/**
 * Storage service for S3 file uploads via pre-signed URLs
 */

import { getApiV1Url } from "./config";

// API_URL getter - uses runtime config

interface UploadUrlResponse {
    uploadUrl: string;
    key: string;
    publicUrl: string;
    expiresIn: number;
}

interface DownloadUrlResponse {
    downloadUrl: string;
    expiresIn: number;
}

/**
 * Get a pre-signed URL for uploading a file
 */
export async function getUploadUrl(
    filename: string,
    contentType: string,
    folder: 'logos' | 'resumes' | 'documents' | 'avatars' = 'documents'
): Promise<UploadUrlResponse> {
    const response = await fetch(`${getApiV1Url()}/storage/upload-url`, {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
        },
        credentials: 'include', // Use httpOnly cookie
        body: JSON.stringify({
            filename,
            contentType,
            folder,
        }),
    });

    if (!response.ok) {
        const error = await response.text();
        throw new Error(`Failed to get upload URL: ${error}`);
    }

    return response.json();
}

/**
 * Upload a file directly to S3 using a pre-signed URL
 */
export async function uploadFileToS3(
    file: File,
    uploadUrl: string
): Promise<void> {
    const response = await fetch(uploadUrl, {
        method: 'PUT',
        headers: {
            'Content-Type': file.type,
        },
        body: file,
    });

    if (!response.ok) {
        throw new Error(`Failed to upload file: ${response.statusText}`);
    }
}

/**
 * Get a pre-signed URL for downloading a file
 */
export async function getDownloadUrl(key: string): Promise<DownloadUrlResponse> {
    const response = await fetch(`${getApiV1Url()}/storage/download-url`, {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
        },
        credentials: 'include', // Use httpOnly cookie
        body: JSON.stringify({ key }),
    });

    if (!response.ok) {
        const error = await response.text();
        throw new Error(`Failed to get download URL: ${error}`);
    }

    return response.json();
}

/**
 * Complete file upload workflow: get pre-signed URL and upload file
 * Returns the public URL of the uploaded file
 */
export async function uploadFile(
    file: File,
    folder: 'logos' | 'resumes' | 'documents' | 'avatars' = 'documents'
): Promise<{ key: string; publicUrl: string }> {
    // Step 1: Get pre-signed upload URL from backend
    const { uploadUrl, key, publicUrl } = await getUploadUrl(
        file.name,
        file.type,
        folder
    );

    // Step 2: Upload file directly to S3
    await uploadFileToS3(file, uploadUrl);

    return { key, publicUrl };
}

/**
 * Delete a file from storage
 */
export async function deleteFile(key: string): Promise<void> {
    const response = await fetch(`${getApiV1Url()}/storage/files?key=${encodeURIComponent(key)}`, {
        method: 'DELETE',
        credentials: 'include', // Use httpOnly cookie
    });

    if (!response.ok) {
        const error = await response.text();
        throw new Error(`Failed to delete file: ${error}`);
    }
}