using Data.SeaHavenIndustries;
using SeaHaven.DataServices.Interfaces;
using SeaHaven.Services.DTOs;
using SeaHaven.Services.Interfaces;

namespace SeaHaven.Services.Implementation
{
    public class SyncService : ISyncService
    {
        private readonly ISyncDataService _data;
        private readonly ISyncExternalSource _external;
        private readonly IWorkOrderAccountResolver _accountResolver;

        public SyncService(
            ISyncDataService data,
            ISyncExternalSource external,
            IWorkOrderAccountResolver accountResolver)
        {
            _data = data;
            _external = external;
            _accountResolver = accountResolver;
        }

        public async Task<SyncWorkOrdersResult> SyncWorkOrdersAsync(CancellationToken cancellationToken)
        {
            var synced = 0;
            var created = 0;
            var updated = 0;

            var lastInternalWO = await _data.GetLastInternalWONumberAsync(cancellationToken);
            int nextInternal = 10000001;
            if (lastInternalWO != null && int.TryParse(lastInternalWO, out var parsed))
                nextInternal = parsed + 1;

            await foreach (var item in _external.ScanWorkOrdersAsync(cancellationToken))
            {
                var externalId = Get(item, "work_order_id");
                if (string.IsNullOrEmpty(externalId)) continue;

                var existing = await _data.GetWorkOrderByExternalIdAsync(externalId, cancellationToken);

                var locationId = await _data.ResolveLocationAsync(
                    Get(item, "site_code"),
                    Get(item, "building"),
                    Get(item, "address"),
                    cancellationToken);

                if (existing == null)
                {
                    var customer = Get(item, "customer");
                    var accountId = await _accountResolver.TryResolveFromCustomerAsync(customer, cancellationToken);
                    if (accountId is not int resolvedAccountId)
                        continue;

                    var wo = new WorkOrder
                    {
                        InternalWONumber = (nextInternal++).ToString("D8"),
                        ExternalWorkOrderId = externalId,
                        WorkerOrderNumber = externalId,
                        WorkerOrderTitle = Get(item, "description"),
                        Description = Get(item, "description"),
                        Status = MapStatus(Get(item, "wo_status")),
                        Priority = MapSeverityToPriority(Get(item, "severity")),
                        Severity = Get(item, "severity"),
                        Customer = customer,
                        AccountId = resolvedAccountId,
                        SiteCode = Get(item, "site_code"),
                        Building = Get(item, "building"),
                        LocationId = locationId,
                        DueDate = ParseDate(Get(item, "due_date")),
                        DateReported = ParseDate(Get(item, "date_reported")),
                        ScheduledStart = ParseDate(Get(item, "scheduled_start")),
                        AssignTo = null,
                        SourceEmailS3Key = Get(item, "source_email_s3_key"),
                        CreatedDate = ParseDate(Get(item, "created_at")) ?? DateTime.UtcNow,
                        istemplate = false
                    };
                    _data.EnqueueWorkOrder(wo);
                    created++;
                }
                else
                {
                    existing.WorkerOrderTitle = Get(item, "description") ?? existing.WorkerOrderTitle;
                    existing.Description = Get(item, "description") ?? existing.Description;
                    existing.Status = MapStatus(Get(item, "wo_status")) ?? existing.Status;
                    existing.Priority = MapSeverityToPriority(Get(item, "severity")) ?? existing.Priority;
                    existing.Severity = Get(item, "severity") ?? existing.Severity;
                    existing.SiteCode = Get(item, "site_code") ?? existing.SiteCode;
                    existing.Building = Get(item, "building") ?? existing.Building;
                    existing.LocationId = locationId ?? existing.LocationId;
                    existing.DueDate = ParseDate(Get(item, "due_date")) ?? existing.DueDate;
                    existing.DateReported = ParseDate(Get(item, "date_reported")) ?? existing.DateReported;
                    existing.ScheduledStart = ParseDate(Get(item, "scheduled_start")) ?? existing.ScheduledStart;
                    existing.SourceEmailS3Key = Get(item, "source_email_s3_key") ?? existing.SourceEmailS3Key;
                    updated++;
                }

                synced++;

                if (synced % 100 == 0)
                    await _data.SaveChangesAsync(cancellationToken);
            }

            await _data.SaveChangesAsync(cancellationToken);

            return new SyncWorkOrdersResult
            {
                Synced = synced,
                Created = created,
                Updated = updated,
                LocationsCreated = await _data.GetLocationCountAsync(cancellationToken)
            };
        }

        public async Task<SyncCommentsResult> SyncCommentsAsync(CancellationToken cancellationToken)
        {
            var synced = 0;
            var created = 0;
            var skipped = 0;

            await foreach (var item in _external.ScanCommentsAsync(cancellationToken))
            {
                var externalCommentId = Get(item, "comment_id");
                var externalWoId = Get(item, "work_order_id");

                if (string.IsNullOrEmpty(externalCommentId) || string.IsNullOrEmpty(externalWoId))
                    continue;

                var alreadyExists = await _data.CommentExistsByExternalIdAsync(externalCommentId, cancellationToken);

                if (alreadyExists)
                {
                    skipped++;
                    synced++;
                    continue;
                }

                var workOrder = await _data.GetWorkOrderByExternalIdAsync(externalWoId, cancellationToken);

                if (workOrder == null)
                {
                    skipped++;
                    continue;
                }

                var comment = new Comments
                {
                    ExternalCommentId = externalCommentId,
                    WorkerOrderId = workOrder.Id,
                    Commenttext = Get(item, "text"),
                    Commenter = Get(item, "commenter"),
                    RecordType = Get(item, "record_type"),
                    CommentType = "customer",
                    CreatedDate = ParseDate(Get(item, "created_at")) ?? DateTime.UtcNow,
                };

                _data.EnqueueComment(comment);
                created++;
                synced++;

                if (synced % 100 == 0)
                    await _data.SaveChangesAsync(cancellationToken);
            }

            await _data.SaveChangesAsync(cancellationToken);

            return new SyncCommentsResult { Synced = synced, Created = created, Skipped = skipped };
        }

        public async Task<BackfillResult> BackfillInternalWONumbersAsync(CancellationToken cancellationToken)
        {
            var wosMissing = await _data.GetWorkOrdersMissingInternalNumberAsync(cancellationToken);

            if (wosMissing.Count == 0)
                return new BackfillResult { Updated = 0 };

            var lastWO = await _data.GetLastInternalWONumberAsync(cancellationToken);

            int next = 10000001;
            if (lastWO != null && int.TryParse(lastWO, out var lastNum))
                next = lastNum + 1;

            foreach (var wo in wosMissing)
            {
                wo.InternalWONumber = next.ToString("D8");
                next++;
            }

            await _data.SaveChangesAsync(cancellationToken);
            return new BackfillResult { Updated = wosMissing.Count };
        }

        public async Task<BackfillResult> BackfillDispatchNumbersAsync(CancellationToken cancellationToken)
        {
            var missing = await _data.GetDispatchesMissingNumberAsync(cancellationToken);
            if (missing.Count == 0) return new BackfillResult { Updated = 0 };

            int next = 1;
            var last = await _data.GetLastDispatchNumberAsync(cancellationToken);
            if (last != null && last.StartsWith("DSP-") && int.TryParse(last.Substring(4), out var n))
                next = n + 1;

            foreach (var d in missing)
            {
                d.DispatchNumber = $"DSP-{next:D5}";
                next++;
            }
            await _data.SaveChangesAsync(cancellationToken);
            return new BackfillResult { Updated = missing.Count };
        }

        public async Task<SyncCommentsResult> SyncVendorRepliesAsync(CancellationToken cancellationToken)
        {
            var synced = 0;
            var created = 0;
            var skipped = 0;

            await foreach (var item in _external.ScanVendorRepliesAsync(cancellationToken))
            {
                var replyId = Get(item, "reply_id");
                var woNumber = Get(item, "internal_wo_number");
                var dispatchNumber = Get(item, "dispatch_number");

                if (string.IsNullOrEmpty(replyId) || string.IsNullOrEmpty(woNumber))
                    continue;

                var alreadyExists = await _data.CommentExistsByExternalIdAsync(replyId, cancellationToken);
                if (alreadyExists) { skipped++; synced++; continue; }

                var workOrder = await _data.GetWorkOrderByInternalNumberAsync(woNumber, cancellationToken);
                if (workOrder == null) { skipped++; continue; }

                int? dispatchId = null;
                if (!string.IsNullOrWhiteSpace(dispatchNumber))
                {
                    var dispatch = await _data.GetDispatchByNumberAndWorkOrderIdAsync(dispatchNumber, workOrder.Id, cancellationToken);
                    dispatchId = dispatch?.Id;
                }

                var comment = new Comments
                {
                    ExternalCommentId = replyId,
                    WorkerOrderId = workOrder.Id,
                    DispatchId = dispatchId,
                    Commenttext = Get(item, "reply_text"),
                    Commenter = Get(item, "sender_email"),
                    CommentType = "vendor",
                    RecordType = "vendor_reply",
                    CreatedDate = ParseDate(Get(item, "received_at")) ?? DateTime.UtcNow,
                };

                _data.EnqueueComment(comment);
                created++;
                synced++;

                if (synced % 50 == 0)
                    await _data.SaveChangesAsync(cancellationToken);
            }

            await _data.SaveChangesAsync(cancellationToken);
            return new SyncCommentsResult { Synced = synced, Created = created, Skipped = skipped };
        }

        public async Task<BackfillResult> BackfillCommentTypesAsync(CancellationToken cancellationToken)
        {
            var updated = await _data.ExecuteBackfillCommentTypesAsync(cancellationToken);
            return new BackfillResult { Updated = updated };
        }

        public async Task<SyncAllResult> SyncAllAsync(CancellationToken cancellationToken)
        {
            var woResult = await SyncWorkOrdersAsync(cancellationToken);
            var commentResult = await SyncCommentsAsync(cancellationToken);

            return new SyncAllResult
            {
                WorkOrders = woResult,
                Comments = commentResult
            };
        }

        private static string? Get(Dictionary<string, string?> item, string key)
        {
            return item.TryGetValue(key, out var val) ? val : null;
        }

        private static DateTime? ParseDate(string? value)
        {
            if (string.IsNullOrWhiteSpace(value)) return null;
            if (DateTime.TryParse(value, out var dt)) return dt;
            return null;
        }

        private static string? MapStatus(string? dynamoStatus)
        {
            return dynamoStatus switch
            {
                "new" => "Open",
                "assigned" => "Open",
                "in_progress" => "In Progress",
                "on_hold" => "On Hold",
                "completed" => "Done",
                "cancelled" => "Cancelled",
                "unknown" => "Open",
                _ => "Open"
            };
        }

        private static string? MapSeverityToPriority(string? severity)
        {
            if (string.IsNullOrWhiteSpace(severity)) return null;
            return $"Sev {severity}";
        }
    }
}