/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import { languages } from '../../fillers/monaco-editor-core';

export const conf: languages.LanguageConfiguration = {
	comments: {
		lineComment: '//',
		blockComment: ['/*', '*/']
	},
	brackets: [
		['{', '}'],
		['[', ']'],
		['(', ')']
	],
	autoClosingPairs: [
		{ open: '{', close: '}' },
		{ open: '[', close: ']' },
		{ open: '(', close: ')' },
		{ open: '"', close: '"' },
		{ open: "'", close: "'" },
		{ open: '`', close: '`' }
	],
	surroundingPairs: [
		{ open: '{', close: '}' },
		{ open: '[', close: ']' },
		{ open: '(', close: ')' },
		{ open: '"', close: '"' },
		{ open: "'", close: "'" },
		{ open: '`', close: '`' }
	]
};

// Ref: Cypher Query Language Reference, Version 9 (https://opencypher.org/resources/)
export const language = <languages.IMonarchLanguage>{
	defaultToken: '',
	tokenPostfix: `.cypher`,
	ignoreCase: true,

	brackets: [
		{ open: '{', close: '}', token: 'delimiter.curly' },
		{ open: '[', close: ']', token: 'delimiter.bracket' },
		{ open: '(', close: ')', token: 'delimiter.parenthesis' }
	],

	keywords: [
		'ALL',
		'AND',
		'AS',
		'ASC',
		'ASCENDING',
		'BY',
		'CALL',
		'CASE',
		'CONTAINS',
		'CREATE',
		'DELETE',
		'DESC',
		'DESCENDING',
		'DETACH',
		'DISTINCT',
		'ELSE',
		'END',
		'ENDS',
		'EXISTS',
		'IN',
		'IS',
		'LIMIT',
		'MANDATORY',
		'MATCH',
		'MERGE',
		'NOT',
		'ON',
		'ON',
		'OPTIONAL',
		'OR',
		'ORDER',
		'REMOVE',
		'RETURN',
		'SET',
		'SKIP',
		'STARTS',
		'THEN',
		'UNION',
		'UNWIND',
		'WHEN',
		'WHERE',
		'WITH',
		'XOR',
		'YIELD'
	],
	builtinLiterals: ['true', 'TRUE', 'false', 'FALSE', 'null', 'NULL'],
	builtinFunctions: [
		'abs',
		'acos',
		'asin',
		'atan',
		'atan2',
		'avg',
		'ceil',
		'coalesce',
		'collect',
		'cos',
		'cot',
		'count',
		'degrees',
		'e',
		'endNode',
		'exists',
		'exp',
		'floor',
		'head',
		'id',
		'keys',
		'labels',
		'last',
		'left',
		'length',
		'log',
		'log10',
		'lTrim',
		'max',
		'min',
		'nodes',
		'percentileCont',
		'percentileDisc',
		'pi',
		'properties',
		'radians',
		'rand',
		'range',
		'relationships',
		'replace',
		'reverse',
		'right',
		'round',
		'rTrim',
		'sign',
		'sin',
		'size',
		'split',
		'sqrt',
		'startNode',
		'stDev',
		'stDevP',
		'substring',
		'sum',
		'tail',
		'tan',
		'timestamp',
		'toBoolean',
		'toFloat',
		'toInteger',
		'toLower',
		'toString',
		'toUpper',
		'trim',
		'type'
	],

	operators: [
		// Math operators
		'+',
		'-',
		'*',
		'/',
		'%',
		'^',
		// Comparison operators
		'=',
		'<>',
		'<',
		'>',
		'<=',
		'>=',
		// Pattern operators
		'->',
		'<-',
		'-->',
		'<--'
	],

	escapes: /\\(?:[tbnrf\\"'`]|u[0-9A-Fa-f]{4}|U[0-9A-Fa-f]{8})/,
	digits: /\d+/,
	octaldigits: /[0-7]+/,
	hexdigits: /[0-9a-fA-F]+/,

	tokenizer: {
		root: [[/[{}[\]()]/, '@brackets'], { include: 'common' }],
		common: [
			{ include: '@whitespace' },
			{ include: '@numbers' },
			{ include: '@strings' },

			// Cypher labels on nodes/relationships, e.g. (n:NodeLabel)-[e:RelationshipLabel]
			[/:[a-zA-Z_][\w]*/, 'type.identifier'],
			[
				/[a-zA-Z_][\w]*(?=\()/,
				{
					cases: {
						'@builtinFunctions': 'predefined.function'
					}
				}
			],
			[
				/[a-zA-Z_$][\w$]*/,
				{
					cases: {
						'@keywords': 'keyword',
						'@builtinLiterals': 'predefined.literal',
						'@default': 'identifier'
					}
				}
			],
			[/`/, 'identifier.escape', '@identifierBacktick'],

			// delimiter and operator after number because of `.\d` floats and `:` in labels
			[/[;,.:|]/, 'delimiter'],
			[
				/[<>=%+\-*/^]+/,
				{
					cases: {
						'@operators': 'delimiter',
						'@default': ''
					}
				}
			]
		],
		numbers: [
			[/-?(@digits)[eE](-?(@digits))?/, 'number.float'],
			[/-?(@digits)?\.(@digits)([eE]-?(@digits))?/, 'number.float'],
			[/-?0x(@hexdigits)/, 'number.hex'],
			[/-?0(@octaldigits)/, 'number.octal'],
			[/-?(@digits)/, 'number']
		],
		strings: [
			[/"([^"\\]|\\.)*$/, 'string.invalid'], // non-teminated string
			[/'([^'\\]|\\.)*$/, 'string.invalid'], // non-teminated string
			[/"/, 'string', '@stringDouble'],
			[/'/, 'string', '@stringSingle']
		],
		whitespace: [
			[/[ \t\r\n]+/, 'white'],
			[/\/\*/, 'comment', '@comment'],
			[/\/\/.*$/, 'comment']
		],
		comment: [
			[/\/\/.*/, 'comment'],
			[/[^/*]+/, 'comment'],
			[/\*\//, 'comment', '@pop'],
			[/[/*]/, 'comment']
		],
		stringDouble: [
			[/[^\\"]+/, 'string'],
			[/@escapes/, 'string'],
			[/\\./, 'string.invalid'],
			[/"/, 'string', '@pop']
		],
		stringSingle: [
			[/[^\\']+/, 'string'],
			[/@escapes/, 'string'],
			[/\\./, 'string.invalid'],
			[/'/, 'string', '@pop']
		],
		identifierBacktick: [
			[/[^\\`]+/, 'identifier.escape'],
			[/@escapes/, 'identifier.escape'],
			[/\\./, 'identifier.escape.invalid'],
			[/`/, 'identifier.escape', '@pop']
		]
	}
};