csamsclient/foreground/src/main/java/com/gyf/csams/association/model/ExamViewModel.kt

package com.gyf.csams.association.model

import androidx.lifecycle.LiveData
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.viewModelScope
import com.gyf.csams.NOT_IMPL_TIP
import com.gyf.csams.uikit.ScrollList
import com.gyf.csams.uikit.StringForm
import kotlinx.coroutines.launch
import kotlin.random.Random

/**
 * 题库界面类型
 *
 */
enum class ExamActivityType(val menuName: String) {
    //入团题库
    SET_EXAM("入团题库"),

    //入团申请表
    JOIN_Association("入团申请表")
}

/**
 * 题型
 *
 */
enum class ExamType(val type: String) {
    //选择题
    CQ("选择题"),

    //开放题
    OQ("开放题")
}

sealed class Exam {
    abstract val examType: ExamType
    abstract val question: StringForm
}


/**
 * 开放题
 *
 * @property examType 题型描述
 * @property question 问题
 */
data class OpenQuestionsVo(
    override val examType: ExamType = ExamType.OQ, override val question: StringForm

) : Exam()

/**
 * 选择题
 *
 * @property examType 题型描述
 * @property answers 答案
 * @property rightAnswer 正确答案
 * @property question 问题
 */
data class ChoiceQuestionVo(
    override val examType: ExamType = ExamType.CQ,
    val answers: List<StringForm>,
    val rightAnswer: Int,
    override val question: StringForm
) : Exam()


/**
 * 问题长度
 */
const val QUESTION_TEXT_LENGTH = 30

/**
 * 选择题选项数
 */
const val ANSWER_SIZE = 4

/**
 * 答案长度
 *
 */
const val ANSWER_TEXT_LENGTH = 15


/**
 * 题库状态管理
 *
 */

class ExamViewModel : ScrollList<Exam>() {
    val questionIsNull: String = "问题不能为空"
    val deleteLeastOne: String = "至少保留一道题目"
    val updateExam = "更新题库"
    val postAnswer = "提交答案"
    val back = "返回"
    val deleteTip = "确定删除此题目？"
    val addTip = "确定添加此题目？"
    val actionLabel = "确定"


    override val initSize = 10


    private val _newExam: MutableLiveData<Exam> = MutableLiveData(createExam(ExamType.CQ))
    val newExam: LiveData<Exam> = _newExam

    init {
        load()
    }

    /**
     * 切换题型
     *
     */
    fun switchType(exam: Exam) {
        if (exam is ChoiceQuestionVo) _newExam.value = createExam(ExamType.OQ) else _newExam.value =
            createExam(ExamType.CQ)
    }


    /**
     * 创建题目
     *
     * @param type
     * @return
     */
    private fun createExam(type: ExamType): Exam {
        val question = StringForm(formDesc = "问题", textLength = QUESTION_TEXT_LENGTH)
        return when (type) {
            ExamType.CQ -> ChoiceQuestionVo(
                answers = ('A'..'D').map {
                    StringForm(
                        formDesc = "选项",
                        textLength = ANSWER_TEXT_LENGTH,
                        value = "选项$it"
                    )
                },
                rightAnswer = 0,
                question = question
            )
            ExamType.OQ -> OpenQuestionsVo(question = question)
        }
    }


    /**
     * 更新题目
     *
     */
    fun update(oldExam: Exam, newExam: Exam) {
        if (oldExam == _newExam.value) {
            _newExam.value = newExam
        } else {
            _data.value?.apply {
                this[indexOf(oldExam)] = newExam
                val list = mutableListOf<Exam>()
                list.addAll(this)
                _data.value?.clear()
                _data.value = list
            }
        }
    }

    /**
     * TODO 更新题库
     *
     * @param callback
     */
    fun updateExam(callback: (message: String) -> Unit) {
        callback(NOT_IMPL_TIP)
    }

    /**
     * TODO 提交答案
     *
     * @param callback
     */
    fun postAnswer(callback: (message: String) -> Unit) {
        callback(NOT_IMPL_TIP)
    }

    /**
     * 加载题目
     *
     */
    override fun load() {
        viewModelScope.launch {
            _data.value?.apply {
                repeat(initSize) {
                    if (Random.nextBoolean()) {
                        add(
                            OpenQuestionsVo(
                                question = StringForm(
                                    formDesc = "问题",
                                    textLength = QUESTION_TEXT_LENGTH,
                                    value = "这是一道开放题：$size"
                                )
                            )
                        )
                    } else {
                        add(
                            ChoiceQuestionVo(
                                question = StringForm(
                                    formDesc = "问题",
                                    textLength = QUESTION_TEXT_LENGTH,
                                    value = "这是一道选择题：$size"
                                ),
                                answers = ('A'..'D').map {
                                    StringForm(
                                        formDesc = "选项",
                                        textLength = ANSWER_TEXT_LENGTH,
                                        value = "选项$it"
                                    )
                                },
                                rightAnswer = Random.nextInt(ANSWER_SIZE)
                            )
                        )
                    }

                }
            }
        }
    }

    /**
     *TODO 加载更多题目
     *
     * @param callback
     */
    override fun loadMore(callback: (message: String) -> Unit) {
//        _data.value?.apply {
//            val list= mutableListOf<Exam>()
//            list.addAll(this)
//            list.apply {
//                repeat(10) {
//                    if (Random.nextBoolean()) add(OpenQuestionsVo(question = "这是一道开放题：$size")) else add(
//                        ChoiceQuestionVo(
//                            question = "这是一道选择题：$size，请从选项中选出正确答案",
//                            answers = listOf("选项A", "选项B", "选项C", "选项D"),
//                            rightAnswer = 3
//                        )
//                    )
//                }
//            }
//            _data.postValue(list)
//            callback("成功加载更多题目")
//        }

//        callback(NOT_IMPL_TIP)
    }

    fun addQuestion() {
        _data.value?.apply {
            _newExam.value?.let {
                val list = mutableListOf<Exam>()
                list.addAll(this)
                list.add(it)
                _data.postValue(list)
            }
            _newExam.value = createExam(ExamType.CQ)
        }
    }

    /**
     * TODO 删除题目
     *
     */
    fun deleteQuestion(exam: Exam) {
        _data.value?.apply {
            val list = mutableListOf<Exam>()
            remove(exam)
            list.addAll(this)
            _data.postValue(list)
        }
    }
}