using System.Diagnostics;

namespace Admin.NET.Plugin.ApprovalFlow.Service;

/// <summary>
/// 流程通知服务（P4-16 重构 + 模板化/DB 配置）
/// - 聚合所有 INotifyPusher，按渠道启用状态串行调度
/// - 标题/正文优先走 FlowNotifyTemplateService 模板渲染（支持 {变量} + BizType 覆盖），未命中回退兜底文案
/// - 渠道开关/凭据优先从 DB（ApprovalFlowNotifyConfig）读取，无记录回退 ApprovalFlow.json
/// - 每次分发写 ApprovalFlowNotifyLog 便于运维追溯与降级审计
/// </summary>
public class FlowNotifyService : ITransient
{
    private readonly IEnumerable<INotifyPusher> _pushers;
    private readonly SqlSugarRepository<ApprovalFlowNotifyLog> _logRep;
    private readonly FlowNotifyTemplateService _tplService;
    private readonly FlowNotifyConfigService _cfgService;

    public FlowNotifyService(
        IEnumerable<INotifyPusher> pushers,
        SqlSugarRepository<ApprovalFlowNotifyLog> logRep,
        FlowNotifyTemplateService tplService,
        FlowNotifyConfigService cfgService)
    {
        _pushers = pushers;
        _logRep = logRep;
        _tplService = tplService;
        _cfgService = cfgService;
    }

    public async Task NotifyUsers(List<long> userIds, FlowNotification notification)
    {
        if (userIds.Count == 0) return;

        // 模板渲染（未命中则用传入的 Title/Content 兜底）
        var ctx = notification.Context ?? new Dictionary<string, string?>();
        var rendered = await _tplService.RenderAsync(notification.Type, notification.BizType, ctx);
        if (rendered != null)
        {
            notification.Title = rendered.Value.title;
            notification.Content = rendered.Value.content;
        }

        var cfg = await _cfgService.GetEffectiveAsync();

        foreach (var pusher in _pushers)
        {
            if (!pusher.IsEnabled(cfg)) continue;

            var sw = Stopwatch.StartNew();
            FlowNotifyPushResult result;
            try
            {
                result = await pusher.PushAsync(userIds, notification);
            }
            catch (Exception ex)
            {
                result = FlowNotifyPushResult.Fail(ex.Message);
            }
            sw.Stop();

            await SafeWriteLog(notification, pusher.Channel, userIds, result, (int)sw.ElapsedMilliseconds);
        }
    }

    // ═══════════════════════════════════════════
    //  事件专用便捷方法（FlowEngineService 调用）
    //  每个方法收 bizType 作为最后一个参数；构造 FlowNotification 时带上变量上下文
    // ═══════════════════════════════════════════

    public Task NotifyUrge(List<long> userIds, long instanceId, string title, string bizType = "")
        => NotifyUsers(userIds, Build(FlowNotificationTypeEnum.Urge, instanceId, bizType,
            fallbackTitle: $"【催办】{title}",
            fallbackContent: "流程发起人催促您尽快审批，请及时处理。",
            ctx: new() { ["title"] = title }));

    public Task NotifyNewTask(List<long> userIds, long instanceId, string title, string? nodeName, string bizType = "")
        => NotifyUsers(userIds, Build(FlowNotificationTypeEnum.NewTask, instanceId, bizType,
            fallbackTitle: $"【待审批】{title}",
            fallbackContent: $"您有一条新的审批任务（{nodeName}），请及时处理。",
            ctx: new() { ["title"] = title, ["nodeName"] = nodeName }));

    public Task NotifyFlowCompleted(long initiatorId, long instanceId, string title, FlowInstanceStatusEnum finalStatus, string bizType = "")
    {
        var statusText = finalStatus == FlowInstanceStatusEnum.Approved ? "已通过" : "已拒绝";
        return NotifyUsers(new List<long> { initiatorId }, Build(FlowNotificationTypeEnum.FlowCompleted, instanceId, bizType,
            fallbackTitle: $"【审批{statusText}】{title}",
            fallbackContent: $"您发起的审批流程已{statusText}。",
            ctx: new() { ["title"] = title, ["statusText"] = statusText }));
    }

    public Task NotifyTransferred(long targetUserId, long instanceId, string title, string? fromName, string bizType = "")
        => NotifyUsers(new List<long> { targetUserId }, Build(FlowNotificationTypeEnum.Transferred, instanceId, bizType,
            fallbackTitle: $"【转办】{title}",
            fallbackContent: $"{fromName} 将一条审批任务转交给您，请及时处理。",
            ctx: new() { ["title"] = title, ["fromName"] = fromName }));

    public Task NotifyReturned(List<long> userIds, long instanceId, string title, string? returnedBy, string bizType = "")
        => NotifyUsers(userIds, Build(FlowNotificationTypeEnum.Returned, instanceId, bizType,
            fallbackTitle: $"【退回】{title}",
            fallbackContent: $"{returnedBy} 已退回该审批，请重新审核。",
            ctx: new() { ["title"] = title, ["fromName"] = returnedBy }));

    public Task NotifyAddSign(long targetUserId, long instanceId, string title, string? fromName, string bizType = "")
        => NotifyUsers(new List<long> { targetUserId }, Build(FlowNotificationTypeEnum.AddSign, instanceId, bizType,
            fallbackTitle: $"【加签】{title}",
            fallbackContent: $"{fromName} 邀请您参与审批，请及时处理。",
            ctx: new() { ["title"] = title, ["fromName"] = fromName }));

    public Task NotifyEscalated(List<long> targetUserIds, long instanceId, string title, string? fromName, string? nodeName, string bizType = "")
        => NotifyUsers(targetUserIds, Build(FlowNotificationTypeEnum.Escalated, instanceId, bizType,
            fallbackTitle: $"【升级】{title}",
            fallbackContent: $"{fromName} 将审批任务（{nodeName}）升级给您，请及时处理。",
            ctx: new() { ["title"] = title, ["fromName"] = fromName, ["nodeName"] = nodeName }));

    public Task NotifyTimeout(List<long> userIds, long instanceId, string title, string bizType = "")
        => NotifyUsers(userIds, Build(FlowNotificationTypeEnum.Timeout, instanceId, bizType,
            fallbackTitle: $"【超时提醒】{title}",
            fallbackContent: "您有一条审批任务已超时，请尽快处理。",
            ctx: new() { ["title"] = title }));

    public Task NotifyWithdrawn(List<long> userIds, long instanceId, string title, string? initiatorName, string bizType = "")
        => NotifyUsers(userIds, Build(FlowNotificationTypeEnum.Withdrawn, instanceId, bizType,
            fallbackTitle: $"【已撤回】{title}",
            fallbackContent: $"{initiatorName} 已撤回该审批流程。",
            ctx: new() { ["title"] = title, ["initiatorName"] = initiatorName }));

    private static FlowNotification Build(FlowNotificationTypeEnum type, long instanceId, string bizType,
        string fallbackTitle, string fallbackContent, Dictionary<string, string?> ctx)
    {
        return new FlowNotification
        {
            Type = type,
            InstanceId = instanceId,
            BizType = bizType ?? "",
            Title = fallbackTitle,
            Content = fallbackContent,
            Context = ctx,
        };
    }

    // ═══════════════════════════════════════════
    //  日志写入
    // ═══════════════════════════════════════════

    private async Task SafeWriteLog(FlowNotification notification, string channel, List<long> userIds,
        FlowNotifyPushResult result, int elapsedMs)
    {
        try
        {
            var csv = string.Join(",", userIds);
            if (csv.Length > 1024) csv = csv.Substring(0, 1020) + "...";
            var err = result.ErrorMessage;
            if (!string.IsNullOrEmpty(err) && err.Length > 1024) err = err.Substring(0, 1020) + "...";

            await _logRep.InsertAsync(new ApprovalFlowNotifyLog
            {
                InstanceId = notification.InstanceId,
                NotifyType = notification.Type.ToString(),
                Channel = channel,
                Title = notification.Title,
                TargetUserIds = csv,
                TargetCount = userIds.Count,
                Success = result.Success,
                ErrorMessage = err,
                ElapsedMs = elapsedMs,
            });
        }
        catch
        {
            // 日志写入失败不能影响主流程
        }
    }
}

public class FlowNotification
{
    public FlowNotificationTypeEnum Type { get; set; }
    public long InstanceId { get; set; }
    /// <summary>业务类型，用于模板 BizType 级覆盖查找</summary>
    public string BizType { get; set; } = "";
    public string Title { get; set; } = "";
    public string Content { get; set; } = "";
    /// <summary>模板渲染上下文（变量表）</summary>
    public Dictionary<string, string?>? Context { get; set; }
}

/// <summary>
/// 通知类型
/// </summary>
public enum FlowNotificationTypeEnum
{
    NewTask,
    Urge,
    FlowCompleted,
    Transferred,
    Returned,
    AddSign,
    Withdrawn,
    Escalated,
    Timeout,
}

/// <summary>
/// 通知渠道配置（来自 ApprovalFlow:Notify JSON 或 ApprovalFlowNotifyConfig 表的聚合结果）
/// </summary>
public class NotifyChannelConfig
{
    public bool SignalR { get; set; } = true;
    public bool DingTalk { get; set; }
    public bool WorkWeixin { get; set; }
    public bool Email { get; set; }
    public bool Sms { get; set; }

    /// <summary>P4-16: 钉钉群机器人 Webhook URL（含 access_token）</summary>
    public string? DingTalkWebhookUrl { get; set; }

    /// <summary>P4-16: 钉钉群机器人加签 Secret（可选，启用加签时必填）</summary>
    public string? DingTalkSecret { get; set; }

    /// <summary>P4-16: 企业微信群机器人 Webhook URL（含 key）</summary>
    public string? WorkWeixinWebhookUrl { get; set; }

    /// <summary>P4-16: 短信运营商侧的通知模板 Id（阿里云/腾讯云/自定义）</summary>
    public string? SmsTemplateId { get; set; }
}