// Form for editing one training: date, trainee, trainer, exercises and their approaches

import { alert, api, h, SOLO, userName } from './common.js';

const jsonRequest = (method, body) => ({
    method,
    headers: { 'Content-Type': 'application/json' },
    body: body === undefined ? undefined : JSON.stringify(body),
});

function field(label, input, className = '') {
    return h('div', { class: className }, h('label', { class: 'form-label small text-muted mb-1' }, label), input);
}

function approachRow(approach) {
    const row = h('div', { class: 'row g-2 align-items-end approach-row mb-2' },
        h('div', { class: 'col-5 col-md-3' },
            h('input', { type: 'number', class: 'form-control form-control-sm', name: 'weight', min: 0, step: 'any', required: true, value: approach.weight, 'aria-label': 'Вес, кг' })),
        h('div', { class: 'col-auto pb-1' }, '×'),
        h('div', { class: 'col-4 col-md-2' },
            h('input', { type: 'number', class: 'form-control form-control-sm', name: 'reps', min: 1, step: 1, required: true, value: approach.reps, 'aria-label': 'Повторения' })),
        h('div', { class: 'col-auto' },
            h('button', { type: 'button', class: 'btn btn-sm btn-outline-danger', title: 'Убрать подход' }, '×')));
    row.querySelector('button').addEventListener('click', () => row.remove());
    return row;
}

function exerciseCard(exercise) {
    const approaches = h('div', {}, ...exercise.approaches.map(approachRow));
    const addApproach = h('button', { type: 'button', class: 'btn btn-sm btn-outline-secondary' }, '+ подход');
    addApproach.addEventListener('click', () => {
        // a new approach starts as a copy of the last one: sets usually repeat
        const last = approaches.lastElementChild;
        approaches.append(approachRow({
            weight: last ? last.querySelector('[name=weight]').value : 0,
            reps: last ? last.querySelector('[name=reps]').value : 10,
        }));
    });

    const remove = h('button', { type: 'button', class: 'btn btn-sm btn-outline-danger', title: 'Убрать упражнение' }, 'Убрать упражнение');
    const card = h('div', { class: 'card exercise-card' },
        h('div', { class: 'card-body' },
            h('div', { class: 'row g-2 align-items-end mb-3' },
                field('Упражнение', h('input', { type: 'text', class: 'form-control', name: 'name', list: 'edit-exercise-names', maxlength: 255, required: true, value: exercise.name }), 'col-12 col-md-6'),
                h('div', { class: 'col-auto form-check ms-2 mb-2' },
                    h('input', { type: 'checkbox', class: 'form-check-input', name: 'splitted_weight', id: `per-arm-${Math.random().toString(36).slice(2)}`, checked: exercise.splitted_weight }),
                    h('label', { class: 'form-check-label' }, 'Вес на каждую руку')),
                h('div', { class: 'col-auto ms-md-auto' }, remove)),
            h('div', { class: 'small text-muted mb-1' }, 'Подходы: вес, кг (0 — без веса) × повторения'),
            approaches,
            addApproach));
    // the checkbox label must point to its checkbox
    const checkbox = card.querySelector('[name=splitted_weight]');
    card.querySelector('.form-check-label').setAttribute('for', checkbox.id);
    remove.addEventListener('click', () => card.remove());
    return card;
}

function readForm(form) {
    return {
        date: form.elements.date.value,
        trainee_id: Number(form.elements.trainee_id.value),
        trainer_id: form.elements.trainer_id.value ? Number(form.elements.trainer_id.value) : null,
        exercises: [...form.querySelectorAll('.exercise-card')].map((card) => ({
            name: card.querySelector('[name=name]').value,
            splitted_weight: card.querySelector('[name=splitted_weight]').checked,
            approaches: [...card.querySelectorAll('.approach-row')].map((row) => ({
                weight: Number(row.querySelector('[name=weight]').value),
                reps: Number(row.querySelector('[name=reps]').value),
            })),
        })),
    };
}

function userSelect(name, users, selectedId, emptyTitle) {
    return h('select', { class: 'form-select', name, required: !emptyTitle },
        emptyTitle ? h('option', { value: '', selected: selectedId === null }, emptyTitle) : null,
        ...users.map((user) => h('option', { value: user.id, selected: user.id === selectedId }, userName(user))));
}

/**
 * trainees / trainers: users to choose from (trainees is null when the trainee can't be changed). onDone() is called after the training was saved
 * or deleted, onCancel() on "Отмена".
 */
export function editForm(training, exerciseNames, { trainees, trainers }, { onDone, onCancel }) {
    const exercisesBox = h('div', {}, ...training.exercises.map(exerciseCard));
    const addExercise = h('button', { type: 'button', class: 'btn btn-outline-secondary mb-3' }, '+ упражнение');
    addExercise.addEventListener('click', () => {
        const card = exerciseCard({ name: '', splitted_weight: false, approaches: [{ weight: 0, reps: 10 }] });
        exercisesBox.append(card);
        card.querySelector('[name=name]').focus();
    });

    const status = h('div', {});
    const save = h('button', { type: 'submit', class: 'btn btn-primary' }, 'Сохранить');
    const cancel = h('button', { type: 'button', class: 'btn btn-outline-secondary' }, 'Отмена');
    cancel.addEventListener('click', onCancel);
    const remove = h('button', { type: 'button', class: 'btn btn-outline-danger ms-auto' }, 'Удалить тренировку');

    const form = h('form', {},
        h('datalist', { id: 'edit-exercise-names' }, ...exerciseNames.map((item) => h('option', { value: item.name }))),
        h('div', { class: 'row g-3 mb-3' },
            field('Дата', h('input', { type: 'date', class: 'form-control', name: 'date', required: true, value: training.date }), 'col-12 col-md-3'),
            trainees
                ? field('Тренирующийся', userSelect('trainee_id', trainees, training.trainee_id), 'col-12 col-md-3')
                : h('input', { type: 'hidden', name: 'trainee_id', value: training.trainee_id }),
            field('Тренер', userSelect('trainer_id', trainers, training.trainer_id, `${SOLO} (без тренера)`), 'col-12 col-md-3')),
        exercisesBox,
        addExercise,
        h('div', { class: 'd-flex gap-2 align-items-center' },
            save,
            cancel,
            remove),
        status);

    form.addEventListener('submit', async (event) => {
        event.preventDefault();
        save.disabled = true;
        try {
            await api(`/trainings/${training.id}/`, jsonRequest('PUT', readForm(form)));
            onDone();
        } catch (error) {
            status.replaceChildren(alert('danger', `Не удалось сохранить: ${error.message}`));
            save.disabled = false;
        }
    });

    remove.addEventListener('click', async () => {
        if (!confirm('Удалить тренировку вместе с упражнениями и подходами?')) {
            return;
        }
        try {
            await api(`/trainings/${training.id}/`, jsonRequest('DELETE'));
            onDone();
        } catch (error) {
            status.replaceChildren(alert('danger', `Не удалось удалить: ${error.message}`));
        }
    });

    return form;
}