<?php

namespace App\Services;

use App\Services\Storage\FileStorageInterface;
use App\Services\Storage\LocalStorageDriver;
use App\Services\Storage\S3StorageDriver;
use CodeIgniter\HTTP\Files\UploadedFile;
use CodeIgniter\HTTP\ResponseInterface;
use Config\Storage;

class FileStorageService
{
    private FileStorageInterface $driver;

    private Storage $config;

    public function __construct(?Storage $config = null)
    {
        $this->config = $config ?? config('Storage');
        $this->driver = $this->createDriver($this->config->driver);
    }

    public function driver(): FileStorageInterface
    {
        return $this->driver;
    }

    public function isS3(): bool
    {
        return $this->config->driver === 's3';
    }

    public function resolveKey(string $module, string $subFolder, string $fileName): string
    {
        $module    = trim($module, '/');
        $subFolder = trim($subFolder, '/');
        $fileName  = ltrim(str_replace('\\', '/', $fileName), '/');

        if ($subFolder === '') {
            return "uploads/{$module}/{$fileName}";
        }

        return "uploads/{$module}/{$subFolder}/{$fileName}";
    }

    public function upload(UploadedFile|string $source, string $key, array $options = []): string
    {
        $storedKey = $this->driver->upload($source, $key, $options);

        if ($this->config->retainLocal && $this->isS3()) {
            (new LocalStorageDriver($this->config))->upload($source, $key, $options);
        }

        return $storedKey;
    }

    public function uploadModuleFile(
        UploadedFile $file,
        string $module,
        string $subFolder = '',
        ?string $fileName = null
    ): string {
        $fileName = $fileName ?: (time() . '_' . $file->getRandomName());

        $this->upload($file, $this->resolveKey($module, $subFolder, $fileName));

        return $fileName;
    }

    public function put(string $key, string $contents, array $options = []): string
    {
        $storedKey = $this->driver->put($key, $contents, $options);

        if ($this->config->retainLocal && $this->isS3()) {
            (new LocalStorageDriver($this->config))->put($key, $contents, $options);
        }

        return $storedKey;
    }

    public function exists(string $module, string $subFolder, string $fileName): bool
    {
        return $this->driver->exists($this->resolveKey($module, $subFolder, $fileName));
    }

    public function existsKey(string $key): bool
    {
        return $this->driver->exists($key);
    }

    public function delete(string $module, string $subFolder, string $fileName): bool
    {
        return $this->driver->delete($this->resolveKey($module, $subFolder, $fileName));
    }

    public function deleteKey(string $key): bool
    {
        return $this->driver->delete($key);
    }

    public function read(string $module, string $subFolder, string $fileName): string
    {
        return $this->driver->read($this->resolveKey($module, $subFolder, $fileName));
    }

    public function readKey(string $key): string
    {
        return $this->driver->read($key);
    }

    public function download(string $module, string $subFolder, string $fileName): ResponseInterface
    {
        return $this->driver->streamDownload(
            $this->resolveKey($module, $subFolder, $fileName),
            $fileName
        );
    }

    public function downloadKey(string $key, ?string $downloadName = null): ResponseInterface
    {
        return $this->driver->streamDownload($key, $downloadName ?: basename($key));
    }

    /**
     * Returns a local filesystem path suitable for pdftotext, Gemini, RAG, etc.
     * For S3, this downloads to a temp file first.
     */
    public function getLocalPathForProcessing(string $module, string $subFolder, string $fileName): string
    {
        return $this->getLocalPathForKey($this->resolveKey($module, $subFolder, $fileName));
    }

    public function getLocalPathForKey(string $key): string
    {
        if ($this->config->driver === 'local') {
            return rtrim($this->config->localRoot, '/\\') . DIRECTORY_SEPARATOR . ltrim(str_replace('/', DIRECTORY_SEPARATOR, $key), '/\\');
        }

        return $this->driver->downloadToTemp($key);
    }

    public function getTemporaryUrl(string $module, string $subFolder, string $fileName, ?int $ttlSeconds = null): string
    {
        return $this->getTemporaryUrlForKey(
            $this->resolveKey($module, $subFolder, $fileName),
            $ttlSeconds
        );
    }

    public function getTemporaryUrlForKey(string $key, ?int $ttlSeconds = null): string
    {
        return $this->driver->temporaryUrl($key, $ttlSeconds ?? $this->config->presignedTtl);
    }

    public function getUrl(string $module, string $subFolder, string $fileName): string
    {
        return $this->driver->url($this->resolveKey($module, $subFolder, $fileName));
    }

    public function copy(string $fromModule, string $fromSubFolder, string $fromFileName, string $toModule, string $toSubFolder, string $toFileName): bool
    {
        return $this->driver->copy(
            $this->resolveKey($fromModule, $fromSubFolder, $fromFileName),
            $this->resolveKey($toModule, $toSubFolder, $toFileName)
        );
    }

    private function createDriver(string $driver): FileStorageInterface
    {
        return match ($driver) {
            's3'    => new S3StorageDriver($this->config),
            default => new LocalStorageDriver($this->config),
        };
    }
}