#!/usr/bin/env node
/**
 * TGN Validator - Validate TGN files by replaying the game
 *
 * Validates:
 * 1. TGN syntax parsing
 * 2. Move legality (no occupied positions, no suicide, etc.)
 * 3. Game integrity
 */

import { TrigoGame, validateTGN } from "@inc/trigo/game.js";
import { calculateTerritory } from "@inc/trigo/gameUtils.js";
import { initializeParsers } from "@inc/trigo/parserInit.js";
import { parseTGN } from "@inc/tgn/tgnParser.js";
import { decodeAb0yz } from "@inc/trigo/ab0yz.js";
import * as fs from "fs";
import * as path from "path";


interface ValidationResult {
	file: string;
	valid: boolean;
	parseError?: string;
	replayError?: string;
	moveCount?: number;
	boardShape?: { x: number; y: number; z: number };
	territory?: {
		black: number;
		white: number;
		neutral: number;
	};
	metadata?: {
		event?: string;
		black?: string;
		white?: string;
		date?: string;
	};
}


function validateTgnFile(filePath: string): ValidationResult {
	const fileName = path.basename(filePath);

	// Check file exists
	if (!fs.existsSync(filePath)) {
		return {
			file: fileName,
			valid: false,
			parseError: "File not found"
		};
	}

	// Read file
	let content: string;
	try {
		content = fs.readFileSync(filePath, "utf-8");
	} catch (err) {
		return {
			file: fileName,
			valid: false,
			parseError: `Failed to read file: ${err instanceof Error ? err.message : String(err)}`
		};
	}

	// Validate TGN syntax
	const syntaxResult = validateTGN(content);
	if (!syntaxResult.valid) {
		return {
			file: fileName,
			valid: false,
			parseError: syntaxResult.error
		};
	}

	// Replay the game with strict move validation
	try {
		const parsed = parseTGN(content);

		// Extract board shape
		let boardShape: { x: number; y: number; z: number };
		if (parsed.tags.Board && Array.isArray(parsed.tags.Board)) {
			const shape = parsed.tags.Board;
			boardShape = {
				x: shape[0] || 5,
				y: shape[1] || 5,
				z: shape[2] || 1
			};
		} else {
			boardShape = { x: 5, y: 5, z: 5 };
		}

		// Create game and replay moves with strict validation
		const game = new TrigoGame(boardShape);
		game.startGame();

		let moveIndex = 0;
		if (parsed.moves && parsed.moves.length > 0) {
			for (const round of parsed.moves) {
				// Validate black's move
				if (round.action_black) {
					moveIndex++;
					const error = applyMoveStrict(game, round.action_black, boardShape, moveIndex, "Black");
					if (error) {
						return {
							file: fileName,
							valid: false,
							replayError: error
						};
					}
				}

				// Validate white's move
				if (round.action_white) {
					moveIndex++;
					const error = applyMoveStrict(game, round.action_white, boardShape, moveIndex, "White");
					if (error) {
						return {
							file: fileName,
							valid: false,
							replayError: error
						};
					}
				}
			}
		}

		const shape = game.getShape();
		const history = game.getHistory();
		const board = game.getBoard();
		const territory = calculateTerritory(board, shape);

		// Extract metadata from TGN
		const metadata: ValidationResult["metadata"] = {};
		const eventMatch = content.match(/\[Event\s+"([^"]+)"\]/);
		const blackMatch = content.match(/\[Black\s+"([^"]+)"\]/);
		const whiteMatch = content.match(/\[White\s+"([^"]+)"\]/);
		const dateMatch = content.match(/\[Date\s+"([^"]+)"\]/);

		if (eventMatch) metadata.event = eventMatch[1];
		if (blackMatch) metadata.black = blackMatch[1];
		if (whiteMatch) metadata.white = whiteMatch[1];
		if (dateMatch) metadata.date = dateMatch[1];

		return {
			file: fileName,
			valid: true,
			moveCount: history.length,
			boardShape: shape,
			territory: {
				black: territory.black,
				white: territory.white,
				neutral: territory.neutral
			},
			metadata: Object.keys(metadata).length > 0 ? metadata : undefined
		};
	} catch (err) {
		return {
			file: fileName,
			valid: false,
			replayError: err instanceof Error ? err.message : String(err)
		};
	}
}


/**
 * Apply a move with strict validation - returns error message if invalid
 */
function applyMoveStrict(
	game: TrigoGame,
	action: { type: string; position?: string },
	boardShape: { x: number; y: number; z: number },
	moveIndex: number,
	player: string
): string | null {
	if (action.type === "pass") {
		game.pass();
		return null;
	} else if (action.type === "resign") {
		game.surrender();
		return null;
	} else if (action.type === "move" && action.position) {
		const coords = decodeAb0yz(action.position, [boardShape.x, boardShape.y, boardShape.z]);
		const position = { x: coords[0], y: coords[1], z: coords[2] };

		// Check move validity before applying
		const validation = game.isValidMove(position);
		if (!validation.valid) {
			return `Move ${moveIndex} (${player} at ${action.position}): ${validation.reason}`;
		}

		// Apply the move
		const success = game.drop(position);
		if (!success) {
			return `Move ${moveIndex} (${player} at ${action.position}): Move rejected`;
		}

		return null;
	}

	return `Move ${moveIndex} (${player}): Unknown action type "${action.type}"`;
}


function printResult(result: ValidationResult, verbose: boolean): void {
	const status = result.valid ? "✓" : "✗";
	const statusColor = result.valid ? "\x1b[32m" : "\x1b[31m";
	const reset = "\x1b[0m";

	console.log(`${statusColor}${status}${reset} ${result.file}`);

	if (!result.valid) {
		if (result.parseError) {
			console.log(`  Parse error: ${result.parseError}`);
		}
		if (result.replayError) {
			console.log(`  Replay error: ${result.replayError}`);
		}
	} else if (verbose) {
		console.log(`  Board: ${result.boardShape?.x}×${result.boardShape?.y}×${result.boardShape?.z}`);
		console.log(`  Moves: ${result.moveCount}`);
		if (result.territory) {
			console.log(`  Territory: B=${result.territory.black}, W=${result.territory.white}, N=${result.territory.neutral}`);
		}
		if (result.metadata) {
			if (result.metadata.event) console.log(`  Event: ${result.metadata.event}`);
			if (result.metadata.black) console.log(`  Black: ${result.metadata.black}`);
			if (result.metadata.white) console.log(`  White: ${result.metadata.white}`);
			if (result.metadata.date) console.log(`  Date: ${result.metadata.date}`);
		}
	}
}


/**
 * Expand paths - if path is a directory, return all .tgn files in it
 */
function expandPaths(paths: string[]): string[] {
	const result: string[] = [];

	for (const p of paths) {
		if (!fs.existsSync(p)) {
			// Keep non-existent paths - will report as error later
			result.push(p);
			continue;
		}

		const stat = fs.statSync(p);
		if (stat.isDirectory()) {
			// Find all .tgn files in directory
			const files = fs.readdirSync(p)
				.filter(f => f.endsWith(".tgn"))
				.map(f => path.join(p, f))
				.sort();
			result.push(...files);
		} else {
			result.push(p);
		}
	}

	return result;
}


function printUsage(): void {
	console.log(`
Usage: npx tsx tools/tgnValidator.ts [options] <path> [<path> ...]

Arguments:
  <path>             TGN file or directory containing TGN files

Options:
  --verbose, -v    Show detailed information for valid files
  --json           Output results as JSON
  --help, -h       Show this help message

Examples:
  npx tsx tools/tgnValidator.ts game.tgn
  npx tsx tools/tgnValidator.ts ./games/              # validate all .tgn in directory
  npx tsx tools/tgnValidator.ts -v ./games/*.tgn
  npx tsx tools/tgnValidator.ts --json ./output/ > results.json
`);
}


async function main(): Promise<void> {
	const args = process.argv.slice(2);

	// Parse options
	let verbose = false;
	let jsonOutput = false;
	const files: string[] = [];

	for (const arg of args) {
		if (arg === "--verbose" || arg === "-v") {
			verbose = true;
		} else if (arg === "--json") {
			jsonOutput = true;
		} else if (arg === "--help" || arg === "-h") {
			printUsage();
			process.exit(0);
		} else if (!arg.startsWith("-")) {
			files.push(arg);
		} else {
			console.error(`Unknown option: ${arg}`);
			printUsage();
			process.exit(1);
		}
	}

	if (files.length === 0) {
		console.error("Error: No TGN files specified\n");
		printUsage();
		process.exit(1);
	}

	// Expand directories to individual files
	const expandedFiles = expandPaths(files);

	if (expandedFiles.length === 0) {
		console.error("Error: No TGN files found in specified path(s)\n");
		process.exit(1);
	}

	// Initialize parser
	await initializeParsers();

	// Validate all files
	const results: ValidationResult[] = [];
	for (const file of expandedFiles) {
		const result = validateTgnFile(file);
		results.push(result);

		process.stdout.write(result.valid ? "." : "!");
	}

	// Output results
	if (jsonOutput) {
		console.log(JSON.stringify(results, null, 2));
	} else {
		console.log(`\nValidating ${expandedFiles.length} TGN file(s)...\n`);

		for (const result of results) {
			printResult(result, verbose);
		}

		// Summary
		const validCount = results.filter(r => r.valid).length;
		const invalidCount = results.length - validCount;

		console.log(`\n${"─".repeat(40)}`);
		console.log(`Total: ${results.length} file(s)`);
		console.log(`  Valid:   ${validCount}`);
		console.log(`  Invalid: ${invalidCount}`);

		if (invalidCount > 0) {
			process.exit(1);
		}
	}
}


main();