'use strict';
const fs = require('fs');

function Parser(options) {
	var self = this;

	options = options || {};

	function debug(message) {
		if (self.params.debug_mode) {
			console.log(`[DEBUG] ${message}`);
		}
	}

	this.defaults = {
		path : './data.json',
		query_delim : '/',
		debug_mode : false
	}

	this.params = Object.assign({}, self.defaults, options);

	this.data = null;

	this.test = {
		'valid_deal' : function(query) {
			return self.get.deals(query)
			.then(function(data) {
				if (query == "") return false;
				if (data.length > 0) {
					return true;
				}
				return false;
			})
		},
		'valid_cluster' : function(query) {
			return self.test.has_hosts(query)
		},
		'valid_host' : function(query) {
			return self.test.has_hosts(query)
		},
		'has_hosts' : function(query) {
			return self.get.hosts(query)
			.then(host_list => {
				if (query == "") return false;
				debug("Host list: "+host_list);
				if (host_list.length > 0) {
					return true;
				}
				return false;
			})
		},
		'is_object' : function(obj) {
			return (typeof obj === 'object' && obj !== null);
		}
	}

	this.xform = {
		'query_str_to_arr' : function(str = "") {
			if (!str || str == "" || str == '') { 
				debug("Transforming empty search string.");
				return [];
			}
			var arr = str.split(self.params.query_delim);
			var split_str=""
			arr.forEach(term => {
				split_str = split_str + " " + term;
			})
			arr = split_str.split(" ");
			arr = arr.filter(term => term != '.');
			arr = arr.filter(term => term != '');
			debug("Query arr: "+arr);
			return arr;
		}
	}

	this.reduce = {
		'once' : function(data = {},name = "") {
			const addressed = self.address(data,[...name]);
			return addressed.data;
		},
		'fuzzy' : function(data = {},names = []) {
			if (!Array.isArray(names) || names.length < 1) {
				return data;
			}
			var name = names.shift();
			var result = self.reduce.once(data,name);
			names.forEach(name => { result = [...result.map(tree => {
				const matches = self.reduce.once(tree,name)
				debug(matches);
				return matches;
			})]})
			result.filter(obj => obj);
			return result;
		},
		'exact' : function(data = {},names = []) {
			if (!Array.isArray(names) || names.length < 1) {
				return data;
			}
			const addressed = self.address(data,names);
			debug("Reduced exact data: "+addressed);
			return addressed.data;
		}
	}

	this.address = function(data = {},names = []) {
		if (!names || names.length < 1 || !data || data == {}) {
			debug("nope");
			return { paths: [['.']], data: [data] };
		}
		var match_paths = new Array();
		var match_data = new Array();
		var branches = new Array({
			root: ".",
			data: data
		});
		for(var i=0; i < branches.length; i++) {
			const data = branches[i].data;
			const root = branches[i].root;
			for (const [name,value] of Object.entries(data)) {
				if (self.test.is_object(value)) {
					branches.push({
						root: [...root,name],
						data: value
					});
				}
				if (name == names[0]) {
					var match = data;
					names.forEach(term => {
						debug("Searching for term: "+term);
						if (match && match[term]) {
							match = match[term];
						}
						else { match = undefined }
					});
					if (match) {
						const match_path=[...root]
						match_paths.push(match_path)
						match_data.push(match)
						debug("match found:" +match_path+"; "+match);
					}
				}
			}
		}
		return { paths: match_paths, data: match_data };
	}

	this.get = {
		'raw' : function(){
			return new Promise(function(resolve, reject){
				if(!self.data){
					fs.readFile(
						self.params.path,
						function(err, data) {
							if(err) reject(err);
							try {
								JSON.parse(data);
								self.data = JSON.parse(data)
								resolve(self.data)
							} catch(err){
								reject(err)
							}
						}
					)
				} else {
					resolve(self.data);
				}
			})
		},
		'reduced' : function(names = [],ascent = [],descent = []) {
			return self.get.raw().then(entire_data => {
				debug(`ascent: ${ascent}`);
				debug(`names: ${names}`);
				debug(`descent: ${descent}`);
				if (names.length+ascent.length+descent.length<1) {
					return entire_data;
				}
				const domain = self.reduce.fuzzy(entire_data,ascent);
				const fence = self.reduce.exact(domain,names);
				const product = self.reduce.fuzzy(fence,descent);
				return product;
				//return self.reduce.exact(entire_data,names);
			})
		},
		'addressed' : function(names) {
			return self.get.raw().then(entire_data => {
				debug(`Addressing raw: ${JSON.stringify(names)}`);
				return self.address(entire_data,names);
			})
		},
		'deals' : function(query){
			return self.get.addressed(
				[...(self.xform.query_str_to_arr(query)),"repo"]
			).then(addressed => { return addressed.paths; })
		},
		'hosts' : function(query){
			return self.get.addressed(
				[...(self.xform.query_str_to_arr(query))]
			).then(cluster_data => { 
				debug("Cluster search data: "
					+JSON.stringify(cluster_data))
				const host_matches = cluster_data.data.map(data =>{
					debug("Data in cluster: "+JSON.stringify(data))
					const hosts = self.address(
						data,
						["remote","host"]
					);
					return hosts.paths;
				})
				return host_matches;
			})
		},
		'host_list': function(query) {
			return self.get.hosts(query).then(paths => {
				const host_list = paths.map(path_list => {
					const return_queries = path_list.map(path_arr => {
						var query_str = "";
						path_arr = path_arr.filter(e => e != '.');
						path_arr.forEach(e => { query_str += e+" "; })
						return query_str.trim();
					})
					return return_queries;
				})
				return host_list;
			})
		},
		'root' : function(query){
			return self.get.addressed(
				[...(self.xform.query_str_to_arr(query))]
			).then(addressed => { return addressed.paths; })
		},
		'path' : function(query) {
			return self.get.root(query).then(roots => {
					var paths = new Array();
					debug(`Roots found: ${roots}`);
					roots.forEach (
						function(root, i, array) {
							var str = "";
							debug(`Formatting ${root}`);
							root.forEach(
								function(key,j,arr) {
									debug(`${j}: ${key}`);
									str = str + "/" + key;
								}
							)
							debug(str);
							var query_arr = query.split(" ");
							query_arr.forEach(
								function(term,j,arr) {
									str = str + "/" + term;
								})
							str = str.slice(3)
							paths.push(str);
						}
					);
					return paths;
			})
		},
		'cluster_data' : function(query) {
			return self.get.reduced(
				self.xform.query_str_to_arr(query),
				["clusters"],
				["ports","ssh"]
			).then(data => { return data; })
		},
		'data' : function(query) {
			return self.get.reduced(
				self.xform.query_str_to_arr(query)
			).then(data => { return data; })
		}
	}
};

module.exports = Parser;