import { monaco } from 'minwebide';
import { numblBuiltinNames } from './builtinNames';

// MATLAB-syntax language support for .m files, adapted from numbl.org's own
// Monaco language definition (numbl's src/numblLanguage.ts, which is not
// published on npm). Registered after the built-in languages so its claim on
// the .m extension takes precedence over VS Code's Objective-C mapping.

const languageConfig: monaco.languages.LanguageConfiguration = {
	comments: {
		lineComment: '%',
		blockComment: ['%{', '%}'],
	},
	brackets: [
		['{', '}'],
		['[', ']'],
		['(', ')'],
	],
	autoClosingPairs: [
		{ open: '{', close: '}' },
		{ open: '[', close: ']' },
		{ open: '(', close: ')' },
		{ open: '"', close: '"' },
	],
	surroundingPairs: [
		{ open: '{', close: '}' },
		{ open: '[', close: ']' },
		{ open: '(', close: ')' },
		{ open: '"', close: '"' },
	],
};

const builtinConstants = ['pi', 'e', 'eps', 'Inf', 'inf', 'NaN', 'nan', 'i', 'j'];

// numbl's "special" builtins (I/O, plotting, path/fs commands) are dispatched
// outside its regular builtin registry, so `numbl list-builtins` (the source
// of builtinNames.ts) doesn't include them — copied from numbl 0.4.8's
// SPECIAL_BUILTIN_NAMES plus the plot-dispatch names.
const specialBuiltinNames = [
	'help', 'disp', 'fprintf', 'arrayfun', 'cellfun', 'structfun', 'feval', 'bsxfun',
	'subsref', 'subsasgn', 'builtin', 'fopen', 'fclose', 'fgetl', 'fgets', 'fileread',
	'feof', 'ferror', 'fread', 'fwrite', 'frewind', 'fseek', 'ftell', 'fileparts',
	'fullfile', 'assignin', 'evalin', 'set', 'get', 'drawnow', 'pause',
	'plot', 'plot3', 'line', 'patch', 'trimesh', 'fill', 'surf', 'surface', 'scatter',
	'imagesc', 'pcolor', 'contour', 'contourf', 'mesh', 'waterfall', 'isosurface',
	'bar', 'barh', 'bar3', 'bar3h', 'stairs', 'errorbar', 'semilogx', 'semilogy',
	'loglog', 'area', 'fplot', 'fplot3', 'scatter3', 'histogram', 'histogram2',
	'boxchart', 'swarmchart', 'swarmchart3', 'piechart', 'donutchart', 'heatmap',
	'quiver', 'quiver3', 'streamline', 'stream2', 'ishold', 'figure', 'uihtml',
	'uigridlayout', 'subplot', 'tiledlayout', 'nexttile', 'title', 'xlabel', 'ylabel',
	'zlabel', 'hold', 'grid', 'box', 'legend', 'close', 'sgtitle', 'shading', 'clf',
	'cla', 'colormap', 'view', 'colorbar', 'axis', 'caxis', 'clim', 'gcf', 'gca',
	'mfilename', 'addpath', 'rmpath', 'savepath', 'path', 'mkdir', 'websave',
	'webread', 'delete', 'rmdir', 'movefile', 'copyfile', 'fileattrib', 'unzip',
	'dir', 'warning', 'input', 'tempdir', 'tempname', 'userpath', 'getenv', 'setenv',
	'pwd', 'cd', 'ode45', 'ode23', 'deval', 'tic', 'toc', 'quadgk', 'gmres', 'eigs',
	'onCleanup',
];

function createTokensProvider(): monaco.languages.IMonarchLanguage {
	return {
		defaultToken: '',

		keywords: [
			'function', 'if', 'else', 'elseif', 'for', 'while', 'break', 'continue',
			'return', 'end', 'classdef', 'properties', 'methods', 'events',
			'enumeration', 'arguments', 'import', 'switch', 'case', 'otherwise',
			'try', 'catch', 'global', 'persistent', 'true', 'false',
		],

		builtinFunctions: [...new Set([...numblBuiltinNames, ...specialBuiltinNames])],
		builtinConstants,

		tokenizer: {
			root: [
				// section markers (must be at line start)
				[/^%%.*$/, 'comment.doc'],

				// block comments
				[/%\{/, 'comment', '@blockComment'],

				// line comments
				[/%.*$/, 'comment'],

				// identifiers and keywords — push afterValue since they produce values
				[
					/[a-zA-Z_]\w*/,
					{
						cases: {
							'@keywords': { token: 'keyword', next: '@afterValue' },
							'@builtinFunctions': { token: 'predefined', next: '@afterValue' },
							'@builtinConstants': { token: 'constant.language', next: '@afterValue' },
							'@default': { token: 'identifier', next: '@afterValue' },
						},
					},
				],

				// numbers — push afterValue since they produce values
				[/\d+\.?\d*([eE][+-]?\d+)?/, { token: 'number.float', next: '@afterValue' }],
				[/\.\d+([eE][+-]?\d+)?/, { token: 'number.float', next: '@afterValue' }],

				// strings (single and double quoted)
				[/"([^"\\]|\\.)*$/, 'string.invalid'],
				[/'([^'\\]|\\.)*$/, 'string.invalid'],
				[/"/, 'string', '@doubleQuotedString'],
				[/'/, 'string', '@singleQuotedString'],

				// closing brackets produce values — push afterValue
				[/[)\]]/, { token: '@brackets', next: '@afterValue' }],
				[/\}/, { token: '@brackets', next: '@afterValue' }],

				// opening brackets
				[/[{([]/, '@brackets'],

				// delimiters and operators (no ' — handled in afterValue as transpose)
				[/[;,.]/, 'delimiter'],
				[/==|~=|<=|>=|&&|\|\||\.\.\.|\.\*|\.\/|\.\\|\.\^|[=<>~+\-*/\\^&|!@?:]/, 'operator'],

				{ include: '@whitespace' },
			],

			// state after a value-producing token (identifier, number, closing
			// bracket, or string) — here ' is transpose, not a string delimiter
			afterValue: [
				[/\.'/, 'operator'],
				[/'/, 'operator'],
				[/$/, { token: '', next: '@pop' }],
				[/(?=[\s\S])/, { token: '', next: '@pop' }],
			],

			blockComment: [
				[/%\}/, 'comment', '@pop'],
				[/./, 'comment'],
			],

			doubleQuotedString: [
				[/[^\\"]+/, 'string'],
				[/\\./, 'string.escape'],
				[/"/, { token: 'string', switchTo: '@afterValue' }],
			],

			singleQuotedString: [
				[/[^\\']+/, 'string'],
				[/''/, 'string.escape'],
				[/'/, { token: 'string', switchTo: '@afterValue' }],
			],

			whitespace: [[/[ \t\r\n]+/, 'white']],
		},
	};
}

let registered = false;

/** Registers MATLAB language support for .m files. Call once, after registerBuiltinLanguages. */
export function registerMatlabLanguage(): void {
	if (registered) {
		return;
	}
	registered = true;
	monaco.languages.register({
		id: 'matlab',
		extensions: ['.m'],
		aliases: ['MATLAB', 'matlab'],
	});
	monaco.languages.setLanguageConfiguration('matlab', languageConfig);
	monaco.languages.setMonarchTokensProvider('matlab', createTokensProvider());
}