// Куда в интерфейсе положить каждую запись issues (P6-5): у строки, ячейки, колонки, поля шапки или у документа.
// Только показ: данные не меняются.
import type { ColumnOut, IssueOut, Severity } from '../../types/api';
import { columnTitle } from './reviewView';
import { type GridRow, cellKey } from './statementGrid';

export const HEADER_BLOCK_FIELDS = ['organization_name', 'inn', 'report_date', 'units'] as const;

export interface IssuePlaces {
	byRow: Map<string, IssueOut[]>;
	/** ключ — cellKey(rowKey, columnId) */
	byCell: Map<string, IssueOut[]>;
	byColumn: Map<string, IssueOut[]>;
	byField: Map<string, IssueOut[]>;
	document: IssueOut[];
}

export interface IssueListItem {
	id: string;
	severity: Severity;
	message: string;
	place: string;
	targetKey: string | null;
}

const push = (map: Map<string, IssueOut[]>, key: string, issue: IssueOut) => {
	const list = map.get(key);
	if (list) list.push(issue);
	else map.set(key, [issue]);
};

export function issuePlaces(
	issues: IssueOut[],
	rows: GridRow[],
	columns: ColumnOut[],
	fields: readonly string[] = HEADER_BLOCK_FIELDS,
): IssuePlaces {
	const places: IssuePlaces = { byRow: new Map(), byCell: new Map(), byColumn: new Map(), byField: new Map(), document: [] };
	const rowByLineId = new Map<string, GridRow>();
	for (const r of rows) if (r.lineId !== null) rowByLineId.set(r.lineId, r);
	const columnIds = new Set(columns.map((c) => c.id));
	for (const issue of issues) {
		const lineIds = issue.line_ids ?? [];
		if (issue.field !== null) {
			if (fields.includes(issue.field)) push(places.byField, issue.field, issue);
			else places.document.push(issue);
			continue;
		}
		const known = lineIds.map((id) => rowByLineId.get(id)).filter((r): r is GridRow => r !== undefined);
		const columnId = issue.column_id !== null && columnIds.has(issue.column_id) ? issue.column_id : null;
		if (lineIds.length > 0 && known.length > 0) {
			for (const r of known) {
				if (columnId !== null) push(places.byCell, cellKey(r.key, columnId), issue);
				else push(places.byRow, r.key, issue);
			}
		} else if (lineIds.length === 0 && columnId !== null) {
			push(places.byColumn, columnId, issue);
		} else {
			places.document.push(issue);
		}
	}
	return places;
}

const FIELD_LABELS: Record<string, string> = {
	organization_name: 'Организация',
	inn: 'ИНН',
	report_date: 'Дата отчёта',
	units: 'Единица измерения',
};

const rowTitle = (row: GridRow): string => {
	switch (row.lineStatus) {
		case 'ok':
			return `строка ${row.code ?? ''}`.trim();
		case 'detail':
			return `расшифровка «${row.name ?? ''}»`;
		default: {
			const text = row.codeText?.trim();
			return text ? `строка без кода «${text}»` : 'строка без кода';
		}
	}
};

const SEVERITY_ORDER: Record<Severity, number> = { error: 0, info: 1 };

/** Список предупреждений документа: только kind = warning, сначала error, затем info, внутри — как пришло. */
export function issueListItems(issues: IssueOut[], places: IssuePlaces, rows: GridRow[], columns: ColumnOut[]): IssueListItem[] {
	const rowByLineId = new Map<string, GridRow>();
	for (const r of rows) if (r.lineId !== null) rowByLineId.set(r.lineId, r);
	const columnById = new Map(columns.map((c) => [c.id, c]));
	const inDocument = new Set(places.document);
	const items = issues
		.filter((issue) => issue.kind === 'warning')
		.map((issue): IssueListItem => {
			const first = (issue.line_ids ?? []).map((id) => rowByLineId.get(id)).find((r) => r !== undefined);
			const column = issue.column_id !== null ? columnById.get(issue.column_id) : undefined;
			let place: string;
			let targetKey: string | null = null;
			if (inDocument.has(issue)) {
				place =
					issue.column_index !== null && issue.column_id === null ? `столбец ${issue.column_index + 1} вне колонок формы` : 'документ';
			} else if (issue.field !== null) {
				place = `поле «${FIELD_LABELS[issue.field] ?? issue.field}»`;
			} else if (first) {
				targetKey = first.key;
				place = column ? `${rowTitle(first)}, колонка «${columnTitle(column)}»` : rowTitle(first);
			} else {
				place = column ? `колонка «${columnTitle(column)}»` : 'документ';
			}
			return { id: issue.id, severity: issue.severity, message: issue.message, place, targetKey };
		});
	// сортировка устойчивая: порядок issues внутри уровня сохраняется
	return items.sort((a, b) => SEVERITY_ORDER[a.severity] - SEVERITY_ORDER[b.severity]);
}

export function worstSeverity(issues: IssueOut[]): Severity | null {
	if (issues.length === 0) return null;
	return issues.some((i) => i.severity === 'error') ? 'error' : 'info';
}

/** Свёрнутый список предупреждений (T11.11): первые `limit` (порядок уже «ошибки первыми») и сколько скрыто. */
export function collapseIssues<T>(items: T[], expanded: boolean, limit: number): { shown: T[]; hidden: number } {
	if (expanded || items.length <= limit) return { shown: items, hidden: 0 };
	return { shown: items.slice(0, limit), hidden: items.length - limit };
}