/**
 * Pinia store for MCTS visualization state
 */

import { defineStore } from "pinia";
import { ref, computed } from "vue";
import type {
	MCTSMoveData,
	MCTSMoveStatistic,
	MCTSStatisticType,
	ColorScaleType
} from "@/types/mcts";
import type { Position } from "../../../inc/trigo/types";


export const useMCTSStore = defineStore("mcts", () => {
	// ============================================================================
	// State
	// ============================================================================

	// Game data
	const gameHistory = ref<MCTSMoveData[]>([]);
	const currentMoveIndex = ref<number>(0);

	// Visualization settings
	const selectedStatistic = ref<MCTSStatisticType>("N");
	const colorScale = ref<ColorScaleType>("linear");
	const topNFilter = ref<number>(10);  // Show top N moves in tree/table

	// Selection state
	const selectedActionKey = ref<string | null>(null);


	// ============================================================================
	// Getters
	// ============================================================================

	const hasData = computed(() => gameHistory.value.length > 0);

	const currentMoveData = computed((): MCTSMoveData | null => {
		if (!hasData.value) return null;
		return gameHistory.value[currentMoveIndex.value] || null;
	});

	const maxMoveIndex = computed(() => {
		return Math.max(0, gameHistory.value.length - 1);
	});

	const currentStatistics = computed((): MCTSMoveStatistic[] => {
		return currentMoveData.value?.statistics || [];
	});

	const topMoves = computed((): MCTSMoveStatistic[] => {
		const stats = currentStatistics.value;
		return stats
			.slice()
			.sort((a, b) => b.N - a.N)
			.slice(0, topNFilter.value);
	});

	const totalVisits = computed((): number => {
		return currentStatistics.value.reduce((sum, stat) => sum + stat.N, 0);
	});

	const selectedMove = computed((): MCTSMoveStatistic | null => {
		if (!selectedActionKey.value) return null;
		return (
			currentStatistics.value.find(
				(stat) => stat.actionKey === selectedActionKey.value
			) || null
		);
	});


	// ============================================================================
	// Actions
	// ============================================================================

	function setGameHistory(history: MCTSMoveData[]) {
		gameHistory.value = history;
		currentMoveIndex.value = 0;
		selectedActionKey.value = null;
	}

	function clearGameHistory() {
		gameHistory.value = [];
		currentMoveIndex.value = 0;
		selectedActionKey.value = null;
	}

	function setCurrentMoveIndex(index: number) {
		if (index < 0 || index > maxMoveIndex.value) return;
		currentMoveIndex.value = index;
		// Clear selection when moving to different move
		selectedActionKey.value = null;
	}

	function nextMove() {
		if (currentMoveIndex.value < maxMoveIndex.value) {
			setCurrentMoveIndex(currentMoveIndex.value + 1);
		}
	}

	function prevMove() {
		if (currentMoveIndex.value > 0) {
			setCurrentMoveIndex(currentMoveIndex.value - 1);
		}
	}

	function firstMove() {
		setCurrentMoveIndex(0);
	}

	function lastMove() {
		setCurrentMoveIndex(maxMoveIndex.value);
	}

	function setSelectedStatistic(stat: MCTSStatisticType) {
		selectedStatistic.value = stat;
	}

	function setColorScale(scale: ColorScaleType) {
		colorScale.value = scale;
	}

	function setTopNFilter(n: number) {
		topNFilter.value = Math.max(3, Math.min(50, n));
	}

	function selectAction(actionKey: string | null) {
		selectedActionKey.value = actionKey;
	}

	function selectPosition(position: Position | null) {
		if (!position) {
			selectedActionKey.value = "pass";
			return;
		}
		selectedActionKey.value = `${position.x},${position.y},${position.z}`;
	}


	// ============================================================================
	// Return
	// ============================================================================

	return {
		// State
		gameHistory,
		currentMoveIndex,
		selectedStatistic,
		colorScale,
		topNFilter,
		selectedActionKey,

		// Getters
		hasData,
		currentMoveData,
		maxMoveIndex,
		currentStatistics,
		topMoves,
		totalVisits,
		selectedMove,

		// Actions
		setGameHistory,
		clearGameHistory,
		setCurrentMoveIndex,
		nextMove,
		prevMove,
		firstMove,
		lastMove,
		setSelectedStatistic,
		setColorScale,
		setTopNFilter,
		selectAction,
		selectPosition
	};
});