import inquirer from "inquirer";
import chalk from 'chalk';
import { createSpinner } from 'nanospinner';

import { Teacher } from "./classes.js";
import { Student } from "./classes.js";
import { Course } from "./classes.js";

let teacher = Teacher.teacher
let student = Student.student
let course = Course.course

let sleep = () => new Promise((r) => setTimeout(r, 1000))

export async function teacherOptions() {
    const result: any = await inquirer.prompt([
        {
            type: 'rawlist',
            name: 'teacherMenu',
            message: 'Teacher Menu : ',
            choices: [
                'Add New Teacher',
                'View Teacher',
                'Assign Course',
                'Back'
            ],
        }
    ]);
    if (result.teacherMenu == "Add New Teacher") {
        await teacherAdd()
    }
    if (result.teacherMenu == "View Teacher") {
        
        await ViewTeacher(teacher)
    }
    if (result.teacherMenu == "Assign Course") {
        
        await assignTeacher(teacher,student,course)
    }
}

async function teacherAdd() {

    const result = await inquirer.prompt([
        {
            type: "input",
            name: "name",
            message: "Enter Teacher Name : "
        },
        {
            type: "number",
            name: "age",
            message: "Enter Teacher Age : "
        }
    ]);
    let newTeachers = new Teacher(result.name, result.age)
    const spinner = createSpinner('Adding Teacher').start()
    await sleep()
    Teacher.addTeacher(newTeachers)
    spinner.success({ text: chalk.greenBright("Teacher Added Successfully") })
    
}

// View Teacher Function

async function ViewTeacher(teacher:Teacher[]) {
    
    if (!teacher.length) {
        console.log(chalk.redBright('############ No Teacher Available ############'))
        return
    }
    console.table(teacher.map((val) => {
        return {
        
            Name: val.name,
            Age: val.age,
            Assigned_Course : val.courseEnroll.length? val.courseEnroll: "No Course Assigned"

        }
    }))
}

async function assignTeacher(teachers:Teacher[],students: Student[], courses: Course[]) {

    if (!teacher.length) {
        console.log(chalk.redBright('############ No Teacher Available ############'))
        return
    }

    ViewTeacher(teacher)
    const input = await inquirer.prompt([
        {
            name: 'index',
            message: 'Enter Index to Register In Course OR Any key to Exit : ',
            type: 'number'
        }
    ]);

    const index: number = input['index'];
    
    if (index <= teacher.length - 1 && index >= 0) {
        
        if (!courses.length) {
            console.log(chalk.redBright('############ No Course Available ############'));
            return;
        }
    
        const courseChoices = courses.map(val => {
            return { name: `${val.courseName}` };
        });

        
        const courseInput = await inquirer.prompt([
            {

                name: 'course',
                message: 'Select Course: ',
                type: 'list',
                choices: courseChoices
            }
        ]);

        const selectedCourseName = courseInput.course;
        const selectedCourse = courses.find((course) => course.courseName === selectedCourseName);
        
        let teacher_Name = teachers[index].name
        let teacher = teachers.at(index) as Teacher
        
        if (teacher?.courseEnroll.includes(selectedCourseName)) {
            console.log(chalk.redBright("############ TEACHER ALREADY ASSIGNED IN THIS COURSE ############") )
            return
        }
      
        if (selectedCourse) {
            teachers[index].courseEnroll.push(courseInput.course);
            selectedCourse.teacherName.push(teacher_Name);
            console.log(chalk.yellowBright(`Course ${selectedCourseName} assign for teacher ${teachers[index].name}.`));
        } else {
            console.log('Course not found or not selected. Assignment failed.');
        }
        
    } else{
        console.log(chalk.redBright('############ Teacher Not Found ############'))
    }  
}