package robot

import (
	"fmt"
	"log"
)

type CaseNode struct {
	testCase *TestCase //用例名
	Next     *CaseNode //测试用例
}

type LinkCase struct {
	Head  *CaseNode
	force bool
}

func NewLinkCase() *LinkCase {
	return &LinkCase{}
}

func NewDefault(testCast *TestCase) *LinkCase {
	return &LinkCase{
		force: true,
		Head:  &CaseNode{testCase: testCast},
	}
}

func (this *LinkCase) isEmpty() bool {
	return this.Head == nil
}

func (this *LinkCase) lastNode() *CaseNode {
	cur := this.Head
	for cur.Next != nil {
		cur = cur.Next
	}
	return cur
}

//尾部追加
func (this *LinkCase) Append(testCase *TestCase) {
	newNode := &CaseNode{testCase: testCase}
	if this.isEmpty() {
		this.Head = newNode
	} else {
		this.lastNode().Next = newNode
	}
}

//头部添加
func (this *LinkCase) Unshift(testCase *TestCase) {
	if this.force {
		log.Fatal("use `NewLinkCase` method create link if you want to use `Unshift` opt")
		return
	}
	newNode := &CaseNode{testCase: testCase}
	newNode.Next = this.Head
	this.Head = newNode
}

func (this *LinkCase) length() int {
	cur := this.Head
	count := 0
	for cur.Next != nil {
		cur = cur.Next
		count++
	}
	return count
}

func (this *LinkCase) Insert(index int, testCase *TestCase) {
	if this.force {
		log.Fatal("use `NewLinkCase` method create link if you want to use `Insert` opt")
		return
	}
	if index < 0 {
		this.Unshift(testCase)
	} else if index > this.length() {
		this.Append(testCase)
	} else {
		preNode := this.Head
		count := 0
		for count < index-1 {
			preNode = preNode.Next
			count++
		}
		newNode := &CaseNode{testCase: testCase, Next: preNode.Next}
		preNode.Next = newNode
	}
}

func (this *CaseNode) String() string {
	return fmt.Sprintf("value=%v", this.testCase.desc)
}