import { mkdir, writeFile } from 'node:fs/promises';
import { dirname, resolve } from 'node:path';

import type { ScanReport } from '../index.js';
import { generateHTML } from './template.js';

/**
 * Generates and persists the S-Edition HTML report under `.supreme2l/reports`.
 */
export async function generateReport(
	projectPath: string,
	report: ScanReport,
): Promise<{ verifiedPath: string; rawPath: string }> {
	const normalizedReport: ScanReport = {
		...report,
		meta: {
			...report.meta,
			s_edition_version: '1.0.0',
		},
	};

	const allCodeFindings = [...normalizedReport.confirmed_findings, ...normalizedReport.filtered_fp];
	const verifiedFindings = allCodeFindings.filter(
		(finding) =>
			finding.fp_analysis.is_likely_fp === false && finding.fp_analysis.reason !== 'verification_skipped_quota',
	);

	const timestamp = formatFileTimestamp(new Date());
	const verifiedFileName = `s-edition-report-${timestamp}.html`;
	const rawFileName = `s-edition-raw-report-${timestamp}.html`;
	const verifiedPath = resolve(projectPath, '.supreme2l', 'reports', verifiedFileName);
	const rawPath = resolve(projectPath, '.supreme2l', 'reports', rawFileName);

	const verifiedReport: ScanReport = {
		...normalizedReport,
		summary: {
			...normalizedReport.summary,
			confirmed: verifiedFindings.length,
			false_positives_filtered: normalizedReport.filtered_fp.length,
			by_severity: countBySeverity(verifiedFindings),
		},
		confirmed_findings: verifiedFindings,
	};

	const rawReport: ScanReport = {
		...normalizedReport,
		summary: {
			...normalizedReport.summary,
			confirmed: allCodeFindings.length,
			false_positives_filtered: 0,
			unverified: 0,
			by_severity: countBySeverity(allCodeFindings),
		},
		confirmed_findings: allCodeFindings,
		filtered_fp: [],
	};

	const verifiedHtml = generateHTML(verifiedReport);
	const rawHtml = generateHTML(rawReport, { isRaw: true });

	await mkdir(dirname(verifiedPath), { recursive: true });
	await writeFile(verifiedPath, verifiedHtml, 'utf8');
	await writeFile(rawPath, rawHtml, 'utf8');

	return { verifiedPath, rawPath };
}

function countBySeverity(findings: Array<{ severity: string }>): Record<string, number> {
	const counts: Record<string, number> = {
		CRITICAL: 0,
		HIGH: 0,
		MEDIUM: 0,
		LOW: 0,
		UNDEFINED: 0,
	};

	for (const finding of findings) {
		const severity = finding.severity.toUpperCase();
		if (counts[severity] !== undefined) {
			counts[severity] += 1;
		} else {
			counts.UNDEFINED += 1;
		}
	}

	return counts;
}

function formatFileTimestamp(date: Date): string {
	const year = String(date.getFullYear());
	const month = String(date.getMonth() + 1).padStart(2, '0');
	const day = String(date.getDate()).padStart(2, '0');
	const hours = String(date.getHours()).padStart(2, '0');
	const minutes = String(date.getMinutes()).padStart(2, '0');
	const seconds = String(date.getSeconds()).padStart(2, '0');

	return `${year}${month}${day}-${hours}${minutes}${seconds}`;
}