window.initFinanceApp = function() {
  window.financeApp = {
    data: null,
    charts: {},
    async load() {
      try {
        let res = await fetch('/api/finance');
        let json = await res.json();
        this.data = json;
        if (!this.data.monthly || !this.data.monthly.labels) {
           this.data.monthly = {labels:['Jan'], income:[0], expenses:[0], spend:[0]};
        }
        if (!this.data.accounts) this.data.accounts = [];
        this.renderCharts();
        this.renderTable();
      } catch (e) {
        console.error("Finance App Load Error:", e);
      }
    },
    async save() {
      await fetch('/api/finance', { method: 'POST', body: JSON.stringify(this.data), headers: {'Content-Type': 'application/json'} });
    },
    renderCharts() {
      const resolveColor = (cssVar, fallback) => {
        const div = document.createElement('div');
        div.style.color = fallback;
        div.style.color = `var(${cssVar})`;
        div.style.display = 'none';
        document.body.appendChild(div);
        const color = getComputedStyle(div).color;
        document.body.removeChild(div);
        return color;
      };

      const cPos = resolveColor('--color-positive', 'hsl(150, 60%, 50%)');
      const cNeg = resolveColor('--color-negative', 'hsl(0, 70%, 65%)');
      const cPri = resolveColor('--color-primary', 'hsl(12, 70%, 60%)');
      const cText = resolveColor('--color-text-subdue', 'rgba(255,255,255,0.6)');
      
      const resolveGridColor = () => {
        const div = document.createElement('div');
        div.style.borderColor = 'rgba(255,255,255,0.05)';
        div.style.borderColor = 'var(--color-widget-content-border)';
        div.style.display = 'none';
        document.body.appendChild(div);
        const color = getComputedStyle(div).borderColor;
        document.body.removeChild(div);
        return color;
      };
      const cGrid = resolveGridColor();
      
      const addAlpha = (rgbStr, alpha) => {
        let m = rgbStr.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)/);
        if (m) {
          return `rgba(${m[1]}, ${m[2]}, ${m[3]}, ${alpha})`;
        }
        return rgbStr;
      };

      const cPosAlpha = addAlpha(cPos, 0.6);
      const cNegAlpha = addAlpha(cNeg, 0.6);
      const cPriAlpha = addAlpha(cPri, 0.2);

      Chart.defaults.color = cText;
      Chart.defaults.font.family = 'Outfit, -apple-system, sans-serif';
      
      const c1 = document.getElementById('incomeExpenseChart');
      if(c1) {
        if(this.charts.incomeExpense) this.charts.incomeExpense.destroy();
        this.charts.incomeExpense = new Chart(c1.getContext('2d'), {
          type: 'bar',
          data: {
            labels: this.data.monthly.labels,
            datasets: [
              { label: 'Income', data: this.data.monthly.income, backgroundColor: cPosAlpha, borderColor: cPos, borderWidth: 1, borderRadius: 3, barPercentage: 0.6 },
              { label: 'Expenses', data: this.data.monthly.expenses, backgroundColor: cNegAlpha, borderColor: cNeg, borderWidth: 1, borderRadius: 3, barPercentage: 0.6 }
            ]
          },
          options: { 
            responsive: true, 
            maintainAspectRatio: false, 
            plugins: { legend: { display: false } },
            layout: { padding: 10 },
            scales: { 
                y: { display: false, beginAtZero: true }, 
                x: { display: false } 
            } 
          }
        });
      }

      const c2 = document.getElementById('spendChart');
      if(c2) {
        if(this.charts.spend) this.charts.spend.destroy();
        this.charts.spend = new Chart(c2.getContext('2d'), {
          type: 'line',
          data: {
            labels: this.data.monthly.labels,
            datasets: [{ 
                label: 'Spend', 
                data: this.data.monthly.spend, 
                borderColor: cPri, 
                borderWidth: 2,
                tension: 0.4, 
                fill: false, 
                pointRadius: 0,
                pointHoverRadius: 5
            }]
          },
          options: { 
            responsive: true, 
            maintainAspectRatio: false, 
            plugins: { legend: { display: false } },
            layout: { padding: 10 },
            scales: { 
                y: { display: false, beginAtZero: true }, 
                x: { display: false } 
            } 
          }
        });
      }
    },
    renderTable() {
      const t = document.getElementById('finance-tbody');
      if(!t) return;
      t.innerHTML = '';
      if(!this.data.accounts || this.data.accounts.length === 0) {
        t.innerHTML = `<tr><td colspan='4' style='text-align:center; padding: 2rem;' class='color-subdue'>No accounts.</td></tr>`;
        return;
      }
      this.data.accounts.forEach((acc, i) => {
        const tr = document.createElement('tr');
        tr.style.borderBottom = '1px solid var(--color-widget-content-border)';
        const inStyle = `width: 100%; background: transparent; border: none; color: var(--color-text-highlight); padding: 1rem; font-family: inherit; font-size: 1.15rem; outline: none; transition: background 0.2s;`;
        
        const td1 = document.createElement('td');
        td1.style.padding = '0';
        td1.innerHTML = `<input style="${inStyle}" value="${acc.name}" onfocus="this.style.background='var(--color-widget-background-highlight)'" onblur="this.style.background='transparent'" onchange="financeApp.update(${i},'name',this.value)">`;
        
        const td2 = document.createElement('td');
        td2.style.padding = '0';
        let amountCol = acc.balance < 0 ? 'color-negative' : 'color-positive';
        td2.innerHTML = `<input type="number" step="0.01" style="${inStyle}" class="${amountCol}" value="${acc.balance}" onfocus="this.style.background='var(--color-widget-background-highlight)'" onblur="this.style.background='transparent'" onchange="financeApp.update(${i},'balance',parseFloat(this.value))">`;
        
        const td3 = document.createElement('td');
        td3.style.padding = '0';
        td3.innerHTML = `<input style="${inStyle}" value="${acc.currency}" onfocus="this.style.background='var(--color-widget-background-highlight)'" onblur="this.style.background='transparent'" onchange="financeApp.update(${i},'currency',this.value)">`;
        
        const td4 = document.createElement('td');
        td4.style.textAlign = 'right';
        td4.style.padding = '1rem';
        td4.innerHTML = `<button onclick="financeApp.delete(${i})" style="padding: 0.4rem 0.8rem; border-radius: 6px; border: none; background: rgba(255, 50, 50, 0.15); color: var(--color-negative); font-weight: 600; cursor: pointer;">Delete</button>`;
        
        tr.appendChild(td1);
        tr.appendChild(td2);
        tr.appendChild(td3);
        tr.appendChild(td4);
        t.appendChild(tr);
      });
    },
    update(i, key, val) { this.data.accounts[i][key] = val; this.renderTable(); this.save(); },
    addAccount() { this.data.accounts.push({name:'New Account',balance:0,currency:'USD'}); this.renderTable(); this.save(); },
    delete(i) { this.data.accounts.splice(i, 1); this.renderTable(); this.save(); }
  };
  window.financeApp.load();
};

if (!window.financeAppLoaded) {
  window.financeAppLoaded = true;
  if (!window.Chart) {
    let script = document.createElement('script');
    script.src = 'https://cdn.jsdelivr.net/npm/chart.js';
    script.onload = () => window.initFinanceApp();
    document.head.appendChild(script);
  } else {
    window.initFinanceApp();
  }
}