<?php
declare(strict_types=1);

/**
 * CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 * @link          https://cakephp.org CakePHP(tm) Project
 * @since         3.0.0
 * @license       https://opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Database\Schema;

use Cake\Core\Configure;
use Cake\Database\Exception\DatabaseException;
use PDO;

/**
 * Schema management/reflection features for Sqlite
 *
 * @internal
 */
class SqliteSchemaDialect extends SchemaDialect
{
    /**
     * Whether there is any table in this connection to SQLite containing sequences.
     *
     * @var bool
     */
    protected bool $_hasSequences;

    /**
     * Convert a column definition to the abstract types.
     *
     * The returned type will be a type that
     * Cake\Database\TypeFactory can handle.
     *
     * @param string $column The column type + length
     * @throws \Cake\Database\Exception\DatabaseException when unable to parse column type
     * @return array<string, mixed> Array of column information.
     */
    protected function _convertColumn(string $column): array
    {
        if ($column === '') {
            return ['type' => TableSchemaInterface::TYPE_TEXT, 'length' => null];
        }

        preg_match('/(unsigned)?\s*([a-z]+)(?:\(([0-9,]+)\))?/i', $column, $matches);
        if (!$matches) {
            throw new DatabaseException(sprintf('Unable to parse column type from `%s`', $column));
        }

        $unsigned = false;
        if (strtolower($matches[1]) === 'unsigned') {
            $unsigned = true;
        }

        $col = strtolower($matches[2]);
        $length = null;
        $precision = null;
        $scale = null;
        if (isset($matches[3])) {
            $length = $matches[3];
            if (str_contains($length, ',')) {
                [$length, $precision] = explode(',', $length);
            }
            $length = (int)$length;
            $precision = (int)$precision;
        }

        $type = $this->_applyTypeSpecificColumnConversion(
            $col,
            compact('length', 'precision', 'scale'),
        );
        if ($type !== null) {
            return $type;
        }

        if ($col === 'bigint') {
            return ['type' => TableSchemaInterface::TYPE_BIGINTEGER, 'length' => $length, 'unsigned' => $unsigned];
        }
        if ($col === 'smallint') {
            return ['type' => TableSchemaInterface::TYPE_SMALLINTEGER, 'length' => $length, 'unsigned' => $unsigned];
        }
        if ($col === 'tinyint') {
            return ['type' => TableSchemaInterface::TYPE_TINYINTEGER, 'length' => $length, 'unsigned' => $unsigned];
        }
        if (str_contains($col, 'int') && $col !== 'point') {
            return ['type' => TableSchemaInterface::TYPE_INTEGER, 'length' => $length, 'unsigned' => $unsigned];
        }
        if (str_contains($col, 'decimal')) {
            return [
                'type' => TableSchemaInterface::TYPE_DECIMAL,
                'length' => $length,
                'precision' => $precision,
                'unsigned' => $unsigned,
            ];
        }
        if (in_array($col, ['float', 'real', 'double'], true)) {
            return [
                'type' => TableSchemaInterface::TYPE_FLOAT,
                'length' => $length,
                'precision' => $precision,
                'unsigned' => $unsigned,
            ];
        }

        if (str_contains($col, 'boolean')) {
            return ['type' => TableSchemaInterface::TYPE_BOOLEAN, 'length' => null];
        }

        if (($col === 'binary' && $length === 16) || strtolower($column) === 'uuid_blob') {
            return ['type' => TableSchemaInterface::TYPE_BINARY_UUID, 'length' => null];
        }
        if (($col === 'char' && $length === 36) || $col === 'uuid') {
            return ['type' => TableSchemaInterface::TYPE_UUID, 'length' => null];
        }
        if ($col === 'char') {
            return ['type' => TableSchemaInterface::TYPE_CHAR, 'length' => $length];
        }
        if (str_contains($col, 'char')) {
            return ['type' => TableSchemaInterface::TYPE_STRING, 'length' => $length];
        }

        if (in_array($col, ['blob', 'clob', 'binary', 'varbinary'], true)) {
            return ['type' => TableSchemaInterface::TYPE_BINARY, 'length' => $length];
        }

        $datetimeTypes = [
            'date',
            'time',
            'timestamp',
            'timestampfractional',
            'timestamptimezone',
            'datetime',
            'datetimefractional',
        ];
        if (in_array($col, $datetimeTypes, true)) {
            return ['type' => $col, 'length' => null];
        }

        if (
            Configure::read('ORM.mapJsonTypeForSqlite') === true &&
            (
                str_contains($col, TableSchemaInterface::TYPE_JSON) &&
                !str_contains($col, 'jsonb')
            )
        ) {
            return ['type' => TableSchemaInterface::TYPE_JSON, 'length' => null];
        }

        if (in_array($col, TableSchemaInterface::GEOSPATIAL_TYPES, true)) {
            // TODO how can srid be preserved? It doesn't come back
            // in the output of show full columns from ...
            return [
                'type' => $col,
                'length' => null,
            ];
        }

        return ['type' => TableSchemaInterface::TYPE_TEXT, 'length' => null];
    }

    /**
     * Generate the SQL to list the tables and views.
     *
     * @param array<string, mixed> $config The connection configuration to use for
     *    getting tables from.
     * @return array An array of (sql, params) to execute.
     */
    public function listTablesSql(array $config): array
    {
        return [
            'SELECT name FROM sqlite_master ' .
            'WHERE (type="table" OR type="view") ' .
            'AND name != "sqlite_sequence" ORDER BY name',
            [],
        ];
    }

    /**
     * Generate the SQL to list the tables, excluding all views.
     *
     * @param array<string, mixed> $config The connection configuration to use for
     *    getting tables from.
     * @return array<mixed> An array of (sql, params) to execute.
     */
    public function listTablesWithoutViewsSql(array $config): array
    {
        return [
            'SELECT name FROM sqlite_master WHERE type="table" ' .
            'AND name != "sqlite_sequence" ORDER BY name',
            [],
        ];
    }

    /**
     * @inheritDoc
     */
    public function describeColumnSql(string $tableName, array $config): array
    {
        $sql = $this->describeColumnQuery($tableName);

        return [$sql, []];
    }

    /**
     * @inheritDoc
     */
    public function convertColumnDescription(TableSchema $schema, array $row): void
    {
        $field = $this->_convertColumn($row['type']);
        $field += [
            'null' => !$row['notnull'],
            'default' => $this->_defaultValue($row['dflt_value'], $row['type']),
        ];
        $primary = $schema->getConstraint('primary');

        if ($row['pk'] && empty($primary)) {
            $field['null'] = false;
            $field['autoIncrement'] = true;
        }

        // SQLite does not support autoincrement on composite keys.
        if ($row['pk'] && !empty($primary)) {
            $existingColumn = $primary['columns'][0];
            $schema->addColumn($existingColumn, ['autoIncrement' => null] + $schema->getColumn($existingColumn));
        }

        $schema->addColumn($row['name'], $field);
        if ($row['pk']) {
            $constraint = (array)$schema->getConstraint('primary') + [
                'type' => TableSchema::CONSTRAINT_PRIMARY,
                'columns' => [],
            ];
            $constraint['columns'] = array_merge($constraint['columns'], [$row['name']]);
            $schema->addConstraint('primary', $constraint);
        }
    }

    /**
     * Helper method for creating SQL to describe columns in a table.
     *
     * @param string $tableName The table to describe.
     * @return string SQL to reflect columns
     */
    private function describeColumnQuery(string $tableName): string
    {
        $pragma = 'table_xinfo';
        if (version_compare($this->_driver->version(), '3.26.0', '<')) {
            $pragma = 'table_info';
        }

        return sprintf(
            'PRAGMA %s(%s)',
            $pragma,
            $this->_driver->quoteIdentifier($tableName),
        );
    }

    /**
     * @inheritDoc
     */
    public function describeColumns(string $tableName): array
    {
        if (str_contains($tableName, '.')) {
            [, $tableName] = explode('.', $tableName);
        }
        $sql = $this->describeColumnQuery($tableName);
        $columns = [];
        $statement = $this->_driver->execute($sql);
        $primary = [];
        foreach ($statement->fetchAll('assoc') as $i => $row) {
            $name = $row['name'];
            $field = $this->_convertColumn($row['type']);
            $field += [
                'name' => $name,
                'null' => !$row['notnull'],
                'default' => $this->_defaultValue($row['dflt_value'], $row['type']),
                'comment' => null,
                'length' => null,
            ];
            if ($row['pk']) {
                $primary[] = $i;
            }
            $columns[] = $field;
        }
        // If sqlite has a single primary column, it can be marked as autoIncrement
        if (count($primary) == 1) {
            $offset = $primary[0];
            $columns[$offset]['autoIncrement'] = true;
            $columns[$offset]['null'] = false;
        }

        return $columns;
    }

    /**
     * Manipulate the default value.
     *
     * Sqlite includes quotes and bared NULLs in default values.
     * We need to remove those.
     *
     * @param string|int|null $default The default value.
     * @param string|null $type The column type.
     * @return string|int|null
     */
    protected function _defaultValue(string|int|null $default, ?string $type = null): string|int|null
    {
        if ($default === 'NULL' || $default === null) {
            return null;
        }

        if ($type !== null && strtolower($type) === TableSchemaInterface::TYPE_BOOLEAN) {
            if ($default === '0' || $default === '1') {
                return (int)$default;
            }

            return (int)filter_var($default, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
        }

        // Remove quotes
        if (is_string($default) && preg_match("/^'(.*)'$/", $default, $matches)) {
            return str_replace("''", "'", $matches[1]);
        }

        return $default;
    }

    /**
     * @inheritDoc
     */
    public function describeIndexSql(string $tableName, array $config): array
    {
        $sql = $this->describeIndexQuery($tableName);

        return [$sql, []];
    }

    /**
     * Generates a regular expression to match identifiers that may or
     * may not be quoted with any of the supported quotes.
     *
     * @param string $identifier The identifier to match.
     * @return string
     */
    protected function possiblyQuotedIdentifierRegex(string $identifier): string
    {
        // Trim all quoting characters from the provided identifier,
        // and double all quotes up because that's how sqlite returns them.
        $identifier = trim($identifier, '\'"`[]');
        $identifier = str_replace(["'", '"', '`'], ["''", '""', '``'], $identifier);
        $quoted = preg_quote($identifier, '/');

        return "[\['\"`]?{$quoted}[\]'\"`]?";
    }

    /**
     * Removes possible escape characters and surrounding quotes from
     * identifiers.
     *
     * @param string $value The identifier to normalize.
     * @return string
     */
    protected function normalizePossiblyQuotedIdentifier(string $value): string
    {
        $value = trim($value);

        if (str_starts_with($value, '[') && str_ends_with($value, ']')) {
            return mb_substr($value, 1, -1);
        }

        foreach (['`', "'", '"'] as $quote) {
            if (str_starts_with($value, $quote) && str_ends_with($value, $quote)) {
                $value = str_replace($quote . $quote, $quote, $value);

                return mb_substr($value, 1, -1);
            }
        }

        return $value;
    }

    /**
     * {@inheritDoc}
     *
     * Since SQLite does not have a way to get metadata about all indexes at once,
     * additional queries are done here. Sqlite constraint names are not
     * stable, and the names for constraints will not match those used to create
     * the table. This is a limitation in Sqlite's metadata features.
     *
     * @param \Cake\Database\Schema\TableSchema $schema The table object to append
     *    an index or constraint to.
     * @param array $row The row data from `describeIndexSql`.
     * @return void
     * @deprecated 5.2.0 Use `describeIndexes` instead.
     */
    public function convertIndexDescription(TableSchema $schema, array $row): void
    {
        // Skip auto-indexes created for non-ROWID primary keys.
        if (($row['origin'] ?? null) === 'pk') {
            return;
        }

        $sql = sprintf(
            'PRAGMA index_info(%s)',
            $this->_driver->quoteIdentifier($row['name']),
        );
        $statement = $this->_driver->execute($sql);
        $columns = [];
        foreach ($statement->fetchAll(PDO::FETCH_ASSOC) as $column) {
            $columns[] = $column['name'];
        }
        if ($row['unique']) {
            if (($row['origin'] ?? null) === 'u') {
                $createTableSql = $this->getCreateTableSql($schema->name());
                $name = $this->extractIndexName($createTableSql, 'UNIQUE', $columns);
                if ($name !== null) {
                    $row['name'] = $name;
                }
            }

            $schema->addConstraint($row['name'], [
                'type' => TableSchema::CONSTRAINT_UNIQUE,
                'columns' => $columns,
            ]);
        } else {
            $schema->addIndex($row['name'], [
                'type' => TableSchema::INDEX_INDEX,
                'columns' => $columns,
            ]);
        }
    }

    /**
     * Helper method for creating SQL to reflect indexes in a table.
     *
     * @param string $tableName The table to get indexes from.
     * @return string SQL to reflect indexes
     */
    private function describeIndexQuery(string $tableName): string
    {
        return sprintf(
            'PRAGMA index_list(%s)',
            $this->_driver->quoteIdentifier($tableName),
        );
    }

    /**
     * Try to extract the original constraint name from table sql.
     *
     * @param string $tableSql The create table statement
     * @param string $type The type of index/constraint
     * @param array $columns The columns in the index.
     * @return string|null The name of the unique index if it could be inferred.
     */
    private function extractIndexName(string $tableSql, string $type, array $columns): ?string
    {
        $columnsPattern = implode(
            '\s*,\s*',
            array_map(
                fn($column) => '(?:' . $this->possiblyQuotedIdentifierRegex($column) . ')',
                $columns,
            ),
        );

        $regex = "/CONSTRAINT\s*(?<name>.+?)\s*{$type}\s*\(\s*{$columnsPattern}\s*\)/i";
        if (preg_match($regex, $tableSql, $matches)) {
            return $this->normalizePossiblyQuotedIdentifier($matches['name']);
        }

        return null;
    }

    /**
     * Try to extract the deferrable clause from the table SQL.
     *
     * @param string $tableSql The create table statement
     * @param array $columns The columns in the index.
     * @return string|null The name of the unique index if it could be inferred.
     */
    private function extractDeferrable(string $tableSql, array $columns): ?string
    {
        $columnsPattern = implode(
            '\s*,\s*',
            array_map(
                fn($column) => '(?:' . $this->possiblyQuotedIdentifierRegex($column) . ')',
                $columns,
            ),
        );
        $regex = "/CONSTRAINT\s*(?<name>.+?)\s*FOREIGN\s+KEY\s*\(\s*{$columnsPattern}\s*\).*?' .
            '(?<deferable>((?:NOT\s+)?DEFERRABLE)?(?:\s+INITIALLY\s+(DEFERRED|IMMEDIATE)))?/i";

        if (preg_match($regex, $tableSql, $matches)) {
            return match ($matches['deferable']) {
                'NOT DEFERRABLE' => ForeignKey::NOT_DEFERRED,
                'DEFERRABLE INITIALLY DEFERRED' => ForeignKey::DEFERRED,
                'DEFERRABLE INITIALLY IMMEDIATE' => ForeignKey::IMMEDIATE,
                default => null,
            };
        }

        return null;
    }

    /**
     * Get the normalized SQL query used to create a table.
     *
     * @param string $tableName The tablename
     * @return string
     */
    private function getCreateTableSql(string $tableName): string
    {
        $masterSql = "SELECT sql FROM sqlite_master WHERE \"type\" = 'table' AND \"name\" = ?";
        $statement = $this->_driver->execute($masterSql, [$tableName]);
        $result = $statement->fetchColumn(0);

        return $result ?: '';
    }

    /**
     * @inheritDoc
     */
    public function describeIndexes(string $tableName): array
    {
        if (str_contains($tableName, '.')) {
            [, $tableName] = explode('.', $tableName);
        }
        $sql = $this->describeIndexQuery($tableName);
        $statement = $this->_driver->execute($sql);
        $indexes = [];
        $createTableSql = $this->getCreateTableSql($tableName);

        $foundPrimary = false;
        foreach ($statement->fetchAll('assoc') as $row) {
            $indexName = $row['name'];
            $indexSql = sprintf(
                'PRAGMA index_info(%s)',
                $this->_driver->quoteIdentifier($indexName),
            );
            $columns = [];
            $indexData = $this->_driver->execute($indexSql)->fetchAll('assoc');
            foreach ($indexData as $indexItem) {
                $columns[] = $indexItem['name'];
            }

            $indexType = TableSchema::INDEX_INDEX;
            if ($row['unique']) {
                $indexType = TableSchema::CONSTRAINT_UNIQUE;
            }
            if (($row['origin'] ?? null) === 'pk') {
                $indexType = TableSchema::CONSTRAINT_PRIMARY;
                $foundPrimary = true;
            }
            if ($indexType == TableSchema::CONSTRAINT_UNIQUE) {
                $name = $this->extractIndexName($createTableSql, 'UNIQUE', $columns);
                if ($name !== null) {
                    $indexName = $name;
                }
            }

            $indexes[$indexName] = [
                'name' => $indexName,
                'type' => $indexType,
                'columns' => $columns,
                'length' => [],
            ];
        }
        // Primary keys aren't always available from the index_info pragma
        // instead we have to read the columns again.
        if (!$foundPrimary) {
            $sql = $this->describeColumnQuery($tableName);
            $statement = $this->_driver->execute($sql);
            foreach ($statement->fetchAll('assoc') as $row) {
                if (!$row['pk']) {
                    continue;
                }
                if (!isset($indexes['primary'])) {
                    $indexes['primary'] = [
                        'name' => 'primary',
                        'type' => TableSchema::CONSTRAINT_PRIMARY,
                        'columns' => [],
                        'length' => [],
                    ];
                }
                $indexes['primary']['columns'][] = $row['name'];
            }
        }

        return array_values($indexes);
    }

    /**
     * @inheritDoc
     */
    public function describeForeignKeySql(string $tableName, array $config): array
    {
        $sql = sprintf(
            'SELECT id FROM pragma_foreign_key_list(%s) GROUP BY id',
            $this->_driver->quoteIdentifier($tableName),
        );

        return [$sql, []];
    }

    /**
     * @inheritDoc
     */
    public function convertForeignKeyDescription(TableSchema $schema, array $row): void
    {
        $sql = sprintf(
            'SELECT * FROM pragma_foreign_key_list(%s) WHERE id = %d ORDER BY seq',
            $this->_driver->quoteIdentifier($schema->name()),
            $row['id'],
        );
        $statement = $this->_driver->prepare($sql);
        $statement->execute();

        $data = [
            'type' => TableSchema::CONSTRAINT_FOREIGN,
            'columns' => [],
            'references' => [],
        ];

        $foreignKey = null;
        foreach ($statement->fetchAll(PDO::FETCH_ASSOC) as $foreignKey) {
            $data['columns'][] = $foreignKey['from'];
            $data['references'][] = $foreignKey['to'];
        }

        if (count($data['references']) === 1) {
            $data['references'] = [$foreignKey['table'], $data['references'][0]];
        } else {
            $data['references'] = [$foreignKey['table'], $data['references']];
        }
        $data['update'] = $this->_convertOnClause($foreignKey['on_update'] ?? '');
        $data['delete'] = $this->_convertOnClause($foreignKey['on_delete'] ?? '');

        $name = implode('_', $data['columns']) . '_' . $row['id'] . '_fk';

        $schema->addConstraint($name, $data);
    }

    /**
     * @inheritDoc
     */
    public function describeForeignKeys(string $tableName): array
    {
        if (str_contains($tableName, '.')) {
            [, $tableName] = explode('.', $tableName);
        }

        $keys = [];
        $sql = sprintf('PRAGMA foreign_key_list(%s)', $this->_driver->quoteIdentifier($tableName));
        $statement = $this->_driver->execute($sql);
        foreach ($statement->fetchAll('assoc') as $row) {
            $id = $row['id'];
            if (!isset($keys[$id])) {
                $keys[$id] = [
                    'name' => $id,
                    'type' => TableSchema::CONSTRAINT_FOREIGN,
                    'columns' => [],
                    'references' => [$row['table'], []],
                    'update' => $this->_convertOnClause($row['on_update'] ?? ''),
                    'delete' => $this->_convertOnClause($row['on_delete'] ?? ''),
                    'deferrable' => null,
                ];
            }
            $keys[$id]['columns'][$row['seq']] = $row['from'];
            $keys[$id]['references'][1][$row['seq']] = $row['to'];
        }

        $createTableSql = $this->getCreateTableSql($tableName);
        foreach ($keys as $id => $data) {
            // sqlite doesn't provide a simple way to get foreign key names, but we
            // can extract them from the normalized create table sql.
            $name = $this->extractIndexName($createTableSql, 'FOREIGN\s*KEY', $data['columns']);
            if ($name === null) {
                $name = implode('_', $data['columns']) . '_' . $id . '_fk';
            }
            $keys[$id]['name'] = $name;

            // Collapse single columns to a string.
            // Long term this should go away, as we can narrow the types on `references`
            if (count($data['references'][1]) === 1) {
                $keys[$id]['references'][1] = $data['references'][1][0];
            }

            // sqlite doesn't provide a simple way to get foreign key names, but we
            // can extract them from the normalized create table sql.
            $keys[$id]['deferrable'] = $this->extractDeferrable($createTableSql, $data['columns']);
        }

        return array_values($keys);
    }

    /**
     * @inheritDoc
     */
    public function describeCheckConstraints(string $tableName): array
    {
        $constraints = [];
        $createSql = $this->getCreateTableSql($tableName);

        // Parse CHECK constraints from CREATE TABLE statement
        // Match CONSTRAINT name CHECK (expression) or just CHECK (expression)
        $pattern = '/(?:CONSTRAINT\s+([^\s]+)\s+)?CHECK\s*\(([^)]+(?:\([^)]*\)[^)]*)*)\)/is';

        if (preg_match_all($pattern, $createSql, $matches, PREG_SET_ORDER)) {
            foreach ($matches as $index => $match) {
                $name = !empty($match[1])
                    ? trim($match[1], '"`[]')
                    : 'check_' . $index;
                $expression = trim($match[2]);

                $constraints[] = [
                    'name' => $name,
                    'type' => TableSchema::CONSTRAINT_CHECK,
                    'expression' => $expression,
                ];
            }
        }

        return $constraints;
    }

    /**
     * @inheritDoc
     */
    public function describeOptions(string $tableName): array
    {
        return [];
    }

    /**
     * {@inheritDoc}
     *
     * @param \Cake\Database\Schema\TableSchema $schema The table instance the column is in.
     * @param string $name The name of the column.
     * @return string SQL fragment.
     * @throws \Cake\Database\Exception\DatabaseException when the column type is unknown
     */
    public function columnSql(TableSchema $schema, string $name): string
    {
        $data = $schema->getColumn($name);
        assert($data !== null);

        $sql = $this->_getTypeSpecificColumnSql($data['type'], $schema, $name);
        if ($sql !== null) {
            return $sql;
        }

        $data['name'] = $name;
        $autoIncrementTypes = [
            TableSchemaInterface::TYPE_TINYINTEGER,
            TableSchemaInterface::TYPE_SMALLINTEGER,
            TableSchemaInterface::TYPE_INTEGER,
            TableSchemaInterface::TYPE_BIGINTEGER,
        ];
        $primaryKey = $schema->getPrimaryKey();
        if (
            in_array($data['type'], $autoIncrementTypes, true) &&
            $primaryKey === [$name]
        ) {
            $data['autoIncrement'] = true;
        }
        // Composite autoincrement columns are not supported.
        if (count($primaryKey) > 1) {
            unset($data['autoIncrement']);
        }

        return $this->columnDefinitionSql($data);
    }

    /**
     * Create a SQL snippet for a column based on the array shape
     * that `describeColumns()` creates.
     *
     * @param array $column The column metadata
     * @return string Generated SQL fragment for a column
     */
    public function columnDefinitionSql(array $column): string
    {
        $name = $column['name'];
        $column += [
            'length' => null,
            'precision' => null,
        ];
        $typeMap = [
            TableSchemaInterface::TYPE_BINARY_UUID => ' BINARY(16)',
            TableSchemaInterface::TYPE_BINARY => ' BLOB',
            TableSchemaInterface::TYPE_UUID => ' CHAR(36)',
            TableSchemaInterface::TYPE_CHAR => ' CHAR',
            TableSchemaInterface::TYPE_STRING => ' VARCHAR',
            TableSchemaInterface::TYPE_TINYINTEGER => ' TINYINT',
            TableSchemaInterface::TYPE_SMALLINTEGER => ' SMALLINT',
            TableSchemaInterface::TYPE_INTEGER => ' INTEGER',
            TableSchemaInterface::TYPE_BIGINTEGER => ' BIGINT',
            TableSchemaInterface::TYPE_BOOLEAN => ' BOOLEAN',
            TableSchemaInterface::TYPE_FLOAT => ' FLOAT',
            TableSchemaInterface::TYPE_DECIMAL => ' DECIMAL',
            TableSchemaInterface::TYPE_DATE => ' DATE',
            TableSchemaInterface::TYPE_TIME => ' TIME',
            TableSchemaInterface::TYPE_DATETIME => ' DATETIME',
            TableSchemaInterface::TYPE_DATETIME_FRACTIONAL => ' DATETIMEFRACTIONAL',
            TableSchemaInterface::TYPE_TIMESTAMP => ' TIMESTAMP',
            TableSchemaInterface::TYPE_TIMESTAMP_FRACTIONAL => ' TIMESTAMPFRACTIONAL',
            TableSchemaInterface::TYPE_TIMESTAMP_TIMEZONE => ' TIMESTAMPTIMEZONE',
            TableSchemaInterface::TYPE_JSON => ' TEXT',
            TableSchemaInterface::TYPE_GEOMETRY => ' GEOMETRY_TEXT',
            TableSchemaInterface::TYPE_POINT => ' POINT_TEXT',
            TableSchemaInterface::TYPE_LINESTRING => ' LINESTRING_TEXT',
            TableSchemaInterface::TYPE_POLYGON => ' POLYGON_TEXT',
        ];

        $out = $this->_driver->quoteIdentifier($name);
        $hasUnsigned = [
            TableSchemaInterface::TYPE_TINYINTEGER,
            TableSchemaInterface::TYPE_SMALLINTEGER,
            TableSchemaInterface::TYPE_INTEGER,
            TableSchemaInterface::TYPE_BIGINTEGER,
            TableSchemaInterface::TYPE_FLOAT,
            TableSchemaInterface::TYPE_DECIMAL,
        ];

        $autoIncrement = (bool)($column['autoIncrement'] ?? false);
        if (
            !$autoIncrement &&
            isset($column['unsigned']) && $column['unsigned'] === true &&
            in_array($column['type'], $hasUnsigned, true)
        ) {
            $out .= ' UNSIGNED';
        }

        $foundType = false;
        if (isset($typeMap[$column['type']])) {
            $out .= $typeMap[$column['type']];
            $foundType = true;
        }

        $hasLength = [
            TableSchemaInterface::TYPE_BINARY,
            TableSchemaInterface::TYPE_STRING,
            TableSchemaInterface::TYPE_CHAR,
            TableSchemaInterface::TYPE_TINYINTEGER,
            TableSchemaInterface::TYPE_SMALLINTEGER,
            TableSchemaInterface::TYPE_INTEGER,
        ];
        if ($column['type'] === TableSchemaInterface::TYPE_TEXT && $column['length'] !== TableSchema::LENGTH_TINY) {
            $out .= ' TEXT';
            $foundType = true;
        } elseif (
            $column['type'] === TableSchemaInterface::TYPE_TEXT &&
            $column['length'] === TableSchema::LENGTH_TINY
        ) {
            $out .= ' VARCHAR';
            $hasLength[] = $column['type'];
            $foundType = true;
        }
        if (!$foundType) {
            $out .= ' ' . strtoupper($column['type']);
            $hasLength[] = $column['type'];
        }

        if (in_array($column['type'], $hasLength, true) && isset($column['length']) && !$autoIncrement) {
            $out .= '(' . (int)$column['length'] . ')';
        }

        $hasPrecision = [TableSchemaInterface::TYPE_FLOAT, TableSchemaInterface::TYPE_DECIMAL];
        if (
            in_array($column['type'], $hasPrecision, true) &&
            (
                isset($column['length']) ||
                isset($column['precision'])
            )
        ) {
            $out .= '(' . (int)$column['length'] . ',' . (int)$column['precision'] . ')';
        }

        if (isset($column['null']) && $column['null'] === false) {
            $out .= ' NOT NULL';
        }

        if ($column['type'] === TableSchemaInterface::TYPE_INTEGER && $autoIncrement) {
            $out .= ' PRIMARY KEY AUTOINCREMENT';
            unset($column['default']);
        }

        $timestampTypes = [
            TableSchemaInterface::TYPE_DATETIME,
            TableSchemaInterface::TYPE_DATETIME_FRACTIONAL,
            TableSchemaInterface::TYPE_TIMESTAMP,
            TableSchemaInterface::TYPE_TIMESTAMP_FRACTIONAL,
            TableSchemaInterface::TYPE_TIMESTAMP_TIMEZONE,
        ];
        if (isset($column['null']) && $column['null'] === true && in_array($column['type'], $timestampTypes, true)) {
            $out .= ' DEFAULT NULL';
        }
        if (isset($column['default'])) {
            $out .= ' DEFAULT ' . $this->_driver->schemaValue($column['default']);
        }
        if (isset($column['comment']) && $column['comment']) {
            $out .= " /* {$column['comment']} */";
        }

        return $out;
    }

    /**
     * {@inheritDoc}
     *
     * Note integer primary keys will return ''. This is intentional as Sqlite requires
     * that integer primary keys be defined in the column definition.
     *
     * @param \Cake\Database\Schema\TableSchema $schema The table instance the column is in.
     * @param string $name The name of the column.
     * @return string SQL fragment.
     */
    public function constraintSql(TableSchema $schema, string $name): string
    {
        $data = $schema->getConstraint($name);
        assert($data !== null, 'Data does not exist');

        $columns = '';
        if (isset($data['columns'])) {
            $column = $schema->getColumn($data['columns'][0]);
            assert($column !== null, 'Data does not exist');

            if (
                $data['type'] === TableSchema::CONSTRAINT_PRIMARY &&
                count($data['columns']) === 1 &&
                $column['type'] === TableSchemaInterface::TYPE_INTEGER
            ) {
                return '';
            }

            $aliased = array_map(
                $this->_driver->quoteIdentifier(...),
                $data['columns'],
            );
            $columns = implode(', ', $aliased);
        }

        $clause = '';
        $type = '';
        if ($data['type'] === TableSchema::CONSTRAINT_PRIMARY) {
            $type = 'PRIMARY KEY';
        } elseif ($data['type'] === TableSchema::CONSTRAINT_UNIQUE) {
            $type = 'UNIQUE';
        } elseif ($data['type'] === TableSchema::CONSTRAINT_FOREIGN) {
            $type = 'FOREIGN KEY';

            $clause = rtrim(sprintf(
                ' REFERENCES %s (%s) ON UPDATE %s ON DELETE %s %s',
                $this->_driver->quoteIdentifier($data['references'][0]),
                $this->_convertConstraintColumns($data['references'][1]),
                $this->_foreignOnClause($data['update']),
                $this->_foreignOnClause($data['delete']),
                $data['deferrable'] ?? null,
            ));
        } elseif ($data['type'] === TableSchema::CONSTRAINT_CHECK) {
            $type = 'CHECK';
            $columns = $data['expression'];
        }

        return sprintf(
            'CONSTRAINT %s %s (%s)%s',
            $this->_driver->quoteIdentifier($name),
            $type,
            $columns,
            $clause,
        );
    }

    /**
     * {@inheritDoc}
     *
     * SQLite can not properly handle adding a constraint to an existing table.
     * This method is no-op
     *
     * @param \Cake\Database\Schema\TableSchema $schema The table instance the foreign key constraints are.
     * @return array SQL fragment.
     */
    public function addConstraintSql(TableSchema $schema): array
    {
        return [];
    }

    /**
     * {@inheritDoc}
     *
     * SQLite can not properly handle dropping a constraint to an existing table.
     * This method is no-op
     *
     * @param \Cake\Database\Schema\TableSchema $schema The table instance the foreign key constraints are.
     * @return array SQL fragment.
     */
    public function dropConstraintSql(TableSchema $schema): array
    {
        return [];
    }

    /**
     * @inheritDoc
     */
    public function indexSql(TableSchema $schema, string $name): string
    {
        $data = $schema->getIndex($name);
        assert($data !== null);
        $columns = array_map(
            $this->_driver->quoteIdentifier(...),
            $data['columns'],
        );

        return sprintf(
            'CREATE INDEX %s ON %s (%s)',
            $this->_driver->quoteIdentifier($name),
            $this->_driver->quoteIdentifier($schema->name()),
            implode(', ', $columns),
        );
    }

    /**
     * @inheritDoc
     */
    public function createTableSql(TableSchema $schema, array $columns, array $constraints, array $indexes): array
    {
        $lines = array_merge($columns, $constraints);
        $content = implode(",\n", array_filter($lines));
        $temporary = $schema->isTemporary() ? ' TEMPORARY ' : ' ';
        $table = sprintf("CREATE%sTABLE \"%s\" (\n%s\n)", $temporary, $schema->name(), $content);
        $out = [$table];
        foreach ($indexes as $index) {
            $out[] = $index;
        }

        return $out;
    }

    /**
     * @inheritDoc
     */
    public function truncateTableSql(TableSchema $schema): array
    {
        $name = $schema->name();
        $sql = [];
        if ($this->hasSequences()) {
            $sql[] = sprintf('DELETE FROM sqlite_sequence WHERE name="%s"', $name);
        }

        $sql[] = sprintf('DELETE FROM "%s"', $name);

        return $sql;
    }

    /**
     * Returns whether there is any table in this connection to SQLite containing
     * sequences
     *
     * @return bool
     */
    public function hasSequences(): bool
    {
        $result = $this->_driver->prepare(
            'SELECT 1 FROM sqlite_master WHERE name = "sqlite_sequence"',
        );
        $result->execute();
        $this->_hasSequences = (bool)$result->fetch();

        return $this->_hasSequences;
    }
}
