/* ============================================================
   STATE
   ============================================================ */
const state = {
    view:              'sources',
    source:            null,   // selected pf.source row
    version:           null,   // selected pf.version row
    selectedVersionId: null,   // in versions grid
    colMeta:           [],     // col_meta for selected source
    slice:             {},     // current pivot selection
    loadDataOp:        null,   // 'baseline' | 'reference'
    previewSchema:     null,
    previewTname:      null,
    grids: {
        tables:   null,
        sources:  null,
        colMeta:  null,
        versions: null,
        pivot:    null,
        log:      null
    }
};

/* ============================================================
   API
   ============================================================ */
async function api(method, path, body) {
    const opts = { method, headers: { 'Content-Type': 'application/json' } };
    if (body !== undefined) opts.body = JSON.stringify(body);
    const res  = await fetch('/api' + path, opts);
    const data = await res.json();
    if (!res.ok) throw new Error(data.error || `HTTP ${res.status}`);
    return data;
}

/* ============================================================
   STATUS BAR
   ============================================================ */
let statusTimer = null;
function showStatus(msg, type = 'info') {
    const bar = document.getElementById('status-bar');
    bar.textContent = msg;
    bar.className   = `status-${type}`;
    bar.classList.remove('hidden');
    clearTimeout(statusTimer);
    if (type !== 'error') statusTimer = setTimeout(() => bar.classList.add('hidden'), 4000);
}

/* ============================================================
   NAVIGATION
   ============================================================ */
function switchView(name) {
    if ((name === 'forecast' || name === 'log') && !state.version) {
        showStatus('Select a version first', 'error');
        return;
    }
    document.querySelectorAll('.view').forEach(el => {
        el.classList.add('hidden');
        el.classList.remove('active');
    });
    const target = document.getElementById(`view-${name}`);
    target.classList.remove('hidden');
    target.classList.add('active');
    document.querySelectorAll('.nav-links li').forEach(li =>
        li.classList.toggle('active', li.dataset.view === name)
    );
    state.view = name;
    if (name === 'versions') renderVersions();
    if (name === 'forecast') loadForecastData();
    if (name === 'log')      loadLogData();
}

function setSource(source) {
    state.source = source;
    const el = document.getElementById('ctx-source');
    if (source) {
        el.classList.remove('hidden');
        document.getElementById('ctx-source-name').textContent = `${source.schema}.${source.tname}`;
    } else {
        el.classList.add('hidden');
    }
}

function setVersion(version) {
    state.version = version;
    const el = document.getElementById('ctx-version');
    if (version) {
        el.classList.remove('hidden');
        document.getElementById('ctx-version-name').textContent = version.name;
        const badge = document.getElementById('ctx-version-status');
        badge.textContent = version.status;
        badge.className = `status-badge ${version.status}`;
    } else {
        el.classList.add('hidden');
    }
}

function getPfUser() {
    return document.getElementById('input-pf-user').value.trim() || 'unknown';
}

/* ============================================================
   SOURCES VIEW — table browser
   ============================================================ */
async function initSourcesView() {
    const tables = await api('GET', '/tables');
    renderTablesGrid(tables);
    const sources = await api('GET', '/sources');
    renderSourcesGrid(sources);
}

function renderTablesGrid(tables) {
    const el = document.getElementById('tables-grid');
    if (state.grids.tables) { state.grids.tables.setGridOption('rowData', tables); return; }

    state.grids.tables = agGrid.createGrid(el, {
        columnDefs: [
            { field: 'schema',       headerName: 'Schema', width: 90 },
            { field: 'tname',        headerName: 'Table',  flex: 1 },
            { field: 'row_estimate', headerName: 'Rows',   width: 80,
              valueFormatter: p => p.value != null ? Number(p.value).toLocaleString() : '—' }
        ],
        rowData:         tables,
        rowSelection:    'single',
        onRowClicked:    onTableRowClicked,
        onRowDoubleClicked: e => showTablePreview(e.data.schema, e.data.tname),
        defaultColDef:   { resizable: true, sortable: true },
        headerHeight:    32, rowHeight: 28
    });
}

function onTableRowClicked(e) {
    const { schema, tname } = e.data;
    state.previewSchema = schema;
    state.previewTname  = tname;
    document.getElementById('btn-register').classList.remove('hidden');
}

async function showTablePreview(schema, tname) {
    try {
        const data = await api('GET', `/tables/${schema}/${tname}/preview`);
        const title = document.getElementById('modal-title');
        const body  = document.getElementById('modal-body');
        title.textContent = `${schema}.${tname}`;

        // columns table
        let colHtml = `<div class="preview-section"><h4>Columns</h4><table class="preview-table">
            <tr><th>Column</th><th>Type</th><th>Nullable</th></tr>`;
        data.columns.forEach(c => {
            colHtml += `<tr><td>${c.column_name}</td><td>${c.data_type}</td><td>${c.is_nullable}</td></tr>`;
        });
        colHtml += '</table></div>';

        // sample rows
        let rowHtml = '';
        if (data.rows.length > 0) {
            const cols = Object.keys(data.rows[0]);
            rowHtml = `<div class="preview-section"><h4>Sample rows</h4><table class="preview-table"><tr>`;
            cols.forEach(c => rowHtml += `<th>${c}</th>`);
            rowHtml += '</tr>';
            data.rows.forEach(row => {
                rowHtml += '<tr>';
                cols.forEach(c => rowHtml += `<td>${row[c] ?? ''}</td>`);
                rowHtml += '</tr>';
            });
            rowHtml += '</table></div>';
        }

        body.innerHTML = colHtml + rowHtml;
        state.previewSchema = schema;
        state.previewTname  = tname;
        document.getElementById('modal-overlay').classList.remove('hidden');
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

async function registerTable(schema, tname) {
    try {
        await api('POST', '/sources', { schema, tname, created_by: getPfUser() });
        showStatus(`Registered ${schema}.${tname}`, 'success');
        const sources = await api('GET', '/sources');
        renderSourcesGrid(sources);
        document.getElementById('modal-overlay').classList.add('hidden');
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

/* ============================================================
   SOURCES VIEW — registered sources + col_meta
   ============================================================ */
function renderSourcesGrid(sources) {
    const el = document.getElementById('sources-list-grid');
    if (state.grids.sources) { state.grids.sources.setGridOption('rowData', sources); return; }

    state.grids.sources = agGrid.createGrid(el, {
        columnDefs: [
            { field: 'schema', headerName: 'Schema', width: 90 },
            { field: 'tname',  headerName: 'Table',  flex: 1 },
            { field: 'label',  headerName: 'Label',  flex: 1 },
            { field: 'status', headerName: 'Status', width: 70 }
        ],
        rowData:       sources,
        rowSelection:  'single',
        onRowClicked:  e => selectSource(e.data),
        defaultColDef: { resizable: true, sortable: true },
        headerHeight:  32, rowHeight: 28
    });
}

async function selectSource(source) {
    setSource(source);
    try {
        state.colMeta = await api('GET', `/sources/${source.id}/cols`);
        renderColMetaGrid(state.colMeta);
        document.getElementById('sources-list-grid').classList.add('hidden');
        document.getElementById('col-meta-grid').classList.remove('hidden');
        document.getElementById('right-panel-title').textContent = `${source.schema}.${source.tname} — Columns`;
        document.getElementById('btn-back-sources').classList.remove('hidden');
        document.getElementById('btn-save-cols').classList.remove('hidden');
        document.getElementById('btn-generate-sql').classList.remove('hidden');
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

function backToSources() {
    document.getElementById('sources-list-grid').classList.remove('hidden');
    document.getElementById('col-meta-grid').classList.add('hidden');
    document.getElementById('right-panel-title').textContent = 'Registered Sources';
    document.getElementById('btn-back-sources').classList.add('hidden');
    document.getElementById('btn-save-cols').classList.add('hidden');
    document.getElementById('btn-generate-sql').classList.add('hidden');
}

function renderColMetaGrid(colMeta) {
    const el = document.getElementById('col-meta-grid');
    if (state.grids.colMeta) { state.grids.colMeta.setGridOption('rowData', colMeta); return; }

    state.grids.colMeta = agGrid.createGrid(el, {
        columnDefs: [
            { field: 'opos',   headerName: '#',      width: 45, sortable: true },
            { field: 'cname',  headerName: 'Column', flex: 1 },
            {
                field: 'role', headerName: 'Role', width: 110, editable: true,
                cellEditor: 'agSelectCellEditor',
                cellEditorParams: { values: ['dimension', 'value', 'units', 'date', 'ignore'] },
                cellStyle: p => {
                    const colors = { dimension: '#eaf4fb', value: '#eafaf1', units: '#fef9e7', date: '#fdf2f8', ignore: '#f9f9f9' };
                    return { background: colors[p.value] || '' };
                }
            },
            {
                field: 'is_key', headerName: 'Key', width: 55, editable: true,
                cellRenderer: p => p.value ? '✓' : '',
                cellEditor: 'agCheckboxCellEditor'
            },
            { field: 'label', headerName: 'Label', flex: 1, editable: true,
              cellEditorParams: { useFormatter: true } }
        ],
        rowData:       colMeta,
        defaultColDef: { resizable: true },
        headerHeight:  32, rowHeight: 28,
        singleClickEdit: true,
        stopEditingWhenCellsLoseFocus: true
    });
}

async function saveColMeta() {
    if (!state.source) return;
    try {
        const rows = [];
        state.grids.colMeta.forEachNode(n => rows.push(n.data));
        state.colMeta = await api('PUT', `/sources/${state.source.id}/cols`, rows);
        state.grids.colMeta.setGridOption('rowData', state.colMeta);
        showStatus('Columns saved', 'success');
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

async function generateSQL() {
    if (!state.source) return;
    try {
        const result = await api('POST', `/sources/${state.source.id}/generate-sql`);
        showStatus(`SQL generated: ${result.operations.join(', ')}`, 'success');
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

/* ============================================================
   VERSIONS VIEW
   ============================================================ */
async function renderVersions() {
    if (!state.source) {
        document.getElementById('versions-source-label').textContent = 'No source selected — go to Sources first';
        return;
    }
    document.getElementById('versions-source-label').textContent = `${state.source.schema}.${state.source.tname}`;
    try {
        const versions = await api('GET', `/sources/${state.source.id}/versions`);
        renderVersionsGrid(versions);
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

function renderVersionsGrid(versions) {
    const el = document.getElementById('versions-grid');

    const colDefs = [
        { field: 'id',          headerName: 'ID',      width: 55 },
        { field: 'name',        headerName: 'Name',    flex: 1 },
        { field: 'description', headerName: 'Desc',    flex: 1 },
        { field: 'status',      headerName: 'Status',  width: 75,
          cellStyle: p => ({ color: p.value === 'open' ? '#27ae60' : '#e74c3c', fontWeight: 600 }) },
        { field: 'created_by',  headerName: 'Created by', width: 100 },
        { field: 'created_at',  headerName: 'Created',    width: 140,
          valueFormatter: p => p.value ? new Date(p.value).toLocaleString() : '' }
    ];

    if (state.grids.versions) {
        state.grids.versions.setGridOption('rowData', versions);
        state.grids.versions.setGridOption('columnDefs', colDefs);
        return;
    }

    state.grids.versions = agGrid.createGrid(el, {
        columnDefs: colDefs,
        rowData:       versions,
        rowSelection:  'single',
        onRowClicked:  onVersionRowClicked,
        defaultColDef: { resizable: true, sortable: true },
        headerHeight:  32, rowHeight: 28
    });
}

function onVersionRowClicked(e) {
    const v = e.data;
    state.selectedVersionId = v.id;
    const panel = document.getElementById('version-actions');
    panel.classList.remove('hidden');
    document.getElementById('version-actions-label').textContent = v.name;
    document.getElementById('vbtn-toggle').textContent = v.status === 'open' ? 'Close Version' : 'Reopen Version';
    document.getElementById('load-data-form').classList.add('hidden');
}

function showNewVersionForm() {
    document.getElementById('new-version-form').classList.remove('hidden');
    document.getElementById('ver-name').focus();
}

async function createVersion() {
    const name = document.getElementById('ver-name').value.trim();
    if (!name) { showStatus('Version name is required', 'error'); return; }
    try {
        await api('POST', `/sources/${state.source.id}/versions`, {
            name,
            description: document.getElementById('ver-desc').value.trim() || undefined,
            created_by:  getPfUser()
        });
        document.getElementById('new-version-form').classList.add('hidden');
        document.getElementById('ver-name').value = '';
        document.getElementById('ver-desc').value = '';
        showStatus(`Version "${name}" created`, 'success');
        await renderVersions();
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

function showLoadForm(op) {
    state.loadDataOp = op;
    document.getElementById('load-data-title').textContent =
        op === 'baseline' ? 'Load Baseline' : 'Load Reference';
    document.getElementById('load-date-from').value  = '';
    document.getElementById('load-date-to').value    = '';
    document.getElementById('load-note').value       = '';
    document.getElementById('load-date-preview').classList.add('hidden');
    document.getElementById('load-data-modal').classList.remove('hidden');
    document.getElementById('load-date-from').focus();
}

function hideLoadModal() {
    document.getElementById('load-data-modal').classList.add('hidden');
}

function updateDatePreview() {
    const fromVal = document.getElementById('load-date-from').value;
    const toVal   = document.getElementById('load-date-to').value;
    const preview = document.getElementById('load-date-preview');
    const chips   = document.getElementById('load-date-chips');
    const label   = preview.querySelector('.load-preview-label');

    if (!fromVal || !toVal) { preview.classList.add('hidden'); return; }

    const from = new Date(fromVal + 'T00:00:00');
    const to   = new Date(toVal   + 'T00:00:00');
    if (isNaN(from) || isNaN(to) || from > to) { preview.classList.add('hidden'); return; }

    const months = [];
    const cur = new Date(from.getFullYear(), from.getMonth(), 1);
    const end = new Date(to.getFullYear(),   to.getMonth(),   1);
    while (cur <= end) { months.push(new Date(cur)); cur.setMonth(cur.getMonth() + 1); }

    const fmt = new Intl.DateTimeFormat('en-US', { month: 'short', year: 'numeric' });
    label.textContent = `${months.length} month${months.length !== 1 ? 's' : ''} covered`;

    if (months.length <= 36) {
        chips.innerHTML = months.map(m => `<span class="date-chip">${fmt.format(m)}</span>`).join('');
    } else {
        chips.innerHTML = `<span class="date-chip-summary">${months.length} months — ${fmt.format(months[0])} → ${fmt.format(months[months.length - 1])}</span>`;
    }

    preview.classList.remove('hidden');
}

async function submitLoadData() {
    const date_from = document.getElementById('load-date-from').value;
    const date_to   = document.getElementById('load-date-to').value;
    if (!date_from || !date_to) { showStatus('Both dates are required', 'error'); return; }
    if (!state.selectedVersionId) { showStatus('No version selected', 'error'); return; }

    const body = {
        date_from, date_to,
        pf_user: getPfUser(),
        note:    document.getElementById('load-note').value.trim() || undefined
    };

    try {
        showStatus(`Loading ${state.loadDataOp}...`, 'info');
        const result = await api('POST', `/versions/${state.selectedVersionId}/${state.loadDataOp}`, body);
        hideLoadModal();
        showStatus(`${state.loadDataOp} loaded — ${result.rows_affected} rows`, 'success');
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

async function toggleVersionStatus() {
    if (!state.selectedVersionId) return;
    // find current status from grid
    let currentStatus = null;
    state.grids.versions.forEachNode(n => {
        if (n.data.id === state.selectedVersionId) currentStatus = n.data.status;
    });
    try {
        const route = currentStatus === 'open'
            ? `/versions/${state.selectedVersionId}/close`
            : `/versions/${state.selectedVersionId}/reopen`;
        const result = await api('POST', route, { pf_user: getPfUser() });
        showStatus(`Version ${result.status}`, 'success');
        await renderVersions();
        document.getElementById('version-actions').classList.add('hidden');
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

async function deleteVersion() {
    if (!state.selectedVersionId) return;
    if (!confirm('Delete this version and its forecast table? This cannot be undone.')) return;
    try {
        await api('DELETE', `/versions/${state.selectedVersionId}`);
        showStatus('Version deleted', 'success');
        if (state.version?.id === state.selectedVersionId) setVersion(null);
        state.selectedVersionId = null;
        document.getElementById('version-actions').classList.add('hidden');
        await renderVersions();
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

function openForecast() {
    if (!state.selectedVersionId) return;
    // find the version object from grid
    let v = null;
    state.grids.versions.forEachNode(n => {
        if (n.data.id === state.selectedVersionId) v = n.data;
    });
    if (!v) return;
    setVersion(v);
    switchView('forecast');
}

/* ============================================================
   FORECAST VIEW — data loading
   ============================================================ */
function parseNumericRows(rows) {
    const numericCols = state.colMeta
        .filter(c => c.role === 'value' || c.role === 'units')
        .map(c => c.cname);
    return rows.map(row => {
        const r = { ...row };
        numericCols.forEach(col => { if (r[col] != null) r[col] = parseFloat(r[col]); });
        return r;
    });
}

async function loadForecastData() {
    if (!state.version) return;
    document.getElementById('forecast-label').textContent =
        `${state.source?.tname || ''} — ${state.version.name} [${state.version.status}]`;
    try {
        // ensure col_meta is loaded (may not be if user navigated directly)
        if (!state.colMeta.length && state.source) {
            state.colMeta = await api('GET', `/sources/${state.source.id}/cols`);
        }
        showStatus('Loading forecast data...', 'info');
        const rawData = await api('GET', `/versions/${state.version.id}/data`);
        const data = parseNumericRows(rawData);
        initPivotGrid(data);
        showStatus(`Loaded ${data.length.toLocaleString()} rows`, 'success');
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

/* ============================================================
   FORECAST VIEW — pivot grid
   ============================================================ */
function buildPivotColDefs() {
    const defs = [];

    state.colMeta.forEach((c) => {
        if (c.role === 'ignore') return;
        const needsGetter = /\W/.test(c.cname);
        const def = {
            field:       c.cname,
            headerName:  c.label || c.cname,
            resizable:   true,
            sortable:    true,
            ...(needsGetter ? { valueGetter: p => p.data ? p.data[c.cname] : undefined } : {})
        };
        if (c.role === 'dimension' || c.role === 'date') {
            def.enableRowGroup = true;
            def.enablePivot    = true;
        }
        if (c.role === 'value' || c.role === 'units') {
            def.enableValue    = true;
            def.aggFunc        = 'sum';
            def.type           = 'numericColumn';
            def.valueFormatter = p => p.value != null
                ? Number(p.value).toLocaleString(undefined, { maximumFractionDigits: 2 })
                : '';
        }
        defs.push(def);

        if (c.role === 'date') {
            defs.push({
                colId:       c.cname + '__month',
                headerName:  (c.label || c.cname) + ' (Month)',
                enableRowGroup: true,
                enablePivot:    true,
                valueGetter: p => {
                    const v = p.data ? p.data[c.cname] : undefined;
                    if (!v) return undefined;
                    const d = new Date(v);
                    return isNaN(d) ? undefined : `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}`;
                }
            });
        }
    });

    // always include iter for grouping context
    defs.push({ field: 'iter', headerName: 'Iter', enableRowGroup: true, enablePivot: true, width: 90 });
    defs.push({ field: 'pf_user',    headerName: 'User',    width: 90, hide: true });
    defs.push({ field: 'created_at', headerName: 'Created', width: 130, hide: true,
        valueFormatter: p => p.value ? new Date(p.value).toLocaleDateString() : '' });

    return defs;
}

function initPivotGrid(data) {
    const el = document.getElementById('pivot-grid');

    if (state.grids.pivot) {
        state.grids.pivot.setGridOption('rowData', data);
        return;
    }

    state.grids.pivot = agGrid.createGrid(el, {
        columnDefs:           buildPivotColDefs(),
        rowData:              data,
        rowSelection:         'single',
        groupDisplayType:     'singleColumn',
        rowGroupPanelShow:    'always',
        groupDefaultExpanded: 1,
        suppressAggFuncInHeader: true,
        animateRows:          true,
        sideBar: {
            toolPanels: [{
                id:             'columns',
                labelDefault:   'Columns',
                labelKey:       'columns',
                iconKey:        'columns',
                toolPanel:      'agColumnsToolPanel',
                toolPanelParams: {}
            }],
            defaultToolPanel: 'columns'
        },
        defaultColDef:        { resizable: true, sortable: true },
        autoGroupColumnDef:   {
            headerName:   'Group',
            minWidth:     200,
            cellRendererParams: { suppressCount: false }
        },
        headerHeight: 32,
        rowHeight:    28,
        onRowClicked: onPivotRowClicked
    });
}

/* ============================================================
   FORECAST VIEW — slice selection
   ============================================================ */
function onPivotRowClicked(event) {
    const node  = event.node;
    state.slice = extractSliceFromNode(node);
    renderSliceDisplay();

    // populate recode and clone fields whenever slice changes
    renderDimFields('recode');
    renderDimFields('clone');
}

function extractSliceFromNode(node) {
    const slice   = {};
    let current = node;
    while (current) {
        if (current.field && current.key != null && current.key !== '') {
            slice[current.field] = current.key;
        }
        current = current.parent;
    }
    return slice;
}

function renderSliceDisplay() {
    const display = document.getElementById('slice-display');
    const hasSlice = Object.keys(state.slice).length > 0;

    if (!hasSlice) {
        display.innerHTML = '<span class="op-hint">Click a row to select a slice</span>';
        document.getElementById('btn-clear-slice').classList.add('hidden');
        document.getElementById('op-forms-area').classList.add('hidden');
        return;
    }

    display.innerHTML = Object.entries(state.slice)
        .map(([k, v]) => `<span class="slice-tag">${k} = ${v}</span>`)
        .join('');

    document.getElementById('btn-clear-slice').classList.remove('hidden');
    document.getElementById('op-forms-area').classList.remove('hidden');
}

function clearSlice() {
    state.slice = {};
    renderSliceDisplay();
}

/* ============================================================
   FORECAST VIEW — operation tabs
   ============================================================ */
function switchOpTab(opName) {
    document.querySelectorAll('.op-tab').forEach(t =>
        t.classList.toggle('active', t.dataset.op === opName)
    );
    document.querySelectorAll('.op-form').forEach(f => f.classList.add('hidden'));
    document.getElementById(`op-${opName}`).classList.remove('hidden');
}

// render input fields for each dimension column (recode / clone)
// is_key columns get a populated <select>, others get a free-text input
async function renderDimFields(op) {
    const container = document.getElementById(`${op}-fields`);
    const dims = state.colMeta.filter(c => c.role === 'dimension');

    // fetch values for all key columns in parallel
    const keyDims = dims.filter(c => c.is_key);
    const valueMap = {};
    await Promise.all(keyDims.map(async c => {
        try {
            const vals = await api('GET', `/sources/${state.source.id}/values/${encodeURIComponent(c.cname)}`);
            valueMap[c.cname] = vals;
        } catch (_) {
            valueMap[c.cname] = [];
        }
    }));

    container.innerHTML = dims.map(c => {
        const current = state.slice[c.cname] ? `current: ${state.slice[c.cname]}` : '';
        const hint    = current ? `<span class="field-hint">${current}</span>` : '';

        let input;
        if (c.is_key && valueMap[c.cname]?.length) {
            const options = valueMap[c.cname]
                .map(v => `<option value="${v}">${v}</option>`)
                .join('');
            input = `<select data-col="${c.cname}"><option value="">— keep current —</option>${options}</select>`;
        } else {
            input = `<input type="text" data-col="${c.cname}" placeholder="new value (leave blank to keep)" />`;
        }

        return `
        <div class="${op}-field">
            <label>${c.label || c.cname}${hint}${input}</label>
        </div>`;
    }).join('');
}

/* ============================================================
   FORECAST VIEW — submit operations
   ============================================================ */
async function submitScale() {
    const value_incr = parseFloat(document.getElementById('scale-value-incr').value) || null;
    const units_incr = parseFloat(document.getElementById('scale-units-incr').value) || null;
    const pct        = document.getElementById('scale-pct').checked;
    const note       = document.getElementById('scale-note').value.trim();

    if (!value_incr && !units_incr) {
        showStatus('Enter a value or units increment', 'error'); return;
    }
    if (Object.keys(state.slice).length === 0) {
        showStatus('Select a slice first', 'error'); return;
    }
    try {
        const result = await api('POST', `/versions/${state.version.id}/scale`, {
            pf_user: getPfUser(), note: note || undefined,
            slice: state.slice, value_incr, units_incr, pct
        });
        showStatus(`Scale applied — ${result.rows_affected} rows inserted`, 'success');
        document.getElementById('scale-value-incr').value = '';
        document.getElementById('scale-units-incr').value = '';
        document.getElementById('scale-note').value = '';
        state.grids.pivot.applyTransaction({ add: parseNumericRows(result.rows) });
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

async function submitRecode() {
    const set  = {};
    document.querySelectorAll('#recode-fields input[data-col], #recode-fields select[data-col]').forEach(inp => {
        if (inp.value.trim()) set[inp.dataset.col] = inp.value.trim();
    });
    if (Object.keys(set).length === 0) {
        showStatus('Enter at least one new dimension value', 'error'); return;
    }
    if (Object.keys(state.slice).length === 0) {
        showStatus('Select a slice first', 'error'); return;
    }
    try {
        const result = await api('POST', `/versions/${state.version.id}/recode`, {
            pf_user: getPfUser(),
            note:    document.getElementById('recode-note').value.trim() || undefined,
            slice:   state.slice,
            set
        });
        showStatus(`Recode applied — ${result.rows_affected} rows inserted`, 'success');
        document.querySelectorAll('#recode-fields input[data-col], #recode-fields select[data-col]').forEach(i => { i.value = ''; });
        state.grids.pivot.applyTransaction({ add: parseNumericRows(result.rows) });
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

async function submitClone() {
    const set = {};
    document.querySelectorAll('#clone-fields input[data-col], #clone-fields select[data-col]').forEach(inp => {
        if (inp.value.trim()) set[inp.dataset.col] = inp.value.trim();
    });
    if (Object.keys(set).length === 0) {
        showStatus('Enter at least one new dimension value', 'error'); return;
    }
    if (Object.keys(state.slice).length === 0) {
        showStatus('Select a slice first', 'error'); return;
    }
    try {
        const scale  = parseFloat(document.getElementById('clone-scale').value) || 1.0;
        const result = await api('POST', `/versions/${state.version.id}/clone`, {
            pf_user: getPfUser(),
            note:    document.getElementById('clone-note').value.trim() || undefined,
            slice:   state.slice,
            set,
            scale
        });
        showStatus(`Clone applied — ${result.rows_affected} rows inserted`, 'success');
        document.querySelectorAll('#clone-fields input[data-col], #clone-fields select[data-col]').forEach(i => { i.value = ''; });
        document.getElementById('clone-scale').value = '1';
        state.grids.pivot.applyTransaction({ add: parseNumericRows(result.rows) });
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

/* ============================================================
   LOG VIEW
   ============================================================ */
async function loadLogData() {
    if (!state.version) return;
    try {
        const logs = await api('GET', `/versions/${state.version.id}/log`);
        renderLogGrid(logs);
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

function renderLogGrid(logs) {
    const el = document.getElementById('log-grid');

    const colDefs = [
        { field: 'id',        headerName: 'ID',        width: 65 },
        { field: 'pf_user',   headerName: 'User',      width: 90 },
        { field: 'stamp',     headerName: 'Time',       width: 140,
          valueFormatter: p => p.value ? new Date(p.value).toLocaleString() : '' },
        { field: 'operation', headerName: 'Operation',  width: 90 },
        { field: 'slice',     headerName: 'Slice',      flex: 1,
          valueFormatter: p => p.value ? JSON.stringify(p.value) : '' },
        { field: 'params',    headerName: 'Params',     flex: 1,
          valueFormatter: p => p.value ? JSON.stringify(p.value) : '' },
        { field: 'note',      headerName: 'Note',       flex: 1 },
        {
            headerName: '',
            width: 70,
            cellRenderer: p => {
                const btn = document.createElement('button');
                btn.className   = 'btn btn-sm btn-danger';
                btn.textContent = 'Undo';
                btn.dataset.logid = p.data.id;
                return btn;
            },
            sortable: false
        }
    ];

    if (state.grids.log) {
        state.grids.log.setGridOption('rowData', logs);
        state.grids.log.setGridOption('columnDefs', colDefs);
        return;
    }

    state.grids.log = agGrid.createGrid(el, {
        columnDefs: colDefs,
        rowData:       logs,
        defaultColDef: { resizable: true, sortable: true },
        headerHeight:  32,
        rowHeight:     28
    });
}

async function undoOperation(logid) {
    if (!confirm(`Undo operation ${logid}? This will delete the associated forecast rows.`)) return;
    try {
        const result = await api('DELETE', `/log/${logid}`);
        showStatus(`Undone — ${result.rows_deleted} rows removed`, 'success');
        await loadLogData();
        // refresh forecast grid if open
        if (state.view === 'forecast') await loadForecastData();
    } catch (err) {
        showStatus(err.message, 'error');
    }
}

/* ============================================================
   INIT
   ============================================================ */
document.addEventListener('DOMContentLoaded', () => {

    // restore pf_user from localStorage
    const savedUser = localStorage.getItem('pf_user');
    if (savedUser) document.getElementById('input-pf-user').value = savedUser;
    document.getElementById('input-pf-user').addEventListener('change', e => {
        localStorage.setItem('pf_user', e.target.value.trim());
    });

    // navigation
    document.querySelectorAll('.nav-links li').forEach(li => {
        li.addEventListener('click', () => switchView(li.dataset.view));
    });

    // sources view buttons
    document.getElementById('btn-register').addEventListener('click', () => {
        if (state.previewSchema && state.previewTname) {
            registerTable(state.previewSchema, state.previewTname);
        }
    });
    document.getElementById('btn-back-sources').addEventListener('click', backToSources);
    document.getElementById('btn-save-cols').addEventListener('click', saveColMeta);
    document.getElementById('btn-generate-sql').addEventListener('click', generateSQL);

    // modal
    document.getElementById('modal-close').addEventListener('click', () =>
        document.getElementById('modal-overlay').classList.add('hidden')
    );
    document.getElementById('btn-modal-close').addEventListener('click', () =>
        document.getElementById('modal-overlay').classList.add('hidden')
    );
    document.getElementById('btn-modal-register').addEventListener('click', () => {
        if (state.previewSchema && state.previewTname) {
            registerTable(state.previewSchema, state.previewTname);
        }
    });

    // versions view buttons
    document.getElementById('btn-new-version').addEventListener('click', showNewVersionForm);
    document.getElementById('btn-create-version').addEventListener('click', createVersion);
    document.getElementById('btn-cancel-version').addEventListener('click', () => {
        document.getElementById('new-version-form').classList.add('hidden');
    });
    document.getElementById('vbtn-forecast').addEventListener('click', openForecast);
    document.getElementById('vbtn-baseline').addEventListener('click', () => showLoadForm('baseline'));
    document.getElementById('vbtn-reference').addEventListener('click', () => showLoadForm('reference'));
    document.getElementById('vbtn-toggle').addEventListener('click', toggleVersionStatus);
    document.getElementById('vbtn-delete').addEventListener('click', deleteVersion);
    document.getElementById('btn-load-submit').addEventListener('click', submitLoadData);
    document.getElementById('btn-load-cancel').addEventListener('click', hideLoadModal);
    document.getElementById('btn-load-close').addEventListener('click', hideLoadModal);
    document.getElementById('load-date-from').addEventListener('change', updateDatePreview);
    document.getElementById('load-date-to').addEventListener('change', updateDatePreview);

    // forecast view buttons
    document.getElementById('btn-forecast-refresh').addEventListener('click', loadForecastData);
    document.getElementById('btn-expand-all').addEventListener('click',   () => state.grids.pivot?.expandAll());
    document.getElementById('btn-collapse-all').addEventListener('click', () => state.grids.pivot?.collapseAll());
    document.getElementById('btn-clear-slice').addEventListener('click', clearSlice);

    document.querySelectorAll('.op-tab').forEach(tab => {
        tab.addEventListener('click', () => switchOpTab(tab.dataset.op));
    });

    document.getElementById('btn-submit-scale').addEventListener('click', submitScale);
    document.getElementById('btn-submit-recode').addEventListener('click', submitRecode);
    document.getElementById('btn-submit-clone').addEventListener('click', submitClone);

    // undo button delegation on log grid
    document.getElementById('log-grid').addEventListener('click', e => {
        const btn = e.target.closest('.btn-danger[data-logid]');
        if (btn) undoOperation(parseInt(btn.dataset.logid));
    });

    // init sources view
    initSourcesView().catch(err => showStatus(err.message, 'error'));
});