using System.IO;
using System.Linq;
using System.Collections.Generic;
using System.Globalization;
using Newtonsoft.Json.Linq;

namespace EliteBGS.EDDB {
    public class PopulatedSystems {
        private string json_file = null;
        private JArray root = null;
        private string[] system_names = null;
        private Dictionary<string, int> to_id;

        public static PopulatedSystems FromFile(string file) {
            PopulatedSystems pop = new PopulatedSystems();
            string content = File.ReadAllText(file);

            pop.json_file = file;
            pop.root = JArray.Parse(content);
            pop.Initialise();

            return pop;
        }

        private void Initialise() {
            MakeSystemNames();

            to_id = root.ToDictionary(x => x.Value<string>("name"), x => x.Value<int>("id"));
        }

        public int ToId(string name) {
            return to_id.First(x => string.Compare(x.Key, name, true) == 0).Value;
        }

        private void MakeSystemNames() {
            if (root == null) {
                throw new InvalidDataException("no JSON loaded");
            }

            if (system_names != null && system_names.Length > 0) {
                return;
            }

            var names = root.Children<JObject>().Select(x => x.Value<string>("name"));
            system_names = names.ToArray();
        }

        public string[] SystemNames {
            get {
                MakeSystemNames();
                return system_names;
            }
        }

        public string[] SystemNamesByFilter(string filter) {
            MakeSystemNames();
            var culture = CultureInfo.InvariantCulture;
            return system_names.Where(x => culture.CompareInfo.IndexOf(x, filter, CompareOptions.IgnoreCase) > -1)
                .ToArray()
                ;
        }

        public string JSONFile {
            get => json_file;
        }

        public JArray Root {
            get => root;
        }
    }
}