use erp_core::events::EventBus;
use sea_orm::ActiveValue::Set;
use sea_orm::{ActiveModelTrait, ColumnTrait, EntityTrait, QueryFilter};
use uuid::Uuid;

/// 启动透析会话工作流编排器
/// 订阅 dialysis.record.created → 自动查找并启动 dialysis_session BPMN 工作流
pub fn start_dialysis_workflow_orchestrator(db: sea_orm::DatabaseConnection, event_bus: EventBus) {
    let (mut receiver, _handle) = event_bus.subscribe_filtered("dialysis.".to_string());

    tokio::spawn(async move {
        loop {
            match receiver.recv().await {
                Some(event) if event.event_type == "dialysis.record.created" => {
                    if let Err(e) = handle_dialysis_record_created(&db, &event_bus, &event).await {
                        tracing::warn!(
                            error = %e,
                            record_id = ?event.payload.get("record_id"),
                            "透析会话工作流启动失败"
                        );
                    }
                }
                Some(_) => {}
                None => {
                    tracing::debug!("透析工作流事件接收器关闭");
                    break;
                }
            }
        }
    });
}

async fn handle_dialysis_record_created(
    db: &sea_orm::DatabaseConnection,
    event_bus: &EventBus,
    event: &erp_core::events::DomainEvent,
) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let record_id = event
        .payload
        .get("record_id")
        .and_then(|v| v.as_str())
        .ok_or("缺少 record_id")?;
    let record_uuid = Uuid::parse_str(record_id)?;

    // 查找 dialysis_session 流程定义
    let definition = erp_workflow::entity::process_definition::Entity::find()
        .filter(erp_workflow::entity::process_definition::Column::Key.eq("dialysis_session"))
        .filter(erp_workflow::entity::process_definition::Column::TenantId.eq(event.tenant_id))
        .filter(erp_workflow::entity::process_definition::Column::Status.eq("published"))
        .filter(erp_workflow::entity::process_definition::Column::DeletedAt.is_null())
        .one(db)
        .await?;

    let definition = match definition {
        Some(d) => d,
        None => {
            tracing::debug!(
                tenant_id = %event.tenant_id,
                "未找到 dialysis_session 流程定义，跳过工作流启动"
            );
            return Ok(());
        }
    };

    let patient_id = event
        .payload
        .get("patient_id")
        .and_then(|v| v.as_str())
        .unwrap_or("unknown");

    let req = erp_workflow::dto::StartInstanceReq {
        definition_id: definition.id,
        business_key: Some(format!("dialysis:{}", record_id)),
        variables: Some(vec![
            erp_workflow::dto::SetVariableReq {
                name: "patient_id".into(),
                var_type: Some("string".into()),
                value: patient_id.into(),
            },
            erp_workflow::dto::SetVariableReq {
                name: "record_id".into(),
                var_type: Some("string".into()),
                value: record_id.into(),
            },
        ]),
    };

    let operator_id = event
        .payload
        .get("created_by")
        .and_then(|v| v.as_str())
        .and_then(|s| Uuid::parse_str(s).ok())
        .unwrap_or_else(Uuid::nil);

    let result = erp_workflow::service::instance_service::InstanceService::start(
        event.tenant_id,
        operator_id,
        &req,
        db,
        event_bus,
    )
    .await?;

    // 更新 dialysis_record 的 workflow_instance_id
    let record = erp_dialysis::entity::dialysis_record::Entity::find_by_id(record_uuid)
        .one(db)
        .await?
        .ok_or("透析记录不存在")?;

    let mut active: erp_dialysis::entity::dialysis_record::ActiveModel = record.into();
    active.version = Set(active.version.take().unwrap_or(0) + 1);
    active.workflow_instance_id = Set(Some(result.id));
    active.updated_at = Set(chrono::Utc::now());
    active.update(db).await?;

    tracing::info!(
        record_id = %record_id,
        instance_id = %result.id,
        "透析会话工作流已启动"
    );

    Ok(())
}

/// 为指定租户种子透析会话 BPMN 流程定义
/// 流程：透前评估 → 上机确认 → 透中监测 → 透后评估 → 医生审核
pub async fn seed_dialysis_session_workflow(
    db: &sea_orm::DatabaseConnection,
    tenant_id: Uuid,
    operator_id: Uuid,
) -> Result<(), sea_orm::DbErr> {
    use erp_workflow::entity::process_definition;

    let existing = process_definition::Entity::find()
        .filter(process_definition::Column::TenantId.eq(tenant_id))
        .filter(process_definition::Column::Key.eq("dialysis_session"))
        .filter(process_definition::Column::DeletedAt.is_null())
        .one(db)
        .await?;

    if existing.is_some() {
        tracing::debug!(tenant_id = %tenant_id, "dialysis_session 流程定义已存在");
        return Ok(());
    }

    let nodes = serde_json::json!([
        {"id": "start", "type": "StartEvent", "name": "开始"},
        {"id": "pre_assessment", "type": "UserTask", "name": "透前评估", "assignee_type": "candidate_groups", "candidate_groups": ["dialysis_nurse"]},
        {"id": "start_dialysis", "type": "UserTask", "name": "上机确认", "assignee_type": "candidate_groups", "candidate_groups": ["dialysis_nurse"]},
        {"id": "monitoring", "type": "UserTask", "name": "透中监测", "assignee_type": "candidate_groups", "candidate_groups": ["dialysis_nurse"]},
        {"id": "post_assessment", "type": "UserTask", "name": "透后评估", "assignee_type": "candidate_groups", "candidate_groups": ["dialysis_nurse"]},
        {"id": "review", "type": "UserTask", "name": "医生审核", "assignee_type": "candidate_groups", "candidate_groups": ["dialysis_doctor"]},
        {"id": "end", "type": "EndEvent", "name": "结束"}
    ]);

    let edges = serde_json::json!([
        {"id": "e1", "from": "start", "to": "pre_assessment"},
        {"id": "e2", "from": "pre_assessment", "to": "start_dialysis"},
        {"id": "e3", "from": "start_dialysis", "to": "monitoring"},
        {"id": "e4", "from": "monitoring", "to": "post_assessment"},
        {"id": "e5", "from": "post_assessment", "to": "review"},
        {"id": "e6", "from": "review", "to": "end"}
    ]);

    let now = chrono::Utc::now();
    let active = process_definition::ActiveModel {
        id: Set(Uuid::now_v7()),
        tenant_id: Set(tenant_id),
        name: Set("透析会话工作流".into()),
        key: Set("dialysis_session".into()),
        version: Set(1),
        category: Set(Some("dialysis".into())),
        description: Set(Some(
            "透析会话标准化流程：透前评估 → 上机确认 → 透中监测 → 透后评估 → 医生审核".into(),
        )),
        nodes: Set(nodes),
        edges: Set(edges),
        status: Set("published".into()),
        created_at: Set(now),
        updated_at: Set(now),
        created_by: Set(operator_id),
        updated_by: Set(operator_id),
        deleted_at: Set(None),
        version_field: Set(1),
    };

    active.insert(db).await?;
    tracing::info!(tenant_id = %tenant_id, "透析会话工作流模板已创建并发布");
    Ok(())
}