"""XLSX export wizard for fusion financial reports."""

import base64
import io

from odoo import _, fields, models
from odoo.exceptions import UserError

from ..services.date_periods import Period


class FusionXlsxExportWizard(models.TransientModel):
    _name = "fusion.xlsx.export.wizard"
    _description = "Export Financial Report to XLSX"

    report_type = fields.Selection([
        ('pnl', 'P&L'),
        ('balance_sheet', 'Balance Sheet'),
        ('trial_balance', 'Trial Balance'),
        ('general_ledger', 'General Ledger'),
    ], required=True, default='pnl')
    date_from = fields.Date(required=True, default=fields.Date.today)
    date_to = fields.Date(required=True, default=fields.Date.today)
    comparison = fields.Selection([
        ('none', 'No Comparison'),
        ('previous_period', 'Previous Period'),
        ('previous_year', 'Previous Year'),
    ], default='none')

    xlsx_file = fields.Binary(readonly=True)
    xlsx_filename = fields.Char(readonly=True)
    state = fields.Selection([('draft', 'Draft'), ('done', 'Done')], default='draft')

    def action_export(self):
        self.ensure_one()
        company_id = self.env.company.id
        engine = self.env['fusion.report.engine']
        if self.report_type == 'pnl':
            period = Period(self.date_from, self.date_to, f"{self.date_from} - {self.date_to}")
            result = engine.compute_pnl(period, comparison=self.comparison, company_id=company_id)
        elif self.report_type == 'balance_sheet':
            result = engine.compute_balance_sheet(self.date_to, comparison=self.comparison, company_id=company_id)
        elif self.report_type == 'trial_balance':
            period = Period(self.date_from, self.date_to, f"{self.date_from} - {self.date_to}")
            result = engine.compute_trial_balance(period, company_id=company_id)
        else:
            period = Period(self.date_from, self.date_to, f"{self.date_from} - {self.date_to}")
            result = engine.compute_gl(period, company_id=company_id)

        try:
            import xlsxwriter
        except ImportError:
            raise UserError(_(
                "xlsxwriter Python package is required for XLSX export. "
                "Install with: pip install xlsxwriter"))

        buf = io.BytesIO()
        wb = xlsxwriter.Workbook(buf, {'in_memory': True})
        ws = wb.add_worksheet(self.report_type[:30])
        bold = wb.add_format({'bold': True})
        money = wb.add_format({'num_format': '#,##0.00'})
        money_bold = wb.add_format({'num_format': '#,##0.00', 'bold': True})

        ws.write(0, 0, result.get('report_name', 'Report'), bold)
        ws.write(1, 0, f"Period: {result.get('period', {}).get('label', '')}")
        if result.get('comparison_period'):
            ws.write(2, 0, f"Comparison: {result['comparison_period']['label']}")

        row_idx = 4
        ws.write(row_idx, 0, 'Line', bold)
        ws.write(row_idx, 1, 'Amount', bold)
        if result.get('comparison_period'):
            ws.write(row_idx, 2, 'Comparison', bold)
            ws.write(row_idx, 3, 'Variance %', bold)

        for row in result.get('rows', []):
            row_idx += 1
            label = ('  ' * (row.get('level', 0) or 0)) + (row.get('label', '') or '')
            fmt = bold if row.get('is_subtotal') else None
            money_fmt = money_bold if row.get('is_subtotal') else money
            ws.write(row_idx, 0, label, fmt)
            ws.write(row_idx, 1, row.get('amount', 0), money_fmt)
            if result.get('comparison_period'):
                if row.get('amount_comparison') is not None:
                    ws.write(row_idx, 2, row['amount_comparison'], money_fmt)
                if row.get('variance_pct') is not None:
                    ws.write(row_idx, 3, row['variance_pct'] / 100,
                             wb.add_format({'num_format': '+0.0%;-0.0%;0.0%'}))

        ws.set_column(0, 0, 40)
        ws.set_column(1, 3, 16)
        wb.close()

        self.write({
            'xlsx_file': base64.b64encode(buf.getvalue()),
            'xlsx_filename': f'{self.report_type}_{self.date_from}_{self.date_to}.xlsx',
            'state': 'done',
        })
        return {
            'type': 'ir.actions.act_window',
            'res_model': self._name,
            'res_id': self.id,
            'view_mode': 'form',
            'target': 'new',
        }