import inquirer from "inquirer";
import chalk from 'chalk';
import { createSpinner } from 'nanospinner';
import { Student } from "./classes.js";
import { Course } from "./classes.js";
import { feesPayment } from "./fees.js";
import { FeesStatus } from "./classes.js";

let course = Course.course
let students = Student.student

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

export async function studentOptions() {
    const result: any = await inquirer.prompt([
        {
            type: 'rawlist',
            name: 'studentMenu',
            message: 'Student Menu : ',
            choices: [
                'Add New Student',
                'View Student',
                'Enroll in Course',
                'Pay Fees',
                'Back'
            ],
        }
    ]);
    if (result.studentMenu == "Add New Student") {
        await studentAdd()
    }
    if (result.studentMenu == "View Student") {
        await ViewStudents(students)
    }
    if (result.studentMenu == "Enroll in Course") {
        await enrollCourse(students,course)
    }
    if (result.studentMenu == "Pay Fees") {
        await feesPayment()
    }
}

async function studentAdd() {

    const result = await inquirer.prompt([
        {
            type: "input",
            name: "name",
            message: "Enter Student Name : "
        },
        {
            type: "number",
            name: "age",
            message: "Enter Student Age : "
        }
    ]);
    let studentId = Math.floor(Math.random()*325850)
    let fees = 0
    let feesDue = 0
    let newStudents = new Student(result.name, result.age,studentId,fees,feesDue)
    
    const spinner = createSpinner('Adding Student').start()
    await sleep()
    Student.addStudent(newStudents)
    spinner.success({ text: chalk.greenBright("Student Added Successfully") })
}

// View Students Function

export async function ViewStudents(students:Student[]) {
           
    if (!students.length) {
        console.log(chalk.redBright('############ No Student Available ############'))
        return
    }
    console.table(students.map((val) => {
        return {
            student_ID: val.studentID,
            Name: val.name,
            Age: val.age,
            Course_Name: val.courseEnroll.length ? val.courseEnroll: "No Course Selected",
            Course_Fees : val.fees,
            Fees_Paid: val.feesPaid
            

        }
    }))
}
   
    async function enrollCourse(students: Student[], courses: Course[]) {
        if (!students.length) {
            console.log(chalk.redBright('############ No Student Available ############'))
            return
        }
    
        ViewStudents(students)
        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 <= students.length - 1 && index >= 0) {
            
            if (!courses.length) {
                console.log(chalk.redBright('############ No Course Available ############'));
                return;
            }
        
            const courseChoices = courses.map(val => {
                return { name: val.courseName, fees: val.courseFees };
            });
    
            
            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 student_Name = students[index].name
            let student = students[index] as Student
            let studentId = students[index].studentID
            let isFeesPaid = false
            let courseIndex = courseChoices.findIndex((item) => item.name === courseInput.course);

            
            if (student?.courseEnroll.includes(selectedCourseName)) {
                console.log(chalk.redBright("############ STUDENT ALREADY ENROLLED IN THIS COURSE ############") )
                return
            }
            let currentFees = students[index].fees + courseChoices[courseIndex].fees
                    
            if (selectedCourse) {
                students[index].courseEnroll.push(courseInput.course);
                students[index].fees = currentFees
                selectedCourse.studentName.push(student_Name);
                let feesstatus = new FeesStatus(student_Name,studentId,isFeesPaid,selectedCourseName)
                FeesStatus.updateFeesStatus(feesstatus)
                console.log(chalk.yellowBright(`Course ${selectedCourseName} enrolled for student ${students[index].name}.`));
            } else {
                console.log('Course not found or not selected. Enrollment failed.');
            }
            
        } else{
            console.log(chalk.redBright('############ Student Not Found ############'))
        }  
    }