch = static_cast<const UChar*>(tail);
    if (ch && *ch)
        error = SQLITE_ERROR;
#ifndef NDEBUG
    m_isPrepared = error == SQLITE_OK;
#endif
    return error;
}

int SQLiteStatement::step()
{
    MutexLocker databaseLock(m_database.databaseMutex());
    if (m_database.isInterrupted())
        return SQLITE_INTERRUPT;
    //ASSERT(m_isPrepared);

    if (!m_statement)
        return SQLITE_OK;

    // The database needs to update its last changes count before each statement
    // in order to compute properly the lastChanges() return value.
    m_database.updateLastChangesCount();

    LOG(SQLDatabase, "SQL - step - %s", m_query.ascii().data());
    int error = sqlite3_step(m_statement);
    if (error != SQLITE_DONE && error != SQLITE_ROW) {
        LOG(SQLDatabase, "sqlite3_step failed (%i)\nQuery - %s\nError - %s", 
            error, m_query.ascii().data(), sqlite3_errmsg(m_database.sqlite3Handle()));
    }

    return error;
}
    
int SQLiteStatement::finalize()
{
#ifndef NDEBUG
    m_isPrepared = false;
#endif
    if (!m_statement)
        return SQLITE_OK;
    LOG(SQLDatabase, "SQL - finalize - %s", m_query.ascii().data());
    int result = sqlite3_finalize(m_statement);
    m_statement = 0;
    return result;
}

int SQLiteStatement::reset() 
{
    ASSERT(m_isPrepared);
    if (!m_statement)
        return SQLITE_OK;
    LOG(SQLDatabase, "SQL - reset - %s", m_query.ascii().data());
    return sqlite3_reset(m_statement);
}

bool SQLiteStatement::executeCommand()
{
    if (!m_statement && prepare() != SQLITE_OK)
        return false;
    ASSERT(m_isPrepared);
    if (step() != SQLITE_DONE) {
        finalize();
        return false;
    }
    finalize();
    return true;
}

bool SQLiteStatement::returnsAtLeastOneResult()
{
    if (!m_statement && prepare() != SQLITE_OK)
        return false;
    ASSERT(m_isPrepared);
    if (step() != SQLITE_ROW) {
        finalize();
        return false;
    }
    finalize();
    return true;

}

int SQLiteStatement::bindBlob(int index, const void* blob, int size)
{
    ASSERT(m_isPrepared);
    ASSERT(index > 0);
    ASSERT(static_cast<unsigned>(index) <= bindParameterCount());
    ASSERT(blob);
    ASSERT(size >= 0);

    if (!m_statement)
        return SQLITE_ERROR;

    return sqlite3_bind_blob(m_statement, index, blob, size, SQLITE_TRANSIENT);
}

int SQLiteStatement::bindBlob(int index, const String& text)
{
    // String::characters() returns 0 for the empty string, which SQLite
    // treats as a null, so we supply a non-null pointer for that case.
    UChar anyCharacter = 0;
    const UChar* characters;
    if (text.isEmpty() && !text.isNull())
        characters = &anyCharacter;
    else
        characters = text.characters();

    return bindBlob(index, characters, text.length() * sizeof(UChar));
}

int SQLiteStatement::bindText(int index, const String& text)
{
    ASSERT(m_isPrepared);
    ASSERT(index > 0);
    ASSERT(static_cast<unsigned>(index) <= bindParameterCount());

    // String::characters() returns 0 for the empty string, which SQLite
    // treats as a null, so we supply a non-null pointer for that case.
    UChar anyCharacter = 0;
    const UChar* characters;
    if (text.isEmpty() && !text.isNull())
        characters = &anyCharacter;
    else
        characters = text.characters();

    return sqlite3_bind_text16(m_statement, index, characters, sizeof(UChar) * text.length(), SQLITE_TRANSIENT);
}

int SQLiteStatement::bindInt(int index, int integer)
{
    ASSERT(m_isPrepared);
    ASSERT(index > 0);
    ASSERT(static_cast<unsigned>(index) <= bindParameterCount());

    return sqlite3_bind_int(m_statement, index, integer);
}

int SQLiteStatement::bindInt64(int index, int64_t integer)
{
    ASSERT(m_isPrepared);
    ASSERT(index > 0);
    ASSERT(static_cast<unsigned>(index) <= bindParameterCount());

    return sqlite3_bind_int64(m_statement, index, integer);
}

int SQLiteStatement::bindDouble(int index, double number)
{
    ASSERT(m_isPrepared);
    ASSERT(index > 0);
    ASSERT(static_cast<unsigned>(index) <= bindParameterCount());

    return sqlite3_bind_double(m_statement, index, number);
}

int SQLiteStatement::bindNull(int index)
{
    ASSERT(m_isPrepared);
    ASSERT(index > 0);
    ASSERT(static_cast<unsigned>(index) <= bindParameterCount());

    return sqlite3_bind_null(m_statement, index);
}

int SQLiteStatement::bindValue(int index, const SQLValue& value)
{
    switch (value.type()) {
        case SQLValue::StringValue:
            return bindText(index, value.string());
        case SQLValue::NumberValue:
            return bindDouble(index, value.number());
        case SQLValue::NullValue:
            return bindNull(index);
    }

    ASSERT_NOT_REACHED();
    return SQLITE_ERROR;
}

unsigned SQLiteStatement::bindParameterCount() const
{
    ASSERT(m_isPrepared);
    if (!m_statement)
        return 0;
    return sqlite3_bind_parameter_count(m_statement);
}

int SQLiteStatement::columnCount()
{
    ASSERT(m_isPrepared);
    if (!m_statement)
        return 0;
    return sqlite3_data_count(m_statement);
}

bool SQLiteStatement::isColumnNull(int col)
{
    ASSERT(col >= 0);
    if (!m_statement)
        if (prepareAndStep() != SQLITE_ROW)
            return false;
    if (columnCount() <= col)
        return false;

    return sqlite3_column_type(m_statement, col) == SQLITE_NULL;
}

bool SQLiteStatement::isColumnDeclaredAsBlob(int col)
{
    ASSERT(col >= 0);
    if (!m_statement) {
        if (prepare() != SQLITE_OK)
            return false;
    }

    return equalIgnoringCase(String("BLOB"), String(reinterpret_cast<const UChar*>(sqlite3_column_decltype16(m_statement, col))));
}

String SQLiteStatement::getColumnName(int col)
{
    ASSERT(col >= 0);
    if (!m_statement)
        if (prepareAndStep() != SQLITE_ROW)
            return String();
    if (columnCount() <= col)
        return String();
    return String(reinterpret_cast<const UChar*>(sqlite3_column_name16(m_statement, col)));
}

SQLValue SQLiteStatement::getColumnValue(int col)
{
    ASSERT(col >= 0);
    if (!m_statement)
        if (prepareAndStep() != SQLITE_ROW)
            return SQLValue();
    if (columnCount() <= col)
        return SQLValue();

    // SQLite is typed per value. optional column types are
    // "(mostly) ignored"
    sqlite3_value* value = sqlite3_column_value(m_statement, col);
    switch (sqlite3_value_type(value)) {
        case SQLITE_INTEGER:    // SQLValue and JS don't represent integers, so use FLOAT -case
        case SQLITE_FLOAT:
            return SQLValue(sqlite3_value_double(value));
        case SQLITE_BLOB:       // SQLValue and JS don't represent blobs, so use TEXT -case
        case SQLITE_TEXT: {
            const UChar* string = reinterpret_cast<const UChar*>(sqlite3_value_text16(value));
            return SQLValue(StringImpl::create8BitIfPossible(string));
        }
        case SQLITE_NULL:
            return SQLValue();
        default:
            break;
    }
    ASSERT_NOT_REACHED();
    return SQLValue();
}

String SQLiteStatement::getColumnText(int col)
{
    ASSERT(col >= 0);
    if (!m_statement)
        if (prepareAndStep() != SQLITE_ROW)
            return String();
    if (columnCount() <= col)
        return String();
    return String(reinterpret_cast<const UChar*>(sqlite3_column_text16(m_statement, col)), sqlite3_column_bytes16(m_statement, col) / sizeof(UChar));
}
    
double SQLiteStatement::getColumnDouble(int col)
{
    ASSERT(col >= 0);
    if (!m_statement)
        if (prepareAndStep() != SQLITE_ROW)
            return 0.0;
    if (columnCount() <= col)
        return 0.0;
    return sqlite3_column_double(m_statement, col);
}

int SQLiteStatement::getColumnInt(int col)
{
    ASSERT(col >= 0);
    if (!m_statement)
        if (prepareAndStep() != SQLITE_ROW)
            return 0;
    if (columnCount() <= col)
        return 0;
    return sqlite3_column_int(m_statement, col);
}

int64_t SQLiteStatement::getColumnInt64(int col)
{
    ASSERT(col >= 0);
    if (!m_statement)
        if (prepareAndStep() != SQLITE_ROW)
            return 0;
    if (columnCount() <= col)
        return 0;
    return sqlite3_column_int64(m_statement, col);
}

String SQLiteStatement::getColumnBlobAsString(int col)
{
    ASSERT(col >= 0);

    if (!m_statement && prepareAndStep() != SQLITE_ROW)
        return String();

    if (columnCount() <= col)
        return String();

    const void* blob = sqlite3_column_blob(m_statement, col);
    if (!blob)
        return String();

    int size = sqlite3_column_bytes(m_statement, col);
    if (size < 0)
        return String();

    ASSERT(!(size % sizeof(UChar)));
    return String(static_cast<const UChar*>(blob), size / sizeof(UChar));
}

void SQLiteStatement::getColumnBlobAsVector(int col, Vector<char>& result)
{
    ASSERT(col >= 0);

    if (!m_statement && prepareAndStep() != SQLITE_ROW) {
        result.clear();
        return;
    }

    if (columnCount() <= col) {
        result.clear();
        return;
    }

    const void* blob = sqlite3_column_blob(m_statement, col);
    if (!blob) {
        result.clear();
        return;
    }
        
    int size = sqlite3_column_bytes(m_statement, col);
    result.resize((size_t)size);
    for (int i = 0; i < size; ++i)
        result[i] = (static_cast<const unsigned char*>(blob))[i];
}

const void* SQLiteStatement::getColumnBlob(int col, int& size)
{
    ASSERT(col >= 0);

    size = 0;

    if (finalize() != SQLITE_OK)
        LOG(SQLDatabase, "Finalize failed");
    if (prepare() != SQLITE_OK) {
        LOG(SQLDatabase, "Prepare failed");
        return 0;
    }
    if (step() != SQLITE_ROW) {
        LOG(SQLDatabase, "Step wasn't a row");
        return 0;
    }

    if (columnCount() <= col)
        return 0;
        
    const void* blob = sqlite3_column_blob(m_statement, col);
    if (!blob)
        return 0;

    size = sqlite3_column_bytes(m_statement, col);
    return blob;
}

bool SQLiteStatement::returnTextResults(int col, Vector<String>& v)
{
    ASSERT(col >= 0);

    v.clear();

    if (m_statement)
        finalize();
    if (prepare() != SQLITE_OK)
        return false;

    while (step() == SQLITE_ROW)
        v.append(getColumnText(col));
    bool result = true;
    if (m_database.lastError() != SQLITE_DONE) {
        result = false;
        LOG(SQLDatabase, "Error reading results from database query %s", m_query.ascii().data());
    }
    finalize();
    return result;
}

bool SQLiteStatement::returnIntResults(int col, Vector<int>& v)
{
    v.clear();

    if (m_statement)
        finalize();
    if (prepare() != SQLITE_OK)
        return false;
        
    while (step() == SQLITE_ROW)
        v.append(getColumnInt(col));
    bool result = true;
    if (m_database.lastError() != SQLITE_DONE) {
        result = false;
        LOG(SQLDatabase, "Error reading results from database query %s", m_query.ascii().data());
    }
    finalize();
    return result;
}

bool SQLiteStatement::returnInt64Results(int col, Vector<int64_t>& v)
{
    v.clear();

    if (m_statement)
        finalize();
    if (prepare() != SQLITE_OK)
        return false;
        
    while (step() == SQLITE_ROW)
        v.append(getColumnInt64(col));
    bool result = true;
    if (m_database.lastError() != SQLITE_DONE) {
        result = false;
        LOG(SQLDatabase, "Error reading results from database query %s", m_query.ascii().data());
    }
    finalize();
    return result;
}

bool SQLiteStatement::returnDoubleResults(int col, Vector<double>& v)
{
    v.clear();

    if (m_statement)
        finalize();
    if (prepare() != SQLITE_OK)
        return false;

    while (step() == SQLITE_ROW)
        v.append(getColumnDouble(col));
    bool result = true;
    if (m_database.lastError() != SQLITE_DONE) {
        result = false;
        LOG(SQLDatabase, "Error reading results from database query %s", m_query.ascii().data());
    }
    finalize();
    return result;
}

bool SQLiteStatement::isExpired()
{
    return !m_statement || sqlite3_expired(m_statement);
}

} // namespace WebCore