/*
 * Copyright (C) 2024-2025  Yomitan Authors
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

import {fetchJson} from '../../core/fetch-utilities.js';
import {log} from '../../core/log.js';
import {querySelectorNotNull} from '../../dom/query-selector.js';

export class RecommendedSettingsController {
    /**
     * @param {import('./settings-controller.js').SettingsController} settingsController
     */
    constructor(settingsController) {
        /** @type {import('./settings-controller.js').SettingsController} */
        this._settingsController = settingsController;
        /** @type {HTMLElement} */
        this._recommendedSettingsModal = querySelectorNotNull(document, '#recommended-settings-modal');
        /** @type {HTMLInputElement} */
        this._languageSelect = querySelectorNotNull(document, '#language-select');
        /** @type {HTMLInputElement} */
        this._applyButton = querySelectorNotNull(document, '#recommended-settings-apply-button');
        /** @type {Map<string, import('settings-controller').RecommendedSetting>} */
        this._recommendedSettings = new Map();
    }

    /** */
    async prepare() {
        this._languageSelect.addEventListener('change', this._onLanguageSelectChanged.bind(this), false);
        this._applyButton.addEventListener('click', this._onApplyButtonClicked.bind(this), false);
    }

    /**
     * @param {Event} _e
     */
    async _onLanguageSelectChanged(_e) {
        const setLanguage = this._languageSelect.value;
        if (typeof setLanguage !== 'string') { return; }

        const recommendedSettings = await this._getRecommendedSettings(setLanguage);
        if (typeof recommendedSettings !== 'undefined') {
            const settingsList = querySelectorNotNull(document, '#recommended-settings-list');
            settingsList.innerHTML = '';
            this._recommendedSettings = new Map();

            for (const [index, setting] of recommendedSettings.entries()) {
                this._recommendedSettings.set(index.toString(), setting);

                const {description} = setting;
                const template = this._settingsController.instantiateTemplate('recommended-settings-list-item');

                // Render label
                this._renderLabel(template, setting);

                // Render description
                const descriptionElement = querySelectorNotNull(template, '.settings-item-description');
                if (description !== 'undefined') {
                    descriptionElement.textContent = description;
                }

                // Render checkbox
                const checkbox = /** @type {HTMLInputElement} */ (querySelectorNotNull(template, 'input[type="checkbox"]'));
                checkbox.value = index.toString();

                settingsList.append(template);
            }
            this._recommendedSettingsModal.hidden = false;
        }
    }

    /**
     *
     * @param {string} language
     * @returns {Promise<import('settings-controller').RecommendedSetting[]>}
     */
    async _getRecommendedSettings(language) {
        if (typeof this._recommendedSettingsByLanguage === 'undefined') {
            /** @type {import('settings-controller').RecommendedSettingsByLanguage} */
            this._recommendedSettingsByLanguage = await fetchJson('/data/recommended-settings.json');
        }

        return this._recommendedSettingsByLanguage[language];
    }

    /**
     * @param {MouseEvent} e
     */
    _onApplyButtonClicked(e) {
        e.preventDefault();
        /** @type {NodeListOf<HTMLInputElement>} */
        const enabledCheckboxes = querySelectorNotNull(document, '#recommended-settings-list').querySelectorAll('input[type="checkbox"]:checked');
        if (enabledCheckboxes.length > 0) {
            const modifications = [];
            for (const checkbox of enabledCheckboxes) {
                const index = checkbox.value;
                const setting = this._recommendedSettings.get(index);
                if (typeof setting === 'undefined') { continue; }
                modifications.push(setting.modification);
            }
            void this._settingsController.modifyProfileSettings(modifications).then(
                (results) => {
                    for (const result of results) {
                        if (Object.hasOwn(result, 'error')) {
                            log.error(new Error(`Failed to apply recommended setting: ${JSON.stringify(result)}`));
                        }
                    }
                },
            );
            void this._settingsController.refresh();
        }
        this._recommendedSettingsModal.hidden = true;
    }

    /**
     * @param {Element} template
     * @param {import('settings-controller').RecommendedSetting} setting
     */
    _renderLabel(template, setting) {
        const label = querySelectorNotNull(template, '.settings-item-label');

        const {modification} = setting;
        switch (modification.action) {
            case 'set': {
                const {path, value} = modification;
                const pathCodeElement = document.createElement('code');
                pathCodeElement.textContent = path;
                const valueCodeElement = document.createElement('code');
                valueCodeElement.textContent = JSON.stringify(value, null, 2);

                label.appendChild(document.createTextNode('Setting '));
                label.appendChild(pathCodeElement);
                label.appendChild(document.createTextNode(' = '));
                label.appendChild(valueCodeElement);
                break;
            }
            case 'delete': {
                const {path} = modification;
                const pathCodeElement = document.createElement('code');
                pathCodeElement.textContent = path;

                label.appendChild(document.createTextNode('Deleting '));
                label.appendChild(pathCodeElement);
                break;
            }
            case 'swap': {
                const {path1, path2} = modification;
                const path1CodeElement = document.createElement('code');
                path1CodeElement.textContent = path1;
                const path2CodeElement = document.createElement('code');
                path2CodeElement.textContent = path2;

                label.appendChild(document.createTextNode('Swapping '));
                label.appendChild(path1CodeElement);
                label.appendChild(document.createTextNode(' and '));
                label.appendChild(path2CodeElement);
                break;
            }
            case 'splice': {
                const {path, start, deleteCount, items} = modification;
                const pathCodeElement = document.createElement('code');
                pathCodeElement.textContent = path;

                label.appendChild(document.createTextNode('Splicing '));
                label.appendChild(pathCodeElement);
                label.appendChild(document.createTextNode(` at ${start} deleting ${deleteCount} items and inserting ${items.length} items`));
                break;
            }
            case 'push': {
                const {path, items} = modification;
                const pathCodeElement = document.createElement('code');
                pathCodeElement.textContent = path;

                label.appendChild(document.createTextNode(`Pushing ${items.length} items to `));
                label.appendChild(pathCodeElement);
                break;
            }
            default: {
                log.error(new Error(`Unknown modification: ${modification}`));
            }
        }
    }
}