import {
	DataAdapter,
	KanbanCard,
	MatrixBoard,
	MatrixConfig,
} from "./types";
import resolveScopedFolderIds from "./folderScope";
import extractGtdBlock from "./gtdBlock";
import buildKanbanCard from "./buildKanbanCard";

export interface MatrixResult {
	board: MatrixBoard;
	warnings: string[];
	scannedFolders: number;
	scannedNotes: number;
	cardCount: number;
}

/**
 * Build a 2x2 Eisenhower matrix from to-dos in scope.
 *
 *  - Notes are excluded (to-dos only).
 *  - Completed to-dos are excluded entirely: the matrix is a
 *    prioritisation view; completions live in the kanban's Done column.
 *  - Quadrants from the two axis tags:
 *      urgent + important -> Do First
 *      important only     -> Schedule
 *      urgent only        -> Delegate
 *      neither            -> Eliminate (default bucket for untagged)
 *
 * The matrix note itself is always excluded.
 */
export default async function collectMatrix(
	adapter: DataAdapter,
	matrixNoteId: string,
	matrixFolderId: string,
	config: MatrixConfig,
	now: Date = new Date()
): Promise<MatrixResult> {
	const warnings: string[] = [];

	const folders = await adapter.getFolders();
	const folderIds = resolveScopedFolderIds(
		folders,
		matrixFolderId,
		config.scopeDepth,
		config.scopeAll
	);

	let scannedNotes = 0;
	const topLeft: KanbanCard[] = [];
	const topRight: KanbanCard[] = [];
	const bottomLeft: KanbanCard[] = [];
	const bottomRight: KanbanCard[] = [];

	// Skeleton mode: a date on or before this ISO threshold is "due soon".
	const soonThreshold = isoDaysFromNow(now, config.urgentWindow);

	// Ordinary notes opt in through their gtd block, independently of the
	// to-do inclusion mode, so bodies are required for every scanned note.

	for (const folderId of folderIds) {
		const notes = await adapter.getNotesInFolder(folderId, true);
		for (const note of notes) {
			scannedNotes += 1;
			if (note.id === matrixNoteId) continue;

			const result = extractGtdBlock(note.body);
			if (note.is_todo) {
				if (note.todo_completed > 0) continue; // prioritisation view
				if (config.todos === "none") continue;
				if (config.todos === "gtd-only" && !result.found) continue;
			} else if (!result.found) {
				continue;
			}

			if (result.error) {
				warnings.push(
					`"${note.title}": gtd block problem — ${result.error}`
				);
			}

			const tags = await adapter.getNoteTagTitles(note.id);
			const card = buildKanbanCard(note, result.block, tags);

			let topRow: boolean;
			let leftColumn: boolean;

			if (config.mode === "eisenhower") {
				// Rows: important / not. Columns: urgent / not.
				topRow = tags.includes(config.importantTag);
				leftColumn = tags.includes(config.urgentTag);
			} else {
				// Skeleton. Rows: active (in-progress) / not.
				// Columns: due soon (urgent tag overrides; else date within
				// the window, overdue included) / not.
				topRow = tags.includes(config.inProgressTag);
				leftColumn =
					tags.includes(config.urgentTag) ||
					(card.date !== null && card.date <= soonThreshold);
			}

			if (topRow && leftColumn) topLeft.push(card);
			else if (topRow) topRight.push(card);
			else if (leftColumn) bottomLeft.push(card);
			else bottomRight.push(card);
		}
	}

	sortColumn(topLeft, config);
	sortColumn(topRight, config);
	sortColumn(bottomLeft, config);
	sortColumn(bottomRight, config);

	return {
		board: { topLeft, topRight, bottomLeft, bottomRight },
		warnings,
		scannedFolders: folderIds.length,
		scannedNotes,
		cardCount:
			topLeft.length +
			topRight.length +
			bottomLeft.length +
			bottomRight.length,
	};
}

/** ISO yyyy-mm-dd for local `now` plus `days`. */
function isoDaysFromNow(now: Date, days: number): string {
	const d = new Date(now.getFullYear(), now.getMonth(), now.getDate() + days);
	return (
		String(d.getFullYear()).padStart(4, "0") +
		"-" +
		String(d.getMonth() + 1).padStart(2, "0") +
		"-" +
		String(d.getDate()).padStart(2, "0")
	);
}


function sortColumn(cards: KanbanCard[], config: MatrixConfig): void {
	const direction = config.sort === "desc" ? -1 : 1;

	cards.sort((a, b) => {
		let comparison: number;

		if (config.sortType === "due-date") {
			const aHas = a.date !== null;
			const bHas = b.date !== null;
			if (aHas && !bHas) return -1;
			if (!aHas && bHas) return 1;
			if (!aHas && !bHas) {
				comparison = 0;
			} else {
				comparison = (a.date as string).localeCompare(b.date as string);
			}
		} else if (config.sortType === "modified-date") {
			comparison = a.updatedTime - b.updatedTime;
		} else {
			comparison = a.title.localeCompare(b.title, undefined, {
				sensitivity: "base",
			});
		}

		return comparison * direction;
	});
}