<?php
namespace App\DevExtreme;
class FilterHelper {
    private static $AND_OP = "AND";
    private static $OR_OP = "OR";
    private static $LIKE_OP = "LIKE";
    private static $NOT_OP = "NOT";
    private static $IS_OP = "IS";
    private static function _GetSqlFieldName($field) {
        $fieldParts = explode(".", $field);
        $result = "";
        $fieldName = Utils::QuoteStringValue(trim($fieldParts[0]));
        if (count($fieldParts) == 2) {
            $dateProperty = trim($fieldParts[1]);
            $sqlDateFunction = "";
            $fieldPattern = "";
            switch ($dateProperty) {
                case "year":
                case "month":
                case "day": {
                    $sqlDateFunction = strtoupper($dateProperty);
                    $fieldPattern = "%s(%s)";
                    break;
                }
                case "dayOfWeek": {
                    $sqlDateFunction = strtoupper($dateProperty);
                    $fieldPattern = "%s(%s) - 1";
                    break;
                }
                default: {
                    throw new \Exception("The \"".$dateProperty."\" command is not supported");
                }
            }
            $result = sprintf($fieldPattern, $sqlDateFunction, $fieldName);
        }
        else {
            $result = $fieldName;
        }
        return $result;
    }
    private static function _GetSimpleSqlExpr($expression) {
        $result = "";
        $itemsCount = count($expression);
        $fieldName = self::_GetSqlFieldName(trim($expression[0]));
        
        // Known operators list
        $knownOperators = ['=', '<>', '>', '>=', '<', '<=', 'startswith', 'endswith', 'contains', 'notcontains', 'in', '==='];
        
        if ($itemsCount == 2) {
            $val = $expression[1];
            $valLower = is_string($val) ? strtolower(trim($val)) : '';
            
            // Check if second element is an operator (means searching for empty values)
            if (in_array($valLower, $knownOperators)) {
                // This is an operator without value - treat as empty value search
                switch ($valLower) {
                    case 'contains':
                    case 'startswith':
                    case 'endswith':
                    case '=':
                        // Search for NULL or empty string
                        $result = sprintf("(%s IS NULL OR %s = '')", $fieldName, $fieldName);
                        break;
                    case '<>':
                    case 'notcontains':
                        // Search for NOT NULL and NOT empty
                        $result = sprintf("(%s IS NOT NULL AND %s != '')", $fieldName, $fieldName);
                        break;
                    default:
                        // For other operators, just check IS NULL
                        $result = sprintf("%s IS NULL", $fieldName);
                        break;
                }
            } elseif ($val === "(Empty)" || $val === "(Boş)" || $val === "") {
                $result = sprintf("%s IS NULL", $fieldName);
            } else {
                $result = sprintf("%s = %s", $fieldName, Utils::QuoteStringValue($val, false));
            }
        }
        else if ($itemsCount == 3) {
            $clause = strtolower(trim($expression[1]));
            $val = $expression[2];
            
            if ($val === "(Empty)" || $val === "(Boş)" || $val === "" || is_null($val)) {
                switch ($clause) {
                    case "=":
                    case "contains":
                    case "startswith":
                    case "endswith": {
                        // Hem NULL hem empty string için kontrol
                        if(strpos($fieldName, 'date') !== false) {
                            $result = sprintf("(%s IS NULL)", $fieldName);
                        } else {
                            $result = sprintf("(%s IS NULL OR %s = '')", $fieldName, $fieldName);
                        }
                        return $result;
                    }
                    case "<>":
                    case "notcontains": {
                        // Ne NULL ne de empty string
                        $result = sprintf("(%s IS NOT NULL AND %s != '')", $fieldName, $fieldName);
                        return $result;
                    }
                }
            }
            else {
                switch ($clause) {
                    case "===": {
                        // Exact match - DO NOT split comma-separated values
                        $result = sprintf("%s = %s", $fieldName, Utils::QuoteStringValue($val, false));
                        return $result;
                    }
                    case "=": {
                        // Exact match - treat comma-separated values as single entity
                        $pattern = "%s %s %s";
                        $val = Utils::QuoteStringValue($val, false);
                        break;
                    }
                    case "<>": {
                        $pattern = "%s %s %s";
                        $val = Utils::QuoteStringValue($val, false);
                        break;
                    }
                    case ">":
                    case ">=":
                    case "<":
                    case "<=": {
                        $pattern = "%s %s %s";
                        $val = Utils::QuoteStringValue($val, false);
                        break;
                    }
                    case "startswith": {
                        $pattern = "%s %s '%s%%'";
                        $clause = self::$LIKE_OP;
                        $val = addcslashes($val, "%_");
                        break;
                    }
                    case "endswith": {
                        $pattern = "%s %s '%%%s'";
                        $val = addcslashes($val, "%_");
                        $clause = self::$LIKE_OP;
                        break;
                    }
                    case "contains": {
                        $pattern = "%s %s '%%%s%%'";
                        $val = addcslashes($val, "%_");
                        $clause = self::$LIKE_OP;
                        break;
                    }
                    case "notcontains": {
                        $pattern = "%s %s '%%%s%%'";
                        $val = addcslashes($val, "%_");
                        $clause = sprintf("%s %s", self::$NOT_OP, self::$LIKE_OP);
                        break;
                    }
                    case "noneof": {
                        if (is_array($val) && count($val) > 0) {
                             $quotedValues = array_map(function($v) {
                                return Utils::QuoteStringValue($v, false);
                            }, $val);
                            $result = sprintf("%s NOT IN (%s)", $fieldName, implode(", ", $quotedValues));
                            return $result;
                        }
                         $pattern = "%s <> %s";
                         $val = Utils::QuoteStringValue($val, false);
                         break;
                    }
                    case "anyof":
                    case "in": {
                        if (is_array($val) && count($val) > 0) {
                            $quotedValues = array_map(function($v) {
                                return Utils::QuoteStringValue($v, false);
                            }, $val);
                            $result = sprintf("%s IN (%s)", $fieldName, implode(", ", $quotedValues));
                            return $result;
                        }
                        // Fall through to default if not array
                    }
                    default: {
                        $clause = $clause ?: "=";
                        $pattern = "%s %s %s";
                        if(!is_array($val)) {
                             $val = Utils::QuoteStringValue($val, false);
                        }
                    }
                }
            } 
            
            if(isset($pattern)) {
                $result = sprintf($pattern, $fieldName, $clause, $val);
                $result = str_replace(" = ''", " is null", $result);
            } else {
                 $result = ""; // Should not happen with new default logic but safe fallback
            }

        }
        return $result;
    }
    public static function GetSqlExprByArray($expression) {
        $result = "(";
        $prevItemWasArray = false;
        foreach ($expression as $index => $item) {
            if (is_string($item)) {
                $prevItemWasArray = false;
                if ($index == 0) {
				    if ($item == "!") {
                        $result .= sprintf("%s ", self::$NOT_OP);
						continue;
                    }
					$result .=  (isset($expression) && is_array($expression)) ? self::_GetSimpleSqlExpr($expression) : "";
					break;
                }
				$strItem = strtoupper(trim($item));
                if ($strItem == self::$AND_OP || $strItem == self::$OR_OP) {
                    $result .= sprintf(" %s ", $strItem);
                }
                continue;
            }
            if (is_array($item)) {
                if ($prevItemWasArray) {
                    $result .= sprintf(" %s ", self::$AND_OP);
                }
                $result .= self::GetSqlExprByArray($item);
                $prevItemWasArray = true;
            }
        }
        $result .= ")";
        return $result;
    }
    public static function GetSqlExprByKey($key) {
        $result = "";
        foreach ($key as $prop => $value) {
            $templ = strlen($result) == 0 ?
                     "%s = %s" :
                     " ".self::$AND_OP." %s = %s";
            $result .= sprintf($templ,
                               Utils::QuoteStringValue($prop),
                               Utils::QuoteStringValue($value, false));
        }
        return $result;
    }
}