import {applyFormMessages} from "./forms";

document.addEventListener('DOMContentLoaded', () => {
    const form = document.querySelector<HTMLFormElement>('#upload-form');
    if (!form) return;
    const upload = document.getElementById('file-upload');
    const uploadLink = document.querySelector<HTMLLinkElement>('#file-upload-link');

    const uploadField = document.querySelector<HTMLInputElement>('#field-upload');

    const neverExpireCheckbox = document.querySelector<HTMLInputElement>('#field-never_expire');
    const expireAfterDaysField = document.querySelector<HTMLInputElement>('#field-expire_after_days');

    const autogenUrlCheckbox = document.querySelector<HTMLInputElement>('#field-autogen_url');
    const slugField = document.querySelector<HTMLInputElement>('#field-slug');

    if (expireAfterDaysField) {
        neverExpireCheckbox?.addEventListener('change', () => {
            expireAfterDaysField.disabled = neverExpireCheckbox.checked;
        });
    }

    if (slugField) {
        autogenUrlCheckbox?.addEventListener('change', () => {
            slugField.disabled = autogenUrlCheckbox.checked;
        });
    }

    let uploadForm: UploadForm | undefined;

    form.addEventListener('submit', e => {
        e.preventDefault();
        if (upload && uploadLink && uploadField && uploadField.files && (!uploadForm || uploadForm.isFinished())) {
            uploadForm = new UploadForm(form, upload, uploadLink, uploadField.files[0].name);
            uploadForm.updateView();
            uploadForm.start();
        }
    });
});


const units = ['K', 'M', 'G', 'T'];

class UploadForm {
    private finished: boolean = false;
    private readonly progressBar: HTMLElement | null;
    private readonly progressBarContent: HTMLElement | null;
    private readonly status: HTMLElement | null;
    private speed: HTMLElement | null;
    private xferSpeed: number[] = [];
    private lastTransferTime: number | null = null;
    private lastLoaded: number = 0;

    private xhr: XMLHttpRequest;

    public constructor(
        private form: HTMLFormElement,
        private upload: HTMLElement,
        private uploadLink: HTMLLinkElement,
        private fileName: string,
    ) {
        this.progressBar = this.upload.querySelector('.progress-bar');
        this.progressBarContent = this.progressBar?.querySelector('.content') || null;
        this.status = this.upload.querySelector('.status');
        this.speed = this.status?.querySelector('.speed') || null;

        if (!this.progressBar)
            throw new Error('Invalid html');

        this.xhr = new XMLHttpRequest();
        this.xhr.responseType = 'json';
        this.xhr.upload.addEventListener('progress', e => {
            if (this.progressBar && this.progressBarContent) {
                if (e.lengthComputable) {
                    this.progressBar.classList.remove('undefined');
                    const percent = (e.loaded / e.total * 100).toFixed(2) + '%';
                    this.progressBar.style.setProperty('--progress', `${percent}`);
                    this.progressBarContent.innerText = percent;
                    this.updateSpeed(e.loaded);
                } else {
                    this.progressBar.classList.add('undefined');
                }
            }
        });
        this.xhr.upload.addEventListener('loadstart', () => {
            this.status?.classList.remove('hidden');
        });
        this.xhr.addEventListener('load', () => {
            this.finished = true;
            const response = this.xhr.response;
            console.log('done', response);
            if (response.status === 'error') {
                if (response.messages) {
                    this.restoreView();
                    applyFormMessages(this.form, response.messages);
                }
            } else if (response.url) {
                if (this.status) {
                    this.status.innerHTML = 'Done!';
                }
                const uploadLinkContent = this.uploadLink.querySelector<HTMLElement>('.content');
                if (uploadLinkContent) {
                    uploadLinkContent.innerText = response.url;
                }
                this.uploadLink.classList.remove('hidden');
            } else {
                window.location.reload();
            }
        });
        this.xhr.addEventListener('error', (e) => {
            this.finished = true;
            console.error('error', e);
            if (this.status) {
                this.status.innerHTML = 'Error; upload was interrupted.';
            }
        });
    }

    public isFinished(): boolean {
        return this.finished;
    }

    public updateView(): void {
        const uploadName = this.upload.querySelector<HTMLElement>('.name');
        if (uploadName) {
            uploadName.innerText = this.fileName;
        }
        this.form.classList.add('hidden');
        this.upload.classList.remove('hidden');
        if (this.status) {
            this.status.innerHTML = `Uploading @ <span class="speed">--</span>`;
            this.speed = this.status.querySelector('.speed');
        }
    }

    public restoreView(): void {
        if (this.status) {
            this.status.classList.add('hidden');
        }
        this.upload.classList.add('hidden');
        this.form.classList.remove('hidden');
    }

    public start(): void {
        const formData = new FormData(this.form);
        this.xhr.open('POST', this.form.action);
        this.xhr.send(formData);
    }

    public updateSpeed(loaded: number): void {
        const time = new Date().getTime();
        if (this.lastTransferTime) {
            this.xferSpeed.push((loaded - this.lastLoaded) / (time - this.lastTransferTime));

            if (this.xferSpeed.length > 100) this.xferSpeed = this.xferSpeed.slice(1);

            let speed = this.xferSpeed.reduce((v, c) => v + c) / this.xferSpeed.length;
            let unit = 0;
            while (speed >= 1000 && unit < units.length - 1) {
                speed /= 1000;
                unit++;
            }

            if (this.speed) {
                this.speed.innerText = speed.toFixed(2) + units[unit] + 'Bps';
            }
        }
        this.lastTransferTime = time;
        this.lastLoaded = loaded;
    }
}