using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

using UnityEditor;
using UnityEngine;

using Crowdin.Plugin.Helpers;
using Crowdin.Plugin.Helpers.PluginLocalization;
using Crowdin.Plugin.Models;
using Crowdin.Plugin.Models.Settings;
using Crowdin.Plugin.Server_API;
using Crowdin.Plugin.Server_API.Helpers;
using Crowdin.Plugin.Server_API.Models.Branches;
using Crowdin.Plugin.Server_API.Services;

namespace Crowdin.Editor
{
    public class BranchSelector : IDisposable
    {
        private int currentIndex = 0;
        private string[] branches = { "main" };
        private Dictionary<string, int> branchIds = new();
        private readonly List<CachedBranchData> rawSettings;
        private readonly CancellationToken ownerLifetime;

        public static BranchSelector CreateAndLoadSettings(CancellationToken ownerLifetime)
        {
            return new BranchSelector(SettingsHelper.GetBranchesList(), ownerLifetime);
        }

        private BranchSelector(List<CachedBranchData> entries, CancellationToken ownerLifetime)
        {
            if (entries is not null && entries.Count > 0)
            {
                branches = entries.Select(entry => entry.name).ToArray();
                branchIds = entries.ToDictionary(data => data.name, data => data.id);
            }

            rawSettings = entries;
            this.ownerLifetime = ownerLifetime;
        }
        
        public void DrawLayout()
        {
            GUILayout.BeginHorizontal("box");
            
            GUILayout.Label(LocalizationHelper.GetLocalStringByKey(LocalKeys.list_branches));
            
            currentIndex = EditorGUILayout.Popup(currentIndex, branches);

            if (GUILayout.Button(LocalizationHelper.GetLocalStringByKey(LocalKeys.button_branches_refresh)))
            {
                RefreshBranchesList();
            }
            
            GUILayout.EndHorizontal();
        }

        public void RefreshBranchesList()
        {
            RefreshBranchesListAsync().Forget();
        }

        private async Task RefreshBranchesListAsync()
        {
            try
            {
                var service = new BranchApiService();

                Debug.Log("Refreshing branches list...");
                List<BranchData> remoteBranches = await service.ListBranches(ownerLifetime);
                Debug.Log($"Branches list: received {remoteBranches.Count}");

                branches = remoteBranches.Select(branch => branch.Name).ToArray();
                branchIds = remoteBranches.ToDictionary(branch => branch.Name, branch => branch.Id);
            }
            catch (CrowdinApiException ex)
            {
                Debug.LogException(ex);
            }
        }

        public int? GetSelectedBranchId()
        {
            return branchIds.TryGetValue(branches[currentIndex], out int branchId) ? branchId : null;
        }

        public void SaveSettings()
        {
            rawSettings.Clear();

            foreach (string branchName in branches)
            {
                if (!branchIds.TryGetValue(branchName, out int branchId))
                {
                    continue;
                }
                
                var entry = new CachedBranchData
                {
                    id = branchId,
                    name = branchName
                };

                rawSettings.Add(entry);
            }
        } 

        public void Dispose()
        {
            SaveSettings();
        }
    }
}