<?php
namespace DatabaseHelper;

use DatabaseHelper\enums\ConditionOperator;
use InvalidArgumentException;

trait Conditionable
{
    protected array $conditions = [];

    // The Schema instance must be available to validate columns.
    protected Schema $table;

    /**
     * Adds a WHERE condition using an "AND" prefix.
     * @param string $col Column name.
     * @param string|ConditionOperator $operator Comparison operator as string or enum.
     * @param mixed $val Value to compare.
     * @return self Current instance for chaining.
     * @throws InvalidArgumentException
     */
    public function where(string $col, string|ConditionOperator $operator, mixed $val): self {
        return $this->addCondition($col, $operator, $val, "AND");
    }

    /**
     * Adds a WHERE condition with an "AND" prefix.
     * @param string $col Column name.
     * @param string|ConditionOperator $operator Comparison operator as string or enum.
     * @param mixed $val Value to compare.
     * @return self Current instance for chaining.
     * @throws InvalidArgumentException
     */
    public function andWhere(string $col, string|ConditionOperator $operator, mixed $val): self {
        return $this->addCondition($col, $operator, $val, "AND");
    }

    /**
     * Adds a WHERE condition with an "OR" prefix.
     * @param string $col Column name.
     * @param string|ConditionOperator $operator Comparison operator as string or enum.
     * @param mixed $val Value to compare.
     * @return self Current instance for chaining.
     * @throws InvalidArgumentException
     */
    public function orWhere(string $col, string|ConditionOperator $operator, mixed $val): self {
        return $this->addCondition($col, $operator, $val, "OR");
    }

    protected function addCondition(string $col, string|ConditionOperator $operator, mixed $val, string $prefix): self {
        if (!$this->table->existsColumn($col))
            throw new InvalidArgumentException("Unknown column: $col");

        // Convert the operator string to a ConditionOperator enum if needed.
        if (is_string($operator))
            $operator = ConditionOperator::fromString($operator);

        $columnType = $this->table->columnType($col);
        $castedValue = $columnType->dbCast($val);

        if (!empty($this->conditions))
            $this->conditions[] = $prefix;
        $this->conditions[] = "$col " . $operator->toString() . " $castedValue";

        return $this;
    }
    
    protected function combineConditions(): string {
        if (!empty($this->conditions))
            return implode(" ", $this->conditions);
        return "";
    }
}