<?php

namespace Ulmus\Adapter;

use Collator;
use Ulmus\Common\PdoObject;
use Ulmus\ConnectionAdapter;
use Ulmus\Entity;
use Ulmus\Migration\FieldDefinition;
use Ulmus\{Migration\MigrateInterface, Repository, QueryBuilder};

class SQLite implements AdapterInterface, MigrateInterface, SqlAdapterInterface {
    use SqlAdapterTrait;

    const ALLOWED_ATTRIBUTES = [
        'default', 'primary_key', 'auto_increment', 'collate nocase', 'collate binary', 'collate rtrim',
    ];

    const DSN_PREFIX = "sqlite";

    public function __construct(
        public null|string $path = null,
        public null|array $pragmaBegin = null,
        public null|array $pragmaClose = null,
    ) { }

    public function connect() : PdoObject
    {
        try {
            $pdo = new PdoObject\SqlitePdoObject($this->buildDataSourceName(), null, null);
            $pdo->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
            $pdo->setAttribute(\PDO::ATTR_EMULATE_PREPARES, false);
            $pdo->setAttribute(\PDO::ATTR_DEFAULT_FETCH_MODE, \PDO::FETCH_ASSOC);

            $pdo->onClose = function(PdoObject $obj) {
                static::registerPragma($obj, $this->pragmaClose);
            };

            $this->exportFunctions($pdo);
            $this->exportCollations($pdo);
            $this->registerPragma($pdo, $this->pragmaBegin);
        }
        catch(\PDOException $ex){
            throw $ex;
        }

        return $pdo;
    }
    
    public function buildDataSourceName() : string
    {
        $parts[] = $this->path;

        return  static::DSN_PREFIX . ":" . implode(';', $parts);
    }
    
    public function setup(array $configuration) : void
    {
        $this->path = $configuration['path'] ?? "";
        $this->pragmaBegin = array_filter($configuration['pragma_begin'] ?? []);
        $this->pragmaClose = array_filter($configuration['pragma_close'] ?? []);
    }

    # https://sqlite.org/lang_keywords.html
    public static function escapeIdentifier(string $segment, int $type) : string
    {
        switch($type) {
            default:
            case static::IDENTIFIER_DATABASE:
            case static::IDENTIFIER_TABLE:
            case static::IDENTIFIER_FIELD:
                return '"' . trim(str_replace('"', '""', $segment), '"') . '"';

            case static::IDENTIFIER_VALUE:
                return "'$segment'";
        }
    }

    public function defaultEngine(): ? string
    {
        return null;
    }

    public function databaseName() : string
    {
        $base = basename($this->path);

        return substr($base, 0, strrpos($base, '.') ?: strlen($base));
    }

    public function schemaTable(ConnectionAdapter $adapter, string $databaseName, string $tableName) : null|object
    {
        return Entity\Sqlite\Table::repository(Repository::DEFAULT_ALIAS, $adapter)
            ->select(\Ulmus\Common\Sql::raw('this.*'))
            ->loadOneFromField(Entity\Sqlite\Table::field('tableName'), $tableName);
    }

    public function mapFieldType(FieldDefinition $field, bool $typeOnly = false) : string
    {
        $type = $field->type;
        $length = $field->length;

        if ( is_a($type, Entity\Field\Date::class, true) || is_a($type, Entity\Field\Time::class, true) || is_a($type, \DateTime::class, true) ) {
            $type = "TEXT";
            $length = strlen((string) $type);
        }
        else {
            switch($type) {
                case "bool":
                    $check = sprintf("CHECK (%s IN (0, 1))", $field->getColumnName());

                case "bigint":
                case "int":
                    $type = "INTEGER";
                    break;

                case "array":
                    $type = "JSON";
                    $length = null;
                    break;

                case "string":
                    $type = "TEXT";
                    $length = null;
                    break;

                case "float":
                    $type = "REAL";
                    break;

                default:
                    $type = "BLOB";
                    break;
            }
        }

        if (in_array($type, [ 'JSON', 'TEXT', 'BLOB', 'GEOMETRY' ])) {
            unset($field->default);
        }

        return $typeOnly ? $type : $type . ( $length ? "($length" . ")" : "" );
    }

    public function tableSyntax() : array
    {
        return [
            'ai' => "AUTOINCREMENT",
            'pk' => "PRIMARY KEY",
            'unsigned' => "",
        ];
    }

    public function repositoryClass() : string
    {
        return Repository\SqliteRepository::class;
    }

    public function queryBuilderClass() : string
    {
        return QueryBuilder\Sql\SqliteQueryBuilder::class;
    }

    public function exportFunctions(PdoObject $pdo) : void
    {
        $pdo->sqliteCreateFunction('if', fn($comparison, $yes, $no) => $comparison ? $yes : $no, 3);
        $pdo->sqliteCreateFunction('length', fn($string) => strlen($string), 1);
        $pdo->sqliteCreateFunction('lcase', fn($string) => strtolower($string), 1);
        $pdo->sqliteCreateFunction('ucase', fn($string) => strtoupper($string), 1);
        $pdo->sqliteCreateFunction('md5', fn($string) => md5($string), 1);
        $pdo->sqliteCreateFunction('sha1', fn($string) => sha1($string), 1);
        $pdo->sqliteCreateFunction('sha256', fn($string) => hash('sha256', $string), 1);
        $pdo->sqliteCreateFunction('sha512', fn($string) => hash('sha512', $string), 1);
        $pdo->sqliteCreateFunction('whirlpool', fn($string) => hash('whirlpool', $string), 1);
        $pdo->sqliteCreateFunction('murmur3a', fn($string) => hash('murmur3a', $string), 1);
        $pdo->sqliteCreateFunction('murmur3c', fn($string) => hash('murmur3c', $string), 1);
        $pdo->sqliteCreateFunction('murmur3f', fn($string) => hash('murmur3f', $string), 1);
        $pdo->sqliteCreateFunction('left', fn($string, $length) => substr($string, 0, $length), 2);
        $pdo->sqliteCreateFunction('right', fn($string, $length) => substr($string, -$length), 2);
        $pdo->sqliteCreateFunction('strcmp', fn($s1, $s2) => strcmp($s1, $s2), 2);
        $pdo->sqliteCreateFunction('lpad', fn($string, $length, $pad) => str_pad($string, $length, $pad, STR_PAD_LEFT), 3);
        $pdo->sqliteCreateFunction('rpad', fn($string, $length, $pad) => str_pad($string, $length, $pad, STR_PAD_RIGHT), 3);
        $pdo->sqliteCreateFunction('concat', fn(...$args) => implode('', $args), -1);
        $pdo->sqliteCreateFunction('concat_ws', fn($separator, ...$args) => implode($separator, $args), -1);
        $pdo->sqliteCreateFunction('find_in_set', function($string, $string_list) {
            if ( $string === null || $string_list === null ) {
                return null;
            }

            if ($string_list === "") {
                return 0;
            }

            return (int) in_array($string, explode(',', $string_list));
        }, 2);
        $pdo->sqliteCreateFunction('day', fn($date) => ( new \DateTime($date) )->format('j'), 1);
        $pdo->sqliteCreateFunction('month', fn($date) => ( new \DateTime($date) )->format('n'), 1);
        $pdo->sqliteCreateFunction('year', fn($date) => ( new \DateTime($date) )->format('Y'), 1);
    }


    public function exportCollations(PdoObject $pdo) : void
    {

        if ( class_exists('Locale') ) {
            # @TODO debug this, case-sensitivity not working properly !!
            $collator = new Collator(\Locale::getDefault());
            $collator->setStrength(Collator::TERTIARY);
            $collator->setAttribute(Collator::NUMERIC_COLLATION, Collator::ON);

            $pdo->sqliteCreateCollation('locale_cmp', fn($e1, $e2) => $collator->compare($e1, $e2));
            $pdo->sqliteCreateCollation('locale_cmp_desc', fn($e1, $e2) => $collator->compare($e2, $e1));

            $collatorCi = new Collator(\Locale::getDefault());
            $collatorCi->setStrength(Collator::SECONDARY);
            $collatorCi->setAttribute(Collator::NUMERIC_COLLATION, Collator::ON);

            $pdo->sqliteCreateCollation('locale_cmp_ci', fn($e1, $e2) => $collatorCi->compare($e1, $e2));
            $pdo->sqliteCreateCollation('locale_cmp_ci_desc', fn($e1, $e2) => $collatorCi->compare($e2, $e1));
        }
        else {
            $comp = fn(string $e1, string $e2) => \iconv('UTF-8', 'ASCII//TRANSLIT', $e1) <=> \iconv('UTF-8', 'ASCII//TRANSLIT', $e2);
            $pdo->sqliteCreateCollation('locale_cmp', fn($e1, $e2) => $comp);
            $pdo->sqliteCreateCollation('locale_cmp_desc', fn($e2, $e1) => $comp);

            $compCi = fn(string $e1, string $e2) => strtoupper(\iconv('UTF-8', 'ASCII//TRANSLIT', $e1)) <=> strtoupper(\iconv('UTF-8', 'ASCII//TRANSLIT', $e2));
            $pdo->sqliteCreateCollation('locale_cmp_ci', fn($e1, $e2) => $compCi);
            $pdo->sqliteCreateCollation('locale_cmp_ci_desc', fn($e2, $e1) => $compCi);
        }
    }

    public static function registerPragma(PdoObject $pdo, array $pragmaList) : void
    {
        $builder = new QueryBuilder\Sql\SqliteQueryBuilder();

        foreach($pragmaList as $pragma) {
            list($key, $value) = explode('=', $pragma) + [ null, null ];

            $sql = $builder->pragma($key, $value)->render();
            $query = $pdo->query($sql);

            if ( ! $query->execute() ) {
                throw new \InvalidArgumentException(sprintf("Pragma query could not be executed : %s", $sql));
            }

            $builder->reset();
        }
    }

    public function generateAlterColumn(FieldDefinition $definition, array $field) : string|\Stringable
    {
        return implode(" ", [
            strtoupper($field['action']),
            $this->escapeIdentifier($definition->getSqlName(), static::IDENTIFIER_FIELD),
            $definition->getSqlType(),
            $definition->getSqlParams(),
        ]);
    }

    public function splitAlterQuery() : bool
    {
        return true;
    }
}