import { average, geometricMean, sizeNumber } from '$lib/helpers/leaderboard';
import type { RankingDataset } from '$lib/types/ranking-data';
import type { BenchmarkScope, GuardModel } from '$lib/types/leaderboard';
import type {
	BenchmarkDetail,
	LanguageFilter,
	LeaderboardRow,
	SortDirection,
	SortKey
} from '$lib/types/ranking';

function isFiniteNumber(value: number | null): value is number {
	return typeof value === 'number' && Number.isFinite(value);
}

export function rankingScopeGroups(scope: BenchmarkScope, dataset: RankingDataset) {
	if (scope === 'robust') return dataset.robustGroups;
	if (scope === 'en') {
		return dataset.allGroups.filter((group) => dataset.groupLanguages[group]?.includes('en'));
	}
	return [...dataset.allGroups];
}

export function filterRankingGroups(
	groups: readonly string[],
	selectedGroups: readonly string[],
	allGroupsSelected: boolean,
	selectedLanguage: LanguageFilter,
	groupLanguages: RankingDataset['groupLanguages']
) {
	let filtered = [...groups];

	if (!allGroupsSelected) {
		filtered = filtered.filter((group) => selectedGroups.includes(group));
	}

	if (selectedLanguage === 'en') {
		filtered = filtered.filter((group) => groupLanguages[group]?.includes('en'));
	}

	if (selectedLanguage === 'ru') {
		filtered = filtered.filter((group) => groupLanguages[group]?.includes('ru'));
	}

	return filtered.length ? filtered : [...groups];
}

export function deriveRankingRow(
	model: GuardModel,
	groups: readonly string[],
	useOverall: boolean,
	allGroupCount: number
): LeaderboardRow {
	if (useOverall) {
		return {
			model,
			integral: model.integral,
			minGroup: model.minGroup,
			fpr: model.fpr,
			fnr: model.fnr,
			f1: model.f1,
			p95: model.p95,
			size: model.size,
			covered: allGroupCount
		};
	}

	const selectedScores = groups.map((group) => model.groups[group]).filter(Boolean);
	const scores = selectedScores.map((group) => group.score).filter(isFiniteNumber);
	const scopedIntegral = geometricMean(scores);

	return {
		model,
		integral: scopedIntegral ?? model.integral,
		minGroup: scores.length ? Math.min(...scores) : model.minGroup,
		fpr: average(selectedScores.map((group) => group.fpr)),
		fnr: average(selectedScores.map((group) => group.fnr)),
		f1: model.f1,
		p95: model.p95,
		size: model.size,
		covered: selectedScores.length
	};
}

export function buildRankingRows(
	groups: readonly string[],
	useOverall: boolean,
	sourceModels: readonly GuardModel[],
	allGroupCount: number
) {
	return sourceModels.map((model) => deriveRankingRow(model, groups, useOverall, allGroupCount));
}

export function rankingSortValue(row: LeaderboardRow, key: SortKey) {
	if (key === 'integral') return row.integral;
	if (key === 'minGroup') return row.minGroup;
	if (key === 'fpr') return row.fpr;
	if (key === 'fnr') return row.fnr;
	if (key === 'p95') return row.p95;
	return sizeNumber(row.size);
}

export function compareRankingRows(
	a: LeaderboardRow,
	b: LeaderboardRow,
	key: SortKey,
	direction: SortDirection
) {
	const first = rankingSortValue(a, key);
	const second = rankingSortValue(b, key);
	const firstMissing = !Number.isFinite(first);
	const secondMissing = !Number.isFinite(second);

	if (firstMissing && secondMissing) return 0;
	if (firstMissing) return 1;
	if (secondMissing) return -1;

	const multiplier = direction === 'asc' ? 1 : -1;
	return (Number(first) - Number(second)) * multiplier;
}

export function benchmarkDetails(model: GuardModel, groups: readonly string[]): BenchmarkDetail[] {
	return groups
		.map((group) => ({
			name: group,
			score: model.groups[group]?.score ?? null,
			minDatasetScore: model.groups[group]?.minDatasetScore ?? null,
			fpr: model.groups[group]?.fpr ?? null,
			fnr: model.groups[group]?.fnr ?? null,
			f1: model.groups[group]?.f1 ?? null
		}))
		.filter((group) => group.score !== null || group.fpr !== null || group.fnr !== null)
		.sort((a, b) => (b.score ?? -1) - (a.score ?? -1));
}

export function rankingRowsToCsv(items: readonly LeaderboardRow[]) {
	const header = [
		'rank',
		'model',
		'size',
		'integral',
		'min_group',
		'overall_fpr',
		'overall_fnr',
		'overall_f1',
		'p95_ms',
		'run_date'
	];
	const lines = items.map((row, index) =>
		[
			index + 1,
			row.model.name,
			row.size,
			row.integral.toFixed(4),
			row.minGroup.toFixed(4),
			row.fpr?.toFixed(4) ?? '',
			row.fnr?.toFixed(4) ?? '',
			row.f1.toFixed(4),
			row.p95.toFixed(1),
			row.model.runDate
		]
			.map((cell) => `"${String(cell).replaceAll('"', '""')}"`)
			.join(',')
	);

	return [header.join(','), ...lines].join('\n');
}