'use strict';

var Node = require('./Node');
var isArray = Array.isArray;
const isValidJavaScriptVarName = require('../util/isValidJavaScriptVarName');

function walkValue(value, walker) {
    if (!value) {
        return value;
    } else if (value instanceof Node) {
        return walker.walk(value);
    } else if (isArray(value)) {
        let array = value;
        for (let i=0; i<array.length; i++) {
            let el = array[i];
            array[i] = walkValue(el, walker);
        }
        return array;
    } else if (typeof value === 'object') {
        let object = value;

        let keys = Object.keys(object);
        for (let i=0; i<keys.length; i++) {
            let key = keys[i];
            let oldValue = object[key];
            let newValue = walkValue(oldValue, walker);
            if (newValue !== oldValue) {
                object[key] = newValue;
            }
        }

        return object;
    } else {
        return value;
    }
}

class Literal extends Node {
    constructor(def) {
        super('Literal');
        this.value = def.value;
    }

    generateCode(codegen) {
        if (this.value != null) {
            if (isArray(this.value)) {
                for (var i=0; i<this.value.length; i++) {
                    this.value[i] = codegen.generateCode(this.value[i]);
                }
            } else if (typeof this.value === 'object') {
                if (!(this.value instanceof RegExp)) {
                    var newObject = {};
                    for (var k in this.value) {
                        if (this.value.hasOwnProperty(k)) {
                            newObject[k] = codegen.generateCode(this.value[k]);
                        }
                    }
                    this.value = newObject;
                }
            }
        }
        return this;
    }

    writeCode(writer) {
        var value = this.value;
        writer.writeLiteral(value);
    }

    toString() {
        var value = this.value;
        if (value === null) {
            return 'null';
        } else if (value === undefined) {
            return 'undefined';
        } else if (typeof value === 'string') {
            return JSON.stringify(value);
        } else if (value === true) {
            return 'true';
        } else if (value === false) {
            return 'false';
        }  else if (isArray(value)) {
            return '[' + value.join(', ') + ']';
        } else if (typeof value === 'number') {
            return value.toString();
        } else if (value instanceof RegExp) {
            return value.toString();
        } else if (typeof value === 'object') {
            let keys = Object.keys(value);
            if (keys.length === 0) {
                return '{}';
            }

            var result = '{ ';

            for (let i=0; i<keys.length; i++) {
                let k = keys[i];
                let v = value[k];

                if (i !== 0) {
                    result += ', ';
                }

                if (isValidJavaScriptVarName(k)) {
                    result += k + ': ';
                } else {
                    result += JSON.stringify(k) + ': ';
                }

                result += v;
            }

            return result + ' }';
        }
    }

    walk(walker) {
        walkValue(this.value, walker);
    }
}

module.exports = Literal;