/**
 * GoingsOn - Saved Views Module
 *
 * Save, apply, pin, and delete named presets of the task-list filters. Wired to the
 * "Save View" menu item (Cmd/Ctrl+S). Tasks view only (Run #27 UX remediation: the
 * backend commands shipped with no frontend). The DOM task filters map onto the
 * backend `ViewFilters`; the milestone filter is not part of a saved view.
 */
(function() {
    'use strict';
    const esc = GoingsOn.utils.escapeHtml;
    const escAttr = GoingsOn.utils.escapeAttrValue;
    const escArg = GoingsOn.utils.escapeHandlerArg;

    // DOM single-value filter controls <-> backend ViewFilters (Vec-valued) enums.
    const STATUS_TO_ENUM = { pending: 'Pending', started: 'Started', completed: 'Completed' };
    const ENUM_TO_STATUS = { Pending: 'pending', Started: 'started', Completed: 'completed' };
    const PRIORITY_TO_ENUM = { H: 'High', M: 'Medium', L: 'Low' };
    const ENUM_TO_PRIORITY = { High: 'H', Medium: 'M', Low: 'L' };

    // Last-listed views, so the inline onclick handlers can resolve by id.
    let viewCache = [];

    /** Map the current task filter DOM controls to a backend ViewFilters object. */
    function currentFiltersToViewFilters() {
        const f = GoingsOn.tasks.getFilters();
        const vf = {};
        if (f.status && STATUS_TO_ENUM[f.status]) vf.status = [STATUS_TO_ENUM[f.status]];
        if (f.projectId) vf.projectId = f.projectId;
        if (f.priority && PRIORITY_TO_ENUM[f.priority]) vf.priority = [PRIORITY_TO_ENUM[f.priority]];
        if (f.showSnoozed) vf.isSnoozed = true;
        if (f.waitingOnly) vf.isWaiting = true;
        return vf;
    }

    /** Apply a saved view's filters back onto the task filter DOM, then reload. */
    function applyView(view) {
        if (!view) return;
        const vf = view.filters || {};
        const setVal = (id, val) => { const el = document.getElementById(id); if (el) el.value = val; };
        const setChk = (id, val) => { const el = document.getElementById(id); if (el) el.checked = !!val; };
        const status = Array.isArray(vf.status) && vf.status.length ? (ENUM_TO_STATUS[vf.status[0]] || '') : '';
        const priority = Array.isArray(vf.priority) && vf.priority.length ? (ENUM_TO_PRIORITY[vf.priority[0]] || '') : '';
        setVal('filter-status', status);
        setVal('filter-project', vf.projectId || '');
        setVal('filter-priority', priority);
        setVal('filter-milestone', '');
        setChk('filter-snoozed', vf.isSnoozed);
        setChk('filter-waiting', vf.isWaiting);
        GoingsOn.ui.closeModal();
        GoingsOn.tasks.applyFilters();
        GoingsOn.ui.showToast(`Applied view "${view.name}"`, 'success');
    }

    /** Build the modal markup: a save row, then the list of existing views. */
    function buildModalHtml() {
        let html = `
            <div class="saved-views-modal">
                <div class="saved-views-save">
                    <input type="text" id="saved-view-name" class="form-input" placeholder="Name these filters" maxlength="100">
                    <label class="form-checkbox-label"><input type="checkbox" id="saved-view-pin"> <span>Pin</span></label>
                    <button type="button" class="btn btn-primary" data-act="savedViews._save">Save current filters</button>
                </div>`;
        if (viewCache.length) {
            html += `<div class="saved-views-list">`;
            for (const v of viewCache) {
                const pinLabel = v.isPinned ? 'Unpin' : 'Pin';
                html += `
                    <div class="saved-views-row">
                        <button type="button" class="btn btn-sm saved-views-apply" data-act="savedViews._apply" data-a1="${escAttr(v.id)}">${esc(v.name)}${v.isPinned ? ' •' : ''}</button>
                        <button type="button" class="btn btn-sm" data-act="savedViews._togglePin" data-a1="${escAttr(v.id)}">${pinLabel}</button>
                        <button type="button" class="btn btn-sm btn-danger" data-act="savedViews._delete" data-a1="${escAttr(v.id)}">Delete</button>
                    </div>`;
            }
            html += `</div>`;
        } else {
            html += `<p class="saved-views-empty">No saved views yet. Set your task filters, then save them here.</p>`;
        }
        html += `</div>`;
        return html;
    }

    /** Refresh the view list and (re)render the modal. openModal just resets
     *  #modal-content, so re-calling it is a safe in-place re-render. */
    async function refresh() {
        try {
            viewCache = await GoingsOn.api.tasks.savedViews.list();
        } catch (err) {
            viewCache = [];
        }
        GoingsOn.ui.openModal('Saved Views', buildModalHtml());
    }

    /** Entry point: the "Save View" menu item / Cmd+S. Tasks view only. */
    async function openSaveModal() {
        const view = GoingsOn.getCurrentView ? GoingsOn.getCurrentView() : 'tasks';
        if (view !== 'tasks') {
            GoingsOn.ui.showToast('Saved views are available on the Tasks view', 'info');
            return;
        }
        await refresh();
    }

    async function _save() {
        const nameEl = document.getElementById('saved-view-name');
        const name = (nameEl?.value || '').trim();
        if (!name) {
            GoingsOn.ui.showToast('Enter a name for the view', 'warning');
            return;
        }
        const isPinned = document.getElementById('saved-view-pin')?.checked || false;
        const input = {
            name,
            viewType: 'tasks',
            filters: currentFiltersToViewFilters(),
            sortBy: null,
            sortOrder: null,
            isPinned,
        };
        try {
            await GoingsOn.api.tasks.savedViews.create(input);
            GoingsOn.ui.showToast(`Saved view "${name}"`, 'success');
            await refresh();
        } catch (err) {
            GoingsOn.ui.showToast(GoingsOn.utils.getErrorMessage(err, 'Failed to save view'), 'error');
        }
    }

    function _apply(id) {
        applyView(viewCache.find(v => v.id === id));
    }

    async function _togglePin(id) {
        try {
            await GoingsOn.api.tasks.savedViews.togglePinned(id);
            await refresh();
        } catch (err) {
            GoingsOn.ui.showToast(GoingsOn.utils.getErrorMessage(err, 'Failed to update view'), 'error');
        }
    }

    async function _delete(id) {
        const view = viewCache.find(v => v.id === id);
        const confirmed = await GoingsOn.ui.confirmDelete(
            'Delete Saved View',
            `Delete "${view ? view.name : 'this view'}"? This cannot be undone.`
        );
        if (!confirmed) return;
        try {
            await GoingsOn.api.tasks.savedViews.delete(id);
            await refresh();
        } catch (err) {
            GoingsOn.ui.showToast(GoingsOn.utils.getErrorMessage(err, 'Failed to delete view'), 'error');
        }
    }

    GoingsOn.savedViews = {
        openSaveModal,
        _save,
        _apply,
        _togglePin,
        _delete,
    };

})();