// Package handler provides HTTP handlers for various endpoints.
package handler

import (
	"context"
	"fmt"
	"net/http"
	"time"

	"modelRT/common/errcode"
	"modelRT/database"
	"modelRT/diagram"
	"modelRT/logger"
	"modelRT/network"
	"modelRT/orm"

	"github.com/gin-gonic/gin"
	"github.com/gofrs/uuid"
	"gorm.io/gorm/clause"
)

// CircuitDiagramDeleteHandler define circuit diagram delete process API
func CircuitDiagramDeleteHandler(c *gin.Context) {
	pgClient := database.GetPostgresDBClient()

	var request network.CircuitDiagramDeleteRequest
	if err := c.ShouldBindJSON(&request); err != nil {
		logger.Error(c, "unmarshal circuit diagram del info failed", "error", err)

		resp := network.FailureResponse{
			Code: http.StatusBadRequest,
			Msg:  err.Error(),
		}
		c.JSON(http.StatusOK, resp)
		return
	}

	graph, err := diagram.GetGraphMap(request.PageID)
	if err != nil {
		logger.Error(c, "get topologic data from set by pageID failed", "error", err)

		resp := network.FailureResponse{
			Code: http.StatusBadRequest,
			Msg:  err.Error(),
			PayLoad: map[string]interface{}{
				"page_id": request.PageID,
			},
		}
		c.JSON(http.StatusOK, resp)
		return
	}

	var topologicDelInfos []network.TopologicUUIDDelInfo
	for _, topologicLink := range request.TopologicLinks {
		var delInfo network.TopologicUUIDDelInfo
		UUIDFrom, err1 := uuid.FromString(topologicLink.UUIDFrom)
		UUIDTo, err2 := uuid.FromString(topologicLink.UUIDTo)
		if err1 != nil || err2 != nil {
			var err error
			if err1 != nil && err2 == nil {
				err = fmt.Errorf("convert uuid from string failed:%w", err1)
			} else if err1 == nil && err2 != nil {
				err = fmt.Errorf("convert uuid from string failed:%w", err2)
			} else {
				err = fmt.Errorf("convert uuid from string failed:%w:%w", err1, err2)
			}

			logger.Error(c, "format uuid from string failed", "error", err)

			resp := network.FailureResponse{
				Code: http.StatusBadRequest,
				Msg:  err.Error(),
				PayLoad: map[string]interface{}{
					"topologic_info": topologicLink,
				},
			}
			c.JSON(http.StatusOK, resp)
			return
		}
		delInfo.UUIDFrom = UUIDFrom
		delInfo.UUIDTo = UUIDTo
		topologicDelInfos = append(topologicDelInfos, delInfo)
	}

	// open transaction
	tx := pgClient.Begin()

	for _, topologicDelInfo := range topologicDelInfos {
		err = database.DeleteTopologicIntoDB(c, tx, request.PageID, topologicDelInfo)
		if err != nil {
			tx.Rollback()

			logger.Error(c, "delete topologic info into DB failed", "topologic_info", topologicDelInfo, "error", err)

			resp := network.FailureResponse{
				Code: http.StatusBadRequest,
				Msg:  err.Error(),
				PayLoad: map[string]interface{}{
					"topologic_info": topologicDelInfo,
				},
			}
			c.JSON(http.StatusOK, resp)
			return
		}

		err = graph.DelEdge(topologicDelInfo.UUIDFrom, topologicDelInfo.UUIDTo)
		if err != nil {
			tx.Rollback()

			logger.Error(c, "delete topologic info failed", "topologic_info", topologicDelInfo, "error", err)

			resp := network.FailureResponse{
				Code: http.StatusBadRequest,
				Msg:  err.Error(),
				PayLoad: map[string]interface{}{
					"topologic_info": topologicDelInfo,
				},
			}
			c.JSON(http.StatusOK, resp)
			return
		}
	}

	if len(graph.VerticeLinks) == 0 && len(graph.FreeVertexs) == 0 {
		diagram.DeleteGraphMap(request.PageID)
	}

	for _, componentInfo := range request.ComponentInfos {
		cancelCtx, cancel := context.WithTimeout(c, 5*time.Second)
		defer cancel()

		globalUUID, err := uuid.FromString(componentInfo.UUID)
		if err != nil {
			tx.Rollback()

			logger.Error(c, "format uuid from string failed", "error", err)

			resp := network.FailureResponse{
				Code: http.StatusBadRequest,
				Msg:  err.Error(),
				PayLoad: map[string]interface{}{
					"uuid": componentInfo.UUID,
				},
			}
			c.JSON(http.StatusOK, resp)
			return

		}

		var component orm.Component
		result := tx.WithContext(cancelCtx).Clauses(clause.Locking{Strength: "UPDATE"}).Where("global_uuid = ?", globalUUID).Find(&component)
		if result.Error != nil || result.RowsAffected == 0 {
			tx.Rollback()

			err := result.Error
			if result.RowsAffected == 0 {
				err = fmt.Errorf("%w:please check uuid conditions", errcode.ErrDeleteRowZero)
			}

			logger.Error(c, "query component info into postgresDB failed", "component_global_uuid", componentInfo.UUID, "error", err)

			resp := network.FailureResponse{
				Code: http.StatusBadRequest,
				Msg:  err.Error(),
				PayLoad: map[string]interface{}{
					"uuid": componentInfo.UUID,
				},
			}
			c.JSON(http.StatusOK, resp)
			return
		}

		result = tx.WithContext(cancelCtx).Delete(component)
		if result.Error != nil || result.RowsAffected == 0 {
			tx.Rollback()

			err := result.Error
			if result.RowsAffected == 0 {
				err = fmt.Errorf("%w:please check uuid conditions", errcode.ErrDeleteRowZero)
			}

			logger.Error(c, "delete component info into postgresDB failed", "component_global_uuid", componentInfo.UUID, "error", err)

			resp := network.FailureResponse{
				Code: http.StatusBadRequest,
				Msg:  err.Error(),
				PayLoad: map[string]interface{}{
					"uuid": componentInfo.UUID,
				},
			}
			c.JSON(http.StatusOK, resp)
			return
		}
		diagram.DeleteComponentMap(component.GlobalUUID.String())
	}

	if len(request.FreeVertexs) > 0 {
		for _, freeVertex := range request.FreeVertexs {
			delete(graph.FreeVertexs, freeVertex)
		}
	}

	// commit transaction
	tx.Commit()
	resp := network.SuccessResponse{
		Code: http.StatusOK,
		Msg:  "success",
		PayLoad: map[string]interface{}{
			"page_id": request.PageID,
		},
	}
	c.JSON(http.StatusOK, resp)
}