using System.Net;
using System.Net.Mail;
using System.Text;

using MesaFabApproval.API.Utilities;
using MesaFabApproval.Models;
using MesaFabApproval.Shared.Models;
using MesaFabApproval.Shared.Utilities;

using Microsoft.Extensions.Caching.Memory;

namespace MesaFabApproval.API.Services;

public interface IPCRBService {
    Task CreateNewPCRB(PCRB pcrb);
    Task<IEnumerable<PCRB>> GetAllPCRBs(bool bypassCache);
    Task<PCRB> GetPCRBByPlanNumber(int planNumber, bool bypassCache);
    Task<PCRB> GetPCRBByTitle(string title, bool bypassCache);
    Task UpdatePCRB(PCRB pcrb);
    Task DeletePCRB(int planNumber);
    Task<UploadResult> UploadAttachment(IFormFile file, PCRBAttachment attachment);
    Task<IEnumerable<PCRBAttachment>> GetAttachmentsByPlanNumber(int planNumber, bool bypassCache);
    Task UpdateAttachment(PCRBAttachment attachment);
    Task DeleteAttachment(PCRBAttachment attachment);
    Task CreateNewActionItem(PCRBActionItem actionItem);
    Task UpdateActionItem(PCRBActionItem actionItem);
    Task DeleteActionItem(int id);
    Task<IEnumerable<PCRBActionItem>> GetActionItemsForPlanNumber(int planNumber, bool bypassCache);
    Task CreateNewAttendee(PCRBAttendee attendee);
    Task UpdateAttendee(PCRBAttendee attendee);
    Task DeleteAttendee(int id);
    Task<IEnumerable<PCRBAttendee>> GetAttendeesByPlanNumber(int planNumber, bool bypassCache);
    Task CreatePCR3Document(PCR3Document document);
    Task UpdatePCR3Document(PCR3Document document);
    Task<IEnumerable<PCR3Document>> GetPCR3DocumentsForPlanNumber(int planNumber, bool bypassCache);
    Task NotifyNewApprovals(PCRB pcrb);
    Task NotifyApprovers(PCRBNotification notification);
    Task NotifyOriginator(PCRBNotification notification);
    Task NotifyResponsiblePerson(PCRBActionItemNotification notification);
    Task CreateFollowUp(PCRBFollowUp followUp);
    Task<IEnumerable<PCRBFollowUp>> GetFollowUpsByPlanNumber(int planNumber, bool bypassCache);
    Task UpdateFollowUp(PCRBFollowUp followUp);
    Task DeleteFollowUp(int id);
}

public class PCRBService : IPCRBService {
    private readonly ILogger<PCRBService> _logger;
    private readonly IDalService _dalService;
    private readonly IMemoryCache _cache;
    private readonly IUserService _userService;
    private readonly IApprovalService _approvalService;
    private readonly ISmtpService _smtpService;

    private readonly string _pcrbAttachmentPath;
    private readonly string _siteBaseUrl;

    public PCRBService(ILogger<PCRBService> logger,
                       IDalService dalService,
                       IMemoryCache cache,
                       IUserService userService,
                       IApprovalService approvalService,
                       ISmtpService smtpService,
                       AppSettings appSettings) {
        _logger = logger ?? throw new ArgumentNullException("ILogger not injected");
        _dalService = dalService ?? throw new ArgumentNullException("IDalService not injected");
        _cache = cache ?? throw new ArgumentNullException("IMemoryCache not injected");
        _userService = userService ?? throw new ArgumentNullException("IUserService not injected");
        _approvalService = approvalService ??
            throw new ArgumentNullException("IApprovalService not injected");
        _smtpService = smtpService ?? throw new ArgumentNullException("ISmtpService not injected");
        _siteBaseUrl = appSettings.SiteBaseUrl;
        _pcrbAttachmentPath = appSettings.PcrbAttachmentPath;
    }

    public async Task CreateNewPCRB(PCRB pcrb) {
        try {
            _logger.LogInformation("Attempting to create new PCRB");

            if (pcrb is null) throw new ArgumentNullException("PCRB cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append("insert into CCChangeControl (OwnerID, Title, ChangeLevel, ReasonForChange, ");
            queryBuilder.Append("ChangeDescription, IsITAR, CurrentStep, InsertTimeStamp, LastUpdateDate) ");
            queryBuilder.Append($"values ({pcrb.OwnerID}, '{pcrb.Title}', '{pcrb.ChangeLevel}', ");
            queryBuilder.Append($"'{pcrb.ReasonForChange}', '{pcrb.ChangeDescription}', ");
            queryBuilder.Append($"{Convert.ToInt32(pcrb.IsITAR)}, {pcrb.CurrentStep}, ");
            queryBuilder.Append($"'{pcrb.InsertTimeStamp.ToString("yyyy-MM-dd HH:mm:ss")}', ");
            queryBuilder.Append($"'{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")}')");

            int rowsCreated = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsCreated <= 0) throw new Exception("unable to insert new PCRB in the database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to create new PCRB, because {ex.Message}");
            throw;
        }
    }

    public async Task<IEnumerable<PCRB>> GetAllPCRBs(bool bypassCache) {
        try {
            _logger.LogInformation("Attempting to get all PCRBs");

            IEnumerable<PCRB>? allPCRBs = null;
            if (!bypassCache) allPCRBs = _cache.Get<IEnumerable<PCRB>>("allPCRBs");

            if (allPCRBs is null) {
                string sql = "select * from CCChangeControl";

                allPCRBs = (await _dalService.QueryAsync<PCRB>(sql)).ToList();

                foreach (PCRB pcrb in allPCRBs) {
                    if (string.IsNullOrWhiteSpace(pcrb.OwnerName) && pcrb.OwnerID > 0)
                        pcrb.OwnerName = (await _userService.GetUserByUserId(pcrb.OwnerID)).GetFullName();
                }

                _cache.Set("allPCRBs", allPCRBs, DateTimeOffset.Now.AddHours(1));
            }

            if (allPCRBs is null || allPCRBs.Count() == 0)
                throw new Exception("no PCRBs found");

            return allPCRBs;
        } catch (Exception ex) {
            _logger.LogError($"Unable to get all PCRBs, because {ex.Message}");
            throw;
        }
    }

    public async Task<PCRB> GetPCRBByPlanNumber(int planNumber, bool bypassCache) {
        try {
            _logger.LogInformation("Attempting to get a PCRB by plan#");

            if (planNumber <= 0) throw new ArgumentException($"{planNumber} is not a valid PCRB#");

            PCRB? pcrb = null;

            if (!bypassCache) pcrb = _cache.Get<PCRB>($"pcrb{planNumber}");

            if (pcrb is null) {
                string sql = $"select * from CCChangeControl where PlanNumber={planNumber}";

                pcrb = (await _dalService.QueryAsync<PCRB>(sql)).FirstOrDefault();

                if (pcrb is not null) {
                    if (string.IsNullOrWhiteSpace(pcrb.OwnerName) && pcrb.OwnerID > 0)
                        pcrb.OwnerName = (await _userService.GetUserByUserId(pcrb.OwnerID)).GetFullName();

                    _cache.Set($"pcrb{planNumber}", pcrb, DateTimeOffset.Now.AddHours(1));
                    _cache.Set($"pcrb{pcrb.Title}", pcrb, DateTimeOffset.Now.AddHours(1));
                }
            }

            if (pcrb is null) throw new Exception($"unable to find PCRB {planNumber}");

            return pcrb;
        } catch (Exception ex) {
            _logger.LogError($"Unable to get PCRB by Plan #, because {ex.Message}");
            throw;
        }
    }

    public async Task<PCRB> GetPCRBByTitle(string title, bool bypassCache) {
        try {
            _logger.LogInformation("Attempting to get a PCRB by title");

            if (string.IsNullOrWhiteSpace(title)) throw new ArgumentException("Title cannot be null or empty");

            PCRB? pcrb = null;

            if (!bypassCache) pcrb = _cache.Get<PCRB>($"pcrb{title}");

            if (pcrb is null) {
                string sql = $"select * from CCChangeControl where Title='{title}'";

                pcrb = (await _dalService.QueryAsync<PCRB>(sql)).FirstOrDefault();

                if (pcrb is not null) {
                    if (string.IsNullOrWhiteSpace(pcrb.OwnerName) && pcrb.OwnerID > 0)
                        pcrb.OwnerName = (await _userService.GetUserByUserId(pcrb.OwnerID)).GetFullName();

                    _cache.Set($"pcrb{title}", pcrb, DateTimeOffset.Now.AddHours(1));
                    _cache.Set($"pcrb{pcrb.PlanNumber}", pcrb, DateTimeOffset.Now.AddHours(1));
                }
            }

            if (pcrb is null) throw new Exception($"unable to find PCRB {title}");

            return pcrb;
        } catch (Exception ex) {
            _logger.LogError($"Unable to get PCRB by title, because {ex.Message}");
            throw;
        }
    }

    public async Task UpdatePCRB(PCRB pcrb) {
        try {
            _logger.LogInformation($"Attempting to update PCRB");

            if (pcrb is null) throw new ArgumentNullException("PCRB cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append($"update CCChangeControl set OwnerID={pcrb.OwnerID}, ");
            queryBuilder.Append($"Title='{pcrb.Title.Replace("'", "''")}', ChangeLevel='{pcrb.ChangeLevel}', ");
            queryBuilder.Append($"CurrentStep={pcrb.CurrentStep}, ReasonForChange='{pcrb.ReasonForChange.Replace("'", "''")}', ");
            queryBuilder.Append($"ChangeDescription='{pcrb.ChangeDescription.Replace("'", "''")}', ");
            queryBuilder.Append($"IsITAR={Convert.ToInt32(pcrb.IsITAR)}, ");
            queryBuilder.Append($"InsertTimeStamp='{pcrb.InsertTimeStamp.ToString("yyyy-MM-dd HH:mm:ss")}', ");
            queryBuilder.Append($"ClosedDate='{pcrb.ClosedDate.ToString("yyyy-MM-dd HH:mm:ss")}', ");
            queryBuilder.Append($"LastUpdateDate='{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")}' ");
            queryBuilder.Append($"where PlanNumber={pcrb.PlanNumber}");

            int rowsAffected = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsAffected <= 0) throw new Exception("unable to perform update in database");

            _cache.Set($"pcrb{pcrb.Title}", pcrb, DateTimeOffset.Now.AddHours(1));
            _cache.Set($"pcrb{pcrb.PlanNumber}", pcrb, DateTimeOffset.Now.AddHours(1));

            IEnumerable<PCRB>? allPCRBs = _cache.Get<IEnumerable<PCRB>>("allPCRBs");
            if (allPCRBs is not null) {
                List<PCRB> pcrbList = allPCRBs.ToList();
                pcrbList.RemoveAll(p => p.PlanNumber == pcrb.PlanNumber);
                pcrbList.Add(pcrb);
                _cache.Set("allPCRBs", pcrbList, DateTimeOffset.Now.AddHours(1));
            }
        } catch (Exception ex) {
            _logger.LogError($"Unable to update PCRB, because {ex.Message}");
            throw;
        }
    }

    public async Task DeletePCRB(int planNumber) {
        try {
            _logger.LogInformation($"Attempting to delete PCRB {planNumber}");

            if (planNumber <= 0) throw new ArgumentException($"{planNumber} is not a valid PCRB Plan #");

            string sql = $"delete from CCChangeControl where PlanNumber={planNumber}";

            int rowsAffected = await _dalService.ExecuteAsync(sql);

            if (rowsAffected <= 0) throw new Exception("delete operation failed in database");

            IEnumerable<PCRB>? allPCRBs = _cache.Get<IEnumerable<PCRB>>("allPCRBs");
            if (allPCRBs is not null) {
                List<PCRB> pcrbList = allPCRBs.ToList();
                pcrbList.RemoveAll(p => p.PlanNumber == planNumber);
                _cache.Set("allPCRBs", pcrbList, DateTimeOffset.Now.AddHours(1));
            }
        } catch (Exception ex) {
            _logger.LogError($"Unable to delete PCRB {planNumber}, because {ex.Message}");
            throw;
        }
    }

    public async Task<UploadResult> UploadAttachment(IFormFile file, PCRBAttachment attachment) {
        try {
            _logger.LogInformation("Attempting to upload attachment");

            UploadResult? uploadResult = null;

            if (file is null) throw new ArgumentNullException("File cannot be null");
            if (file.Length <= 0) throw new ArgumentException("File size cannot be zero");
            if (attachment is null) throw new ArgumentNullException("Attachment cannot be null");

            try {
                string encodedName = WebUtility.HtmlEncode(file.FileName);
                string path = $"{_pcrbAttachmentPath}\\{attachment.PlanNumber}\\{attachment.Step}\\{encodedName}";

                attachment.Path = path;

                await FileUtilities.SaveFileToFileSystem(file, path);
                await SaveAttachmentInDb(file, attachment);

                uploadResult = new() {
                    UploadSuccessful = true,
                    FileName = file.FileName
                };
            } catch (Exception ex) {
                uploadResult = new() {
                    UploadSuccessful = false,
                    FileName = file.FileName,
                    Error = ex.Message
                };
            }

            return uploadResult;
        } catch (Exception ex) {
            _logger.LogError($"Unable to upload attachment, because {ex.Message}");
            throw;
        }
    }

    public async Task<IEnumerable<PCRBAttachment>> GetAttachmentsByPlanNumber(int planNumber, bool bypassCache) {
        try {
            _logger.LogInformation($"Attempting to get all attachments for PCRB Plan# {planNumber}");

            if (planNumber <= 0) throw new ArgumentException($"{planNumber} is not a valid PCRB Plan#");

            IEnumerable<PCRBAttachment>? attachments = null;

            if (!bypassCache)
                attachments = _cache.Get<IEnumerable<PCRBAttachment>>($"pcrbAttachments{planNumber}");

            if (attachments is null) {
                string sql = $"select * from CCAttachment where PlanNumber={planNumber}";

                attachments = await _dalService.QueryAsync<PCRBAttachment>(sql);

                _cache.Set($"pcrbAttachments{planNumber}", attachments, DateTimeOffset.Now.AddMinutes(15));
            }

            return attachments;
        } catch (Exception ex) {
            _logger.LogError($"Unable to get all attachments for PCRB Plan# {planNumber}, because {ex.Message}");
            throw;
        }
    }

    public async Task UpdateAttachment(PCRBAttachment attachment) {
        try {
            _logger.LogInformation("Attempting to update an attachment");

            if (attachment is null)
                throw new ArgumentNullException("attachment cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append($"update CCAttachment ");
            queryBuilder.Append($"set Title='{attachment.Title.Replace("'", "''")}' where ID={attachment.ID}");

            int rowsAffected = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsAffected <= 0) throw new Exception("update failed in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to update attachment, because {ex.Message}");
            throw;
        }
    }

    public async Task DeleteAttachment(PCRBAttachment attachment) {
        try {
            _logger.LogInformation("Attempting to update an attachment");

            if (attachment is null)
                throw new ArgumentNullException("attachment cannot be null");

            if (!File.Exists(attachment.Path)) throw new FileNotFoundException("No file found at provided path");

            File.Delete(attachment.Path);

            string sql = $"delete from CCAttachment where ID={attachment.ID}";

            int rowsAffected = await _dalService.ExecuteAsync(sql);

            if (rowsAffected <= 0) throw new Exception("update failed in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to update attachment, because {ex.Message}");
            throw;
        }
    }

    public async Task CreateNewActionItem(PCRBActionItem actionItem) {
        try {
            _logger.LogInformation("Attempting to create new action item");

            if (actionItem is null) throw new ArgumentNullException("action item cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append("insert into CCPCRBActionItem (Name, Gating, ClosedStatus, ClosedDate, ");
            queryBuilder.Append("ClosedByID, UploadedByID, UploadedDateTime, ResponsiblePersonID, PlanNumber, ");
            queryBuilder.Append($"Step) values ('{actionItem.Name}', {Convert.ToInt32(actionItem.Gating)}, ");
            queryBuilder.Append($"{Convert.ToInt32(actionItem.ClosedStatus)}, ");
            DateTime closedDateCopy = actionItem.ClosedDate ?? DateTimeUtilities.MAX_DT;
            queryBuilder.Append($"'{closedDateCopy.ToString("yyyy-MM-dd HH:mm:ss")}', {actionItem.ClosedByID}, ");
            queryBuilder.Append($"{actionItem.UploadedByID}, '{actionItem.UploadedDateTime.ToString("yyyy-MM-dd HH:mm:ss")}', ");
            queryBuilder.Append($"{actionItem.ResponsiblePersonID}, {actionItem.PlanNumber}, ");
            queryBuilder.Append($"{actionItem.Step});");

            int rowsCreated = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsCreated <= 0) throw new Exception("unable to insert new action item in the database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to create new action item, because {ex.Message}");
            throw;
        }
    }

    public async Task UpdateActionItem(PCRBActionItem actionItem) {
        try {
            _logger.LogInformation("Attempting to update an action item");

            if (actionItem is null)
                throw new ArgumentNullException("action item cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append($"update CCPCRBActionItem set Name='{actionItem.Name.Replace("'", "''")}', Gating={Convert.ToInt32(actionItem.Gating)}, ");
            queryBuilder.Append($"ClosedStatus={Convert.ToInt32(actionItem.ClosedStatus)}, ");
            DateTime closedDateCopy = actionItem.ClosedDate ?? DateTimeUtilities.MAX_DT;
            queryBuilder.Append($"ClosedDate='{closedDateCopy.ToString("yyyy-MM-dd HH:mm:ss")}', ");
            queryBuilder.Append($"ClosedByID={actionItem.ClosedByID}, ResponsiblePersonID={actionItem.ResponsiblePersonID}, ");
            queryBuilder.Append($"Step={actionItem.Step} where ID={actionItem.ID}");

            int rowsAffected = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsAffected <= 0) throw new Exception("update failed in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to update attachment, because {ex.Message}");
            throw;
        }
    }

    public async Task DeleteActionItem(int id) {
        try {
            _logger.LogInformation($"Attempting to delete action item {id}");

            if (id <= 0) throw new ArgumentException($"{id} is not a valid PCRB action item ID");

            string sql = $"delete from CCPCRBActionItem where ID={id}";

            int rowsAffected = await _dalService.ExecuteAsync(sql);

            if (rowsAffected <= 0) throw new Exception("delete operation failed in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to delete action item {id}, because {ex.Message}");
            throw;
        }
    }

    public async Task<IEnumerable<PCRBActionItem>> GetActionItemsForPlanNumber(int planNumber, bool bypassCache) {
        try {
            _logger.LogInformation($"Attempting to get all action items for PCRB plan# {planNumber}");

            if (planNumber <= 0) throw new ArgumentException($"{planNumber} is not a valid PCRB plan#");

            IEnumerable<PCRBActionItem>? actionItems = null;

            if (!bypassCache)
                actionItems = _cache.Get<IEnumerable<PCRBActionItem>>($"pcrbActionItems{planNumber}");

            if (actionItems is null) {
                string sql = $"select * from CCPCRBActionItem where PlanNumber={planNumber}";

                actionItems = await _dalService.QueryAsync<PCRBActionItem>(sql);

                _cache.Set($"pcrbActionItems{planNumber}", actionItems, DateTimeOffset.Now.AddMinutes(15));
            }

            return actionItems;
        } catch (Exception ex) {
            _logger.LogError($"Unable to get all action items for PCRB plan# {planNumber}, because {ex.Message}");
            throw;
        }
    }

    public async Task CreateNewAttendee(PCRBAttendee attendee) {
        try {
            _logger.LogInformation("Attempting to create new attendee");

            if (attendee is null) throw new ArgumentNullException("attendee item cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append("insert into CCPCRBAttendee (PlanNumber, JobTitle, Location, Attended, AttendeeID, Step) ");
            queryBuilder.Append($"values ({attendee.PlanNumber}, '{attendee.JobTitle}', '{attendee.Location}', ");
            queryBuilder.Append($"{Convert.ToInt32(attendee.Attended)}, {attendee.AttendeeID}, ");
            queryBuilder.Append($"{attendee.Step});");

            int rowsCreated = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsCreated <= 0) throw new Exception("unable to insert new attendee in the database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to create new attendee, because {ex.Message}");
            throw;
        }
    }

    public async Task UpdateAttendee(PCRBAttendee attendee) {
        try {
            _logger.LogInformation("Attempting to update an attendee");

            if (attendee is null)
                throw new ArgumentNullException("attendee cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append($"update CCPCRBAttendee set JobTitle='{attendee.JobTitle}', ");
            queryBuilder.Append($"Location='{attendee.Location}', Attended={Convert.ToInt32(attendee.Attended)}, ");
            queryBuilder.Append($"AttendeeID={attendee.AttendeeID}, ");
            queryBuilder.Append($"Step={attendee.Step} where ID={attendee.ID}");

            int rowsAffected = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsAffected <= 0) throw new Exception("update failed in database");

            IEnumerable<PCRBAttendee>? attendees = _cache.Get<IEnumerable<PCRBAttendee>>($"pcrbAttendees{attendee.PlanNumber}");
            if (attendees is not null) {
                foreach (PCRBAttendee cachedAttendee in attendees) {
                    if (cachedAttendee.ID == attendee.ID) {
                        cachedAttendee.Location = attendee.Location;
                        cachedAttendee.Attended = attendee.Attended;
                        cachedAttendee.JobTitle = attendee.JobTitle;
                        cachedAttendee.AttendeeID = attendee.AttendeeID;
                        cachedAttendee.Step = attendee.Step;
                    }
                }
                _cache.Set($"pcrbAttendees{attendee.PlanNumber}", attendees, DateTimeOffset.Now.AddMinutes(15));
            }
        } catch (Exception ex) {
            _logger.LogError($"Unable to update attendee, because {ex.Message}");
            throw;
        }
    }

    public async Task DeleteAttendee(int id) {
        try {
            _logger.LogInformation($"Attempting to delete attendee {id}");

            if (id <= 0) throw new ArgumentException($"{id} is not a valid attendee ID");

            string sql = $"delete from CCPCRBAttendee where ID={id}";

            int rowsAffected = await _dalService.ExecuteAsync(sql);

            if (rowsAffected <= 0) throw new Exception("delete operation failed in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to delete attendee {id}, because {ex.Message}");
            throw;
        }
    }

    public async Task<IEnumerable<PCRBAttendee>> GetAttendeesByPlanNumber(int planNumber, bool bypassCache) {
        try {
            _logger.LogInformation($"Attempting to get all attendees for PCRB plan# {planNumber}");

            if (planNumber <= 0) throw new ArgumentException($"{planNumber} is not a valid PCRB plan#");

            IEnumerable<PCRBAttendee>? attendees = null;

            if (!bypassCache)
                attendees = _cache.Get<IEnumerable<PCRBAttendee>>($"pcrbAttendees{planNumber}");

            if (attendees is null) {
                string sql = $"select * from CCPCRBAttendee where PlanNumber={planNumber}";

                attendees = await _dalService.QueryAsync<PCRBAttendee>(sql);

                _cache.Set($"pcrbAttendees{planNumber}", attendees, DateTimeOffset.Now.AddMinutes(15));
            }

            return attendees;
        } catch (Exception ex) {
            _logger.LogError($"Unable to get all attendees for PCRB plan# {planNumber}, because {ex.Message}");
            throw;
        }
    }

    public async Task CreatePCR3Document(PCR3Document document) {
        try {
            _logger.LogInformation("Attempting to create new PCR3 document");

            if (document is null) throw new ArgumentNullException("document item cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append("insert into CCPCR3Document (PlanNumber, DocType) ");
            queryBuilder.Append($"values ({document.PlanNumber}, '{document.DocType}')");

            int rowsCreated = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsCreated <= 0) throw new Exception("unable to insert new PCR3 document in the database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to create new PCR3 document, because {ex.Message}");
            throw;
        }
    }

    public async Task UpdatePCR3Document(PCR3Document document) {
        try {
            _logger.LogInformation("Attempting to update a PCR3 document");

            if (document is null) throw new ArgumentNullException("document cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append($"update CCPCR3Document set DocNumbers='{document.DocNumbers}', ");
            queryBuilder.Append($"Comment='{document.Comment.Replace("'", "''")}', ECNNumber={document.ECNNumber}, ");
            queryBuilder.Append($"CompletedDate='{document.CompletedDate.ToString("yyyy-MM-dd HH:mm:ss")}', ");
            queryBuilder.Append($"CompletedByID={document.CompletedByID} ");
            queryBuilder.Append($"where ID={document.ID}");

            int rowsAffected = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsAffected <= 0) throw new Exception("update failed in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to update PCR3 document, because {ex.Message}");
            throw;
        }
    }

    public async Task<IEnumerable<PCR3Document>> GetPCR3DocumentsForPlanNumber(int planNumber, bool bypassCache) {
        try {
            _logger.LogInformation($"Attempting to get all PCR3 documents for PCRB plan# {planNumber}");

            if (planNumber <= 0) throw new ArgumentException($"{planNumber} is not a valid PCRB plan#");

            IEnumerable<PCR3Document>? documents = null;

            if (!bypassCache)
                documents = _cache.Get<IEnumerable<PCR3Document>>($"pcr3Documents{planNumber}");

            if (documents is null) {
                string sql = $"select * from CCPCR3Document where PlanNumber={planNumber}";

                documents = await _dalService.QueryAsync<PCR3Document>(sql);

                _cache.Set($"pcr3Documents{planNumber}", documents, DateTimeOffset.Now.AddMinutes(15));
            }

            return documents;
        } catch (Exception ex) {
            _logger.LogError($"Unable to get all PCR3 documents for PCRB plan# {planNumber}, because {ex.Message}");
            throw;
        }
    }

    public async Task NotifyNewApprovals(PCRB pcrb) {
        try {
            _logger.LogInformation("Attempting to notify approvers");

            if (pcrb is null) throw new ArgumentNullException("PCRB cannot be null");

            IEnumerable<Approval> approvals = await _approvalService.GetApprovalsForIssueId(pcrb.PlanNumber, true);

            List<Approval> approvalsNeedingNotification = approvals.Where(a => a.Step == pcrb.CurrentStep &&
                                                                               a.NotifyDate <= DateTimeUtilities.MIN_DT &&
                                                                               a.AssignedDate > DateTimeUtilities.MIN_DT).ToList();

            HashSet<string> emailsAlreadySent = new();
            foreach (Approval approval in approvalsNeedingNotification) {
                User user = await _userService.GetUserByUserId(approval.UserID);

                if (!emailsAlreadySent.Contains(user.Email.ToLower())) {
                    emailsAlreadySent.Add(user.Email);

                    List<MailAddress> toAddresses = new();
                    toAddresses.Add(new MailAddress(user.Email.ToLower()));

                    List<MailAddress> ccAddresses = new();

                    string subject = $"[New Task] Mesa Fab Approval - PCRB# {pcrb.PlanNumber} - {pcrb.Title}";

                    StringBuilder bodyBuilder = new();
                    bodyBuilder.Append($"PCRB# {pcrb.PlanNumber} [{pcrb.Title}] PCR{approval.Step} is ready for your approval. ");
                    bodyBuilder.Append($"The assigned role is {approval.SubRoleCategoryItem}. <br /> <br />");
                    bodyBuilder.Append($"Click {_siteBaseUrl}/redirect?redirectPath=pcrb/{approval.IssueID} to view the PCRB.");

                    await _smtpService.SendEmail(toAddresses, ccAddresses, subject, bodyBuilder.ToString());

                    approval.NotifyDate = DateTime.Now;
                    await _approvalService.UpdateApproval(approval);
                }
            }
        } catch (Exception ex) {
            _logger.LogError($"Unable to notify approvers, because {ex.Message}");
            throw;
        }
    }

    public async Task NotifyApprovers(PCRBNotification notification) {
        try {
            _logger.LogInformation("Attempting to send notification to approvers");

            if (notification is null) throw new ArgumentNullException("notification cannot be null");
            if (notification.PCRB is null) throw new ArgumentNullException("PCRB cannot be null");
            if (string.IsNullOrWhiteSpace(notification.Message)) throw new ArgumentException("message cannot be null or empty");

            IEnumerable<Approval> approvals = await _approvalService.GetApprovalsForIssueId(notification.PCRB.PlanNumber, true);

            HashSet<string> emailsAlreadySent = new();
            foreach (Approval approval in approvals) {
                User user = await _userService.GetUserByUserId(approval.UserID);

                if (!emailsAlreadySent.Contains(user.Email)) {
                    emailsAlreadySent.Add(user.Email);

                    List<MailAddress> toAddresses = new();
                    toAddresses.Add(new MailAddress(user.Email));

                    List<MailAddress> ccAddresses = new();

                    string subject = $"[Update] Mesa Fab Approval - PCRB# {notification.PCRB.PlanNumber} - {notification.PCRB.Title}";

                    StringBuilder bodyBuilder = new();
                    bodyBuilder.Append($"{notification.Message} <br /> <br />");
                    bodyBuilder.Append($"Click {_siteBaseUrl}/redirect?redirectPath=pcrb/{approval.IssueID} to view the PCRB.");

                    await _smtpService.SendEmail(toAddresses, ccAddresses, subject, bodyBuilder.ToString());

                    approval.NotifyDate = DateTime.Now;
                    await _approvalService.UpdateApproval(approval);
                }
            }
        } catch (Exception ex) {
            _logger.LogError($"Unable to send notification to originator, because {ex.Message}");
            throw;
        }
    }

    public async Task NotifyOriginator(PCRBNotification notification) {
        try {
            _logger.LogInformation("Attempting to send notification to originator");

            if (notification is null) throw new ArgumentNullException("notification cannot be null");
            if (notification.PCRB is null) throw new ArgumentNullException("PCRB cannot be null");
            if (string.IsNullOrWhiteSpace(notification.Message)) throw new ArgumentException("message cannot be null or empty");

            User user = await _userService.GetUserByUserId(notification.PCRB.OwnerID);

            List<MailAddress> toAddresses = new();
            toAddresses.Add(new MailAddress(user.Email));

            List<MailAddress> ccAddresses = new();

            string subject = $"[Update] Mesa Fab Approval - PCRB# {notification.PCRB.PlanNumber} - {notification.PCRB.Title}";

            StringBuilder bodyBuilder = new();
            bodyBuilder.Append($"{notification.Message} <br /> <br />");
            bodyBuilder.Append($"Click {_siteBaseUrl}/redirect?redirectPath=pcrb/{notification.PCRB.PlanNumber} to view the PCRB.");

            await _smtpService.SendEmail(toAddresses, ccAddresses, subject, bodyBuilder.ToString());
        } catch (Exception ex) {
            _logger.LogError($"Unable to send notification to originator, because {ex.Message}");
            throw;
        }
    }

    public async Task NotifyResponsiblePerson(PCRBActionItemNotification notification) {
        try {
            _logger.LogInformation("Attempting to notify responsible person");

            if (notification is null) throw new ArgumentNullException("notification cannot be null");
            if (string.IsNullOrWhiteSpace(notification.Message))
                throw new ArgumentException("message cannot be null or empty");

            if (notification.ActionItem.ResponsiblePerson is null)
                notification.ActionItem.ResponsiblePerson = await _userService.GetUserByUserId(notification.ActionItem.ResponsiblePersonID);

            List<MailAddress> toAddresses = new();
            toAddresses.Add(new MailAddress(notification.ActionItem.ResponsiblePerson.Email));

            List<MailAddress> ccAddresses = new();

            string subject = $"[New Task] Mesa Fab Approval - PCRB# {notification.PCRB.PlanNumber} - {notification.PCRB.Title}";

            StringBuilder bodyBuilder = new();
            bodyBuilder.Append($"{notification.Message} <br /> <br />");
            bodyBuilder.Append($"Click {_siteBaseUrl}/redirect?redirectPath=pcrb/{notification.PCRB.PlanNumber} to view the PCRB.");

            await _smtpService.SendEmail(toAddresses, ccAddresses, subject, bodyBuilder.ToString());
        } catch (Exception ex) {
            _logger.LogError($"Unable to notify responsible person, because {ex.Message}");
            throw;
        }
    }

    public async Task CreateFollowUp(PCRBFollowUp followUp) {
        try {
            _logger.LogInformation("Attempting to create PCRB follow up");

            if (followUp is null) throw new ArgumentNullException("follow up cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append("insert into CCPCRBFollowUp (PlanNumber, Step, FollowUpDate, CompletedDate) ");
            queryBuilder.Append("values (@PlanNumber, @Step, @FollowUpDate, @CompletedDate)");

            int rowsReturned = await _dalService.ExecuteAsync<PCRBFollowUp>(queryBuilder.ToString(), followUp);

            if (rowsReturned <= 0) throw new Exception("unable to insert new follow up in the database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to create new follow up, because {ex.Message}");
            throw;
        }
    }

    public async Task<IEnumerable<PCRBFollowUp>> GetFollowUpsByPlanNumber(int planNumber, bool bypassCache) {
        try {
            _logger.LogInformation($"Attempting to fetch follow ups for PCRB {planNumber}");

            if (planNumber <= 0) throw new ArgumentException($"{planNumber} is not a valid PCRB Plan#");

            IEnumerable<PCRBFollowUp>? followUps = new List<PCRBFollowUp>();

            if (!bypassCache)
                followUps = _cache.Get<IEnumerable<PCRBFollowUp>>($"pcrbFollowUps{planNumber}");

            if (followUps is null || followUps.Count() == 0) { 
                string sql = "select * from CCPCRBFollowUp where PlanNumber=@PlanNumber";

                followUps = await _dalService.QueryAsync<PCRBFollowUp>(sql, new { PlanNumber = planNumber });

                if (followUps is not null)
                    _cache.Set($"pcrbFollowUps{planNumber}", followUps, DateTimeOffset.Now.AddMinutes(15));
            }

            return followUps ?? new List<PCRBFollowUp>();
        } catch (Exception ex) {
            _logger.LogError($"Unable to fetch follow ups for PCRB {planNumber}, because {ex.Message}");
            throw;
        }
    }

    public async Task UpdateFollowUp(PCRBFollowUp followUp) {
        try {
            _logger.LogInformation("Attempting to update a follow up");

            if (followUp is null)
                throw new ArgumentNullException("follow up cannot be null");

            StringBuilder queryBuilder = new();
            queryBuilder.Append("update CCPCRBFollowUp set Step=@Step, FollowUpDate=@FollowUpDate, IsComplete=@IsComplete, ");
            queryBuilder.Append("IsDeleted=@IsDeleted, CompletedDate=@CompletedDate, Comments=@Comments ");
            queryBuilder.Append("where ID=@ID");

            int rowsAffected = await _dalService.ExecuteAsync<PCRBFollowUp>(queryBuilder.ToString(), followUp);

            if (rowsAffected <= 0) throw new Exception("update failed in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to update follow up, because {ex.Message}");
            throw;
        }
    }

    public async Task DeleteFollowUp(int id) {
        try {
            _logger.LogInformation($"Attempting to delete follow up {id}");

            if (id <= 0) throw new ArgumentException($"{id} is not a valid follow up ID");

            string sql = "delete from CCPCRBFollowUp where ID=@ID";

            int rowsAffected = await _dalService.ExecuteAsync(sql, new { ID = id });

            if (rowsAffected <= 0) throw new Exception("delete operation failed in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to delete follow up {id}, because {ex.Message}");
            throw;
        }
    }

    private async Task SaveAttachmentInDb(IFormFile file, PCRBAttachment attachment) {
        try {
            _logger.LogInformation($"Attempting to save attachment to database");

            if (file is null) throw new ArgumentNullException("File cannot be null");
            if (string.IsNullOrWhiteSpace(attachment.Path)) throw new ArgumentException("Path cannot be null or empty");
            if (attachment.PlanNumber <= 0) throw new ArgumentException($"{attachment.PlanNumber} is not a valid PCRB Plan#");

            StringBuilder queryBuilder = new();
            queryBuilder.Append("insert into CCAttachment (PlanNumber, FileName, UploadDateTime, Path, UploadedByID, Title, ");
            queryBuilder.Append($"Step) values ({attachment.PlanNumber}, '{file.FileName}', ");
            queryBuilder.Append($"'{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")}', '{attachment.Path}', {attachment.UploadedByID}, ");
            queryBuilder.Append($"'{attachment.Title}', {attachment.Step});");

            int rowsAffected = await _dalService.ExecuteAsync(queryBuilder.ToString());

            if (rowsAffected <= 0)
                throw new Exception("Unable to insert attachment in database");
        } catch (Exception ex) {
            _logger.LogError($"Unable to save file to DB, because {ex.Message}");
            throw;
        }
    }
}