<?php

/**
 * Modern base model with typed properties and automatic journaling.
 *
 * Filter operators: =exact, !not, >, <, >=, <=
 * Array values become IN/NOT IN clauses, null checks IS NULL/IS NOT NULL
 */
abstract class mfBaseModelV2 {

    protected static string $__tableName = '';
    protected static string $__primaryKey = 'id';
    protected static ?array $__databaseConfig = null;
    protected static array $__journalFieldMap = [];
    protected static bool $__enableJournaling = true;

    private static array $__db_instances = [];
    protected ?FronkDB $__db = null;
    protected ?mfLoghandler $__log = null;
    private ?stdClass $__originalData = null;
    private bool $__isLoaded = false;

    public function __construct(int|string $id = null) {
        static::__init_db();
        $this->__db = self::$__db_instances[static::class];
        $this->__log = mfLoghandler::singleton();
        $this->__originalData = new stdClass();

        if ($id !== null) $this->__load($id);
    }

    protected static function __init_db(): void {
        if (isset(self::$__db_instances[static::class])) return;

        if (empty(static::$__tableName)) {
            throw new Exception('$__tableName must be set in ' . get_called_class());
        }

        self::$__db_instances[static::class] = static::$__databaseConfig !== null
            ? FronkDB::singleton(
                static::$__databaseConfig['host'],
                static::$__databaseConfig['user'],
                static::$__databaseConfig['pass'],
                static::$__databaseConfig['name']
            )
            : FronkDB::singleton();
    }

    protected static function __getDb(): FronkDB {
        static::__init_db();
        return self::$__db_instances[static::class];
    }

    public static function get(int|string $id): ?static {
        static::__init_db();
        $model = new static();
        return $model->__load($id) ? $model : null;
    }

    public static function getFirst(array $filter = [], array $order = []): ?static {
        $results = static::getAll($filter, 1, 0, $order);
        return $results[0] ?? null;
    }

    public static function getAll(array $filter = [], int $limit = null, int $offset = 0, array $order = []): array {
        static::__init_db();
        $db = self::$__db_instances[static::class];
        $table = static::$__tableName;
        $whereSql = static::__buildFilterSql($filter);

        $orderSql = "";
        if (!empty($order['column'])) {
            $dir = (strtoupper($order['dir'] ?? '') === 'DESC') ? 'DESC' : 'ASC';
            $orderSql = "ORDER BY `" . $db->escape($order['column']) . "` $dir";
        }

        $limitSql = $limit !== null ? "LIMIT " . (int)$offset . ", " . (int)$limit : "";
        $res = $db->query("SELECT * FROM `$table` $whereSql $orderSql $limitSql");

        $items = [];
        if ($db->num_rows($res)) {
            while ($data = $db->fetch_object($res)) {
                $model = new static();
                $model->__populate($data);
                $model->__isLoaded = true;
                $items[] = $model;
            }
        }
        return $items;
    }

    public static function search(array $filter = [], int $limit = null, int $offset = 0, array $order = []): array {
        return static::getAll($filter, $limit, $offset, $order);
    }

    public static function count(array $filter = []): int {
        static::__init_db();
        $db = self::$__db_instances[static::class];
        $whereSql = static::__buildFilterSql($filter);
        $res = $db->query("SELECT COUNT(*) as cnt FROM `" . static::$__tableName . "` $whereSql");
        return $db->num_rows($res) ? (int)$db->fetch_object($res)->cnt : 0;
    }

    public function isLoaded(): bool { return $this->__isLoaded; }

    public function getId(): int|string|null {
        return $this->{static::$__primaryKey} ?? null;
    }

    public function save(): bool {
        try {
            $isInsert = !$this->__isLoaded;
            $userId = $this->__getUserId();
            $now = time();

            if (property_exists($this, 'edit')) $this->edit = $now;
            if (property_exists($this, 'edit_by')) $this->edit_by = $userId;

            if ($isInsert) {
                if (property_exists($this, 'create')) $this->create = $now;
                if (property_exists($this, 'create_by')) $this->create_by = $userId;
            }

            $errors = $this->validate();
            if (!empty($errors)) {
                $this->__log->warn('Validation failed: ' . implode(', ', $errors));
                return false;
            }

            if (!$this->beforeSave($isInsert)) return false;

            $data = $this->__getPublicData();
            $changes = $this->__getChangedFields($data);
            $pk = static::$__primaryKey;

            if (!$isInsert && empty($changes)) return true;

            if ($isInsert) {
                if (array_key_exists($pk, $data) && $data[$pk] === null) unset($data[$pk]);
                if (!$this->__db->insert(static::$__tableName, $data)) {
                    throw new Exception("INSERT failed: " . $this->__db->getLastError());
                }
                $this->{$pk} = $this->__db->insert_id;
                $this->__isLoaded = true;
            } else {
                $pkValue = $this->{$pk};
                $updateData = [];
                foreach ($changes as $field => $change) $updateData[$field] = $change['new'];

                if (!empty($updateData)) {
                    if (!$this->__db->update(static::$__tableName, $updateData, "`$pk` = '" . $this->__db->escape($pkValue) . "'")) {
                        throw new Exception("UPDATE failed: " . $this->__db->getLastError());
                    }
                }
            }

            $this->__originalData = (object)$this->__getPublicData();
            $this->afterSave($isInsert, $changes);

            if (static::$__enableJournaling) $this->__writeToJournal($changes, $isInsert);

            return true;
        } catch (Exception $e) {
            $this->__log->error("mfBaseModelV2 save() error: " . $e->getMessage());
            return false;
        }
    }

    public function delete(): bool {
        if (!$this->__isLoaded) return false;

        $pk = static::$__primaryKey;
        $pkValue = $this->{$pk};

        if ($this->__db->delete(static::$__tableName, "`$pk` = '" . $this->__db->escape($pkValue) . "'")) {
            if (static::$__enableJournaling) $this->__writeToJournal([], false, true);
            $this->__isLoaded = false;
            return true;
        }
        return false;
    }

    public function getJournalHistory(): array {
        $journalDb = FronkDB::singleton();
        $pkValue = $this->{static::$__primaryKey} ?? null;
        if ($pkValue === null) return [];

        $modelName = $journalDb->escape(get_called_class());
        $recordId = $journalDb->escape($pkValue);

        $res = $journalDb->query("SELECT * FROM `Journal` WHERE `model` = '$modelName' AND `record_id` = '$recordId' ORDER BY `timestamp` DESC");
        $history = [];

        if ($journalDb->num_rows($res)) {
            while ($row = $journalDb->fetch_object($res)) {
                if ($row->field && isset(static::$__journalFieldMap[$row->field])) {
                    $row->field_readable = static::$__journalFieldMap[$row->field];
                }
                $history[] = $row;
            }
        }
        return $history;
    }

    public function toArray(): array { return $this->__getPublicData(); }
    public function toJson(): string { return json_encode($this->toArray()); }

    // Hooks
    public function validate(): array { return []; }
    protected function beforeSave(bool $isInsert): bool { return true; }
    protected function afterSave(bool $isInsert, array $changes): void {}

    // Internal methods
    private function __load(int|string $id): bool {
        $pk = static::$__primaryKey;
        $res = $this->__db->select(static::$__tableName, "*", "`$pk` = '" . $this->__db->escape($id) . "' LIMIT 1");

        if ($this->__db->num_rows($res)) {
            $this->__populate($this->__db->fetch_object($res));
            $this->__isLoaded = true;
            return true;
        }
        return false;
    }

    private function __populate(stdClass $data): void {
        $reflector = new ReflectionClass($this);
        foreach ($reflector->getProperties(ReflectionProperty::IS_PUBLIC) as $prop) {
            $name = $prop->getName();
            if (!property_exists($data, $name)) continue;

            $type = $prop->getType()?->getName();
            $value = $data->{$name};

            $this->{$name} = $value === null ? null : match ($type) {
                'int' => (int)$value,
                'float' => (float)$value,
                'bool' => (bool)$value,
                'string' => (string)$value,
                default => $value,
            };
        }
        $this->__originalData = (object)$this->__getPublicData();
    }

    private function __getPublicData(): array {
        $data = [];
        $reflector = new ReflectionClass($this);
        foreach ($reflector->getProperties(ReflectionProperty::IS_PUBLIC) as $prop) {
            $name = $prop->getName();
            $data[$name] = $prop->isInitialized($this)
                ? $this->{$name}
                : ($prop->hasDefaultValue() ? $prop->getDefaultValue() : null);
        }
        return $data;
    }

    private function __getChangedFields(array $currentData): array {
        $changes = [];
        if (!$this->__isLoaded || !$this->__originalData) {
            foreach ($currentData as $key => $value) $changes[$key] = ['old' => null, 'new' => $value];
            return $changes;
        }

        foreach ($currentData as $key => $value) {
            if (!property_exists($this->__originalData, $key) || $this->__originalData->{$key} != $value) {
                $changes[$key] = ['old' => $this->__originalData->{$key} ?? null, 'new' => $value];
            }
        }
        return $changes;
    }

    private function __writeToJournal(array $changes, bool $isInsert, bool $isDelete = false): void {
        try {
            $journalDb = FronkDB::singleton();
            $baseData = [
                'user_id' => $this->__getUserId(),
                'model' => get_called_class(),
                'record_id' => $this->{static::$__primaryKey},
            ];

            if ($isDelete) {
                $journalDb->insert('Journal', $baseData + ['action' => 'delete']);
            } elseif ($isInsert) {
                $journalDb->insert('Journal', $baseData + ['action' => 'create']);
            } else {
                foreach ($changes as $field => $change) {
                    $journalDb->insert('Journal', $baseData + [
                        'action' => 'update',
                        'field' => $field,
                        'old_value' => is_array($change['old']) || is_object($change['old']) ? json_encode($change['old']) : $change['old'],
                        'new_value' => is_array($change['new']) || is_object($change['new']) ? json_encode($change['new']) : $change['new'],
                    ]);
                }
            }
        } catch (Exception $e) {
            $this->__log->error("Journal write failed: " . $e->getMessage());
        }
    }

    private function __getUserId(): ?int {
        try {
            $me = new User();
            $me->loadMe();
            return $me->id ?? null;
        } catch (Exception) {
            return null;
        }
    }

    /**
     * Builds WHERE clause from filter array.
     * Operators: =exact, !not, >, <, >=, <=
     * Arrays become IN/NOT IN, null becomes IS NULL/IS NOT NULL
     */
    private static function __buildFilterSql(array $filter): string {
        $whereClauses = ["1=1"];
        $db = self::$__db_instances[static::class];
        $reflector = new ReflectionClass(static::class);

        foreach ($filter as $key => $value) {
            $column = $key;
            $operator = '=';
            $forceExact = false;

            // Parse operator from key prefix
            if (str_starts_with($key, '>=')) { $operator = '>='; $column = substr($key, 2); }
            elseif (str_starts_with($key, '<=')) { $operator = '<='; $column = substr($key, 2); }
            elseif (str_starts_with($key, '!')) { $operator = '!='; $column = substr($key, 1); }
            elseif (str_starts_with($key, '>')) { $operator = '>'; $column = substr($key, 1); }
            elseif (str_starts_with($key, '<')) { $operator = '<'; $column = substr($key, 1); }
            elseif (str_starts_with($key, '=')) { $operator = '='; $column = substr($key, 1); $forceExact = true; }

            if (!$reflector->hasProperty($column)) {
                mfLoghandler::singleton()->warn("Filter: Unknown property '$column' on " . static::class);
                continue;
            }

            // NULL handling
            if ($value === null) {
                $whereClauses[] = "`$column` " . ($operator === '!=' ? 'IS NOT NULL' : 'IS NULL');
                continue;
            }

            // Array = IN/NOT IN
            if (is_array($value)) {
                $op = ($operator === '!=') ? 'NOT IN' : 'IN';
                if (empty($value)) {
                    $whereClauses[] = ($op === 'IN') ? "0=1" : "1=1";
                    continue;
                }
                $escaped = array_map(fn($v) => "'" . $db->escape($v) . "'", $value);
                $whereClauses[] = "`$column` $op (" . implode(',', $escaped) . ")";
                continue;
            }

            // String lazy search vs exact/numeric
            $prop = $reflector->getProperty($column);
            $type = $prop->getType()?->getName() ?? 'string';

            if ($type === 'string' && $operator === '=' && !$forceExact) {
                foreach (explode(' ', (string)$value) as $term) {
                    if (empty($term)) continue;
                    $whereClauses[] = "`$column` LIKE '%" . $db->escape($term) . "%'";
                }
            } else {
                $whereClauses[] = "`$column` $operator '" . $db->escape($value) . "'";
            }
        }

        return "WHERE " . implode(" AND ", $whereClauses);
    }
}