<?php
/**
 * Data verification class
 */
class DataVerifier {

    public array $data;
    public array $rules;

    /**
     * Generate validation rules
     */
    public function __construct(array $data, array $rules)
    {
        $this->data = $data;
        $compound_rules = [];
        foreach ($rules as $rule) {
            $rule_info = explode(".",$rule);
            $compound_rule = [
                "key" => $rule_info[0],
                "type" => $rule_info[1],
                "min" => $rule_info[2] ?? null,
                "max" => $rule_info[3] ?? null,
                "mandatory" => $rule_info[4] ?? true
            ];
            foreach(["min","max"] as $k) {
                if ($compound_rule[$k] == "null") {
                    $compound_rule[$k] = null;
                }
            }
            if ($compound_rule["mandatory"] == "none") {
                $compound_rule["mandatory"] = false;
            } else {
                $compound_rule["mandatory"] = true;
            }
            $compound_rules[] = $compound_rule;
        }
        $this->rules = $compound_rules;
    }

    /**
     * Execute validation
     * @return bool
     */
    public function validate() : bool {
        foreach($this->rules as $rule) {
            $value = $this->data[$rule["key"]] ?? null;
            if ($rule["mandatory"] && $value === null) {
                return false;
            }
            $min = $rule["min"];
            $max = $rule["max"];

            if ($rule["type"] == "string") {
                if (!is_string((string) $value)) {
                    return false;
                }
                if ($min !== null && strlen($value) < $min) {
                    return false;
                }
                if ($max !== null && strlen($value) > $max) {
                    return false;
                }
            }

            if ($rule["type"] == "numeric") {
                if (!is_numeric((int) $value)) {
                    return false;
                }
                $value = (int) $value;
                if ($min !== null && $value < $min) {
                    return false;
                }
                if ($max !== null && $value > $max) {
                    return false;
                }
            }

            if ($rule["type"] == "email") {
                if (!is_string($value)) {
                    return false;
                }
                if ($min !== null && strlen($value) < $min) {
                    return false;
                }
                if ($max !== null && strlen($value) > $max) {
                    return false;
                }
                if (!filter_var($value, FILTER_VALIDATE_EMAIL)) {
                    return false;
                }
            }

            if ($rule["type"] == "array") {
                if (!is_array($value)) {
                    return false;
                }
                if ($min !== null && count($value) < $min) {
                    return false;
                }
                if ($max !== null && count($value) > $max) {
                    return false;
                }
            }

            if ($rule["type"] == "regex") {
                if(empty($rule["min"])) {
                    throw new Exception("No regex specified for rule: {$rule['key']}");
                }
                $regex = $rule["min"];
                if (empty(preg_match($regex, $value))) {
                    return false;
                }
            }
        }
        return true;
    }
}