<?php

declare(strict_types=1);

namespace KTXM\Mail\Stores;

use DI\Attribute\Inject;
use KTXF\Resource\BinaryResource;

final class CompositionStore {

    private const COMPOSITION_FILENAME = 'composition.json';

    private string $storagePath;

    public function __construct(
        #[Inject('rootDir')] private readonly string $rootDir,
    ) {
        $this->storagePath = $this->rootDir . '/var/cache/mail/composer';
    }

    public function compositionFetch(string $tenantId, string $userId, string $draftId): ?array {
        $draftDir = $this->draftDir($tenantId, $userId, $draftId);
        if (!is_dir($draftDir)) {
            return null;
        }

        $messagePath = $draftDir . '/' . self::COMPOSITION_FILENAME;
        if (!file_exists($messagePath)) {
            return null;
        }

        $decoded = json_decode((string)file_get_contents($messagePath), true);
        return is_array($decoded) ? $decoded : null;
    }

    public function compositionSave(string $tenantId, string $userId, string $draftId, array $snapshot): array {
        $draftDir = $this->draftDir($tenantId, $userId, $draftId);
        if (!is_dir($draftDir)) {
            mkdir($draftDir, 0755, true);
        }

        file_put_contents($draftDir . '/' . self::COMPOSITION_FILENAME, json_encode($snapshot, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES));
        return $snapshot;
    }

    public function compositionDiscard(string $tenantId, string $userId, string $draftId): bool {
        $draftDir = $this->draftDir($tenantId, $userId, $draftId);
        if (!is_dir($draftDir)) {
            return false;
        }

        $this->deleteDir($draftDir);
        return true;
    }

    public function attachmentStageFromStream(
        string $tenantId,
        string $userId,
        string $compositionId,
        string $attachmentId,
        BinaryResource $data,
    ): array {
        $attachmentDir = $this->attachmentDir($tenantId, $userId, $compositionId);
        if (!is_dir($attachmentDir)) {
            mkdir($attachmentDir, 0755, true);
        }

        $contentPath = $attachmentDir . '/' . $attachmentId . '.blob';
        $handle = fopen($contentPath, 'wb');
        $size = 0;

        foreach ($data->stream() as $chunk) {
            $chunkString = (string)$chunk;
            $size += strlen($chunkString);
            fwrite($handle, $chunkString);
        }

        fclose($handle);

        $meta = [
            'identifier' => $attachmentId,
            'composition' => $compositionId,
            'name' => $data->filename(),
            'type' => $data->mimeType(),
            'size' => $size,
        ];

        file_put_contents($attachmentDir . '/' . $attachmentId . '.meta', json_encode($meta, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES));

        return $meta;
    }

    public function attachmentStageFromBase64(
        string $tenantId,
        string $userId,
        string $compositionId,
        string $attachmentId,
        string $name,
        string $type,
        string $data,
    ): array {
        $decoded = base64_decode($data, true);
        if ($decoded === false) {
            throw new \InvalidArgumentException('Attachment payload is not valid base64');
        }

        $attachmentDir = $this->attachmentDir($tenantId, $userId, $compositionId);
        if (!is_dir($attachmentDir)) {
            mkdir($attachmentDir, 0755, true);
        }

        file_put_contents($attachmentDir . '/' . $attachmentId . '.blob', $decoded);

        $metadata = [
            'identifier' => $attachmentId,
            'composition' => $compositionId,
            'name' => $name,
            'type' => $type,
            'size' => strlen($decoded),
        ];

        file_put_contents($attachmentDir . '/' . $attachmentId . '.meta', json_encode($metadata, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES));

        return $metadata;
    }

    public function attachmentFetchData(string $tenantId, string $userId, string $compositionId, string $attachmentId): ?string {
        $path = $this->attachmentDir($tenantId, $userId, $compositionId) . '/' . $attachmentId . '.blob';
        if (!file_exists($path)) {
            return null;
        }

        return file_get_contents($path) ?: null;
    }

    public function fetchAttachmentMeta(string $tenantId, string $userId, string $compositionId, string $attachmentId): ?array {
        $path = $this->attachmentDir($tenantId, $userId, $compositionId) . '/' . $attachmentId . '.meta';
        if (!file_exists($path)) {
            return null;
        }

        $decoded = json_decode((string)file_get_contents($path), true);
        return is_array($decoded) ? $decoded : null;
    }

    private function attachmentDir(string $tenantId, string $userId, string $draftId): string {
        return $this->draftDir($tenantId, $userId, $draftId) . '/attachments';
    }

    private function draftDir(string $tenantId, string $userId, string $draftId): string {
        return $this->storagePath . '/' . $tenantId . '/' . $userId . '/' . $draftId;
    }

    private function deleteDir(string $path): void {
        if (!is_dir($path)) {
            return;
        }

        foreach (scandir($path) ?: [] as $entry) {
            if ($entry === '.' || $entry === '..') {
                continue;
            }

            $child = $path . '/' . $entry;
            if (is_dir($child)) {
                $this->deleteDir($child);
                continue;
            }

            unlink($child);
        }

        rmdir($path);
    }
}