package model

import (
	"approveflow/app/base"
	"approveflow/app/provider/abstract/connect"
	"approveflow/app/provider/flow_definition"
	"approveflow/app/utils"
	"encoding/json"
	"fmt"
	"github.com/google/uuid"
)

const (
	StepStatusPending   = "Pending"   // 待审批
	StepStatusApproved  = "Approved"  // 已批准
	StepStatusRejected  = "Rejected"  // 已驳回
	StepStatusReversed  = "Reversed"  // 已反转
	StepStatusCompleted = "Completed" // 步骤已完成
)

// InstanceStep 审批步骤实例表
type InstanceStep struct {
	ID                  int64                      `gorm:"primaryKey;autoIncrement" json:"id"`  // 主键ID
	InstanceID          int64                      `gorm:"index;not null" json:"instance_id"`   // 所属审批实例ID
	StepID              int64                      `gorm:"type:bigint;not null" json:"step_id"` // 关联的流程步骤ID
	StepName            string                     `gorm:"type:varchar(50);not null" json:"step_name"`
	StepCode            string                     `gorm:"type:varchar(100)" json:"step_code"`                                         // 步骤编号用于标识特殊的审批节点
	ApproverKey         string                     `gorm:"type:varchar(50);not null" json:"approver_id"`                               // 审批人ID
	Status              string                     `gorm:"-" json:"status"`                                                            // 审批状态
	ApproverComments    string                     `gorm:"type:text" json:"approver_comments"`                                         // 审批意见
	IsDynamic           bool                       `gorm:"not null;default:false" json:"is_dynamic"`                                   // 是否为动态步骤
	StatusEvents        []*InstanceStepStatusEvent `gorm:"foreignKey:StepID;constraint:OnDelete:CASCADE" json:"status_events"`         // 状态事件表
	InstancePathConfigs []*InstancePathConfig      `gorm:"foreignKey:NodeID;constraint:OnDelete:CASCADE" json:"instance_path_configs"` // 动态路径配置，自定义，不直接存储
	Records             []*ApprovalRecord          `gorm:"foreignKey:InstanceStepID;constraint:OnDelete:CASCADE" json:"records"`       // 审批记录
	Reversals           []*ApprovalReversal        `gorm:"foreignKey:StepID;constraint:OnDelete:CASCADE" json:"reversals"`             // 反转记录
	base.Model
}

// InstanceStepStatusEvent 审批步骤状态表
type InstanceStepStatusEvent struct {
	StepID    int64  `gorm:"type:bigint;not null" json:"step_id"`
	Status    string `gorm:"type:varchar(50);not null" json:"status"`
	Extension string `gorm:"type:varchar(50);not null" json:"extension"`
	base.Model
}

type ByCreatedAt []*InstanceStepStatusEvent

func (a ByCreatedAt) Len() int           { return len(a) }
func (a ByCreatedAt) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a ByCreatedAt) Less(i, j int) bool { return a[i].CreatedAt.After(a[j].CreatedAt) }

func (step *InstanceStep) GetStatus() string {
	return step.StatusEvents[len(step.StatusEvents)-1].Status
}

func (step *InstanceStep) AddStatusEvent(status string) {
	if step.StatusEvents == nil {
		step.StatusEvents = make([]*InstanceStepStatusEvent, 0)
	}
	if len(step.StatusEvents) > 0 && step.GetStatus() == status {
		return
	}
	step.StatusEvents = append(step.StatusEvents, &InstanceStepStatusEvent{
		StepID: step.ID, Status: status, Extension: "",
	})
	step.Status = status
}

func (step *InstanceStep) AddPendingEvent() {
	step.AddStatusEvent(StepStatusPending)
}

func (step *InstanceStep) AddApprovedEvent() {
	step.AddStatusEvent(StepStatusApproved)
}

func (step *InstanceStep) AddRejectedEvent() {
	step.AddStatusEvent(StepStatusRejected)
}

func (step *InstanceStep) AddReversedEvent() {
	step.AddStatusEvent(StepStatusReversed)
}

func (step *InstanceStep) AddCompletedEvent() {
	step.AddStatusEvent(StepStatusCompleted)
}

func (step *InstanceStep) MarshalBinary() ([]byte, error) {
	return json.Marshal(step)
}

func (step *InstanceStep) UnmarshalBinary(data []byte) error {
	return json.Unmarshal(data, step)
}

func (step *InstanceStep) GetPathConfigs() []connect.AbstractNodePathConfig {
	return utils.ConvertToAbstractNodes(step.InstancePathConfigs, func(t *InstancePathConfig) connect.AbstractNodePathConfig {
		return t
	})
}

func (step *InstanceStep) SetPathConfigs(configs []connect.AbstractNodePathConfig) {
	convertedConfigs, err := utils.ConvertToSpecificType(configs, func(item connect.AbstractNodePathConfig) (*InstancePathConfig, bool) {
		specificConfig, ok := item.(*InstancePathConfig)
		return specificConfig, ok
	})
	if err != nil {
		panic(fmt.Sprintf("Error in SetPathConfigs: %v", err))
	}
	step.InstancePathConfigs = convertedConfigs
}

func (step *InstanceStep) GetKey() string {
	return step.Key
}

func NewInstanceStep(flowStep *flow_definition.ApprovalStep, approverKey string, isDynamic bool) *InstanceStep {
	instanceStep := &InstanceStep{
		StepID:      flowStep.ID,
		StepName:    flowStep.Name,
		StepCode:    flowStep.StepCode,
		ApproverKey: approverKey,
		IsDynamic:   isDynamic,
	}
	instanceStep.AddPendingEvent()
	instanceStep.Key = uuid.New().String()
	return instanceStep
}

// Approve 审批通过
func (step *InstanceStep) Approve(comments string) error {
	if step.GetStatus() != StepStatusPending {
		return fmt.Errorf("当前步骤不是待审批状态")
	}
	step.AddApprovedEvent()
	step.ApproverComments = comments
	step.addApprovalRecord(StepStatusApproved, comments)
	return nil
}

// Reject 审批驳回
func (step *InstanceStep) Reject(comments string) error {
	//if step.GetStatus() != StepStatusPending {
	//	return fmt.Errorf("当前步骤不是待审批状态")
	//}
	step.AddRejectedEvent()
	step.ApproverComments = comments
	step.addApprovalRecord(StepStatusRejected, comments)
	return nil
}

// addApprovalRecord 添加审批记录
func (step *InstanceStep) addApprovalRecord(status string, comments string) {
	record := &ApprovalRecord{
		InstanceStepID: step.ID,
		ApproverKey:    step.ApproverKey,
		Status:         status,
		Comments:       comments,
	}
	step.Records = append(step.Records, record)
}

func (step *InstanceStep) addApprovalReversal(reversal *ApprovalReversal) {
	var reversals []*ApprovalReversal
	reversals = append(reversals, reversal)
	step.Reversals = reversals
}