import logging
from odoo import fields
from datetime import timedelta

_logger = logging.getLogger(__name__)


def get_ap_aging(env, params):
    today = fields.Date.today()
    domain = [
        ('account_id.account_type', '=', 'liability_payable'),
        ('parent_state', '=', 'posted'),
        ('reconciled', '=', False),
        ('company_id', '=', env.company.id),
    ]
    amls = env['account.move.line'].search(domain)

    buckets = {'current': 0, '1_30': 0, '31_60': 0, '61_90': 0, '90_plus': 0}
    for aml in amls:
        amt = abs(aml.amount_residual)
        if not aml.date_maturity or aml.date_maturity >= today:
            buckets['current'] += amt
        else:
            days = (today - aml.date_maturity).days
            if days <= 30:
                buckets['1_30'] += amt
            elif days <= 60:
                buckets['31_60'] += amt
            elif days <= 90:
                buckets['61_90'] += amt
            else:
                buckets['90_plus'] += amt

    return {'total': sum(buckets.values()), 'buckets': buckets, 'line_count': len(amls)}


def find_duplicate_bills(env, params):
    window_days = int(params.get('window_days', 7))
    bills = env['account.move'].search([
        ('move_type', 'in', ('in_invoice', 'in_refund')),
        ('state', '=', 'posted'),
        ('company_id', '=', env.company.id),
    ], order='partner_id, amount_total, date')

    duplicates = []
    prev = None
    for bill in bills:
        if prev and (
            prev.partner_id == bill.partner_id
            and abs(prev.amount_total - bill.amount_total) < 0.01
            and abs((prev.date - bill.date).days) <= window_days
        ):
            duplicates.append({
                'bill_1': {'id': prev.id, 'name': prev.name, 'date': str(prev.date)},
                'bill_2': {'id': bill.id, 'name': bill.name, 'date': str(bill.date)},
                'partner': bill.partner_id.name,
                'amount': bill.amount_total,
            })
        prev = bill

    return {'count': len(duplicates), 'duplicates': duplicates[:20]}


def match_bill_to_po(env, params):
    bill_id = int(params['bill_id'])
    bill = env['account.move'].browse(bill_id)
    if not bill.exists():
        return {'error': 'Bill not found'}
    matches = []
    for line in bill.invoice_line_ids:
        if line.purchase_line_id:
            matches.append({
                'bill_line': line.name or '',
                'po': line.purchase_line_id.order_id.name,
                'po_line': line.purchase_line_id.name,
                'po_qty': line.purchase_line_id.product_qty,
                'bill_qty': line.quantity,
                'match': abs(line.quantity - line.purchase_line_id.product_qty) < 0.01,
            })
    return {'bill': bill.name, 'matches': matches, 'unmatched_lines': len(bill.invoice_line_ids) - len(matches)}


def get_unpaid_bills(env, params):
    domain = [
        ('move_type', 'in', ('in_invoice', 'in_refund')),
        ('state', '=', 'posted'),
        ('payment_state', 'in', ('not_paid', 'partial')),
        ('company_id', '=', env.company.id),
    ]
    if params.get('partner_id'):
        domain.append(('partner_id', '=', int(params['partner_id'])))
    bills = env['account.move'].search(domain, order='invoice_date_due asc', limit=int(params.get('limit', 50)))
    return {
        'count': len(bills),
        'total': sum(b.amount_residual for b in bills),
        'bills': [{
            'id': b.id, 'name': b.name,
            'partner': b.partner_id.name if b.partner_id else '',
            'amount_total': b.amount_total,
            'amount_residual': b.amount_residual,
            'date_due': str(b.invoice_date_due) if b.invoice_date_due else '',
        } for b in bills],
    }


def verify_bill_taxes(env, params):
    bill_id = int(params['bill_id'])
    bill = env['account.move'].browse(bill_id)
    if not bill.exists():
        return {'error': 'Bill not found'}
    issues = []
    for line in bill.invoice_line_ids:
        if line.product_id and not line.tax_ids:
            issues.append({
                'line': line.name or line.product_id.name,
                'issue': 'No tax applied to product line',
            })
    return {'bill': bill.name, 'issues': issues, 'clean': len(issues) == 0}


def get_payment_schedule(env, params):
    days_ahead = int(params.get('days_ahead', 30))
    cutoff = fields.Date.today() + timedelta(days=days_ahead)
    bills = env['account.move'].search([
        ('move_type', '=', 'in_invoice'),
        ('state', '=', 'posted'),
        ('payment_state', 'in', ('not_paid', 'partial')),
        ('invoice_date_due', '<=', cutoff),
        ('company_id', '=', env.company.id),
    ], order='invoice_date_due asc')
    return {
        'period': f'Next {days_ahead} days',
        'total': sum(b.amount_residual for b in bills),
        'bills': [{
            'id': b.id, 'name': b.name,
            'partner': b.partner_id.name if b.partner_id else '',
            'amount_residual': b.amount_residual,
            'date_due': str(b.invoice_date_due) if b.invoice_date_due else '',
        } for b in bills[:50]],
    }


TOOLS = {
    'get_ap_aging': get_ap_aging,
    'find_duplicate_bills': find_duplicate_bills,
    'match_bill_to_po': match_bill_to_po,
    'get_unpaid_bills': get_unpaid_bills,
    'verify_bill_taxes': verify_bill_taxes,
    'get_payment_schedule': get_payment_schedule,
}