<?php

/*

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "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 THE COPYRIGHT

 * OWNER 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.

 *

 * This software consists of voluntary contributions made by many individuals

 * and is licensed under the LGPL. For more information, see

 * <http://www.doctrine-project.org>.

 */

namespace Doctrine\DBAL\Schema;

/**

 * Compare to Schemas and return an instance of SchemaDiff

 *

 * @copyright Copyright (C) 2005-2009 eZ Systems AS. All rights reserved.

 * @license http://ez.no/licenses/new_bsd New BSD License

 * @license http://www.opensource.org/licenses/lgpl-license.php LGPL

 * @link    www.doctrine-project.org

 * @since   2.0

 * @version $Revision$

 * @author  Benjamin Eberlei <kontakt@beberlei.de>

 */

class Comparator

{

    /**

     * @param Schema $fromSchema

     * @param Schema $toSchema

     * @return SchemaDiff

     */

    static public function compareSchemas( Schema $fromSchema, Schema $toSchema )

    {

        $c = new self();

        return $c->compare($fromSchema, $toSchema);

    }

    /**

     * Returns a SchemaDiff object containing the differences between the schemas $fromSchema and $toSchema.

     *

     * The returned diferences are returned in such a way that they contain the

     * operations to change the schema stored in $fromSchema to the schema that is

     * stored in $toSchema.

     *

     * @param Schema $fromSchema

     * @param Schema $toSchema

     *

     * @return SchemaDiff

     */

    public function compare(Schema $fromSchema, Schema $toSchema)

    {

        $diff = new SchemaDiff();

        $foreignKeysToTable = array();

        foreach ( $toSchema->getTables() AS $tableName => $table ) {

            if ( !$fromSchema->hasTable($tableName) ) {

                $diff->newTables[$tableName] = $table;

            } else {

                $tableDifferences = $this->diffTable( $fromSchema->getTable($tableName), $table );

                if ( $tableDifferences !== false ) {

                    $diff->changedTables[$tableName] = $tableDifferences;

                }

            }

        }

        /* Check if there are tables removed */

        foreach ( $fromSchema->getTables() AS $tableName => $table ) {

            if ( !$toSchema->hasTable($tableName) ) {

                $diff->removedTables[$tableName] = $table;

            }

            // also remember all foreign keys that point to a specific table

            foreach ($table->getForeignKeys() AS $foreignKey) {

                $foreignTable = strtolower($foreignKey->getForeignTableName());

                if (!isset($foreignKeysToTable[$foreignTable])) {

                    $foreignKeysToTable[$foreignTable] = array();

                }

                $foreignKeysToTable[$foreignTable][] = $foreignKey;

            }

        }

        foreach ($diff->removedTables AS $tableName => $table) {

            if (isset($foreignKeysToTable[$tableName])) {

                $diff->orphanedForeignKeys = array_merge($diff->orphanedForeignKeys, $foreignKeysToTable[$tableName]);

            }

        }

        foreach ( $toSchema->getSequences() AS $sequenceName => $sequence) {

            if (!$fromSchema->hasSequence($sequenceName)) {

                $diff->newSequences[] = $sequence;

            } else {

                if ($this->diffSequence($sequence, $fromSchema->getSequence($sequenceName))) {

                    $diff->changedSequences[] = $toSchema->getSequence($sequenceName);

                }

            }

        }

        foreach ($fromSchema->getSequences() AS $sequenceName => $sequence) {

            if (!$toSchema->hasSequence($sequenceName)) {

                $diff->removedSequences[] = $sequence;

            }

        }

        return $diff;

    }

    /**

     *

     * @param Sequence $sequence1

     * @param Sequence $sequence2

     */

    public function diffSequence(Sequence $sequence1, Sequence $sequence2)

    {

        if($sequence1->getAllocationSize() != $sequence2->getAllocationSize()) {

            return true;

        }

        if($sequence1->getInitialValue() != $sequence2->getInitialValue()) {

            return true;

        }

        return false;

    }

    /**

     * Returns the difference between the tables $table1 and $table2.

     *

     * If there are no differences this method returns the boolean false.

     *

     * @param Table $table1

     * @param Table $table2

     *

     * @return bool|TableDiff

     */

    public function diffTable(Table $table1, Table $table2)

    {

        $changes = 0;

        $tableDifferences = new TableDiff($table1->getName());

        $table1Columns = $table1->getColumns();

        $table2Columns = $table2->getColumns();

        /* See if all the fields in table 1 exist in table 2 */

        foreach ( $table2Columns as $columnName => $column ) {

            if ( !$table1->hasColumn($columnName) ) {

                $tableDifferences->addedColumns[$columnName] = $column;

                $changes++;

            }

        }

        /* See if there are any removed fields in table 2 */

        foreach ( $table1Columns as $columnName => $column ) {

            if ( !$table2->hasColumn($columnName) ) {

                $tableDifferences->removedColumns[$columnName] = $column;

                $changes++;

            }

        }

        foreach ( $table1Columns as $columnName => $column ) {

            if ( $table2->hasColumn($columnName) ) {

                $changedProperties = $this->diffColumn( $column, $table2->getColumn($columnName) );

                if (count($changedProperties) ) {

                    $columnDiff = new ColumnDiff($column->getName(), $table2->getColumn($columnName), $changedProperties);

                    $tableDifferences->changedColumns[$column->getName()] = $columnDiff;

                    $changes++;

                }

            }

        }

        $this->detectColumnRenamings($tableDifferences);

        $table1Indexes = $table1->getIndexes();

        $table2Indexes = $table2->getIndexes();

        foreach ($table2Indexes AS $index2Name => $index2Definition) {

            foreach ($table1Indexes AS $index1Name => $index1Definition) {

                if ($this->diffIndex($index1Definition, $index2Definition) === false) {

                    unset($table1Indexes[$index1Name]);

                    unset($table2Indexes[$index2Name]);

                } else {

                    if ($index1Name == $index2Name) {

                        $tableDifferences->changedIndexes[$index2Name] = $table2Indexes[$index2Name];

                        unset($table1Indexes[$index1Name]);

                        unset($table2Indexes[$index2Name]);

                        $changes++;

                    }

                }

            }

        }

        foreach ($table1Indexes AS $index1Name => $index1Definition) {

            $tableDifferences->removedIndexes[$index1Name] = $index1Definition;

            $changes++;

        }

        foreach ($table2Indexes AS $index2Name => $index2Definition) {

            $tableDifferences->addedIndexes[$index2Name] = $index2Definition;

            $changes++;

        }

        $fromFkeys = $table1->getForeignKeys();

        $toFkeys = $table2->getForeignKeys();

        foreach ($fromFkeys AS $key1 => $constraint1) {

            foreach ($toFkeys AS $key2 => $constraint2) {

                if($this->diffForeignKey($constraint1, $constraint2) === false) {

                    unset($fromFkeys[$key1]);

                    unset($toFkeys[$key2]);

                } else {

                    if (strtolower($constraint1->getName()) == strtolower($constraint2->getName())) {

                        $tableDifferences->changedForeignKeys[] = $constraint2;

                        $changes++;

                        unset($fromFkeys[$key1]);

                        unset($toFkeys[$key2]);

                    }

                }

            }

        }

        foreach ($fromFkeys AS $key1 => $constraint1) {

            $tableDifferences->removedForeignKeys[] = $constraint1;

            $changes++;

        }

        foreach ($toFkeys AS $key2 => $constraint2) {

            $tableDifferences->addedForeignKeys[] = $constraint2;

            $changes++;

        }

        return $changes ? $tableDifferences : false;

    }

    /**

     * Try to find columns that only changed their name, rename operations maybe cheaper than add/drop

     * however ambiguouties between different possibilites should not lead to renaming at all.

     * 

     * @param TableDiff $tableDifferences

     */

    private function detectColumnRenamings(TableDiff $tableDifferences)

    {

        $renameCandidates = array();

        foreach ($tableDifferences->addedColumns AS $addedColumnName => $addedColumn) {

            foreach ($tableDifferences->removedColumns AS $removedColumnName => $removedColumn) {

                if (count($this->diffColumn($addedColumn, $removedColumn)) == 0) {

                    $renameCandidates[$addedColumn->getName()][] = array($removedColumn, $addedColumn, $addedColumnName);

                }

            }

        }

        foreach ($renameCandidates AS $candidate => $candidateColumns) {

            if (count($candidateColumns) == 1) {

                list($removedColumn, $addedColumn) = $candidateColumns[0];

                $removedColumnName = strtolower($removedColumn->getName());

                $addedColumnName = strtolower($addedColumn->getName());

                $tableDifferences->renamedColumns[$removedColumnName] = $addedColumn;

                unset($tableDifferences->addedColumns[$addedColumnName]);

                unset($tableDifferences->removedColumns[$removedColumnName]);

            }

        }

    }

    /**

     * @param ForeignKeyConstraint $key1

     * @param ForeignKeyConstraint $key2

     * @return bool

     */

    public function diffForeignKey(ForeignKeyConstraint $key1, ForeignKeyConstraint $key2)

    {

        if (array_map('strtolower', $key1->getLocalColumns()) != array_map('strtolower', $key2->getLocalColumns())) {

            return true;

        }

        if (array_map('strtolower', $key1->getForeignColumns()) != array_map('strtolower', $key2->getForeignColumns())) {

            return true;

        }

        if ($key1->onUpdate() != $key2->onUpdate()) {

            return true;

        }

        if ($key1->onDelete() != $key2->onDelete()) {

            return true;

        }

        return false;

    }

    /**

     * Returns the difference between the fields $field1 and $field2.

     *

     * If there are differences this method returns $field2, otherwise the

     * boolean false.

     *

     * @param Column $column1

     * @param Column $column2

     *

     * @return array

     */

    public function diffColumn(Column $column1, Column $column2)

    {

        $changedProperties = array();

        if ( $column1->getType() != $column2->getType() ) {

            $changedProperties[] = 'type';

        }

        if ($column1->getNotnull() != $column2->getNotnull()) {

            $changedProperties[] = 'notnull';

        }

        if ($column1->getDefault() != $column2->getDefault()) {

            $changedProperties[] = 'default';

        }

        if ($column1->getUnsigned() != $column2->getUnsigned()) {

            $changedProperties[] = 'unsigned';

        }

        if ($column1->getType() instanceof \Doctrine\DBAL\Types\StringType) {

            // check if value of length is set at all, default value assumed otherwise.

            $length1 = $column1->getLength() ?: 255;

            $length2 = $column2->getLength() ?: 255;

            if ($length1 != $length2) {

                $changedProperties[] = 'length';

            }

            if ($column1->getFixed() != $column2->getFixed()) {

                $changedProperties[] = 'fixed';

            }

        }

        if ($column1->getType() instanceof \Doctrine\DBAL\Types\DecimalType) {

            if (($column1->getPrecision()?:10) != ($column2->getPrecision()?:10)) {

                $changedProperties[] = 'precision';

            }

            if ($column1->getScale() != $column2->getScale()) {

                $changedProperties[] = 'scale';

            }

        }

        if ($column1->getAutoincrement() != $column2->getAutoincrement()) {

            $changedProperties[] = 'autoincrement';

        }

        // only allow to delete comment if its set to '' not to null.

        if ($column1->getComment() !== null && $column1->getComment() != $column2->getComment()) {

            $changedProperties[] = 'comment';

        }

        return $changedProperties;

    }

    /**

     * Finds the difference between the indexes $index1 and $index2.

     *

     * Compares $index1 with $index2 and returns $index2 if there are any

     * differences or false in case there are no differences.

     *

     * @param Index $index1

     * @param Index $index2

     * @return bool

     */

    public function diffIndex(Index $index1, Index $index2)

    {

        if ($index1->isFullfilledBy($index2) && $index2->isFullfilledBy($index1)) {

            return false;

        }

        return true;

    }

}