<?php
// HttpUploadedFile.php
// Created: 2022-02-10
// Updated: 2024-08-01

namespace Index\Http;

use Index\MediaType;
use Index\ICloseable;
use Index\IO\Stream;
use Index\IO\FileStream;
use InvalidArgumentException;
use RuntimeException;

/**
 * Represents an uploaded file in a multipart/form-data request.
 */
class HttpUploadedFile implements ICloseable {
    private int $errorCode;
    private int $size;
    private string $localFileName;
    private string $suggestedFileName;
    private MediaType $suggestedMediaType;
    private bool $hasMoved = false;
    private ?Stream $stream = null;

    /**
     * @param int $errorCode PHP file upload error code.
     * @param int $size Size, as provided by the client.
     * @param string $localFileName Filename generated by PHP on the server.
     * @param string $suggestedFileName Filename included by the client.
     * @param MediaType|string $suggestedMediaType Mediatype included by the client.
     */
    public function __construct(
        int $errorCode,
        int $size,
        string $localFileName,
        string $suggestedFileName,
        MediaType|string $suggestedMediaType
    ) {
        if(!($suggestedMediaType instanceof MediaType))
            $suggestedMediaType = MediaType::parse($suggestedMediaType);

        $this->errorCode = $errorCode;
        $this->size = $size;
        $this->localFileName = $localFileName;
        $this->suggestedFileName = $suggestedFileName;
        $this->suggestedMediaType = $suggestedMediaType;
    }

    /**
     * Retrieves the PHP file upload error code.
     *
     * @return int PHP file upload error code.
     */
    public function getErrorCode(): int {
        return $this->errorCode;
    }

    /**
     * Retrieves the size of the uploaded file.
     *
     * @return int Size of uploaded file.
     */
    public function getSize(): int {
        return $this->size;
    }

    /**
     * Retrieves the local path to the uploaded file.
     *
     * @return ?string Path to file, or null.
     */
    public function getLocalFileName(): ?string {
        return $this->localFileName;
    }

    /**
     * Retrieves media type of the uploaded file.
     *
     * @return ?MediaType Type of file, or null.
     */
    public function getLocalMediaType(): ?MediaType {
        return MediaType::fromPath($this->localFileName);
    }

    /**
     * Retrieves the suggested name for the uploaded file.
     *
     * @return string Suggested name for the file.
     */
    public function getSuggestedFileName(): string {
        return $this->suggestedFileName;
    }

    /**
     * Retrieves the suggested media type for the uploaded file.
     *
     * @return MediaType Suggested type for the file.
     */
    public function getSuggestedMediaType(): MediaType {
        return $this->suggestedMediaType;
    }

    /**
     * Checks whether the file has been moved to its final destination.
     *
     * @return bool true if it has been moved.
     */
    public function hasMoved(): bool {
        return $this->hasMoved;
    }

    /**
     * Gets a read-only stream to the uploaded file.
     *
     * @throws RuntimeException If the file cannot be opened.
     * @return Stream Read-only stream of the upload file.
     */
    public function getStream(): Stream {
        if($this->stream === null) {
            if($this->errorCode !== UPLOAD_ERR_OK)
                throw new RuntimeException('Can\'t open stream because of an upload error.');
            if($this->hasMoved)
                throw new RuntimeException('Can\'t open stream because file has already been moved.');

            $this->stream = FileStream::openRead($this->localFileName);
        }

        return $this->stream;
    }

    /**
     * Moves the uploaded file to its final destination.
     *
     * @param string $path Path to move the file to.
     * @throws RuntimeException If the file has already been moved.
     * @throws RuntimeException If an upload error occurred.
     * @throws InvalidArgumentException If the provided $path is not valid.
     * @throws RuntimeException If the file failed to move.
     */
    public function moveTo(string $path): void {
        if($this->hasMoved)
            throw new RuntimeException('This uploaded file has already been moved.');
        if($this->errorCode !== UPLOAD_ERR_OK)
            throw new RuntimeException('Can\'t move file because of an upload error.');

        if(empty($path))
            throw new InvalidArgumentException('$path is not a valid path.');

        if($this->stream !== null)
            $this->stream->close();

        $this->hasMoved = PHP_SAPI === 'CLI'
            ? rename($this->localFileName, $path)
            : move_uploaded_file($this->localFileName, $path);

        if(!$this->hasMoved)
            throw new RuntimeException('Failed to move file to ' . $path);

        $this->localFileName = $path;
    }

    public function close(): void {
        if($this->stream !== null)
            $this->stream->close();
    }

    public function __destruct() {
        $this->close();
    }

    /**
     * Creates a HttpUploadedFile instance from an entry in the $_FILES superglobal.
     *
     * @return HttpUploadedFile Uploaded file info.
     */
    public static function createFromFILE(array $file): self {
        return new HttpUploadedFile(
            $file['error'] ?? UPLOAD_ERR_NO_FILE,
            $file['size'] ?? -1,
            $file['tmp_name'] ?? '',
            $file['name'] ?? '',
            $file['type'] ?? ''
        );
    }

    /**
     * Creates a collection of HttpUploadedFile instances from the $_FILES superglobal.
     *
     * @return array<string, mixed> Uploaded files.
     */
    public static function createFromFILES(array $files): array {
        if(empty($files))
            return [];

        return self::createObjectInstances(self::normalizeFILES($files));
    }

    private static function traverseFILES(array $files, string $keyName): array {
        $arr = [];

        foreach($files as $key => $val) {
            $key = "_{$key}";

            if(is_array($val)) {
                $arr[$key] = self::traverseFILES($val, $keyName);
            } else {
                $arr[$key][$keyName] = $val;
            }
        }

        return $arr;
    }

    private static function normalizeFILES(array $files): array {
        $out = [];

        foreach($files as $key => $arr) {
            if(empty($arr))
                continue;

            $key = '_' . $key;

            if(is_int($arr['error'])) {
                $out[$key] = $arr;
                continue;
            }

            if(is_array($arr['error'])) {
                $keys = array_keys($arr);

                foreach($keys as $keyName) {
                    $out[$key] = array_merge_recursive($out[$key] ?? [], self::traverseFILES($arr[$keyName], $keyName));
                }
                continue;
            }
        }

        return $out;
    }

    private static function createObjectInstances(array $files): array {
        $coll = [];

        foreach($files as $key => $val) {
            $key = substr($key, 1);

            if(isset($val['error'])) {
                $coll[$key] = self::createFromFILE($val);
            } else {
                $coll[$key] = self::createObjectInstances($val);
            }
        }

        return $coll;
    }
}