using System;
using System.Text.Json;
using System.Threading.Tasks;
using Azure.Storage.Blobs;
using Azure.Storage.Blobs.Models;
using Azure.Messaging.ServiceBus;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Logging;
using Google.Protobuf.Reflection;

namespace CDP
{
    public class EventProcessor
    {
        private static string FileAuditContainer = "FileAudits";
        private static string UserAuditContainer = "UserAudits";
        private static string GroupAuditContainer = "GroupAudits";
        private static string TenantAuditContainer = "TenantAudits";
        private readonly ILogger<EventProcessor> _logger;

        public EventProcessor(ILogger<EventProcessor> logger)
        {
            _logger = logger;
        }

        [Function("ProcessEvent")]
        public async Task ProcessCDPJob(
            [ServiceBusTrigger("mail-events-queue", Connection = "ServiceBusConnectionString")]
            ServiceBusReceivedMessage message,
            ServiceBusMessageActions messageActions)
        {
            _logger.LogInformation("Message ID: {id}", message.MessageId);
            _logger.LogInformation("Message Body: {body}", message.Body);
            _logger.LogInformation("Message Content-Type: {contentType}", message.ContentType);
            Job cdpJob;
            try
            {
                cdpJob = JsonSerializer.Deserialize<Job>(message.Body);
            }
            catch (Exception ex)
            {
                _logger.LogError("received incorrect structure in body: {0} got exception: {1}", message.Body, ex);
                await messageActions.CompleteMessageAsync(message);
                return;
            }
            if (cdpJob != null)
            {
                switch (cdpJob.EventType)
                {
                    case JobType.MailMetaProcessing:
                        await ProcessMailMetaJob(cdpJob);
                        break;
                    case JobType.KeyVaultInsertion:
                        _logger.LogInformation("key vault insertion processing");
                        await ProcessKeyVaultInsertionJob(cdpJob);
                        break;
                    case JobType.AddAudits:
                        _logger.LogInformation("Adding cdp audits");
                        await ProcessAuditEvent(cdpJob);
                        break;
                    case JobType.KeyVaultInsertionBatch:
                        _logger.LogInformation("batch key vault insertion processing");
                        await ProcessKeyVaultBatchJob(cdpJob);
                        break;
                    case JobType.AddAuditsBatch:
                        _logger.LogInformation("batch audit insertion in progress");
                        await ProcessAuditsBatchJob(cdpJob);
                        break;
                    default:
                        break;
                }
            }
            // Complete the message
            await messageActions.CompleteMessageAsync(message);
        }

        internal async Task ProcessAuditEvent(Job job)
        {
            AuditEventMetadata auditEventMetadata = JsonSerializer.Deserialize<AuditEventMetadata>(job.JobMetadata);
            await AuditFunctions.AddAudits(job.AppKey, auditEventMetadata.FileId, auditEventMetadata.FileName, auditEventMetadata.UserId, "", auditEventMetadata.Action, auditEventMetadata.Message);
            return;
        }

        internal async Task ProcessKeyVaultBatchJob(Job job)
        {
            KeyVaultService kvs = new KeyVaultService(Constants.KeyVaultURI);
            List<KeyVaultEvent> events = new List<KeyVaultEvent>();
            try
            {
                events = JsonSerializer.Deserialize<List<KeyVaultEvent>>(job.JobMetadata);
                events.ForEach(async (KeyVaultEvent evt) =>
                {
                    await kvs.SetSecretAsync(evt.FileId, evt.AESKey);
                });
            } catch (Exception ex)
            {
                _logger.LogError("Error parsing job: {1} keyvault event metadata error: {0}", ex.ToString(), JsonSerializer.Serialize(job));
                return;
            }
        }

        internal async Task ProcessAuditsBatchJob(Job job)
        {
            try
            {
                List<AuditRecord> tenantAuditRecords = new List<AuditRecord>();
                List<AuditRecord> userAuditRecords = new List<AuditRecord>();
                List<AuditEventMetadata> auditEventMetadata = JsonSerializer.Deserialize<List<AuditEventMetadata>>(job.JobMetadata);
                for(int i = 0; i<auditEventMetadata.Count; i++)
                {
                    FileAuditRecord fileAuditRecord = new FileAuditRecord
                    {
                        Action = auditEventMetadata[i].Action,
                        FileId = auditEventMetadata[i].FileId,
                        FileName = auditEventMetadata[i].FileName,
                        Message = auditEventMetadata[i].Message,
                        UserId = auditEventMetadata[i].UserId,
                        GroupId = ""
                    };
                    await AuditDB.AppendRecord(fileAuditRecord.id, fileAuditRecord, FileAuditContainer);
                    TenantAuditRecord auditRecord = new TenantAuditRecord
                    {
                        AppKey = job.AppKey,
                        Action = auditEventMetadata[i].Action,
                        FileId = auditEventMetadata[i].FileId,
                        FileName = auditEventMetadata[i].FileName,
                        Message = auditEventMetadata[i].Message,
                        UserId = auditEventMetadata[i].UserId,
                        GroupId = "",
                        EventTime = DateTime.UtcNow,
                    };

                    tenantAuditRecords.Add(auditRecord);

                    UserAuditRecord userAuditRecord = new UserAuditRecord
                    {
                        AppKey = job.AppKey,
                        FileId = auditEventMetadata[i].FileId,
                        FileName = auditEventMetadata[i].FileName,
                        Message = auditEventMetadata[i].Message,
                        UserId = auditEventMetadata[i].UserId,
                        Action = auditEventMetadata[i].Action,
                        EventTime = DateTime.UtcNow,
                        GroupId = ""
                    };
                    userAuditRecords.Add(userAuditRecord);
                }

                await AuditDB.AppendRecordsList(job.AppKey, tenantAuditRecords, TenantAuditContainer);
                await AuditDB.AppendRecordsList(userAuditRecords[0].UserId, userAuditRecords, UserAuditContainer);
            } 
            catch (Exception ex)
            {
                _logger.LogError($"{ex.Message}");
            }
            return;
        }

        internal async Task ProcessKeyVaultInsertionJob(Job cdpJob)
        {
            KeyVaultService kvs = new KeyVaultService(Constants.KeyVaultURI);
            KeyVaultEvent vaultEvent;
            try
            {
                vaultEvent = JsonSerializer.Deserialize<KeyVaultEvent>(cdpJob.JobMetadata);
            } catch (Exception ex)
            {
                _logger.LogError("Error parsing keyvault event metadata error: {0}",ex.ToString());
                return;
            }
            await kvs.SetSecretAsync(vaultEvent.FileId, vaultEvent.AESKey);
            return;
        }

        internal async Task ProcessMailMetaJob(Job cdpJob)
        {
            string Connection = Constants.StorageConnString;
            var blobServiceClient = new BlobServiceClient(Connection);
            var blobClient = blobServiceClient.GetBlobContainerClient(cdpJob.AppKey.ToLower());
            var blob = blobClient.GetBlobClient(string.Format("{0}", cdpJob.Id));
            var exists = await blob.ExistsAsync();
            if (!exists)
            {
                return;
            }
            BlobDownloadInfo blobDownloadInfo = await blob.DownloadAsync();
            _logger.LogDebug($"Exists?: {exists.ToString()}");
            _logger.LogDebug($"Download resp: {blobDownloadInfo.Details}");
            using (MemoryStream ms = new MemoryStream())
            {
                await blobDownloadInfo.Content.CopyToAsync(ms);
                byte[] byteArray = ms.ToArray();
                string mailRecJson = System.Text.Encoding.UTF8.GetString(byteArray);
                _logger.LogInformation("got event json from blob: " + mailRecJson);
                MailRecord record = JsonSerializer.Deserialize<MailRecord>(mailRecJson);
                await MailProcessor.ProcessMailEvent(record, _logger);
            }
            return;
        }
    }

    public class MailRecord
    {
        public required string AppKey { get; set; }
        public required string SenderEmail { get; set; }
        public required string MailId { get; set; } // this is actually body Id
        public required string BodyContent { get; set; } // this is body content
        public required List<string> Attachments { get; set; }
        public required List<string> ReceiverEmails { get; set; }
        public required List<AttachmentDetails> AttachmentDetails { get; set; }
    }

    public class AttachmentDetails
    {
        public required string FileId { get; set; }
        public required string HeadRevisionId { get; set; }
        public string? FileType { get; set; }
        public required string FileName { get; set; }
    }

    public class Job
    {
        public required string Id { get; set; }
        public required string AppKey { get; set; }
        public required JobType EventType { get; set; }
        public string? JobMetadata {  get; set; }
    }

    public enum JobType
    {
        MailMetaProcessing,
        KeyVaultInsertion,
        AddAudits,
        KeyVaultInsertionBatch,
        AddAuditsBatch
    }
    public class KeyVaultEvent
    {
        public required string FileId { get; set; }
        public required string AESKey { get; set; }
    }

    public class AuditEventMetadata
    {
        public required string FileId { get; set; }
        public string FileName { get; set; }
        public string UserId { get; set; }
        public string GroupId { get; set; }
        public string Action { get; set; }
        public string Message { get; set; }
    }
}