# pyrefly: ignore [missing-import]
from odoo import api, fields, models
# pyrefly: ignore [missing-import]
from odoo.exceptions import ValidationError


class EducationStudentDiscount(models.Model):
    _name = 'education.student.discount'
    _description = 'Student Fee Discount'
    _order = 'id desc'

    student_id = fields.Many2one('education.student', string='Student', required=True, index=True)
    type = fields.Selection([
        ('percentage', 'Percentage'),
        ('fixed', 'Fixed Amount')
    ], string='Discount Type', required=True, default='fixed')
    
    currency_id = fields.Many2one(
        'res.currency',
        string='Currency',
        required=True,
        default=lambda self: self.env.company.currency_id,
    )
    amount = fields.Monetary(string='Discount Value', required=True, currency_field='currency_id', default=0.0)
    reason = fields.Text(string='Reason for Discount', required=True)
    approved_by = fields.Many2one('res.users', string='Approved By', default=lambda self: self.env.user, required=True)
    validity = fields.Date(string='Validity Date')
    state = fields.Selection([
        ('draft', 'Draft'),
        ('confirmed', 'Confirmed'),
        ('cancelled', 'Cancelled')
    ], string='Status', default='draft', required=True, index=True)
    active = fields.Boolean(default=True)
    company_id = fields.Many2one(
        'res.company',
        string='Company',
        required=True,
        default=lambda self: self.env.company,
        index=True,
    )

    @api.constrains('amount')
    def _check_amount(self):
        for rec in self:
            if rec.amount <= 0:
                raise ValidationError('Discount value must be greater than zero.')
            if rec.type == 'percentage' and rec.amount > 100:
                raise ValidationError('Discount percentage cannot exceed 100%.')

    def action_confirm(self):
        for rec in self:
            if rec.state == 'confirmed':
                continue
            
            discount_amount = rec.amount
            if rec.type == 'percentage':
                outstanding = rec.student_id.outstanding_amount
                discount_amount = outstanding * (rec.amount / 100.0)
            
            if discount_amount <= 0:
                raise ValidationError('Calculated discount amount must be greater than zero.')
            if discount_amount > rec.student_id.outstanding_amount:
                raise ValidationError(f'Cannot apply a discount of {discount_amount} because it exceeds the student outstanding dues of {rec.student_id.outstanding_amount}.')

            self.env['education.student.ledger'].create({
                'student_id': rec.student_id.id,
                'date': fields.Date.today(),
                'ref': f"DISC/{rec.id}",
                'description': f"Discount Applied - {rec.reason} (Approved by: {rec.approved_by.name})",
                'debit': 0.0,
                'credit': discount_amount,
                'status': 'paid',
                'company_id': rec.company_id.id,
            })
            rec.state = 'confirmed'

    def action_cancel(self):
        for rec in self:
            if rec.state == 'confirmed':
                ledger_entries = self.env['education.student.ledger'].search([
                    ('student_id', '=', rec.student_id.id),
                    ('ref', '=', f"DISC/{rec.id}"),
                ])
                ledger_entries.unlink()
            rec.state = 'cancelled'