(function () {
  'use strict';

  // Security: validate any member id before fetch / DOM use.
  var ID_RE = /^[A-Z]\d{6}$|^S\d{3,4}$/;
  var MAX_SELECTED = 6;
  var PARTY_COLORS = { R: '#d9534f', D: '#337ab7', I: '#5cb85c' };
  var PALETTE = ['#1f77b4', '#ff7f0e', '#2ca02c', '#d62728', '#9467bd', '#8c564b'];
  var ALIGN_KEYS = ['Helped Republicans', 'Helped Democrats', 'Helped Both', 'Helped Neither'];

  var state = {
    manifest: null,
    membersById: {},
    BASE: './data/',
    selectedIds: [],
    memberCache: {},
    colorById: {},
    currentAlignClass: 'Helped Republicans',
    skipPush: false
  };

  var els = {};
  var charts = {};

  document.addEventListener('DOMContentLoaded', init);

  function init() {
    var root = document.getElementById('polisci-root');
    if (!root) return;
    state.BASE = root.dataset.base || './data/';

    els.root = root;
    els.search = document.getElementById('member-search');
    els.results = document.getElementById('member-results');
    els.pills = document.getElementById('selected-pills');
    els.emptyHint = document.getElementById('compare-empty-hint');
    els.lastGen = document.getElementById('last-generated');
    els.filterChamber = document.getElementById('filter-chamber');
    els.filterParty = document.getElementById('filter-party');
    els.filterState = document.getElementById('filter-state-select');
    els.filterReset = document.getElementById('filter-reset');
    els.sidebarToggle = document.getElementById('sidebar-toggle');
    els.sidebar = document.getElementById('sidebar');
    els.alignSwitcher = document.getElementById('align-class-switcher');

    var inline = document.getElementById('polisci-manifest');
    if (inline && inline.textContent) {
      try { onManifest(JSON.parse(inline.textContent)); return; }
      catch (e) { /* fall through */ }
    }
    fetch(state.BASE + 'manifest.json', { credentials: 'omit' })
      .then(function (r) { if (!r.ok) throw new Error('HTTP ' + r.status); return r.json(); })
      .then(onManifest)
      .catch(function (e) { showFatal('Failed to load manifest: ' + e.message + ' — if you opened this file directly, serve it over HTTP.'); });
  }

  function showFatal(msg) {
    els.root.replaceChildren();
    var p = document.createElement('p');
    p.style.padding = '20px';
    p.style.color = '#c0392b';
    p.textContent = msg;
    els.root.appendChild(p);
  }

  function onManifest(m) {
    state.manifest = m;
    var members = m.members || [];
    for (var i = 0; i < members.length; i++) {
      state.membersById[members[i].id] = members[i];
    }
    els.lastGen.textContent = m.generated_at || '';

    populateStateOptions(members);
    wireEvents();
    buildCharts();
    initFromURL();
    window.addEventListener('popstate', onPopState);
  }

  function populateStateOptions(members) {
    var states = {};
    for (var i = 0; i < members.length; i++) states[members[i].s] = true;
    var keys = Object.keys(states).sort();
    els.filterState.replaceChildren();
    for (var j = 0; j < keys.length; j++) {
      var opt = document.createElement('option');
      opt.value = keys[j];
      opt.textContent = keys[j];
      opt.selected = true;
      els.filterState.appendChild(opt);
    }
  }

  function wireEvents() {
    var chamberInputs = els.filterChamber.querySelectorAll('input[type=checkbox]');
    var partyInputs = els.filterParty.querySelectorAll('input[type=checkbox]');
    chamberInputs.forEach(function (i) { i.addEventListener('change', refreshFilter); });
    partyInputs.forEach(function (i) { i.addEventListener('change', refreshFilter); });
    els.filterState.addEventListener('change', refreshFilter);
    els.filterReset.addEventListener('click', resetFilters);

    els.search.addEventListener('input', refreshFilter);
    els.search.addEventListener('focus', refreshFilter);
    document.addEventListener('click', function (e) {
      if (!els.results.contains(e.target) && e.target !== els.search) {
        els.results.classList.add('is-hidden');
        els.search.setAttribute('aria-expanded', 'false');
      }
    });

    if (els.sidebarToggle) {
      els.sidebarToggle.addEventListener('click', function () {
        var open = els.sidebar.classList.toggle('is-open');
        els.sidebarToggle.setAttribute('aria-expanded', open ? 'true' : 'false');
      });
    }

    els.alignSwitcher.addEventListener('change', function () {
      state.currentAlignClass = els.alignSwitcher.value;
      renderAlignmentTime();
    });
  }

  function resetFilters() {
    var inputs = els.filterChamber.querySelectorAll('input[type=checkbox]');
    inputs.forEach(function (i) { i.checked = true; });
    inputs = els.filterParty.querySelectorAll('input[type=checkbox]');
    inputs.forEach(function (i) { i.checked = true; });
    for (var j = 0; j < els.filterState.options.length; j++) {
      els.filterState.options[j].selected = true;
    }
    els.search.value = '';
    refreshFilter();
  }

  function getCheckedValues(group) {
    var out = [];
    group.querySelectorAll('input[type=checkbox]:checked').forEach(function (i) { out.push(i.value); });
    return out;
  }

  function getSelectedStates() {
    var out = [];
    for (var i = 0; i < els.filterState.options.length; i++) {
      if (els.filterState.options[i].selected) out.push(els.filterState.options[i].value);
    }
    return out;
  }

  function initialsOf(name) {
    var parts = name.split(/\s+/);
    var out = '';
    for (var i = 0; i < parts.length; i++) {
      if (parts[i]) out += parts[i].charAt(0).toUpperCase();
    }
    return out;
  }

  function refreshFilter() {
    var chambers = getCheckedValues(els.filterChamber);
    var parties = getCheckedValues(els.filterParty);
    var states = getSelectedStates();
    var q = (els.search.value || '').trim();
    var qLower = q.toLowerCase();
    var qUpper = q.toUpperCase();
    var initialsMode = q.length > 0 && q.length <= 4 && /^[A-Za-z]+$/.test(q);

    var members = state.manifest.members;
    var matches = [];
    for (var i = 0; i < members.length && matches.length < 50; i++) {
      var m = members[i];
      if (chambers.indexOf(m.c) < 0) continue;
      if (parties.indexOf(m.p) < 0) continue;
      if (states.indexOf(m.s) < 0) continue;
      if (q) {
        var nameLower = m.n.toLowerCase();
        var hit = nameLower.indexOf(qLower) >= 0;
        if (!hit && initialsMode) {
          if (initialsOf(m.n) === qUpper) hit = true;
        }
        if (!hit) continue;
      }
      matches.push(m);
    }
    matches.sort(function (a, b) { return a.n.localeCompare(b.n); });
    renderResults(matches, q);
  }

  function renderResults(matches, q) {
    els.results.replaceChildren();
    if (!q && matches.length === state.manifest.members.length) {
      els.results.classList.add('is-hidden');
      els.search.setAttribute('aria-expanded', 'false');
      return;
    }
    if (!matches.length) {
      var li0 = document.createElement('li');
      li0.textContent = 'No members match.';
      li0.setAttribute('aria-disabled', 'true');
      els.results.appendChild(li0);
    } else {
      for (var i = 0; i < matches.length; i++) {
        var m = matches[i];
        var li = document.createElement('li');
        li.setAttribute('role', 'option');
        li.setAttribute('data-id', m.id);
        var alreadyIn = state.selectedIds.indexOf(m.id) >= 0;
        var atCap = state.selectedIds.length >= MAX_SELECTED;
        li.textContent = m.n + ' (' + m.p + '-' + m.s + ', ' + (m.c === 'H' ? 'House' : 'Senate') + ')' +
          (alreadyIn ? ' — selected' : (atCap ? ' — max 6' : ''));
        if (alreadyIn || atCap) {
          li.setAttribute('aria-disabled', 'true');
        } else {
          li.addEventListener('click', onResultClick);
        }
        els.results.appendChild(li);
      }
    }
    els.results.classList.remove('is-hidden');
    els.search.setAttribute('aria-expanded', 'true');
  }

  function onResultClick(e) {
    var id = e.currentTarget.getAttribute('data-id');
    if (!isValidId(id)) return;
    els.results.classList.add('is-hidden');
    els.search.setAttribute('aria-expanded', 'false');
    els.search.value = '';
    addMember(id);
  }

  function isValidId(id) {
    return typeof id === 'string' && ID_RE.test(id) &&
      Object.prototype.hasOwnProperty.call(state.membersById, id);
  }

  function pickColor() {
    var used = {};
    for (var k in state.colorById) {
      if (Object.prototype.hasOwnProperty.call(state.colorById, k)) used[state.colorById[k]] = true;
    }
    for (var i = 0; i < PALETTE.length; i++) {
      if (!used[PALETTE[i]]) return PALETTE[i];
    }
    return PALETTE[0];
  }

  function addMember(id) {
    if (!isValidId(id)) return;
    if (state.selectedIds.indexOf(id) >= 0) return;
    if (state.selectedIds.length >= MAX_SELECTED) return;

    var version = state.manifest.version || '';
    var url = state.BASE + 'members/' + encodeURIComponent(id) + '.json?v=' + encodeURIComponent(version);
    fetch(url, { credentials: 'omit' })
      .then(function (r) { if (!r.ok) throw new Error('HTTP ' + r.status); return r.json(); })
      .then(function (member) {
        if (state.selectedIds.indexOf(id) >= 0) return;
        if (state.selectedIds.length >= MAX_SELECTED) return;
        state.memberCache[id] = member;
        state.colorById[id] = pickColor();
        state.selectedIds.push(id);
        renderPills();
        pushUrlState();
        renderAllCharts();
      })
      .catch(function (e) {
        // Silent for one member load failure — surface via empty hint area.
        els.emptyHint.textContent = 'Failed to load member ' + id + ': ' + e.message;
      });
  }

  function removeMember(id) {
    var idx = state.selectedIds.indexOf(id);
    if (idx < 0) return;
    state.selectedIds.splice(idx, 1);
    delete state.memberCache[id];
    delete state.colorById[id];
    renderPills();
    pushUrlState();
    renderAllCharts();
  }

  function renderPills() {
    els.pills.replaceChildren();
    for (var i = 0; i < state.selectedIds.length; i++) {
      var id = state.selectedIds[i];
      var member = state.memberCache[id];
      if (!member) continue;
      var color = state.colorById[id] || '#888';

      var li = document.createElement('li');
      li.className = 'compare-pill';
      li.style.setProperty('--pill-color', color);
      li.style.borderColor = color;
      li.style.backgroundColor = color + '22';

      var swatch = document.createElement('span');
      swatch.className = 'compare-pill-swatch';
      swatch.style.backgroundColor = color;
      swatch.setAttribute('aria-hidden', 'true');
      li.appendChild(swatch);

      var nameBtn = document.createElement('button');
      nameBtn.type = 'button';
      nameBtn.className = 'compare-pill-name';
      nameBtn.textContent = member.name + ' (' + member.party + '-' + member.state + ')';
      nameBtn.title = 'Open ' + member.name + ' dashboard in new tab';
      (function (mid) {
        nameBtn.addEventListener('click', function () {
          window.open('app.html?id=' + encodeURIComponent(mid), '_blank', 'noopener');
        });
      })(id);
      li.appendChild(nameBtn);

      var rm = document.createElement('button');
      rm.type = 'button';
      rm.className = 'compare-pill-remove';
      rm.setAttribute('aria-label', 'Remove ' + member.name);
      rm.textContent = '×';
      (function (mid) {
        rm.addEventListener('click', function () { removeMember(mid); });
      })(id);
      li.appendChild(rm);

      els.pills.appendChild(li);
    }

    if (state.selectedIds.length === 0) {
      els.emptyHint.textContent = 'Pick up to 6 members to compare. Click a pill to open the member’s full dashboard in a new tab.';
    } else {
      els.emptyHint.textContent = state.selectedIds.length + ' of ' + MAX_SELECTED +
        ' selected. Click a pill name to open that member’s full dashboard in a new tab.';
    }
  }

  // ---- Charts ----

  function buildCharts() {
    if (typeof Chart === 'undefined') return;
    var common = { responsive: true, maintainAspectRatio: false };

    charts.alignmentTime = new Chart(document.getElementById('cmp-chart-alignment-time'), {
      type: 'line',
      data: { labels: [], datasets: [] },
      options: Object.assign({}, common, {
        plugins: { legend: { position: 'bottom' } },
        scales: { y: { beginAtZero: true } }
      })
    });

    charts.againstOwn = new Chart(document.getElementById('cmp-chart-against-own'), {
      type: 'line',
      data: { labels: [], datasets: [] },
      options: Object.assign({}, common, {
        plugins: { legend: { position: 'bottom' } },
        scales: { y: { beginAtZero: true } }
      })
    });

    charts.kpi = new Chart(document.getElementById('cmp-chart-kpi'), {
      type: 'bar',
      data: {
        labels: ['% against GOP', '% against Dem', 'Lone Wolf %', 'Participation %', 'Blocked Dem', 'Blocked GOP'],
        datasets: []
      },
      options: Object.assign({}, common, {
        plugins: {
          legend: { position: 'bottom' },
          tooltip: {
            callbacks: {
              label: function (ctx) {
                var v = Number(ctx.parsed.y);
                if (isNaN(v)) v = Number(ctx.parsed) || 0;
                return String(ctx.dataset.label) + ': ' + v.toFixed(1);
              }
            }
          }
        },
        scales: { y: { beginAtZero: true } }
      })
    });

    charts.defection = new Chart(document.getElementById('cmp-chart-defection'), {
      type: 'scatter',
      data: { datasets: [] },
      options: Object.assign({}, common, {
        plugins: {
          legend: { display: false },
          tooltip: {
            callbacks: {
              label: function (ctx) {
                var p = ctx.raw || {};
                return String(ctx.dataset.label) + ': (' +
                  (Number(p.x) || 0).toFixed(1) + '% R, ' +
                  (Number(p.y) || 0).toFixed(1) + '% D)';
              }
            }
          }
        },
        scales: {
          x: { beginAtZero: true, title: { display: true, text: '% against GOP majority' } },
          y: { beginAtZero: true, title: { display: true, text: '% against Dem majority' } }
        }
      })
    });

    charts.voteDist = new Chart(document.getElementById('cmp-chart-vote-dist'), {
      type: 'bar',
      data: { labels: ['Yea', 'Nay', 'Present', 'Not Voting'], datasets: [] },
      options: Object.assign({}, common, {
        plugins: { legend: { position: 'bottom' } },
        scales: { y: { beginAtZero: true } }
      })
    });
  }

  function renderAllCharts() {
    renderAlignmentTime();
    renderAgainstOwn();
    renderKpi();
    renderDefection();
    renderVoteDist();
  }

  function unionMonths() {
    var set = {};
    for (var i = 0; i < state.selectedIds.length; i++) {
      var m = state.memberCache[state.selectedIds[i]];
      var months = m && m.metrics && Array.isArray(m.metrics.months) ? m.metrics.months : [];
      for (var j = 0; j < months.length; j++) set[months[j]] = true;
    }
    return Object.keys(set).sort();
  }

  function replaceArray(target, source) {
    target.length = 0;
    for (var i = 0; i < source.length; i++) target.push(source[i]);
  }

  function monthlySeries(member, alignClass, months) {
    var mMonths = (member.metrics && member.metrics.months) || [];
    var arr = (member.metrics && member.metrics.monthly && member.metrics.monthly[alignClass]) || [];
    var idx = {};
    for (var i = 0; i < mMonths.length; i++) idx[mMonths[i]] = i;
    return months.map(function (mo) {
      var k = idx[mo];
      return (k != null && arr[k] != null) ? Number(arr[k]) : 0;
    });
  }

  function renderAlignmentTime() {
    if (!charts.alignmentTime) return;
    var months = unionMonths();
    replaceArray(charts.alignmentTime.data.labels, months);
    var datasets = [];
    for (var i = 0; i < state.selectedIds.length; i++) {
      var id = state.selectedIds[i];
      var member = state.memberCache[id];
      if (!member) continue;
      var color = state.colorById[id];
      datasets.push({
        label: member.name,
        data: monthlySeries(member, state.currentAlignClass, months),
        borderColor: color,
        backgroundColor: color + '33',
        tension: 0.2,
        fill: false
      });
    }
    replaceArray(charts.alignmentTime.data.datasets, datasets);
    charts.alignmentTime.update('none');
  }

  // "Voted against own party" per month is NOT directly emitted by analyze.py.
  // We use monthly['Helped Neither'] as a proxy; caveat noted in NOTES.md item 6.
  function renderAgainstOwn() {
    if (!charts.againstOwn) return;
    var months = unionMonths();
    replaceArray(charts.againstOwn.data.labels, months);
    var datasets = [];
    for (var i = 0; i < state.selectedIds.length; i++) {
      var id = state.selectedIds[i];
      var member = state.memberCache[id];
      if (!member) continue;
      var color = state.colorById[id];
      datasets.push({
        label: member.name,
        data: monthlySeries(member, 'Helped Neither', months),
        borderColor: color,
        backgroundColor: color + '33',
        tension: 0.2,
        fill: false
      });
    }
    replaceArray(charts.againstOwn.data.datasets, datasets);
    charts.againstOwn.update('none');
  }

  function kpiValues(member) {
    var x = (member && member.metrics) || {};
    var voting = Number(x.voting) || 0;
    var total = Number(x.total) || 0;
    var againstGop = Number(x.voted_against_gop) || 0;
    var withGop = Number(x.voted_with_gop) || 0;
    var againstDem = Number(x.voted_against_dem) || 0;
    var withDem = Number(x.voted_with_dem) || 0;
    var lone = Number(x.lone_wolf) || 0;
    var denomGop = againstGop + withGop;
    var denomDem = againstDem + withDem;
    return [
      denomGop > 0 ? (100 * againstGop / denomGop) : 0,
      denomDem > 0 ? (100 * againstDem / denomDem) : 0,
      voting > 0 ? (100 * lone / voting) : 0,
      total > 0 ? (100 * voting / total) : 0,
      Number(x.blocked_dem_count) || 0,
      Number(x.blocked_rep_count) || 0
    ];
  }

  function renderKpi() {
    if (!charts.kpi) return;
    var datasets = [];
    for (var i = 0; i < state.selectedIds.length; i++) {
      var id = state.selectedIds[i];
      var member = state.memberCache[id];
      if (!member) continue;
      var color = state.colorById[id];
      datasets.push({
        label: member.name,
        data: kpiValues(member),
        backgroundColor: color,
        borderColor: color
      });
    }
    replaceArray(charts.kpi.data.datasets, datasets);
    charts.kpi.update('none');
  }

  function renderDefection() {
    if (!charts.defection) return;
    var datasets = [];
    for (var i = 0; i < state.selectedIds.length; i++) {
      var id = state.selectedIds[i];
      var member = state.memberCache[id];
      if (!member) continue;
      var vals = kpiValues(member);
      var partyColor = PARTY_COLORS[member.party] || '#888';
      datasets.push({
        label: member.name,
        data: [{ x: vals[0], y: vals[1] }],
        backgroundColor: partyColor,
        borderColor: partyColor,
        pointBackgroundColor: partyColor,
        pointRadius: 8,
        pointHoverRadius: 10
      });
    }
    replaceArray(charts.defection.data.datasets, datasets);
    charts.defection.update('none');
  }

  function voteDistValues(member) {
    var mv = (member && member.metrics && member.metrics.member) || {};
    // Some procedural votes use Aye/No instead of Yea/Nay — sum them for display.
    var yea = (Number(mv.Yea) || 0) + (Number(mv.Aye) || 0);
    var nay = (Number(mv.Nay) || 0) + (Number(mv.No) || 0);
    var present = Number(mv.Present) || 0;
    var nv = Number(mv['Not Voting']) || 0;
    return [yea, nay, present, nv];
  }

  function renderVoteDist() {
    if (!charts.voteDist) return;
    var datasets = [];
    for (var i = 0; i < state.selectedIds.length; i++) {
      var id = state.selectedIds[i];
      var member = state.memberCache[id];
      if (!member) continue;
      var color = state.colorById[id];
      datasets.push({
        label: member.name,
        data: voteDistValues(member),
        backgroundColor: color,
        borderColor: color
      });
    }
    replaceArray(charts.voteDist.data.datasets, datasets);
    charts.voteDist.update('none');
  }

  // ---- URL state ----

  function parseIdsParam() {
    var params = new URLSearchParams(window.location.search);
    var raw = params.get('ids');
    if (!raw) return [];
    var parts = raw.split(',');
    var out = [];
    for (var i = 0; i < parts.length && out.length < MAX_SELECTED; i++) {
      var id = parts[i];
      if (isValidId(id) && out.indexOf(id) < 0) out.push(id);
    }
    return out;
  }

  function pushUrlState() {
    if (state.skipPush) { state.skipPush = false; return; }
    var u;
    if (state.selectedIds.length === 0) {
      u = window.location.pathname;
    } else {
      u = '?ids=' + state.selectedIds.join(',');
    }
    history.pushState({ ids: state.selectedIds.slice() }, '', u);
  }

  function initFromURL() {
    refreshFilter();
    var ids = parseIdsParam();
    if (ids.length === 0) {
      renderPills();
      renderAllCharts();
      return;
    }
    // Sequentially add (each fetch independent; order preserved via URL parse).
    state.skipPush = true;
    var pending = ids.slice();
    var loaded = [];
    function next() {
      if (pending.length === 0) {
        renderPills();
        renderAllCharts();
        return;
      }
      var id = pending.shift();
      var version = state.manifest.version || '';
      var url = state.BASE + 'members/' + encodeURIComponent(id) + '.json?v=' + encodeURIComponent(version);
      fetch(url, { credentials: 'omit' })
        .then(function (r) { if (!r.ok) throw new Error('HTTP ' + r.status); return r.json(); })
        .then(function (member) {
          state.memberCache[id] = member;
          state.colorById[id] = pickColor();
          state.selectedIds.push(id);
          loaded.push(id);
        })
        .catch(function () { /* skip broken id */ })
        .then(next);
    }
    next();
  }

  function onPopState() {
    var ids = parseIdsParam();
    // Reset selection and reload from URL.
    state.selectedIds = [];
    state.memberCache = {};
    state.colorById = {};
    state.skipPush = true;
    if (ids.length === 0) {
      renderPills();
      renderAllCharts();
      return;
    }
    var pending = ids.slice();
    function next() {
      if (pending.length === 0) {
        renderPills();
        renderAllCharts();
        return;
      }
      var id = pending.shift();
      var version = state.manifest.version || '';
      var url = state.BASE + 'members/' + encodeURIComponent(id) + '.json?v=' + encodeURIComponent(version);
      fetch(url, { credentials: 'omit' })
        .then(function (r) { if (!r.ok) throw new Error('HTTP ' + r.status); return r.json(); })
        .then(function (member) {
          state.memberCache[id] = member;
          state.colorById[id] = pickColor();
          state.selectedIds.push(id);
        })
        .catch(function () {})
        .then(next);
    }
    next();
  }

})();