/**
 * builder.js — Rosary Builder interactive logic
 * Depends on: window.PRAYERS_DATA (from PHP), window.EXISTING_STEPS (edit mode)
 */
(function () {
    'use strict';

    /* ─────────────────────────────────────────────────────────
       State
    ───────────────────────────────────────────────────────── */
    let STEPS   = [];      // [{prayer_id, attribution, _prayer: {...}}]
    let PRAYERS = [];      // full list from PHP
    let activeTab    = 'all';
    let searchQuery  = '';
    let editingPrayerId = null;  // null = create, int = edit

    /* ─────────────────────────────────────────────────────────
       Boot
    ───────────────────────────────────────────────────────── */
    function init() {
        PRAYERS = window.PRAYERS_DATA || [];

        // Populate existing steps when editing a session
        if (window.EXISTING_STEPS && window.EXISTING_STEPS.length) {
            window.EXISTING_STEPS.forEach(function (s) {
                const prayer = PRAYERS.find(p => String(p.id) === String(s.prayer_id));
                if (prayer) STEPS.push({ prayer_id: s.prayer_id, attribution: s.attribution, _prayer: prayer });
            });
        }

        renderLibrary();
        renderSequence();
        bindEvents();
    }

    // Scripts are at end of body — DOM is fully parsed by the time this runs,
    // so DOMContentLoaded may have already fired. Check readyState first.
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', init);
    } else {
        init();
    }

    /* ─────────────────────────────────────────────────────────
       Event bindings
    ───────────────────────────────────────────────────────── */
    function bindEvents() {
        // Search
        document.getElementById('prayer-search').addEventListener('input', function () {
            searchQuery = this.value.trim().toLowerCase();
            renderLibrary();
        });

        // Tabs
        document.querySelectorAll('.tab-btn').forEach(function (btn) {
            btn.addEventListener('click', function () {
                document.querySelectorAll('.tab-btn').forEach(b => b.classList.remove('active'));
                this.classList.add('active');
                activeTab = this.dataset.tab;
                renderLibrary();
            });
        });

        // Create prayer button
        document.getElementById('btn-create-prayer').addEventListener('click', function () {
            openModal(null);
        });

        // Modal cancel
        document.getElementById('modal-cancel').addEventListener('click', closeModal);
        document.getElementById('prayer-modal').addEventListener('click', function (e) {
            if (e.target === this) closeModal();
        });

        // Modal attribution radios
        document.querySelectorAll('input[name="modal-attr"]').forEach(function (radio) {
            radio.addEventListener('change', updateModalFields);
        });

        // Modal save
        document.getElementById('modal-save').addEventListener('click', saveModalPrayer);

        // Save session
        document.getElementById('btn-save').addEventListener('click', saveSession);
    }

    /* ─────────────────────────────────────────────────────────
       Library rendering
    ───────────────────────────────────────────────────────── */
    function filteredPrayers() {
        return PRAYERS.filter(function (p) {
            if (activeTab === 'standard' && p.source_tag !== 'standard') return false;
            if (activeTab === 'mine'     && p.source_tag !== 'mine')     return false;
            if (searchQuery) {
                const hay = (p.name + ' ' + (p.leader_text || '') + ' ' + (p.all_text || '')).toLowerCase();
                return hay.includes(searchQuery);
            }
            return true;
        });
    }

    function renderLibrary() {
        const list    = document.getElementById('prayer-list');
        const visible = filteredPrayers();

        if (!visible.length) {
            list.innerHTML = '<div class="library-empty">No prayers found. Try a different search or tab.</div>';
            return;
        }

        list.innerHTML = visible.map(function (p) {
            const preview = (p.leader_text || p.all_text || '').replace(/\n/g, ' ').substring(0, 100);
            const badgeClass = p.source_tag === 'standard' ? 'standard' : (p.source_tag === 'global' ? 'global' : 'mine');
            const badgeLabel = p.source_tag === 'standard' ? 'Standard' : (p.source_tag === 'global' ? 'Global' : 'Mine');
            const canEdit    = p.source_tag === 'mine' || window.IS_ADMIN;

            return `<div class="prayer-card">
                <div class="prayer-card-top">
                    <span class="prayer-card-name">${esc(p.name)}</span>
                    <span class="source-badge ${badgeClass}">${badgeLabel}</span>
                </div>
                <div class="prayer-card-preview">${esc(preview)}${preview.length >= 100 ? '…' : ''}</div>
                <div class="prayer-card-footer">
                    <button class="btn btn-sm btn-primary" onclick="builderAddPrayer(${p.id})">+ Add</button>
                    ${canEdit ? `<button class="btn btn-sm btn-ghost" onclick="builderEditPrayer(${p.id})">Edit</button>` : ''}
                </div>
            </div>`;
        }).join('');
    }

    /* ─────────────────────────────────────────────────────────
       Sequence rendering
    ───────────────────────────────────────────────────────── */
    function renderSequence() {
        const list  = document.getElementById('step-list');
        const badge = document.getElementById('step-count-badge');

        badge.textContent = STEPS.length + (STEPS.length === 1 ? ' prayer' : ' prayers');
        badge.className   = 'step-count-badge' + (STEPS.length ? ' has-steps' : '');

        if (!STEPS.length) {
            list.innerHTML = `<div class="step-empty">
                <div style="font-size:32px;opacity:.25;margin-bottom:8px">✝</div>
                Select a prayer from the library to begin building your sequence
            </div>`;
            return;
        }

        list.innerHTML = STEPS.map(function (step, i) {
            const p         = step._prayer;
            const leaderPrev = (p.leader_text || '').replace(/\n/g, ' ').substring(0, 60);
            const allPrev    = (p.all_text    || '').replace(/\n/g, ' ').substring(0, 60);

            return `<div class="step-card">
                <div class="step-num">${i + 1}</div>
                <div class="step-body">
                    <div class="step-name">${esc(p.name)}</div>
                    ${leaderPrev ? `<div class="step-preview leader">Leader: ${esc(leaderPrev)}${leaderPrev.length >= 60 ? '…' : ''}</div>` : ''}
                    ${allPrev    ? `<div class="step-preview response">All: ${esc(allPrev)}${allPrev.length >= 60 ? '…' : ''}</div>` : ''}
                    <select class="step-attribution-select" onchange="builderSetAttribution(${i}, this.value)">
                        <option value="leader_all"  ${step.attribution==='leader_all'  ? 'selected':''}>Leader / All</option>
                        <option value="leader_only" ${step.attribution==='leader_only' ? 'selected':''}>Leader only</option>
                        <option value="all_only"    ${step.attribution==='all_only'    ? 'selected':''}>All together (unison)</option>
                        <option value="none"        ${step.attribution==='none'        ? 'selected':''}>No attribution</option>
                    </select>
                </div>
                <div class="step-actions">
                    <button class="btn-icon" title="Move up"    onclick="builderMove(${i}, -1)" ${i===0 ? 'disabled' : ''}>↑</button>
                    <button class="btn-icon" title="Move down"  onclick="builderMove(${i},  1)" ${i===STEPS.length-1 ? 'disabled' : ''}>↓</button>
                    <button class="btn-icon remove" title="Remove" onclick="builderRemove(${i})">✕</button>
                </div>
            </div>`;
        }).join('');
    }

    /* ─────────────────────────────────────────────────────────
       Step manipulation (exposed globally)
    ───────────────────────────────────────────────────────── */
    window.builderAddPrayer = function (prayerId) {
        const prayer = PRAYERS.find(p => String(p.id) === String(prayerId));
        if (!prayer) return;

        // Default attribution: leader_all if prayer has both parts, else leader_only / all_only / none
        let attr = 'leader_all';
        if (!prayer.leader_text && !prayer.all_text) attr = 'none';
        else if (!prayer.all_text) attr = 'leader_only';
        else if (!prayer.leader_text) attr = 'all_only';

        STEPS.push({ prayer_id: prayerId, attribution: attr, _prayer: prayer });
        renderSequence();
        // Briefly highlight the new step
        const list = document.getElementById('step-list');
        const cards = list.querySelectorAll('.step-card');
        const last  = cards[cards.length - 1];
        if (last) {
            last.style.outline = '2px solid var(--primary)';
            setTimeout(() => { last.style.outline = ''; }, 800);
            last.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
        }
    };

    window.builderRemove = function (index) {
        STEPS.splice(index, 1);
        renderSequence();
    };

    window.builderMove = function (index, dir) {
        const target = index + dir;
        if (target < 0 || target >= STEPS.length) return;
        [STEPS[index], STEPS[target]] = [STEPS[target], STEPS[index]];
        renderSequence();
    };

    window.builderSetAttribution = function (index, value) {
        if (STEPS[index]) STEPS[index].attribution = value;
    };

    window.builderEditPrayer = function (prayerId) {
        openModal(prayerId);
    };

    /* ─────────────────────────────────────────────────────────
       Modal — create / edit prayer
    ───────────────────────────────────────────────────────── */
    function openModal(prayerId) {
        editingPrayerId = prayerId;
        const modal = document.getElementById('prayer-modal');
        const title = document.getElementById('modal-title');

        // Reset form
        document.getElementById('modal-name').value    = '';
        document.getElementById('modal-leader').value  = '';
        document.getElementById('modal-all').value     = '';
        document.getElementById('modal-global').checked = false;
        document.querySelector('input[name="modal-attr"][value="leader_all"]').checked = true;

        if (prayerId) {
            const p = PRAYERS.find(pr => String(pr.id) === String(prayerId));
            if (!p) return;
            title.textContent = 'Edit Prayer';
            document.getElementById('modal-name').value   = p.name;
            document.getElementById('modal-leader').value = p.leader_text || '';
            document.getElementById('modal-all').value    = p.all_text    || '';
            document.getElementById('modal-global').checked = !!p.is_global;

            // Determine existing attribution for radio pre-selection
            const hasLeader = !!(p.leader_text || '').trim();
            const hasAll    = !!(p.all_text    || '').trim();
            const attrVal   = hasLeader && hasAll ? 'leader_all'
                            : hasLeader ? 'leader_only'
                            : hasAll    ? 'all_only' : 'none';
            const radio = document.querySelector(`input[name="modal-attr"][value="${attrVal}"]`);
            if (radio) radio.checked = true;
        } else {
            title.textContent = 'New Custom Prayer';
        }

        updateModalFields();
        updateAttrRadioStyles();
        modal.hidden = false;
        document.getElementById('modal-name').focus();
    }

    function closeModal() {
        document.getElementById('prayer-modal').hidden = true;
        editingPrayerId = null;
    }

    function updateModalFields() {
        const attr        = getSelectedAttr();
        const leaderGroup = document.getElementById('modal-leader-group');
        const allGroup    = document.getElementById('modal-all-group');

        leaderGroup.style.display = (attr === 'all_only') ? 'none' : '';
        allGroup.style.display    = (attr === 'leader_only' || attr === 'none') ? 'none' : '';

        updateAttrRadioStyles();
    }

    function updateAttrRadioStyles() {
        document.querySelectorAll('.attr-radio-label').forEach(function (label) {
            const radio = label.querySelector('input[type=radio]');
            label.classList.toggle('checked', radio && radio.checked);
        });
    }

    function getSelectedAttr() {
        const checked = document.querySelector('input[name="modal-attr"]:checked');
        return checked ? checked.value : 'leader_all';
    }

    function saveModalPrayer() {
        const name   = document.getElementById('modal-name').value.trim();
        const leader = document.getElementById('modal-leader').value.trim();
        const all    = document.getElementById('modal-all').value.trim();
        const global = document.getElementById('modal-global').checked ? 1 : 0;
        const attr   = getSelectedAttr();

        if (!name) {
            document.getElementById('modal-name').focus();
            showModalError('Prayer name is required.');
            return;
        }

        // Set text fields based on attribution mode
        const sendLeader = (attr !== 'all_only')               ? leader : '';
        const sendAll    = (attr !== 'leader_only' && attr !== 'none') ? all    : '';

        const method  = editingPrayerId ? 'PUT' : 'POST';
        const url     = BASE_URL + '/api/prayers_api.php' + (editingPrayerId ? '?id=' + editingPrayerId : '');
        const saveBtn = document.getElementById('modal-save');

        saveBtn.disabled = true;
        saveBtn.textContent = 'Saving…';

        fetch(url, {
            method: method,
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ name, leader_text: sendLeader, all_text: sendAll, is_global: global }),
        })
        .then(r => r.json())
        .then(function (data) {
            if (data.error) { showModalError(data.error); return; }
            const prayer = data.prayer;

            if (editingPrayerId) {
                // Update in local list
                const idx = PRAYERS.findIndex(p => String(p.id) === String(prayer.id));
                if (idx >= 0) PRAYERS[idx] = prayer;
                // Also update any steps referencing this prayer
                STEPS.forEach(function (step) {
                    if (String(step.prayer_id) === String(prayer.id)) step._prayer = prayer;
                });
                renderSequence();
            } else {
                PRAYERS.unshift(prayer);
            }
            renderLibrary();
            closeModal();
        })
        .catch(function () { showModalError('Network error. Please try again.'); })
        .finally(function () {
            saveBtn.disabled = false;
            saveBtn.textContent = 'Save Prayer';
        });
    }

    function showModalError(msg) {
        let el = document.getElementById('modal-error');
        if (!el) {
            el = document.createElement('div');
            el.id = 'modal-error';
            el.className = 'alert alert-error';
            el.style.marginBottom = '12px';
            document.querySelector('.modal-box').prepend(el);
        }
        el.textContent = msg;
        el.style.display = '';
        setTimeout(() => { el.style.display = 'none'; }, 5000);
    }

    /* ─────────────────────────────────────────────────────────
       Save session
    ───────────────────────────────────────────────────────── */
    function saveSession() {
        const name = document.getElementById('session-name').value.trim();
        if (!name) {
            document.getElementById('session-name').focus();
            showMsg('Please enter a session label.', 'error');
            return;
        }
        if (!STEPS.length) {
            showMsg('Add at least one prayer to your sequence before saving.', 'error');
            return;
        }

        const payload = {
            id:               window.EDIT_SESSION_ID || 0,
            name:             name,
            is_public:        document.getElementById('is-public').checked,
            subject_name:     document.getElementById('subject-name').value.trim(),
            subject_pronoun:  document.getElementById('subject-pronoun').value,
            subject_dates:    document.getElementById('subject-dates').value.trim(),
            steps:            STEPS.map(s => ({ prayer_id: s.prayer_id, attribution: s.attribution })),
        };

        const btn = document.getElementById('btn-save');
        btn.disabled = true;
        btn.textContent = 'Saving…';

        fetch(BASE_URL + '/api/builder_session.php', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify(payload),
        })
        .then(r => r.json())
        .then(function (data) {
            if (data.error) { showMsg(data.error, 'error'); return; }

            window.EDIT_SESSION_ID = data.session_id;

            // Update page title & edit button
            const presentLink = document.getElementById('present-link');
            if (presentLink) {
                presentLink.href    = data.present_url;
                presentLink.style.display = '';
            }
            document.title = name + ' — Rosary Builder';

            // Update URL without reload
            history.replaceState(null, '', BASE_URL + '/admin/builder.php?id=' + data.session_id);

            showMsg('Session saved! <a href="' + data.present_url + '" target="_blank">Open presentation &rarr;</a>', 'success');
        })
        .catch(function () { showMsg('Network error. Please try again.', 'error'); })
        .finally(function () {
            btn.disabled = false;
            btn.textContent = 'Save Session';
        });
    }

    function showMsg(html, type) {
        const wrap = document.getElementById('builder-msg');
        wrap.innerHTML = `<div class="alert alert-${type}">${html}</div>`;
        wrap.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
        if (type === 'success') setTimeout(() => { wrap.innerHTML = ''; }, 6000);
    }

    /* ─────────────────────────────────────────────────────────
       Utility
    ───────────────────────────────────────────────────────── */
    function esc(str) {
        if (!str) return '';
        return str.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;').replace(/"/g,'&quot;');
    }

})();