using Fake.Application;
using Fake.Domain.Exceptions;
using Microsoft.AspNetCore.Mvc;
using Oms.Application.Dtos.Orders;
using Oms.Application.Services.Orders.Issues;
using Oms.Domain.ChannelsAggregate.Consts;
using Oms.Domain.ChannelsAggregate.Entities;
using Oms.Domain.ChannelsAggregate.Repositories;
using Oms.Domain.OrdersAggregate.Consts;
using Oms.Domain.OrdersAggregate.Entities;
using Oms.Domain.OrdersAggregate.Repositories;
using Oms.Domain.Shared.Enums;

namespace Oms.Application.Services.Orders;

public partial class OrderService
{
    private const int MaxExceptionBatchSize = 200;

    private IIssueTemplateRepository IssueTemplateRepository =>
        LazyServiceProvider.GetRequiredService<IIssueTemplateRepository>();

    private IOrderExceptionEventRepository OrderExceptionEventRepository =>
        LazyServiceProvider.GetRequiredService<IOrderExceptionEventRepository>();

    private OrderExceptionWorkflowService ExceptionWorkflowService =>
        LazyServiceProvider.GetRequiredService<OrderExceptionWorkflowService>();

    /// <summary>
    /// 批量创建问题件。
    /// </summary>
    [HttpPost("/order/mark-problematic")]
    public async Task<OrderBatchActionResultOutput> MarkProblematicAsync([FromBody] OrderMarkProblematicInput input)
    {
        var payload = await ResolveProblematicPayloadAsync(input);
        var request = new ProblematicMarkRequest
        {
            IssueType = payload.IssueType,
            Title = payload.Title,
            Content = payload.Content,
            IssueTemplateId = payload.IssueTemplateId,
            NotifyMethod = payload.NotifyMethod,
            Remark = payload.Remark
        };

        return await ExecuteProblematicBatchAsync(input.OrderIds, request);
    }

    /// <summary>
    /// 批量创建理赔件。
    /// </summary>
    [HttpPost("/order/mark-claimed")]
    public async Task<OrderBatchActionResultOutput> MarkClaimedAsync([FromBody] OrderMarkClaimedInput input)
    {
        var payload = NormalizeClaimedPayload(input);
        return await ExecuteExceptionBatchAsync(
            input.OrderIds,
            order =>
            {
                if (!OrderExceptionStatusRules.CanMarkException(order.OrderStatus))
                {
                    return OrderExceptionStatusRules.GetForbiddenReason(order.OrderStatus);
                }

                var fromStatus = order.OrderStatus;
                order.PreviousOrderStatus = fromStatus;
                order.OrderStatus = OrderStatusCodes.Claimed;
                order.HandleStatus = OrderHandleStatusCodes.Pending;
                order.ClaimType = payload.ClaimType;
                order.ClaimAmount = payload.ClaimAmount;
                order.ClaimCurrency = payload.ClaimCurrency;
                order.ClaimReason = payload.ClaimReason;
                order.ClaimTime = DateTime.Now;
                order.IssueType = null;
                order.IssueTitle = null;
                order.IssueContent = null;
                order.IssueTemplateId = null;
                order.IssueRemark = null;
                order.IssueTime = null;
                return null;
            },
            (order, remark) => new OrderExceptionEvent
            {
                OrderId = order.Id,
                EventType = OrderExceptionEventTypeCodes.MarkClaimed,
                FromStatus = order.PreviousOrderStatus,
                ToStatus = OrderStatusCodes.Claimed,
                FromHandleStatus = null,
                ToHandleStatus = OrderHandleStatusCodes.Pending,
                ClaimType = payload.ClaimType,
                ClaimAmount = payload.ClaimAmount,
                ClaimCurrency = payload.ClaimCurrency,
                ClaimReason = payload.ClaimReason,
                Remark = remark
            },
            payload.Remark);
    }

    /// <summary>
    /// 批量更新处理子状态。
    /// </summary>
    [HttpPost("/order/handle-status/update")]
    public async Task<OrderBatchActionResultOutput> UpdateHandleStatusAsync([FromBody] OrderHandleStatusUpdateInput input)
    {
        var targetStatus = input.HandleStatus?.Trim().ToLowerInvariant();
        if (!string.Equals(targetStatus, OrderHandleStatusCodes.Processed, StringComparison.Ordinal))
        {
            throw new BusinessException("仅支持标记为已处理");
        }

        return await ExecuteExceptionBatchAsync(
            input.OrderIds,
            order =>
            {
                if (order.OrderStatus is not (OrderStatusCodes.Problematic or OrderStatusCodes.Claimed))
                {
                    return "仅问题件或理赔件可更新处理状态";
                }

                if (OrderHandleStatusCodes.IsProcessed(order.HandleStatus))
                {
                    return "订单已处理";
                }

                order.HandleStatus = OrderHandleStatusCodes.Processed;
                return null;
            },
            (order, remark) => new OrderExceptionEvent
            {
                OrderId = order.Id,
                EventType = OrderExceptionEventTypeCodes.HandleProcessed,
                FromStatus = order.OrderStatus,
                ToStatus = order.OrderStatus,
                FromHandleStatus = OrderHandleStatusCodes.Pending,
                ToHandleStatus = OrderHandleStatusCodes.Processed,
                Remark = remark
            },
            input.Remark?.Trim());
    }

    private async Task<OrderBatchActionResultOutput> ExecuteProblematicBatchAsync(
        IReadOnlyCollection<int> orderIds,
        ProblematicMarkRequest request)
    {
        var ids = NormalizeOrderIds(orderIds);
        var result = new OrderBatchActionResultOutput();
        var operatorUserId = CurrentUser.GetId<int>();
        var sendNotification = !string.IsNullOrWhiteSpace(request.NotifyMethod);

        foreach (var orderId in ids)
        {
            Order? order;
            try
            {
                order = await GetOrderOrThrowAsync(orderId);
            }
            catch (BusinessException ex)
            {
                result.Failures.Add(new OrderBatchActionFailureOutput
                {
                    OrderId = orderId,
                    Reason = ex.Message
                });
                continue;
            }

            var reason = await ExceptionWorkflowService.TryMarkProblematicAsync(
                order,
                request,
                operatorUserId,
                sendNotification);
            if (!string.IsNullOrWhiteSpace(reason))
            {
                result.Failures.Add(new OrderBatchActionFailureOutput
                {
                    OrderId = order.Id,
                    ServiceNo = order.ServiceNo,
                    Reason = reason
                });
                continue;
            }

            result.SuccessCount++;
        }

        return result;
    }

    private async Task<OrderBatchActionResultOutput> ExecuteExceptionBatchAsync(
        IReadOnlyCollection<int> orderIds,
        Func<Order, string?> tryApply,
        Func<Order, string?, OrderExceptionEvent> buildEvent,
        string? remark)
    {
        var ids = NormalizeOrderIds(orderIds);
        var result = new OrderBatchActionResultOutput();
        foreach (var orderId in ids)
        {
            Order? order;
            try
            {
                order = await GetOrderOrThrowAsync(orderId);
            }
            catch (BusinessException ex)
            {
                result.Failures.Add(new OrderBatchActionFailureOutput
                {
                    OrderId = orderId,
                    Reason = ex.Message
                });
                continue;
            }

            var reason = tryApply(order);
            if (!string.IsNullOrWhiteSpace(reason))
            {
                result.Failures.Add(new OrderBatchActionFailureOutput
                {
                    OrderId = order.Id,
                    ServiceNo = order.ServiceNo,
                    Reason = reason
                });
                continue;
            }

            await OrderRepository.UpdateAsync(order);
            await OrderExceptionEventRepository.InsertAsync(buildEvent(order, remark));
            result.SuccessCount++;
        }

        return result;
    }

    private static List<int> NormalizeOrderIds(IReadOnlyCollection<int>? orderIds)
    {
        if (orderIds == null || orderIds.Count == 0)
        {
            throw new BusinessException("请至少选择一条订单");
        }

        var ids = orderIds.Where(x => x > 0).Distinct().ToList();
        if (ids.Count == 0)
        {
            throw new BusinessException("请至少选择一条订单");
        }

        if (ids.Count > MaxExceptionBatchSize)
        {
            throw new BusinessException($"单次最多处理 {MaxExceptionBatchSize} 条订单");
        }

        return ids;
    }

    private async Task<ResolvedProblematicPayload> ResolveProblematicPayloadAsync(OrderMarkProblematicInput input)
    {
        IssueTemplate? template = null;
        if (input.IssueTemplateId is int templateId && templateId > 0)
        {
            template = await IssueTemplateRepository.FirstOrDefaultAsync(x =>
                x.Id == templateId && x.Status == EnableStatus.Enabled);
            if (template == null)
            {
                throw new BusinessException("问题模板不存在或未启用");
            }
        }

        var issueType = (template?.IssueType ?? input.IssueType)?.Trim().ToLowerInvariant();
        if (string.IsNullOrWhiteSpace(issueType) || !IssueTypeCodes.All.Contains(issueType))
        {
            throw new BusinessException("问题类型不合法");
        }

        var title = (input.Title?.Trim().Length > 0 ? input.Title.Trim() : template?.Title)?.Trim();
        if (string.IsNullOrWhiteSpace(title))
        {
            throw new BusinessException("问题标题不能为空");
        }

        if (title.Length > 128)
        {
            throw new BusinessException("问题标题长度不能超过128");
        }

        var content = (input.Content?.Trim().Length > 0 ? input.Content.Trim() : template?.Content)?.Trim();
        if (string.IsNullOrWhiteSpace(content))
        {
            throw new BusinessException("问题内容不能为空");
        }

        var remark = input.Remark?.Trim();
        if (!string.IsNullOrWhiteSpace(remark) && remark.Length > 512)
        {
            throw new BusinessException("备注长度不能超过512");
        }

        return new ResolvedProblematicPayload
        {
            IssueType = issueType,
            Title = title,
            Content = content,
            IssueTemplateId = template?.Id,
            NotifyMethod = template == null ? null : IssueNotifyMethodCodes.Normalize(template.NotifyMethod),
            Remark = remark
        };
    }

    private static ResolvedClaimedPayload NormalizeClaimedPayload(OrderMarkClaimedInput input)
    {
        var claimType = input.ClaimType?.Trim().ToLowerInvariant();
        if (string.IsNullOrWhiteSpace(claimType) || !ClaimTypeCodes.All.Contains(claimType))
        {
            throw new BusinessException("理赔类型不合法");
        }

        if (input.ClaimAmount is not > 0)
        {
            throw new BusinessException("索赔金额必须大于0");
        }

        var currency = input.ClaimCurrency?.Trim().ToUpperInvariant();
        if (string.IsNullOrWhiteSpace(currency))
        {
            throw new BusinessException("索赔币种不能为空");
        }

        if (currency.Length > 16)
        {
            throw new BusinessException("索赔币种长度不能超过16");
        }

        var reason = input.ClaimReason?.Trim();
        if (string.IsNullOrWhiteSpace(reason))
        {
            throw new BusinessException("理赔原因不能为空");
        }

        if (reason.Length > 512)
        {
            throw new BusinessException("理赔原因长度不能超过512");
        }

        var remark = input.Remark?.Trim();
        if (!string.IsNullOrWhiteSpace(remark) && remark.Length > 512)
        {
            throw new BusinessException("备注长度不能超过512");
        }

        return new ResolvedClaimedPayload
        {
            ClaimType = claimType,
            ClaimAmount = input.ClaimAmount.Value,
            ClaimCurrency = currency,
            ClaimReason = reason,
            Remark = remark
        };
    }

    private sealed class ResolvedProblematicPayload
    {
        public string IssueType { get; set; } = string.Empty;

        public string Title { get; set; } = string.Empty;

        public string Content { get; set; } = string.Empty;

        public int? IssueTemplateId { get; set; }

        public string? NotifyMethod { get; set; }

        public string? Remark { get; set; }
    }

    private sealed class ResolvedClaimedPayload
    {
        public string ClaimType { get; set; } = string.Empty;

        public decimal ClaimAmount { get; set; }

        public string ClaimCurrency { get; set; } = string.Empty;

        public string ClaimReason { get; set; } = string.Empty;

        public string? Remark { get; set; }
    }
}