import { fail } from '@sveltejs/kit';
import prisma from '$lib/server/prisma';
import type { Actions } from './$types';

export const actions: Actions = {
	import: async ({ request }) => {
		const formData = await request.formData();
		const file = formData.get('csvFile') as File;

		if (!file || file.size === 0) {
			return fail(400, {
				error: 'Please select a CSV file'
			});
		}

		try {
			const text = await file.text();
			const lines = text.split('\n').filter((line) => line.trim());

			// Skip header line
			const dataLines = lines.slice(1);

			const legislations = [];
			let errorCount = 0;
			const errors: string[] = [];

			for (let i = 0; i < dataLines.length; i++) {
				const line = dataLines[i].trim();
				if (!line) continue;

				try {
					// Split CSV line (simple implementation - may need more robust CSV parsing)
					const columns = line.split(',').map((col) => col.trim().replace(/^"|"$/g, ''));

					// Map CSV columns to database fields
					// Adjust indices based on your CSV structure
					const legislation = {
						number: columns[0] || null,
						title: columns[1] || null,
						dateGazetted: columns[2] ? new Date(columns[2]) : null,
						gazetteDetails: columns[3] || null,
						kenyaGazetteSuppNo: columns[4] || null,
						availability: columns[5] || null,
						availabilityAt: columns[6] ? new Date(columns[6]) : null,
						uploadedAt: columns[7] ? new Date(columns[7]) : null,
						kgsPublicationAt: columns[8] ? new Date(columns[8]) : null,
						commencementAt: columns[9] ? new Date(columns[9]) : null,
						revocationsAmendments: columns[10] || null,
						pagination: columns[11] || null,
						statusOnDatabase: columns[12] || null,
						legislativeUpdates: columns[13] || null,
						comments: columns[14] || null,
						year: new Date().getFullYear(), // Default to current year
						type: 'SUBLEG' as const // Default type
					};

					// Extract year from number if available (e.g., "L.N. 1 of 2023")
					if (legislation.number) {
						const yearMatch = legislation.number.match(/(\d{4})/);
						if (yearMatch) {
							legislation.year = parseInt(yearMatch[1]);
						}
					}

					legislations.push(legislation);
				} catch (lineError) {
					errorCount++;
					errors.push(`Line ${i + 2}: ${lineError}`);
				}
			}

			if (legislations.length === 0) {
				return fail(400, {
					error: 'No valid data found in CSV file'
				});
			}

			// Bulk insert
			const result = await prisma.legislationItem.createMany({
				data: legislations,
				skipDuplicates: true
			});

			return {
				success: true,
				imported: result.count,
				errors: errors.length > 0 ? errors : null
			};
		} catch (error) {
			console.error('CSV import error:', error);
			return fail(500, {
				error: 'Failed to process CSV file'
			});
		}
	}
};