// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

;(function (mod) {
    if (typeof exports == 'object' && typeof module == 'object')
        // CommonJS
        mod(require('../../lib/codemirror'))
    else if (typeof define == 'function' && define.amd)
        // AMD
        define(['../../lib/codemirror'], mod)
    // Plain browser env
    else mod(CodeMirror)
})(function (CodeMirror) {
    'use strict'

    CodeMirror.defineMode('turtle', function (config) {
        var indentUnit = config.indentUnit
        var curPunc

        function wordRegexp(words) {
            return new RegExp('^(?:' + words.join('|') + ')$', 'i')
        }
        var ops = wordRegexp([])
        var keywords = wordRegexp(['@prefix', '@base', 'a'])
        var operatorChars = /[*+\-<>=&|]/

        function tokenBase(stream, state) {
            var ch = stream.next()
            curPunc = null
            if (ch == '<' && !stream.match(/^[\s\u00a0=]/, false)) {
                stream.match(/^[^\s\u00a0>]*>?/)
                return 'atom'
            } else if (ch == '"' || ch == "'") {
                state.tokenize = tokenLiteral(ch)
                return state.tokenize(stream, state)
            } else if (/[{}\(\),\.;\[\]]/.test(ch)) {
                curPunc = ch
                return null
            } else if (ch == '#') {
                stream.skipToEnd()
                return 'comment'
            } else if (operatorChars.test(ch)) {
                stream.eatWhile(operatorChars)
                return null
            } else if (ch == ':') {
                return 'operator'
            } else {
                stream.eatWhile(/[_\w\d]/)
                if (stream.peek() == ':') {
                    return 'variable-3'
                } else {
                    var word = stream.current()

                    if (keywords.test(word)) {
                        return 'meta'
                    }

                    if (ch >= 'A' && ch <= 'Z') {
                        return 'comment'
                    } else {
                        return 'keyword'
                    }
                }
                var word = stream.current()
                if (ops.test(word)) return null
                else if (keywords.test(word)) return 'meta'
                else return 'variable'
            }
        }

        function tokenLiteral(quote) {
            return function (stream, state) {
                var escaped = false,
                    ch
                while ((ch = stream.next()) != null) {
                    if (ch == quote && !escaped) {
                        state.tokenize = tokenBase
                        break
                    }
                    escaped = !escaped && ch == '\\'
                }
                return 'string'
            }
        }

        function pushContext(state, type, col) {
            state.context = { prev: state.context, indent: state.indent, col: col, type: type }
        }
        function popContext(state) {
            state.indent = state.context.indent
            state.context = state.context.prev
        }

        return {
            startState: function () {
                return { tokenize: tokenBase, context: null, indent: 0, col: 0 }
            },

            token: function (stream, state) {
                if (stream.sol()) {
                    if (state.context && state.context.align == null) state.context.align = false
                    state.indent = stream.indentation()
                }
                if (stream.eatSpace()) return null
                var style = state.tokenize(stream, state)

                if (style != 'comment' && state.context && state.context.align == null && state.context.type != 'pattern') {
                    state.context.align = true
                }

                if (curPunc == '(') pushContext(state, ')', stream.column())
                else if (curPunc == '[') pushContext(state, ']', stream.column())
                else if (curPunc == '{') pushContext(state, '}', stream.column())
                else if (/[\]\}\)]/.test(curPunc)) {
                    while (state.context && state.context.type == 'pattern') popContext(state)
                    if (state.context && curPunc == state.context.type) popContext(state)
                } else if (curPunc == '.' && state.context && state.context.type == 'pattern') popContext(state)
                else if (/atom|string|variable/.test(style) && state.context) {
                    if (/[\}\]]/.test(state.context.type)) pushContext(state, 'pattern', stream.column())
                    else if (state.context.type == 'pattern' && !state.context.align) {
                        state.context.align = true
                        state.context.col = stream.column()
                    }
                }

                return style
            },

            indent: function (state, textAfter) {
                var firstChar = textAfter && textAfter.charAt(0)
                var context = state.context
                if (/[\]\}]/.test(firstChar)) while (context && context.type == 'pattern') context = context.prev

                var closing = context && firstChar == context.type
                if (!context) return 0
                else if (context.type == 'pattern') return context.col
                else if (context.align) return context.col + (closing ? 0 : 1)
                else return context.indent + (closing ? 0 : indentUnit)
            },

            lineComment: '#',
        }
    })

    CodeMirror.defineMIME('text/turtle', 'turtle')
})