chart.js

//////////////////////////////////////////////////////////
let monthlyChart;

async function renderMonthlyChart(transactionsParam = null) {
  const transactions = transactionsParam || await (await fetch('/api/accounting')).json();

  const contribution = Array(12).fill(0);
  const donation = Array(12).fill(0);
  const sale = Array(12).fill(0);
  const expenses = Array(12).fill(0);

  transactions.forEach(tx => {
    if (!tx.month) return;
    const parts = tx.month.split('-');
    if (parts.length !== 2) return;
    const monthIndex = parseInt(parts[1], 10) - 1;
    if (monthIndex < 0 || monthIndex > 11) return;

    if (tx.category === 'contribution') contribution[monthIndex] += tx.amount;
    else if (tx.category === 'donation') donation[monthIndex] += tx.amount;
    else if (tx.category === 'sale') sale[monthIndex] += tx.amount;
    else if (tx.category === 'expense') expenses[monthIndex] += tx.amount;
  });

  const ctx = document.getElementById('monthlyChart').getContext('2d');
  if (monthlyChart) monthlyChart.destroy();

  monthlyChart = new Chart(ctx, {
    type: 'bar',
    data: {
      labels: ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'],
      datasets: [
        { label: 'Contribution', data: contribution, backgroundColor: 'rgba(75,192,192,0.7)' },
        { label: 'Donation', data: donation, backgroundColor: 'rgba(54,162,235,0.7)' },
        { label: 'Sale', data: sale, backgroundColor: 'rgba(255,206,86,0.7)' },
        { label: 'Expense', data: expenses, backgroundColor: 'rgba(255,99,132,0.7)' }
      ]
    },
    options: { responsive: true, plugins: { legend: { position: 'top' }, title: { display: true, text: 'Monthly Income & Expenses by Category' } }, scales: { y: { beginAtZero: true } } }
  });
}

async function loadTransactions() {
  const res = await fetch('/api/accounting', { cache: 'no-store' });
  let transactions = await res.json();

  if (filters.start || filters.end) {
    const startDate = filters.start ? new Date(filters.start + "-01") : null;
    const endDate = filters.end ? new Date(filters.end + "-01") : null;

    transactions = transactions.filter(tx => {
      if (!tx.month) return false;
      const txDate = new Date(tx.month + "-01");
      return (!startDate || txDate >= startDate) && (!endDate || txDate <= endDate);
    });
  }

  const tbody = document.getElementById('accountingBody');
  tbody.innerHTML = transactions.map((t, i) => `
    <tr class="${t.category === 'expense' ? 'expense' : 'income'}">
      <td>${i + 1}</td>
      <td>${t.payerType === 'member' ? t.memberId : t.payerName}</td>
      <td>${t.payerType}</td>
      <td>${t.month}</td>
      <td>${t.amount.toFixed(2)}</td>
      <td>${t.category}</td>
      <td>${t.description || ''}</td>
    </tr>
  `).join('');

  updateAccountingSummary(transactions);
  renderMonthlyChart(transactions);
  renderIncomeExpenseChart(transactions);
}



// Call this on page load and after adding a transaction
renderMonthlyChart();
//////////////////////////////////////////
let filters = { start: null, end: null };

async function loadTransactions() {
  const res = await fetch('/api/accounting');
  let transactions = await res.json();

  // Apply filter if set
  if (filters.start || filters.end) {
    transactions = transactions.filter(tx => {
      if (!tx.month) return false;
      const txDate = new Date(tx.month + "-01");
      const startDate = filters.start ? new Date(filters.start + "-01") : null;
      const endDate = filters.end ? new Date(filters.end + "-01") : null;

      return (!startDate || txDate >= startDate) &&
             (!endDate || txDate <= endDate);
    });
  }

  const tbody = document.getElementById('accountingBody');
  tbody.innerHTML = transactions
    .map((t, i) => `
      <tr class="${t.category === 'expense' ? 'expense' : 'income'}">
        <td>${i + 1}</td>
        <td>${t.payerType === 'member' ? t.memberId : t.payerName}</td>
        <td>${t.payerType}</td>
        <td>${t.month}</td>
        <td>${t.amount}</td>
        <td>${t.category}</td>
        <td>${t.description || ''}</td>
      </tr>
    `).join('');
  
  // Refresh charts/summary with filtered data
  updateAccountingSummary(transactions);
  renderMonthlyChart(transactions);
  renderIncomeExpenseChart(transactions);
}

let incomeExpenseChart;

async function renderIncomeExpenseChart(transactionsParam = null) {
  const transactions = transactionsParam || await (await fetch('/api/accounting')).json();

  let totalIncome = 0, totalExpenses = 0;

  transactions.forEach(tx => {
    if (tx.category === 'expense') totalExpenses += tx.amount;
    else totalIncome += tx.amount;
  });

  const ctx = document.getElementById('incomeExpenseChart').getContext('2d');
  if (incomeExpenseChart) incomeExpenseChart.destroy();

  incomeExpenseChart = new Chart(ctx, {
    type: 'pie',
    data: {
      labels: ['Income', 'Expenses'],
      datasets: [{
        data: [totalIncome, totalExpenses],
        backgroundColor: ['rgba(75,192,192,0.7)', 'rgba(255,99,132,0.7)']
      }]
    },
    options: { responsive: true, plugins: { legend: { position: 'top' }, title: { display: true, text: 'Income vs Expenses' } } }
  });
}


document.getElementById('applyFilters').addEventListener('click', () => {
  filters.start = document.getElementById('filterStart').value || null;
  filters.end = document.getElementById('filterEnd').value || null;
  loadTransactions();
});

document.getElementById('clearFilters').addEventListener('click', () => {
  filters.start = null;
  filters.end = null;
  document.getElementById('filterStart').value = '';
  document.getElementById('filterEnd').value = '';
  loadTransactions();
});


document.getElementById("exportPdf").addEventListener("click", async () => {
  const { jsPDF } = window.jspdf;
  const pdf = new jsPDF("p", "pt", "a4");

  // Title
  pdf.setFontSize(18);
  pdf.text("Church Accounting Report", 40, 40);

  // Capture summary table
  const summaryElement = document.getElementById("summaryTable"); 
  const summaryCanvas = await html2canvas(summaryElement);
  const summaryImg = summaryCanvas.toDataURL("image/png");
  pdf.addImage(summaryImg, "PNG", 40, 60, 500, 0);

  pdf.addPage();

  // Capture monthly chart
  const chartCanvas = document.getElementById("monthlyChart");
  const chartImg = chartCanvas.toDataURL("image/png");
  pdf.text("Monthly Breakdown", 40, 40);
  pdf.addImage(chartImg, "PNG", 40, 60, 500, 300);

  pdf.addPage();

  // Capture income vs expense pie
  const pieCanvas = document.getElementById("incomeExpenseChart");
  const pieImg = pieCanvas.toDataURL("image/png");
  pdf.text("Income vs Expense", 40, 40);
  pdf.addImage(pieImg, "PNG", 40, 60, 400, 300);

  // Save file
  pdf.save("accounting-report.pdf");
});