/**
 * @file   This file provides abstracted functions to interact with the api
 * @author Arlo Filley
 * 
 */

/**
 * This class provides all the useful methods to interact with the api.
 */
class API {
    constructor() { this.url = "/api"; }

    async createTest() {
        const test = screenManager.screen.textbox.getLetters();
        const testType = "words";
        const testLength = test.length;
        const testTime = screenManager.screen.timer.getTime();
        const testSeed = 0;
        const quoteId = 0;
        const userId = Number(user.userId);
        const testContent = screenManager.screen.textbox.getTestContent();

        let correctLetters = 0;
        test.forEach((letter, index) => {
            if (letter === testContent[index]) correctLetters++;
        });

        const accuracy = Math.round((correctLetters / test.length) * 100);
        const wpm = Math.round((correctLetters / 5) * (60 / testTime));

        const validations = [
            {value: testType, type: "string"},
            {value: testLength, type: "number", min: 0},
            {value: testTime, type: "number", min: 1},
            {value: testSeed, type: "number", min: 0},
            {value: quoteId, type: "number", min: 0},
            {value: wpm, type: "number", min: 0},
            {value: accuracy, type: "number", min: 0, max: 100},
            {value: userId, type: "number", min: 0}
        ];

        for (let {value, type, min, max} of validations) {
            if (typeof value !== type || value < min || (max !== undefined && value > max)) {
                console.error(`Validation failed for value: ${value}, Type: ${type}, Min: ${min}, Max: ${max}`);
                return;
            }
        }

        const data = {
            test_type: testType,
            test_length: testLength,
            test_time: testTime,
            test_seed: testSeed,
            quote_id: quoteId,
            wpm: wpm,
            accuracy: accuracy,
            user_id: userId,
            secret: user.secret
        };

        try {
            const response = await fetch(`${this.url}/user/test`, {
                method: "POST",
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify(data)
            });
            
            if (!response.ok) {
                throw new Error('Network response was not ok');
            }

            // const responseData = await response.json();
            // console.log(responseData);
            user.lastTest = data; // Consider updating user.lastTest only on successful response
            window.location.href = "/typing/pages/end/index.html"
        } catch (error) {
            console.error('There has been a problem with your fetch operation:', error);
        }
    }

    /**
     * Fetches the latest test for a given user.
     * @param {number} userId The user's ID.
     * @param {string} secret The secret key for authentication.
     * @returns {Promise<Object>} The latest test object or an error message.
     */
    async getLatestUserTest() {
        let userId = Number(user.userId);
        let secret = user.secret;
        const url = `${this.url}/user/test/${userId}/${secret}`;
        
        try {
            const response = await fetch(url);
            if (!response.ok) {
                // Handle HTTP errors
                throw new Error(`HTTP error! status: ${response.status}`);
            }
            const data = await response.json();
            console.log("Successfully fetched latest test:", data);
            return data;
        } catch (error) {
            console.error("Error fetching the latest user test:", error);
            return null; // or handle as needed
        }
    }

    /**
     * takes a validated name and password and sends
     * a post request to make a user with the given
     * username and password
     * @param {String} username 
     * @param {String} password 
     * @returns
     */
    createUser( username, password ) {
        console.log( username, password );
        const user = {
            username: username,
            password: password
        };

        const xhr = new XMLHttpRequest(); 
        xhr.open( "POST", `${this.url}/user/create/` );

        xhr.send( JSON.stringify(user) );

        xhr.onload = () => {
            if (xhr.status === 500) {
                alert("Sorry, looks like your username isn't unique");
                console.error("Sorry, looks like your username isn't unique")
            } else {
                this.login(username, password);
            }
        };
    }


    /**
     * takes a validated name and password and sends
     * a post request to make a user with the given
     * username and password
     * @param {String} username 
     * @param {String} password 
     * @param {boolean} initial
     * @returns
     */
    login(pUsername, pPassword, initial = false) {
        // If Local Storage has the information we need there is no need to make a request to the server
        if (localStorage.getItem("username") === pUsername || (initial && localStorage.length === 3) ) {
            user.userId = localStorage.getItem("userId");
            user.secret = localStorage.getItem("secret");
            user.username = localStorage.getItem("username");

            return
        }

        // Variable Validation
        if (pUsername == undefined || pPassword == undefined) {
            return
        }

        let xhr = new XMLHttpRequest();
        xhr.open('GET', `${this.url}/user/login/${pUsername}/${pPassword}`);
        xhr.send();
        xhr.onload = () => {
            let response = JSON.parse(xhr.response);

            // If there is an error with the login we need 
            if (xhr.response === null) {
                alert("Error Logging in, maybe check your password");
                return 
            }

            user.userId = response.user_id;
            user.username = pUsername
            user.secret = response.secret;

            localStorage.setItem("userId", user.userId);
            localStorage.setItem("username", pUsername);
            localStorage.setItem("secret", user.secret);
        };
    }

    logout() {
        user = new User();
        user.username = "no one";
        user.password = "";
        user.userId = 0;
        user.tests = [];
        localStorage.clear();
        this.getTest();
    }

    getUserTests() {
        if (user.userId === 0) {
            user.tests = undefined;
            return;
        }
        let xhr = new XMLHttpRequest();

        xhr.open('GET', `${this.url}/user/tests/${user.userId}/${user.secret}`);
        xhr.send();
        xhr.onload = () => {
            user.tests = JSON.parse(xhr.response);
        };
    }

    async getLeaderBoard() {
        try {
            const response = await fetch(`${this.url}/leaderboard/`);
            if (!response.ok) {
                throw new Error('Network response was not ok.');
            }
            user.leaderboard = await response.json();
        } catch (error) {
            console.error('Failed to fetch leaderboard:', error);
        }
    }
    

    async getTest() {
        try {
            const response = await fetch(`${this.url}/test/`);
            if (!response.ok) {
                throw new Error('Network response was not ok.');
            }

            const effectiveWidth = (windowWidth - 200) / 13;
            let textArr = await response.json();
            let finalText = [];
            let text = "";
            for (let i = 0; i < textArr.length; i++) {
                if (text.length + textArr[i].length < effectiveWidth) {
                    text += `${textArr[i]} `
                } else {
                    finalText.push(text.substring(0,text.length-1));
                    text = `${textArr[i]} `;
                }
            }
            user.nextTest = finalText;
        } catch (error) {
            console.error('Failed to fetch a test:', error);
        }
    }
}