feat: Implement file upload and management system with database integration

src/app/api/files/[fileId]/route.js

@@ -0,0 +1,79 @@
+import { NextResponse } from "next/server";
+import { unlink } from "fs/promises";
+import path from "path";
+import db from "@/lib/db";
+
+export async function DELETE(request, { params }) {
+	try {
+		const fileId = params.fileId;
+
+		// Get file info from database
+		const file = db.prepare(`
+			SELECT * FROM file_attachments WHERE file_id = ?
+		`).get(parseInt(fileId));
+
+		if (!file) {
+			return NextResponse.json(
+				{ error: "File not found" },
+				{ status: 404 }
+			);
+		}
+
+		// Delete physical file
+		try {
+			const fullPath = path.join(process.cwd(), "public", file.file_path);
+			await unlink(fullPath);
+		} catch (fileError) {
+			console.warn("Could not delete physical file:", fileError.message);
+			// Continue with database deletion even if file doesn't exist
+		}
+
+		// Delete from database
+		const result = db.prepare(`
+			DELETE FROM file_attachments WHERE file_id = ?
+		`).run(parseInt(fileId));
+
+		if (result.changes === 0) {
+			return NextResponse.json(
+				{ error: "File not found" },
+				{ status: 404 }
+			);
+		}
+
+		return NextResponse.json({ success: true });
+
+	} catch (error) {
+		console.error("Error deleting file:", error);
+		return NextResponse.json(
+			{ error: "Failed to delete file" },
+			{ status: 500 }
+		);
+	}
+}
+
+export async function GET(request, { params }) {
+	try {
+		const fileId = params.fileId;
+
+		// Get file info from database
+		const file = db.prepare(`
+			SELECT * FROM file_attachments WHERE file_id = ?
+		`).get(parseInt(fileId));
+
+		if (!file) {
+			return NextResponse.json(
+				{ error: "File not found" },
+				{ status: 404 }
+			);
+		}
+
+		return NextResponse.json(file);
+
+	} catch (error) {
+		console.error("Error fetching file:", error);
+		return NextResponse.json(
+			{ error: "Failed to fetch file" },
+			{ status: 500 }
+		);
+	}
+}

src/app/api/files/route.js

@@ -0,0 +1,162 @@
+import { NextRequest, NextResponse } from "next/server";
+import { writeFile, mkdir } from "fs/promises";
+import { existsSync } from "fs";
+import path from "path";
+import db from "@/lib/db";
+import { auditLog } from "@/lib/middleware/auditLog";
+
+const UPLOAD_DIR = path.join(process.cwd(), "public", "uploads");
+const MAX_FILE_SIZE = 10 * 1024 * 1024; // 10MB
+const ALLOWED_TYPES = [
+	"application/pdf",
+	"application/msword",
+	"application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+	"application/vnd.ms-excel",
+	"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+	"image/jpeg",
+	"image/png",
+	"image/gif",
+	"text/plain"
+];
+
+export async function POST(request) {
+	try {
+		const formData = await request.formData();
+		const file = formData.get("file");
+		const entityType = formData.get("entityType");
+		const entityId = formData.get("entityId");
+		const description = formData.get("description") || "";
+
+		if (!file || !entityType || !entityId) {
+			return NextResponse.json(
+				{ error: "File, entityType, and entityId are required" },
+				{ status: 400 }
+			);
+		}
+
+		// Validate entity type
+		if (!["contract", "project", "task"].includes(entityType)) {
+			return NextResponse.json(
+				{ error: "Invalid entity type" },
+				{ status: 400 }
+			);
+		}
+
+		// Validate file
+		if (file.size > MAX_FILE_SIZE) {
+			return NextResponse.json(
+				{ error: "File size too large (max 10MB)" },
+				{ status: 400 }
+			);
+		}
+
+		if (!ALLOWED_TYPES.includes(file.type)) {
+			return NextResponse.json(
+				{ error: "File type not allowed" },
+				{ status: 400 }
+			);
+		}
+
+		// Create upload directory structure
+		const entityDir = path.join(UPLOAD_DIR, entityType + "s", entityId);
+		if (!existsSync(entityDir)) {
+			await mkdir(entityDir, { recursive: true });
+		}
+
+		// Generate unique filename
+		const timestamp = Date.now();
+		const sanitizedOriginalName = file.name.replace(/[^a-zA-Z0-9.-]/g, "_");
+		const storedFilename = `${timestamp}_${sanitizedOriginalName}`;
+		const filePath = path.join(entityDir, storedFilename);
+		const relativePath = `/uploads/${entityType}s/${entityId}/${storedFilename}`;
+
+		// Save file
+		const bytes = await file.arrayBuffer();
+		const buffer = Buffer.from(bytes);
+		await writeFile(filePath, buffer);
+
+		// Save to database
+		const stmt = db.prepare(`
+			INSERT INTO file_attachments (
+				entity_type, entity_id, original_filename, stored_filename, 
+				file_path, file_size, mime_type, description, uploaded_by
+			) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
+		`);
+
+		const result = stmt.run(
+			entityType,
+			parseInt(entityId),
+			file.name,
+			storedFilename,
+			relativePath,
+			file.size,
+			file.type,
+			description,
+			null // TODO: Get from session when auth is implemented
+		);
+
+		const newFile = {
+			file_id: result.lastInsertRowid,
+			entity_type: entityType,
+			entity_id: parseInt(entityId),
+			original_filename: file.name,
+			stored_filename: storedFilename,
+			file_path: relativePath,
+			file_size: file.size,
+			mime_type: file.type,
+			description: description,
+			upload_date: new Date().toISOString()
+		};
+
+		return NextResponse.json(newFile, { status: 201 });
+
+	} catch (error) {
+		console.error("File upload error:", error);
+		return NextResponse.json(
+			{ error: "Failed to upload file" },
+			{ status: 500 }
+		);
+	}
+}
+
+export async function GET(request) {
+	try {
+		const { searchParams } = new URL(request.url);
+		const entityType = searchParams.get("entityType");
+		const entityId = searchParams.get("entityId");
+
+		if (!entityType || !entityId) {
+			return NextResponse.json(
+				{ error: "entityType and entityId are required" },
+				{ status: 400 }
+			);
+		}
+
+		const files = db.prepare(`
+			SELECT 
+				file_id,
+				entity_type,
+				entity_id,
+				original_filename,
+				stored_filename,
+				file_path,
+				file_size,
+				mime_type,
+				description,
+				upload_date,
+				uploaded_by
+			FROM file_attachments 
+			WHERE entity_type = ? AND entity_id = ?
+			ORDER BY upload_date DESC
+		`).all(entityType, parseInt(entityId));
+
+		return NextResponse.json(files);
+
+	} catch (error) {
+		console.error("Error fetching files:", error);
+		return NextResponse.json(
+			{ error: "Failed to fetch files" },
+			{ status: 500 }
+		);
+	}
+}

src/app/contracts/[id]/page.js

@@ -10,6 +10,8 @@ import PageContainer from "@/components/ui/PageContainer";
 import PageHeader from "@/components/ui/PageHeader";
 import { LoadingState } from "@/components/ui/States";
 import { formatDate } from "@/lib/utils";
+import FileUploadModal from "@/components/FileUploadModal";
+import FileAttachmentsList from "@/components/FileAttachmentsList";
 
 export default function ContractDetailsPage() {
 	const params = useParams();
@@ -17,6 +19,8 @@ export default function ContractDetailsPage() {
 	const [contract, setContract] = useState(null);
 	const [projects, setProjects] = useState([]);
 	const [loading, setLoading] = useState(true);
+	const [showUploadModal, setShowUploadModal] = useState(false);
+	const [attachments, setAttachments] = useState([]);
 
 	useEffect(() => {
 		async function fetchContractDetails() {
@@ -52,6 +56,14 @@ export default function ContractDetailsPage() {
 			fetchContractDetails();
 		}
 	}, [contractId]);
+	const handleFileUploaded = (newFile) => {
+		setAttachments(prev => [newFile, ...prev]);
+	};
+
+	const handleFilesChange = (files) => {
+		setAttachments(files);
+	};
+
 	if (loading) {
 		return (
 			<PageContainer>
@@ -245,6 +257,44 @@ export default function ContractDetailsPage() {
 				</div>
 			</div>
 
+			{/* Contract Documents */}
+			<Card className="mb-8">
+				<CardHeader>
+					<div className="flex justify-between items-center">
+						<h2 className="text-xl font-semibold text-gray-900">
+							Contract Documents ({attachments.length})
+						</h2>
+						<Button
+							variant="primary"
+							size="sm"
+							onClick={() => setShowUploadModal(true)}
+						>
+							<svg
+								className="w-4 h-4 mr-2"
+								fill="none"
+								stroke="currentColor"
+								viewBox="0 0 24 24"
+							>
+								<path
+									strokeLinecap="round"
+									strokeLinejoin="round"
+									strokeWidth={2}
+									d="M7 16a4 4 0 01-.88-7.903A5 5 0 1115.9 6L16 6a5 5 0 011 9.9M15 13l-3-3m0 0l-3 3m3-3v12"
+								/>
+							</svg>
+							Upload Document
+						</Button>
+					</div>
+				</CardHeader>
+				<CardContent>
+					<FileAttachmentsList
+						entityType="contract"
+						entityId={contractId}
+						onFilesChange={handleFilesChange}
+					/>
+				</CardContent>
+			</Card>
+
 			{/* Associated Projects */}
 			<Card>
 				<CardHeader>
@@ -386,6 +436,15 @@ export default function ContractDetailsPage() {
 					)}
 				</CardContent>
 			</Card>
+
+			{/* File Upload Modal */}
+			<FileUploadModal
+				isOpen={showUploadModal}
+				onClose={() => setShowUploadModal(false)}
+				entityType="contract"
+				entityId={contractId}
+				onFileUploaded={handleFileUploaded}
+			/>
 		</PageContainer>
 	);
 }