using System;
using System.Collections.Generic;
using System.Linq;
#if !NET8
using System.Web;
using System.Web.Mvc;
#endif

#if NET8
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Authorization;
#endif

using Fab2ApprovalSystem.DMO;
using Fab2ApprovalSystem.Misc;
using Fab2ApprovalSystem.Models;

#if !NET8
using Kendo.Mvc.Extensions;
using Kendo.Mvc.UI;
#endif

namespace Fab2ApprovalSystem.Controllers;

[Authorize]
#if !NET8
[OutputCache(NoStore = true, Duration = 0, VaryByParam = "*")]
[SessionExpireFilter]
#endif
#if NET8
[Route("[controller]")]
#endif
public class PartsRequestController : Controller {

    private const int WorkflowNumber = 1;
    private readonly PartsRequestDMO prDMO = new();
    private readonly UserAccountDMO userDMO = new();
    private readonly WorkflowDMO wfDMO = new();
    private readonly AppSettings? _AppSettings = GlobalVars.AppSettings;

    public PartsRequestController() {
        ViewBag.ShowReAssignApprovers = false;
    }

    protected ActionResult HandleValidationError(string msg) {
        Response.StatusCode = (int)System.Net.HttpStatusCode.BadRequest;
        return Json(new { result = "Invalid", detail = msg });
    }

    protected ActionResult HandleAPIException(int issueID, Exception ex, string additionalKeys = "") {
        HandleException(issueID, ex, additionalKeys);

        Response.StatusCode = (int)System.Net.HttpStatusCode.InternalServerError;
        return Json(new { result = "Error", issueID = issueID, detail = ex.Message });
    }

    protected void HandleException(int issueID, Exception ex, string additionalKeys = "") {
        System.Diagnostics.StackTrace st = new();
        System.Diagnostics.StackFrame? sf = st.GetFrame(1);

        string controller = sf.GetMethod().DeclaringType.Name.Replace("Controller", "");
        string method = sf.GetMethod().Name;

        string detailedException = string.Format(
            "Exception for issue # {0}\r\n" +
            "Controller: {1}, Method: {2}, User: {3}, Keys: {4}\r\n" +
            "=====\r\n",
            issueID,
            controller,
            method,
            User?.Identity?.Name,
            additionalKeys);

        Exception x = ex;
        while (x != null) {
            detailedException += x.ToString();
            detailedException += "\r\n=====\r\n";
            x = x.InnerException;
        }

        Functions.WriteEvent(_AppSettings, detailedException, System.Diagnostics.EventLogEntryType.Error);

        EventLogDMO.Add(new WinEventLog() {
            IssueID = issueID,
            UserID = GetUserIdentityName(),
            DocumentType = controller,
            OperationType = "Error",
            Comments = detailedException
        });
    }

    public ActionResult Index() {
        return View();
    }

    public ActionResult Edit(int issueID) {
        PartsRequest pr = new();
        try {
            pr = prDMO.Get(issueID);

            if (pr == null) {
                ViewBag.ErrorDescription = "Document does not exist";
                return View("Error");
            } else if (pr.CurrentStep < 0) {
                ViewBag.ErrorDescription = "Document is deleted";
                return View("Error");
            } else if (pr.CurrentStep >= 1) {
                return RedirectToAction("EditApproval", new { issueID = issueID });
            } else {
                if (pr.OriginatorID != GlobalVars.GetUserId(GetSession())) {
                    if (!GlobalVars.IsAdmin(GetSession())) {
                        return RedirectToAction("ReadOnly", new { issueID = issueID });
                    }
                }

                ViewBag.UserList = userDMO.GetAllUsers();
                return View(pr);
            }
        } catch (Exception e) {
            HandleException(issueID, e);
            return View("Error");
        }
    }

#if !NET8

    [HttpPost]
    public ActionResult Edit(PartsRequest pr) {
        try {
            var pr_srv = prDMO.Get(pr.PRNumber);

            if (pr_srv == null) {
                return new HttpStatusCodeResult(System.Net.HttpStatusCode.BadRequest, "Document does not exist");
            }
            if (pr_srv.CurrentStep < 0) {
                return new HttpStatusCodeResult(System.Net.HttpStatusCode.BadRequest, "Document is deleted");
            }

            if (pr_srv.CurrentStep >= 1) {
                return new HttpStatusCodeResult(System.Net.HttpStatusCode.BadRequest, "Parts Request is not editable");
            }

            prDMO.Update(pr);
            return Content("");
        } catch (Exception e) {
            return HandleAPIException(pr.PRNumber, e);
        }
    }

#endif

    public ActionResult EditApproval(int issueID) {
        PartsRequest pr = new();
        try {
            int myUserID = GlobalVars.GetUserId(GetSession());

            pr = prDMO.Get(issueID);

            if (pr == null) {
                ViewBag.ErrorDescription = "Document does not exist";
                return View("Error");
            }
            if (pr.CurrentStep < 0) {
                ViewBag.ErrorDescription = "Document is deleted";
                return View("Error");
            }

            var wfStep = wfDMO.GetWorkflowStep((int)GlobalVars.DocumentType.PartsRequest, WorkflowNumber, pr.CurrentStep);

            var userList = MiscDMO.GetPendingApproversListByDocument(issueID, Convert.ToByte(pr.CurrentStep), (int)GlobalVars.DocumentType.PartsRequest);
            ViewBag.IsApprover = (userList.Count(u => u.UserID == myUserID) > 0);

            if (ViewBag.IsApprover == false) {
                if (pr.OriginatorID != myUserID) {
                    if (!GlobalVars.IsAdmin(GetSession())) {
                        return RedirectToAction("ReadOnly", new { issueID = issueID });
                    }
                }
            }

            ViewBag.IsAdmin = GlobalVars.IsAdmin(GetSession());
            ViewBag.IsOriginator = (pr.OriginatorID == myUserID);
            ViewBag.AllowReject = (wfStep != null && (wfStep.AllowReject.HasValue && wfStep.AllowReject.Value));
            ViewBag.ShowReAssignApprovers = ViewBag.IsAdmin || ViewBag.IsOriginator;
            ViewBag.ShowAddApprovers = ViewBag.IsAdmin || ViewBag.IsApprover || ViewBag.IsOriginator;
            ViewBag.UserList = userDMO.GetAllUsers();
            return View(pr);
        } catch (Exception e) {
            HandleException(issueID, e);
            return View("Error");
        }
    }

    public ActionResult ReadOnly(int issueID) {
        PartsRequest pr = new();
        try {
            int myUserID = GlobalVars.GetUserId(GetSession());

            pr = prDMO.Get(issueID);

            if (pr == null) {
                ViewBag.ErrorDescription = "Document does not exist";
                return View("Error");
            }
            if (pr.CurrentStep < 0) {
                ViewBag.ErrorDescription = "Document is deleted";
                return View("Error");
            }

            ViewBag.IsAdmin = GlobalVars.IsAdmin(GetSession());
            ViewBag.IsOriginator = (pr.OriginatorID == myUserID);
            ViewBag.UserList = userDMO.GetAllUsers();
            return View(pr);
        } catch (Exception e) {
            HandleException(issueID, e);
            return View("Error");
        }
    }

    public ActionResult Create() {
        PartsRequest pr = new();
        try {
            pr.OriginatorID = GlobalVars.GetUserId(GetSession());

            if (!CanCreatePartsRequest(pr.OriginatorID) && !GlobalVars.GetCanCreatePartsRequest(GetSession()))
                throw new Exception("User does not have permission to create Parts Request");

            prDMO.Insert(pr);

            return RedirectToAction("Edit", new { issueID = pr.PRNumber });
        } catch (Exception e) {
            return HandleAPIException(pr.PRNumber, e);
        }
    }

    public static bool CanCreatePartsRequest(int userID) {
        AdminDMO adminDMO = new();
        Role? role = adminDMO.GetSubRoles().FirstOrDefault(r => string.Equals(r.RoleName, "Parts Request", StringComparison.OrdinalIgnoreCase));
        if (role != null) {
            var subrole = role.SubRoles.FirstOrDefault(sr => string.Equals(sr.SubRoleCategoryItem, "Originator", StringComparison.OrdinalIgnoreCase));
            if (subrole != null) {
                var users = adminDMO.GetAllUsersBySubRole(subrole.SubRoleID);
                if (users.Count(u => u.UserID == userID) > 0) {
                    return true;
                }
            }
        }
        return false;
    }

#if !NET8

    public ActionResult Attachment_Read([DataSourceRequest] DataSourceRequest request, int prNumber) {
        try {
            return GetJsonResult(prDMO.GetAttachments(prNumber).ToDataSourceResult(request));
        } catch (Exception ex) {
            return HandleAPIException(prNumber, ex);
        }
    }

    [HttpPost]
    public ActionResult AttachSave(IEnumerable<HttpPostedFileBase> files, int prNumber) {
        // The Name of the Upload component is "files"
        if (files != null) {
            int userId = GlobalVars.GetUserId(GetSession());
            foreach (var file in files) {
                PartsRequestHelper.AttachSave(_AppSettings, prDMO, prNumber, userId, file.FileName, file.InputStream);
            }
        }

        return Content("");
    }

#endif

    public FileResult DownloadFile(string attachmentID, string prNumber) {
        string fileName = prDMO.GetFileName(attachmentID);

        string folderPath = _AppSettings.AttachmentFolder + "PartsRequest\\" + prNumber.ToString();
        var sDocument = System.IO.Path.Combine(folderPath, fileName);

        var FDir_AppData = _AppSettings.AttachmentFolder;
        if (!sDocument.StartsWith(FDir_AppData)) {
            // Ensure that we are serving file only inside the Fab2ApprovalAttachments folder
            // and block requests outside like "../web.config"
            throw new HttpException(403, "Forbidden");
        }

        if (!System.IO.File.Exists(sDocument))
            return null;

        return File(sDocument, System.Net.Mime.MediaTypeNames.Application.Octet, fileName);
    }

    [HttpPost]
    public ActionResult DeleteAttachment(int attachmentID, string fileName, int prNumber) {
        try {
            if (ModelState.IsValid) {
                prDMO.DeleteAttachment(attachmentID);
                var physicalPath = System.IO.Path.Combine(_AppSettings.AttachmentFolder + @"PartsRequest\" + prNumber.ToString(), fileName);

                if (System.IO.File.Exists(physicalPath)) {
                    System.IO.File.Delete(physicalPath);
                }
            }
            return Content("");
        } catch (Exception e) {
            return HandleAPIException(prNumber, e, "AttachmentID=" + attachmentID.ToString());
        }
    }

#if !NET8

    [HttpPost]
    public ActionResult Submit(int prNumber) {
        try {
            int myUserID = GlobalVars.GetUserId(GetSession());

            var pr = prDMO.Get(prNumber);

            if (pr == null)
                return new HttpStatusCodeResult(System.Net.HttpStatusCode.BadRequest, "Document does not exist");

            if (string.IsNullOrWhiteSpace(pr.Title))
                return HandleValidationError("Title is required");
            if (pr.RequestorID <= 0)
                return HandleValidationError("Requestor is required");
            if (pr.TechLeadID <= 0)
                return HandleValidationError("Tech Lead is required");

            prDMO.Submit(prNumber, myUserID);

            var approvers = MiscDMO.GetApprovalsByDocument(prNumber, (int)GlobalVars.DocumentType.PartsRequest);

            if (approvers.Count(a => a.Step.HasValue && a.Step.Value == 1 && a.UserID == myUserID) > 0) {
                // Auto-Approve if the user is an approver for workflow step 1
                var c = Approve(prNumber, 1, "Auto-Approve");
                if (c != null && c is ContentResult contentResult) {
                    var result = contentResult.Content;
                    if (!string.Equals(result, "OK"))
                        throw new Exception(result);
                }
                if (c != null && c is JsonResult)
                    return c;
            } else {
                // Do step 1 notification
                NotifyApprovers(prNumber, 1);
            }

            if (IsAjaxRequest()) {
                return Content("Redirect");
            } else {
                return Content("Invalid");
            }

        } catch (Exception e) {
            return HandleAPIException(prNumber, e);
        }
    }

    public ActionResult GetApproversList([DataSourceRequest] DataSourceRequest request, int issueID, byte step) {
        try {
            return Json(MiscDMO.GetApproversListByDocument(issueID, step, (int)GlobalVars.DocumentType.PartsRequest).ToDataSourceResult(request));
        } catch (Exception e) {
            return HandleAPIException(issueID, e, "Step=" + step.ToString());
        }
    }

    public ActionResult GetAllUsersList() {
        try {
            UserAccountDMO userDMO = new UserAccountDMO();
            IEnumerable<LoginModel> userlist = userDMO.GetAllUsers();
            return GetJsonResult(userlist);
        } catch (Exception e) {
            return HandleAPIException(0, e);
        }
    }

#endif

    [HttpPost]
    public ActionResult ReAssignApproval(int issueID, int fromUserID, int userIDs, byte step) {
        try {
            string email = wfDMO.ReAssignApproval(
                issueID, fromUserID, userIDs, step, (int)GlobalVars.DocumentType.PartsRequest);

            NotifyReAssignment(issueID, email);

            return Content("OK");
        } catch (Exception e) {
            return HandleAPIException(issueID, e);
        }
    }

#if !NET8

    [HttpPost]
    public ActionResult Approve(int prNumber, byte currentStep, string comments) {
        try {
            bool lastStep = false;
            bool lastApproverInCurrentStep = false;
            int myUserID = GlobalVars.GetUserId(GetSession());

            var pr = prDMO.Get(prNumber);

            if (pr == null)
                return new HttpStatusCodeResult(System.Net.HttpStatusCode.BadRequest, "Document does not exist");

            while (true) {
                lastApproverInCurrentStep = wfDMO.Approve(
                    _AppSettings,
                    prNumber,
                    currentStep,
                    comments,
                    out lastStep,
                    GlobalVars.GetUserId(GetSession()),
                    (int)GlobalVars.DocumentType.PartsRequest,
                    WorkflowNumber);

                if (!lastApproverInCurrentStep)
                    break;
                if (lastStep) {
                    NotifyCompletion(prNumber);
                    break;
                }

                currentStep++;

                var approvers = MiscDMO.GetApprovalsByDocument(prNumber, (int)GlobalVars.DocumentType.PartsRequest);
                if (approvers.Count(a => a.Step.HasValue && a.Step.Value == currentStep) == 0)
                    return Content("No approvers found for next step, contact support!");

                // only continue with approving if the next step has me as an approver also
                if (approvers.Count(a => a.Step.HasValue && a.Step.Value == currentStep && a.UserID == myUserID) == 0) {
                    NotifyApprovers(prNumber, currentStep);
                    break;
                }
            }

            return Content("OK");
        } catch (Exception e) {
            return HandleAPIException(prNumber, e);
        }
    }

#endif

    protected void NotifyReAssignment(int prNumber, string email) {
        var pr = prDMO.Get(prNumber);

        if (pr == null)
            return;

        string username = GlobalVars.GetUserName(GetSession());
        PartsRequestHelper.SendEmailNotification(_AppSettings, username,
            subject: string.Format("Parts Request Re-Assignment notice for # {0} - {1}", pr.PRNumber, pr.Title),
            prNumber: prNumber,
            toEmail: email,
            emailTemplate: "PRReAssigned.txt");

        EventLogDMO.Add(new WinEventLog() {
            IssueID = prNumber,
            UserID = GetUserIdentityName(),
            DocumentType = "PR",
            OperationType = "Email",
            Comments = "ReAssigned Approver: " + email
        });
    }

    protected void NotifyCompletion(int prNumber) {
        var pr = prDMO.Get(prNumber);

        if (pr == null)
            return;

        var u = userDMO.GetUserByID(pr.RequestorID);
        if ((u != null) && (!string.IsNullOrWhiteSpace(u.Email))) {
            string username = GlobalVars.GetUserName(GetSession());
            PartsRequestHelper.SendEmailNotification(_AppSettings, username,
                  subject: string.Format("Parts Request Completion notice for # {0} - {1}", pr.PRNumber, pr.Title),
                  prNumber: prNumber,
                  toEmail: u.Email,
                  emailTemplate: "PRCompleted.txt");

            EventLogDMO.Add(new WinEventLog() {
                IssueID = prNumber,
                UserID = GetUserIdentityName(),
                DocumentType = "PR",
                OperationType = "Email",
                Comments = "Completed: " + u.Email
            });
        }
    }

    public void NotifyRejection(int prNumber) {
        var pr = prDMO.Get(prNumber);

        if (pr == null)
            return;

        var u = userDMO.GetUserByID(pr.OriginatorID);
        if ((u != null) && (!string.IsNullOrWhiteSpace(u.Email))) {
            string username = GlobalVars.GetUserName(GetSession());
            PartsRequestHelper.SendEmailNotification(_AppSettings, username,
                  subject: string.Format("Parts Request Rejection notice for # {0} - {1}", pr.PRNumber, pr.Title),
                  prNumber: prNumber,
                  toEmail: u.Email,
                  emailTemplate: "PRReject.txt");

            EventLogDMO.Add(new WinEventLog() {
                IssueID = prNumber,
                UserID = GetUserIdentityName(),
                DocumentType = "PR",
                OperationType = "Email",
                Comments = "Rejected: " + u.Email
            });
        }
    }

    protected void NotifyApprovers(int prNumber, byte step) {
        try {
            string emailSentList = "";

            var pr = prDMO.Get(prNumber);

            if (pr == null)
                throw new Exception("Invalid pr#");

            List<string> emailList = MiscDMO.GetApproverEmailListByDocument(
                prNumber, step, (int)GlobalVars.DocumentType.PartsRequest).Distinct().ToList();

            foreach (string email in emailList) {
                try {
                    string username = GlobalVars.GetUserName(GetSession());
                    PartsRequestHelper.SendEmailNotification(_AppSettings, username,
                                    subject: string.Format("Parts Request Assignment notice for # {0} - {1}", pr.PRNumber, pr.Title),
                                    prNumber: prNumber,
                                    toEmail: email,
                                    emailTemplate: "PRAssigned.txt");
                } catch (Exception ex) {
                    HandleException(prNumber, ex, "email=" + email);
                }

                emailSentList += email + ",";
            }

            try {
                EventLogDMO.Add(new WinEventLog() {
                    IssueID = prNumber,
                    UserID = GetUserIdentityName(),
                    DocumentType = "PR",
                    OperationType = "Email",
                    Comments = "Approvers for Step " + step.ToString() + ":" + emailSentList
                });
            } catch { }
        } catch (Exception e) {
            HandleException(prNumber, e, "Step=" + step.ToString());
        }
    }

    [HttpPost]
    public ActionResult Reject(int prNumber, byte currentStep, string comments) {
        try {
            if (GlobalVars.IsUserIdValueNotNull(GetSession())) {
                wfDMO.Reject(prNumber, currentStep, comments, GlobalVars.GetUserId(GetSession()), (int)GlobalVars.DocumentType.PartsRequest);
                NotifyRejection(prNumber);
            } else {
                Response.Redirect("~/Account/Login");
            }

            return Content("OK");
        } catch (Exception e) {
            return HandleAPIException(prNumber, e);
        }
    }

#if !NET8

    public ActionResult ApprovalLogHistory_Read([DataSourceRequest] DataSourceRequest request, int prNumber) {
        return GetJsonResult(prDMO.GetApprovalLogHistory(prNumber).ToDataSourceResult(request));
    }

#endif

    protected void NotifyAssignment(int prNumber, string email) {
        var pr = prDMO.Get(prNumber);

        if (pr == null)
            return;

        string username = GlobalVars.GetUserName(GetSession());
        PartsRequestHelper.SendEmailNotification(_AppSettings, username,
            subject: string.Format("Parts Request Assignment notice for # {0} - {1}", pr.PRNumber, pr.Title),
            prNumber: prNumber,
            toEmail: email,
            emailTemplate: "PRAssigned.txt");

        EventLogDMO.Add(new WinEventLog() {
            IssueID = prNumber,
            UserID = GetUserIdentityName(),
            DocumentType = "PR",
            OperationType = "Email",
            Comments = "Assigned Approver: " + email
        });
    }

    [HttpPost]
    public void AddAdditionalApproval(int issueID, byte step, string userIDs) {
        var emailArray = "";
        try {
            emailArray = wfDMO.AddAdditionalApproval(issueID, userIDs, step, (int)GlobalVars.DocumentType.PartsRequest);
        } catch (Exception e) {
            HandleAPIException(issueID, e);
        }

        string emailSentList = "";
        string[] emaiList = emailArray.Split(new char[] { '~' });
        foreach (string email in emaiList) {
            if (email.Length > 0) {
                NotifyAssignment(issueID, email);
                emailSentList += email + ",";
            }

        }

        try {
            EventLogDMO.Add(new WinEventLog() {
                IssueID = issueID,
                UserID = GetUserIdentityName(),
                DocumentType = "PR",
                OperationType = "Email",
                Comments = "Additional Approver: " + emailSentList
            });
        } catch { }
    }

#if !NET8

    private System.Web.HttpSessionStateBase GetSession() =>
        Session;

    private JsonResult GetJsonResult(object? data) =>
        Json(data, JsonRequestBehavior.AllowGet);

    private bool IsAjaxRequest() =>
        Request.IsAjaxRequest();

#endif

#if NET8

    private Microsoft.AspNetCore.Http.ISession GetSession() =>
        HttpContext.Session;

    private JsonResult GetJsonResult(object? data) =>
        Json(data);

    private bool IsAjaxRequest() =>
        Request.Headers.TryGetValue("X-Requested-With", out Microsoft.Extensions.Primitives.StringValues strings) && strings[0] == "XMLHttpRequest";

#endif

    private string GetUserIdentityName() =>
        @User.Identity.Name;

}