<?php

class Helper {
    /**
     * Generate SQL Filter condition (space separated) for a given column.
     *
     * @param string|null|array $filterValue The filter value to match against.
     * @param string $columnName The name of the column in the database table.
     * @return string The SQL condition generated based on the filter value and column name.
     */
    public static function generateFilterCondition($filterValue, string $columnName, bool $exactMatch = false): string {
        $sql = "";

        if (is_array($filterValue)) {
            if (isset($filterValue['from']) && isset($filterValue['to'])) {
                $sql = " AND `$columnName` >= " . $filterValue['from'] . " AND `$columnName` <= " . $filterValue['to'];
            } elseif (isset($filterValue['from'])) {
                $sql = " AND `$columnName` >= " . $filterValue['from'];
            } elseif (isset($filterValue['to'])) {
                $sql = " AND `$columnName` <= " . $filterValue['to'];
            } else if (isset($filterValue['exact'])) {
                $sql = " AND `$columnName` = " . "'{$filterValue['exact']}'";
            }
        } else if ($filterValue === "0" || $filterValue === "1") {
            $sql .= " AND `$columnName` = " . $filterValue;
        } else if ($filterValue === null) {
            $sql .= " AND `$columnName` IS NULL";
        } else if (!empty($filterValue)) {
            if ($exactMatch) {
                $sql .= " AND `$columnName` = '" . $filterValue . "'";
            } else if ($filterValue[0] === "%") {
                $sql .= " AND `$columnName` LIKE '" . $filterValue . "'";
            } else if ($filterValue[strlen($filterValue) - 1] === "%") {
                $sql .= " AND `$columnName` LIKE '" . $filterValue . "'";
            } else {
                $filterItems = explode(" ", $filterValue);
                foreach ($filterItems as $item) {
                    $sql .= " AND `$columnName` LIKE '%" . $item . "%'";
                }
            }
        } else if ($filterValue === 0) {
            $sql .= " AND `$columnName` = 0";
        }

        return $sql;
    }

    /**
     * Validates an array of data based on a set of predefined rules.
     *
     * @param array $data The data to validate. Keys represent field names, and values are the corresponding data.
     * @param array $checkArray An associative array defining validation rules for each field:
     *                          - key: The field name to validate.
     *                          - value: An associative array of validation rules for that field:
     *                              - required (bool, optional): Whether the field is required. Default: false.
     *                              - title (string, optional): The human-readable name of the field to use in error messages.
     *                              - required_length (int, optional): The minimum required length of the value. Default: 1.
     *                              - regex (string, optional): A regular expression pattern the value must match.
     *
     * @return array|true Returns `true` if validation passes for all fields. Otherwise, returns an associative array of errors
     *               where keys are field names, and values are error messages.
     */
    public static function validateArray(array $data, array $checkArray, bool $printErrors = true) {
        $errors = [];

        foreach ($checkArray as $key => $rules) {
            $value = $data[$key] ?? null;
            $title = $rules['title'] ?? $key;

            //TODO: fix this, skip arrays for now
            if (is_array($value)) {
                continue;
            }

            // Apply default values for missing rules

            $rules = array_merge(['required' => false,
                                  'required_length' => 1,
                                  'regex' => false,], $rules);

            // Required Check
            if ($rules['required'] && (is_null($value) || $value === '')) {
                $errors[$key] = "$title wird benötigt.";
            }

            // Length Check (only if value exists)
            if (!is_null($value) && strlen($value) < $rules['required_length']) {
                $errors[$key] = "$title muss mindestens $rules[required_length] Zeichen lang sein.";
            }

            // Regex Check (only if value exists and regex is provided)
            if (!is_null($value) && $rules['regex'] && !preg_match($rules['regex'], $value)) {
                $errors[$key] = "$title hat ein ungültiges Format.";
            }
        }

        if ($printErrors) {
            if (!empty($errors)) {
                header('Content-Type: application/json');
                die(json_encode(['success' => false,
                                 'errors' => $errors]));
            }
        }

        return empty($errors) ? true : $errors;
    }

    /**
     * Displays Vue component with the given header title.
     *
     * @param mfBaseController $controller The controller instance to generate $JSGlobals for.
     * @param string $pageName The name of the Vue component to render.
     * @param string $headerTitle The title to display in the header.
     * @param array $additionalGlobals Additional global variables to pass to the Vue component.
     */
    public static function renderVue(mfBaseController $controller, string $pageName, string $headerTitle, array $additionalGlobals = []) {
        $JSGlobals = ["BASE_URL" => $controller::getUrl($pageName),
                      "MF_URL" => $controller::getUrl(""),
                      "DASHBOARD_URL" => $controller::getUrl("Dashboard"),
                      "MF_APP_NAME" => MFAPPNAME_SLUG,
                      "BASE_PATH" => $controller::getUrl(""),
                      "PAGE_TITLE" => $headerTitle,
                      "PATH" => [["text" => MFAPPNAME_SLUG, "href" => $controller::getUrl("Dashboard")],
                                 ["text" => $headerTitle, "href" => $controller::getUrl($pageName)]],];

        $JSGlobals = array_merge($JSGlobals, $additionalGlobals);

        $controller->layout()->set("vueViewName", $pageName);
        $controller->layout()->set("JSGlobals", $JSGlobals);
        $controller->layout()->setTemplate("VueViews/Vue");
    }

    /**
     * Converts an array of objects to a CSV file.
     * @param array $rows The array of objects to convert to CSV.
     * @return string The CSV file content.
     */
    public static function arrayToCsv(array $rows): string {
        $output = fopen('php://temp', 'w');

        // Add headers
        fputcsv($output, array_keys((array) $rows[0]));

        // Add rows
        foreach ($rows as $row) {
            fputcsv($output, (array) $row);
        }

        rewind($output);
        $csv = stream_get_contents($output);
        fclose($output);

        return $csv;
    }

    /**
     * Formats a number with the given number of decimals, decimal point, and thousands separator.
     * @param $number
     * @param int $decimals
     * @param string $decPoint
     * @param string $thousandsSep
     * @return float
     */
    public static function formatNumber($number, int $decimals = 2, string $decPoint = ",", string $thousandsSep = "."): string {
        if(!is_numeric($number)) return "";
        return number_format($number, $decimals, $decPoint, $thousandsSep);
    }

}