using Mesa_Backlog.Library;
using Mesa_Backlog.Library.WorkItems;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Http = System.Net.Http;
using IO = System.IO;
using WebApi = Microsoft.TeamFoundation.WorkItemTracking.WebApi;

namespace Mesa_Backlog.Pages;

public class FetchData : PageModel
{

    [BindProperty]
    public string? JSON { get; set; }

    [BindProperty]
    public string? PageName { get; set; }

    [BindProperty]
    public string? JsonFileName { get; set; }

    public bool AreLoaded { init; get; }
    public List<string> JsonFiles { init; get; }

    private readonly string _Directory;
    private readonly AppSettings _AppSettings;
    private readonly bool _IsEnvironmentDevelopment;
    private readonly IHostEnvironment _HostEnvironment;
    private readonly IHttpClientFactory _HttpClientFactory;
    public List<ViewModels.WorkItem> WorkItems { init; get; }
    private readonly Dictionary<string, int?> _KeyValuePairs;
    private readonly WebApi.WorkItemTrackingHttpClient _WorkItemTrackingHttpClient;

    public FetchData(IHostEnvironment hostEnvironment, AppSettings appSettings, IHttpClientFactory httpClientFactory, WebApi.WorkItemTrackingHttpClient workItemTrackingHttpClient, Dictionary<string, int?> keyValuePairs)
    {
        JsonFiles = new();
        WorkItems = new();
        _AppSettings = appSettings;
        _KeyValuePairs = keyValuePairs;
        _HostEnvironment = hostEnvironment;
        _HttpClientFactory = httpClientFactory;
        _WorkItemTrackingHttpClient = workItemTrackingHttpClient;
        _IsEnvironmentDevelopment = hostEnvironment.IsDevelopment();
        AreLoaded = (from l in keyValuePairs where l.Value is not null select true).Any();
        _Directory = Path.Combine(_HostEnvironment.ContentRootPath, ".vscode", "Uploads");
        if (!Directory.Exists(_Directory))
            _ = Directory.CreateDirectory(_Directory);
    }

    private void UpdateKeyValuePairs(FIBacklogMesa[] fIBacklogMesaCollection)
    {
        foreach (FIBacklogMesa fIBacklogMesa in fIBacklogMesaCollection)
        {
            if (!_KeyValuePairs.ContainsKey(fIBacklogMesa.Req))
                _KeyValuePairs.Add(fIBacklogMesa.Req, null);
        }
    }

    private void SetWorkItems(FIBacklogMesa[] fIBacklogMesaCollection)
    {
        UpdateKeyValuePairs(fIBacklogMesaCollection);
        string project = _AppSettings.Client.Project;
        string workItemsAddress = $"{_AppSettings.Client.BaseAddress}{_AppSettings.Client.BasePage}{project}/_workItems/edit/";
        List<ViewModels.WorkItem> workItems = ViewModels.WorkItem.GetWorkItems(_KeyValuePairs, workItemsAddress, fIBacklogMesaCollection);
        WorkItems.AddRange(workItems);
    }

    private IActionResult GetPage(string json)
    {
        IActionResult result;
        FIBacklogMesa[] fIBacklogMesaCollection = ExcelReader.GetFIBacklogMesaCollection(json);
        SetWorkItems(fIBacklogMesaCollection);
        JSON = ExcelReader.GetJson(fIBacklogMesaCollection);
        string fileName = Path.Combine(_Directory, $"{DateTime.Now.Ticks}.json");
        IO.File.WriteAllText(fileName, JSON);
        result = Page();
        return result;
    }

    private IActionResult GetPage(List<string> jsonFiles, string jsonFileName)
    {
        IActionResult result;
        string json = IO.File.ReadAllText(jsonFileName);
        FIBacklogMesa[] fIBacklogMesaCollection = ExcelReader.GetFIBacklogMesaCollection(json);
        SetWorkItems(fIBacklogMesaCollection);
        if (!jsonFiles.Any())
        {
            jsonFiles.AddRange(Directory.GetFiles(_Directory, "*.json"));
            JsonFiles.AddRange(jsonFiles.OrderByDescending(l => l));
        }
        if (!jsonFiles.Contains(jsonFileName))
        {
            string fileName = Path.Combine(_Directory, $"{DateTime.Now.Ticks}.json");
            IO.File.WriteAllText(fileName, JSON);
        }
        JSON = json;
        result = Page();
        return result;
    }

    private Dictionary<int, string> GetFlopped()
    {
        Dictionary<int, string> results = new();
        foreach (KeyValuePair<string, int?> keyValuePair in _KeyValuePairs)
        {
            if (keyValuePair.Value is null)
                continue;
            results.Add(keyValuePair.Value.Value, keyValuePair.Key);
        }
        return results;
    }

    private void MergeBack(Dictionary<int, string> keyValuePairs)
    {
        foreach (KeyValuePair<int, string> keyValuePair in keyValuePairs)
        {
            if (_KeyValuePairs.ContainsKey(keyValuePair.Value))
                _KeyValuePairs[keyValuePair.Value] = keyValuePair.Key;
            else
                _KeyValuePairs.Add(keyValuePair.Value, keyValuePair.Key);
        }
    }

    private List<Root> GetWorkItems()
    {
        List<Root> results = new();
        Root workItem;
        string query = _AppSettings.Client.Query;
        using Http.HttpClient httpClient = _HttpClientFactory.CreateClient(nameof(FetchData));
        Library.WIQL.WorkItem[] workItems = Library.HttpClient.GetWorkItems(httpClient, _AppSettings.Client.BasePage, _AppSettings.Client.API, query);
        for (int i = 0; i < workItems.Length; i++)
        {
            workItem = Library.HttpClient.GetWorkItem(httpClient, _AppSettings.Client.BasePage, _AppSettings.Client.API, workItems[i].Id);
            if (workItem is null)
                break;
            results.Add(workItem);
        }
        return results;
    }

    private void CreateNew(string project, Dictionary<int, string> keyValuePairs, List<FIBacklogMesa> fIBacklogMesaCollection)
    {
        Task<WebApi.Models.WorkItem> workItemTask;
        foreach (FIBacklogMesa fIBacklogMesa in fIBacklogMesaCollection.OrderBy(l => int.Parse(l.Req)))
        {
            if (string.IsNullOrEmpty(fIBacklogMesa.Title))
                continue;
            workItemTask = WorkItemTrackingHttpClient.CreateWorkItem(_IsEnvironmentDevelopment, _WorkItemTrackingHttpClient, project, fIBacklogMesa);
            workItemTask.Wait();
            if (workItemTask.Result is null)
                throw new NullReferenceException(nameof(workItemTask.Result));
            if (workItemTask.Result?.Id is not null)
                keyValuePairs.Add(workItemTask.Result.Id.Value, fIBacklogMesa.Req);
        }
    }

    private void PossiblyCreate(FIBacklogMesa[] fIBacklogMesaCollection, Dictionary<int, string> keyValuePairs)
    {
        List<FIBacklogMesa> collection = new();
        foreach (FIBacklogMesa fIBacklogMesa in fIBacklogMesaCollection)
        {
            if (string.IsNullOrEmpty(fIBacklogMesa.Title))
                continue;
            if (_KeyValuePairs.ContainsKey(fIBacklogMesa.Req) && _KeyValuePairs[fIBacklogMesa.Req] is not null)
                continue;
            collection.Add(fIBacklogMesa);
        }
        if (collection.Any() && fIBacklogMesaCollection.Length != collection.Count)
            CreateNew(_AppSettings.Client.Project, keyValuePairs, collection);
    }

    private void Update(string project, List<(int, FIBacklogMesa)> collection)
    {
        Task<WebApi.Models.WorkItem> workItemTask;
        foreach ((int id, FIBacklogMesa fIBacklogMesa) in collection)
        {
            if (string.IsNullOrEmpty(fIBacklogMesa.Title))
                continue;
            workItemTask = WorkItemTrackingHttpClient.UpdateWorkItem(_WorkItemTrackingHttpClient, project, id, fIBacklogMesa);
            workItemTask.Wait();
            if (workItemTask.Result is null)
                throw new NullReferenceException(nameof(workItemTask.Result));
        }
    }

    private void PossiblyUpdate(FIBacklogMesa[] fIBacklogMesaCollection, List<Root> workItems)
    {
        int? index;
        string title;
        FIBacklogMesa fIBacklogMesa;
        List<(int, FIBacklogMesa)> collection = new();
        foreach (Root workItem in workItems)
        {
            index = null;
            for (int i = 0; i < fIBacklogMesaCollection.Length; i++)
            {
                fIBacklogMesa = fIBacklogMesaCollection[i];
                if (string.IsNullOrEmpty(fIBacklogMesa.Title))
                    continue;
                if (string.IsNullOrEmpty(workItem.Fields.MicrosoftVSTSTCMSystemInfo) || !workItem.Fields.MicrosoftVSTSTCMSystemInfo.Contains(fIBacklogMesa.Req))
                    continue;
                index = i;
                break;
            }
            if (index is null)
                continue;
            fIBacklogMesa = fIBacklogMesaCollection[index.Value];
            title = fIBacklogMesa.Title.Length > 254 ? fIBacklogMesa.Title[..255] : fIBacklogMesa.Title;
            if (workItem.Fields.SystemTitle != title)
                collection.Add((workItem.Id, fIBacklogMesa));
            else if (workItem.Fields.SystemDescription != fIBacklogMesa.Definition)
                collection.Add((workItem.Id, fIBacklogMesa));
        }
        if (collection.Any() && fIBacklogMesaCollection.Length != collection.Count)
            Update(_AppSettings.Client.Project, collection);
    }

    private IActionResult GetPage(string json, string pageName)
    {
        IActionResult result;
        FIBacklogMesa[]? fIBacklogMesaCollection = System.Text.Json.JsonSerializer.Deserialize<FIBacklogMesa[]>(json);
        if (fIBacklogMesaCollection is null)
            throw new NullReferenceException(nameof(fIBacklogMesaCollection));
        UpdateKeyValuePairs(fIBacklogMesaCollection);
        List<Root> workItems = GetWorkItems();
        if (!workItems.Any())
            throw new Exception("Failed to get work items!");
        Dictionary<int, string> keyValuePairs = GetFlopped();
        PossiblyCreate(fIBacklogMesaCollection, keyValuePairs);
        PossiblyUpdate(fIBacklogMesaCollection, workItems);
        SetWorkItems(fIBacklogMesaCollection);
        MergeBack(keyValuePairs);
        result = RedirectToPage($"./{nameof(FetchData)}");
        return result;
    }

    public IActionResult OnPost()
    {
        IActionResult result;
        WorkItems.Clear();
        if (!string.IsNullOrEmpty(JsonFileName))
            result = GetPage(JsonFiles, JsonFileName);
        else if (!string.IsNullOrEmpty(JSON) && string.IsNullOrEmpty(PageName))
            result = GetPage(JSON);
        else if (!string.IsNullOrEmpty(JSON) && !string.IsNullOrEmpty(PageName))
            result = GetPage(JSON, PageName);
        else
            result = Page();
        return result;
    }

    private IActionResult SetWorkItemsAndGetPage(string json)
    {
        IActionResult result;
        FIBacklogMesa[] fIBacklogMesaCollection = ExcelReader.GetFIBacklogMesaCollection(json);
        SetWorkItems(fIBacklogMesaCollection);
        result = Page();
        return result;
    }

    public IActionResult OnGet()
    {
        IActionResult result;
        JsonFiles.Clear();
        WorkItems.Clear();
        string[] jsonFiles = Directory.GetFiles(_Directory, "*.json");
        JsonFiles.AddRange(jsonFiles.OrderByDescending(l => l));
        if (!string.IsNullOrEmpty(JSON))
            result = SetWorkItemsAndGetPage(JSON);
        else if (!string.IsNullOrEmpty(JsonFileName) && IO.File.Exists(JsonFileName))
        {
            string json = IO.File.ReadAllText(JsonFileName);
            result = SetWorkItemsAndGetPage(json);
        }
        else
            result = Page();
        return result;
    }

}