<?php

declare(strict_types=1);

namespace App\Framework\ErrorHandling\ValueObjects;

use App\Framework\Exception\Core\ErrorSeverity;

/**
 * Value Object representing error classification metadata.
 *
 * Replaces primitive array pattern in ErrorHandler::createExceptionMetadata()
 * with type-safe, immutable Value Object following framework principles.
 *
 * This is distinct from ExceptionMetadata (behavior control) - this handles
 * error classification and HTTP response metadata.
 */
final readonly class ErrorMetadata
{
    /**
     * @param string $exceptionClass Fully qualified exception class name
     * @param ErrorSeverity $errorLevel Error severity level
     * @param int $httpStatus HTTP status code for response
     * @param string|null $errorCode Optional error code from FrameworkException
     * @param string|null $errorCategory Optional error category (e.g., 'AUTH', 'VAL')
     * @param string|null $errorSeverity Optional severity from ErrorCode
     * @param bool|null $isRecoverable Whether error is recoverable
     * @param string|null $recoveryHint Optional hint for recovery (debug mode)
     * @param array<string, string> $additionalHeaders HTTP headers to add to response
     */
    public function __construct(
        public string $exceptionClass,
        public ErrorSeverity $errorLevel,
        public int $httpStatus,
        public ?string $errorCode = null,
        public ?string $errorCategory = null,
        public ?string $errorSeverity = null,
        public ?bool $isRecoverable = null,
        public ?string $recoveryHint = null,
        public array $additionalHeaders = []
    ) {}

    /**
     * Create basic metadata for non-FrameworkException errors.
     */
    public static function basic(
        string $exceptionClass,
        ErrorSeverity $errorLevel,
        int $httpStatus
    ): self {
        return new self(
            exceptionClass: $exceptionClass,
            errorLevel: $errorLevel,
            httpStatus: $httpStatus
        );
    }

    /**
     * Create enhanced metadata for FrameworkException errors.
     */
    public static function enhanced(
        string $exceptionClass,
        ErrorSeverity $errorLevel,
        int $httpStatus,
        string $errorCode,
        string $errorCategory,
        string $errorSeverity,
        bool $isRecoverable,
        ?string $recoveryHint = null
    ): self {
        return new self(
            exceptionClass: $exceptionClass,
            errorLevel: $errorLevel,
            httpStatus: $httpStatus,
            errorCode: $errorCode,
            errorCategory: $errorCategory,
            errorSeverity: $errorSeverity,
            isRecoverable: $isRecoverable,
            recoveryHint: $recoveryHint
        );
    }

    /**
     * Add additional HTTP headers (immutable).
     */
    public function withAdditionalHeaders(array $headers): self
    {
        return new self(
            exceptionClass: $this->exceptionClass,
            errorLevel: $this->errorLevel,
            httpStatus: $this->httpStatus,
            errorCode: $this->errorCode,
            errorCategory: $this->errorCategory,
            errorSeverity: $this->errorSeverity,
            isRecoverable: $this->isRecoverable,
            recoveryHint: $this->recoveryHint,
            additionalHeaders: array_merge($this->additionalHeaders, $headers)
        );
    }

    /**
     * Check if this is enhanced metadata (from FrameworkException).
     */
    public function isEnhanced(): bool
    {
        return $this->errorCode !== null;
    }

    /**
     * Check if metadata has additional headers.
     */
    public function hasAdditionalHeaders(): bool
    {
        return !empty($this->additionalHeaders);
    }

    /**
     * Convert to array for legacy compatibility.
     *
     * @return array<string, mixed>
     */
    public function toArray(): array
    {
        $array = [
            'exception_class' => $this->exceptionClass,
            'error_level' => $this->errorLevel->name,
            'http_status' => $this->httpStatus,
        ];

        // Add enhanced fields if present
        if ($this->errorCode !== null) {
            $array['error_code'] = $this->errorCode;
        }

        if ($this->errorCategory !== null) {
            $array['error_category'] = $this->errorCategory;
        }

        if ($this->errorSeverity !== null) {
            $array['error_severity'] = $this->errorSeverity;
        }

        if ($this->isRecoverable !== null) {
            $array['is_recoverable'] = $this->isRecoverable;
        }

        if ($this->recoveryHint !== null) {
            $array['recovery_hint'] = $this->recoveryHint;
        }

        if (!empty($this->additionalHeaders)) {
            $array['additional_headers'] = $this->additionalHeaders;
        }

        return $array;
    }

    /**
     * Create from array (for testing/migration).
     *
     * @param array<string, mixed> $data
     */
    public static function fromArray(array $data): self
    {
        return new self(
            exceptionClass: $data['exception_class'] ?? '',
            errorLevel: ErrorSeverity::from($data['error_level'] ?? 'ERROR'),
            httpStatus: $data['http_status'] ?? 500,
            errorCode: $data['error_code'] ?? null,
            errorCategory: $data['error_category'] ?? null,
            errorSeverity: $data['error_severity'] ?? null,
            isRecoverable: $data['is_recoverable'] ?? null,
            recoveryHint: $data['recovery_hint'] ?? null,
            additionalHeaders: $data['additional_headers'] ?? []
        );
    }
}