"""
Export Service — CSV, Excel, and PDF generation for transactions and reports.
"""
import io
import csv
from datetime import date
from flask import current_app
from app.models.transaction import Transaction
# ── CSV export ────────────────────────────────────────────────────────────────
def transactions_to_csv(transactions):
"""Return a CSV string of transactions."""
output = io.StringIO()
writer = csv.writer(output)
writer.writerow(['Date', 'Type', 'Description', 'Category', 'Account', 'Amount', 'Notes'])
for txn in transactions:
writer.writerow([
txn.date.strftime('%Y-%m-%d'),
txn.transaction_type,
txn.description,
txn.category.name if txn.category else '',
txn.account.name if txn.account else '',
float(txn.amount),
txn.notes or '',
])
output.seek(0)
return output.getvalue()
# ── Excel export ──────────────────────────────────────────────────────────────
def transactions_to_excel(transactions, period_label='Transactions'):
"""Return Excel bytes for a list of transactions."""
from openpyxl import Workbook
from openpyxl.styles import Font, PatternFill, Alignment, Border, Side
from openpyxl.utils import get_column_letter
wb = Workbook()
ws = wb.active
ws.title = period_label[:31] # max 31 chars
symbol = current_app.config.get('APP_CURRENCY_SYMBOL', '$')
# Header style
header_fill = PatternFill(start_color='0F172A', end_color='0F172A', fill_type='solid')
header_font = Font(color='F1F5F9', bold=True, size=10)
thin = Side(style='thin', color='E2E8F0')
border = Border(bottom=Side(style='thin', color='E2E8F0'))
headers = ['Date', 'Type', 'Description', 'Category', 'Account', f'Amount ({symbol})', 'Notes']
col_widths = [12, 10, 40, 18, 18, 16, 30]
for col, (header, width) in enumerate(zip(headers, col_widths), 1):
cell = ws.cell(row=1, column=col, value=header)
cell.font = header_font
cell.fill = header_fill
cell.alignment = Alignment(horizontal='left', vertical='center')
ws.column_dimensions[get_column_letter(col)].width = width
ws.row_dimensions[1].height = 22
# Data rows
income_fill = PatternFill(start_color='F0FDF4', end_color='F0FDF4', fill_type='solid')
expense_fill = PatternFill(start_color='FFF7F7', end_color='FFF7F7', fill_type='solid')
for row_num, txn in enumerate(transactions, 2):
fill = income_fill if txn.transaction_type == 'income' else expense_fill
data = [
txn.date.strftime('%Y-%m-%d'),
txn.transaction_type.title(),
txn.description,
txn.category.name if txn.category else '',
txn.account.name if txn.account else '',
float(txn.amount),
txn.notes or '',
]
for col, value in enumerate(data, 1):
cell = ws.cell(row=row_num, column=col, value=value)
cell.fill = fill
cell.border = border
cell.font = Font(size=10)
if col == 6:
cell.number_format = f'#,##0.00'
cell.alignment = Alignment(horizontal='right')
# Totals row
total_row = len(transactions) + 2
ws.cell(row=total_row, column=5, value='TOTAL').font = Font(bold=True, size=10)
total_cell = ws.cell(row=total_row, column=6,
value=sum(float(t.amount) for t in transactions))
total_cell.font = Font(bold=True, size=10)
total_cell.number_format = f'#,##0.00'
total_cell.alignment = Alignment(horizontal='right')
output = io.BytesIO()
wb.save(output)
output.seek(0)
return output.getvalue()
# ── PDF export ────────────────────────────────────────────────────────────────
def report_to_pdf(html_content):
"""Convert HTML string to PDF bytes using WeasyPrint."""
try:
from weasyprint import HTML, CSS
pdf = HTML(string=html_content).write_pdf()
return pdf
except Exception as e:
import logging
logging.getLogger(__name__).error(f'[export] PDF generation failed: {e}')
return None
def build_report_html(report_data, report_type, currency_symbol='$'):
"""Build a clean HTML string for PDF export."""
today = date.today().strftime('%B %d, %Y')
period = report_data.get('period', '')
income = report_data.get('income', 0)
expense = report_data.get('expense', 0)
net = report_data.get('net', 0)
savings_rate = report_data.get('savings_rate', 0)
def fmt(v):
return f"{currency_symbol}{abs(float(v)):,.2f}"
# Expense categories table rows
cat_rows = ''
total_exp = sum(c['total'] for c in report_data.get('expense_categories', []))
for cat in report_data.get('expense_categories', []):
pct = round(cat['total'] / total_exp * 100, 1) if total_exp > 0 else 0
cat_rows += f'''
| {cat['name']} |
{fmt(cat['total'])} |
{pct}% |
'''
html = f'''
Personal Finance Report — {period}
Generated {today}
Savings Rate
{savings_rate}%
Expense Breakdown
| Category | Amount | % of Total |
|---|
{cat_rows or '| No expenses |
'}
'''
return html