/**
 * AniWorld - Delete Anime Modal Module
 *
 * Handles the delete confirmation modal for anime series.
 * Users must type "delete" to enable the confirm button.
 *
 * Dependencies: constants.js, api-client.js, ui-utils.js
 */

var AniWorld = window.AniWorld || {};

AniWorld.DeleteModal = (function() {
    'use strict';

    const API = '/api/anime';

    let currentKey = null;
    let currentSeriesName = null;
    let modalElement = null;
    let confirmBtn = null;
    let confirmInput = null;
    let deleteDbCheckbox = null;
    let deleteFolderCheckbox = null;
    let errorElement = null;
    let isSubmitting = false;

    /**
     * Initialize the modal — inject HTML into body if not already present.
     */
    function init() {
        injectModalHTML();
        cacheElements();
        bindEvents();
        console.info('[DeleteModal] initialized');
    }

    /**
     * Build the modal HTML once and append to document.body.
     */
    function injectModalHTML() {
        if (document.getElementById('delete-modal')) return;
        var div = document.createElement('div');
        div.id = 'delete-modal';
        div.className = 'modal hidden';
        div.innerHTML =
            '<div class="modal-overlay"></div>' +
            '<div class="modal-content">' +
                '<div class="modal-header">' +
                    '<h3>Delete Anime</h3>' +
                '</div>' +
                '<div class="modal-body">' +
                    '<div class="delete-modal-series-info">' +
                        '<p class="delete-modal-series-name" id="delete-modal-series-name"></p>' +
                        '<p class="delete-modal-series-key" id="delete-modal-series-key"></p>' +
                    '</div>' +
                    '<div class="delete-modal-options">' +
                        '<label>' +
                            '<input type="checkbox" id="delete-db-checkbox" checked> ' +
                            'Remove from database (recommended)' +
                        '</label>' +
                        '<label>' +
                            '<input type="checkbox" id="delete-folder-checkbox"> ' +
                            'Delete folder from filesystem' +
                        '</label>' +
                        '<p class="delete-modal-warning" id="delete-folder-warning" style="display:none;">' +
                            '<i class="fas fa-exclamation-triangle"></i> ' +
                            'This will permanently delete the folder and ALL files inside it!' +
                        '</p>' +
                    '</div>' +
                    '<label class="delete-modal-confirm-label" for="delete-confirm-input">' +
                        'Type <strong>delete</strong> to confirm:' +
                    '</label>' +
                    '<input type="text" id="delete-confirm-input" ' +
                        'placeholder="delete" autocomplete="off" spellcheck="false">' +
                    '<div id="delete-error" class="hidden"></div>' +
                '</div>' +
                '<div class="modal-footer delete-modal-actions">' +
                    '<button class="btn" id="delete-cancel-btn">Cancel</button>' +
                    '<button class="btn btn-danger" id="delete-confirm-btn" disabled>Delete</button>' +
                '</div>' +
            '</div>';
        document.body.appendChild(div);
    }

    /**
     * Cache DOM element references.
     */
    function cacheElements() {
        modalElement = document.getElementById('delete-modal');
        confirmBtn = document.getElementById('delete-confirm-btn');
        confirmInput = document.getElementById('delete-confirm-input');
        deleteDbCheckbox = document.getElementById('delete-db-checkbox');
        deleteFolderCheckbox = document.getElementById('delete-folder-checkbox');
        errorElement = document.getElementById('delete-error');
    }

    /**
     * Bind event listeners on the modal.
     */
    function bindEvents() {
        // Guard against missing modal
        if (!modalElement) return;

        // Cancel button
        var cancelBtn = document.getElementById('delete-cancel-btn');
        if (cancelBtn) cancelBtn.addEventListener('click', hide);

        // Close on backdrop click
        var overlay = modalElement.querySelector('.modal-overlay');
        if (overlay) overlay.addEventListener('click', hide);

        // Escape key to close
        document.addEventListener('keydown', function(e) {
            if (e.key === 'Escape' && !isSubmitting && modalElement && !modalElement.classList.contains('hidden')) {
                hide();
            }
        });

        // Folder checkbox toggle — show/hide warning
        if (deleteFolderCheckbox) {
            deleteFolderCheckbox.addEventListener('change', function() {
                var warning = document.getElementById('delete-folder-warning');
                if (warning) {
                    warning.style.display = deleteFolderCheckbox.checked ? 'flex' : 'none';
                }
            });
        }

        // Confirm input — validate and update button state
        if (confirmInput) {
            confirmInput.addEventListener('input', function() {
                var value = confirmInput.value;
                var isMatch = value === 'delete';
                if (confirmBtn) confirmBtn.disabled = !isMatch || isSubmitting;
                confirmInput.classList.toggle('matched', isMatch);
            });
        }

        // Confirm button
        if (confirmBtn) confirmBtn.addEventListener('click', handleConfirm);

        // Click outside modal content to close
        modalElement.addEventListener('click', function(e) {
            if (e.target === modalElement) {
                hide();
            }
        });
    }

    /**
     * Show the delete modal for a given series.
     * @param {string} key - Series key
     */
    function show(key) {
        console.info('[DeleteModal] Opening for key:', key);

        // Ensure elements are cached (in case DOM was replaced)
        cacheElements();

        // Guard against missing elements
        if (!modalElement || !confirmInput || !confirmBtn) {
            console.error('[DeleteModal] Modal elements not found in DOM. Re-injecting.');
            injectModalHTML();
            cacheElements();
            if (!modalElement) {
                console.error('[DeleteModal] Failed to create modal element.');
                return;
            }
        }

        // Get series info from SeriesManager if available
        var seriesData = null;
        if (AniWorld.SeriesManager && AniWorld.SeriesManager.findByKey) {
            seriesData = AniWorld.SeriesManager.findByKey(key);
        }

        currentKey = key;
        currentSeriesName = seriesData ? (seriesData.name || key) : key;

        // Populate modal — guard against missing elements
        var seriesNameEl = document.getElementById('delete-modal-series-name');
        var seriesKeyEl = document.getElementById('delete-modal-series-key');
        var folderWarningEl = document.getElementById('delete-folder-warning');
        if (seriesNameEl) seriesNameEl.textContent = currentSeriesName;
        if (seriesKeyEl) seriesKeyEl.textContent = 'Key: ' + key;

        // Reset state
        confirmInput.value = '';
        confirmInput.classList.remove('matched');
        confirmBtn.disabled = true;
        isSubmitting = false;
        if (errorElement) {
            errorElement.classList.add('hidden');
            errorElement.textContent = '';
        }
        if (deleteDbCheckbox) deleteDbCheckbox.checked = true;
        if (deleteFolderCheckbox) deleteFolderCheckbox.checked = false;
        if (folderWarningEl) folderWarningEl.style.display = 'none';

        // Show modal
        modalElement.classList.remove('hidden');
        confirmInput.focus();
    }

    /**
     * Hide the modal and reset state.
     */
    function hide() {
        if (isSubmitting) return; // Don't close while submitting
        modalElement.classList.add('hidden');
        currentKey = null;
        currentSeriesName = null;
    }

    /**
     * Handle confirm button click.
     */
    async function handleConfirm() {
        if (confirmBtn.disabled || isSubmitting) return;

        var deleteDb = deleteDbCheckbox.checked;
        var deleteFolder = deleteFolderCheckbox.checked;
        var confirmText = confirmInput.value.trim();

        // Validate confirm text
        if (confirmText !== 'delete') {
            showError('You must type exactly "delete" to confirm.');
            return;
        }

        // Validate at least one option selected
        if (!deleteDb && !deleteFolder) {
            showError('Please select at least one delete option.');
            return;
        }

        isSubmitting = true;
        confirmBtn.disabled = true;
        confirmBtn.textContent = 'Deleting...';
        errorElement.classList.add('hidden');

        console.info('[DeleteModal] Initiating delete:', {
            key: currentKey,
            delete_database: deleteDb,
            delete_folder: deleteFolder
        });

        try {
            var response = await AniWorld.ApiClient.request(
                API + '/' + encodeURIComponent(currentKey),
                {
                    method: 'DELETE',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({
                        delete_database: deleteDb,
                        delete_folder: deleteFolder,
                        confirm_text: confirmText
                    })
                }
            );

            if (!response) {
                // Auth failure already redirected
                hide();
                return;
            }

            if (response.status === 401) {
                AniWorld.Auth.removeToken();
                window.location.href = '/login';
                hide();
                return;
            }

            if (response.status === 400) {
                var body = await response.json().catch(function() { return {}; });
                showError(body.detail || 'Invalid request: ' + response.status);
                isSubmitting = false;
                confirmBtn.textContent = 'Delete';
                confirmBtn.disabled = false;
                return;
            }

            if (response.status === 404) {
                showError('Series not found: ' + currentKey);
                isSubmitting = false;
                confirmBtn.textContent = 'Delete';
                return;
            }

            if (!response.ok) {
                var text = await response.text();
                showError('Delete failed: HTTP ' + response.status + ' ' + text);
                isSubmitting = false;
                confirmBtn.textContent = 'Delete';
                confirmBtn.disabled = false;
                return;
            }

            var result = await response.json();
            console.info('[DeleteModal] Delete succeeded:', result);

            // Capture key before hide() nulls currentKey
            var deletedKey = currentKey;

            // Show success message based on what was deleted
            var msgParts = [];
            if (result.deleted_from_database) msgParts.push('removed from database');
            if (result.deleted_folder) msgParts.push('folder deleted from filesystem');
            if (result.database_error) msgParts.push('DB error: ' + result.database_error);
            if (result.folder_error) msgParts.push('Folder error: ' + result.folder_error);
            var successMsg = msgParts.length > 0
                ? msgParts.join('; ')
                : 'Delete completed.';

            AniWorld.UI.showToast(successMsg, result.success ? 'success' : 'warning');

            // Close modal and reset submission state together — isSubmitting must
            // be cleared before hide(), otherwise hide() bails out (early return
            // on the !isSubmitting guard) and the modal stays visible.
            isSubmitting = false;
            if (confirmBtn) confirmBtn.textContent = 'Delete';
            hide();

            // Remove the card from the grid directly
            if (AniWorld.SeriesManager && AniWorld.SeriesManager.removeSeries) {
                AniWorld.SeriesManager.removeSeries(deletedKey);
            }

        } catch (err) {
            console.error('[DeleteModal] Delete request failed:', err);
            showError('Network error: ' + (err && err.message ? err.message : String(err)));
            isSubmitting = false;
            confirmBtn.textContent = 'Delete';
            confirmBtn.disabled = false;
        }
    }

    /**
     * Show an error message in the modal.
     * @param {string} msg
     */
    function showError(msg) {
        errorElement.textContent = msg;
        errorElement.classList.remove('hidden');
    }

    // Public API
    return {
        init: init,
        show: show,
        hide: hide
    };
})();