from odoo import models, fields, api
from dateutil.relativedelta import relativedelta
class LoanContract(models.Model):
    _name = 'loan.contract'
    _description = 'Loan Contract'

    code_contract = fields.Char(
        string='Contract Code',
        required=True,
        copy=False,
        readonly=True,
        default=lambda self: self.env['ir.sequence'].next_by_code('loan.contract')
    )
    repayment_line_ids = fields.One2many('repayment.line', 'contract_id', string='Lịch trả nợ')
    loan_request_id = fields.Many2one(
        'loan.request',
        string='Loan Request',
        required=True,
        ondelete='restrict'
    )

    borrower_id = fields.Many2one(
        'loan.borrower',
        string='Borrower',
        required=True,
        ondelete='restrict'
    )

    loan_type_id = fields.Many2one(
        'loan.type1',
        string='Loan Type',
        readonly=True
    )

    amount = fields.Float(
        string='Loan Amount',
        required=True
    )

    term = fields.Integer(
        string='Term (Months)',
        required=True
    )
    payment_method = fields.Selection([
        ('cash', 'Cash'),
        ('bank_transfer', 'Bank Transfer'),
        ('check', 'Check')
    ], string='Payment Method', required=True, default='cash',readonly=True)

    repayment_type = fields.Selection([
        ('fixed_principal', 'Trả gốc đều, lãi giảm dần'),
        ('annuity', 'Trả góp đều (gốc + lãi)'),
        ('interest_only', 'Chỉ trả lãi hàng kỳ, gốc trả cuối'),
        ('lump_sum', 'Trả 1 lần cuối kỳ'),
    ], string='Kiểu trả nợ', required=True, readonly=True)

    interest_rate = fields.Float(
        string='Interest Rate (%)',
        required=True
    )

    processing_fee = fields.Float(
        string='Processing Fee',
        compute='_compute_processing_fee_amount_count',
        store=True,
        readonly=True
    )

    amount_count = fields.Float(
        string='Amount Count',
        compute='_compute_processing_fee_amount_count',
        store=True,
        readonly=True
    )

    start_date = fields.Date(
        string='Start Date',
        required=True,
        default=fields.Date.context_today
    )

    end_date = fields.Date(
        string='End Date',
        compute='_compute_end_date',
        store=True,
        readonly=True,
    )

    state = fields.Selection([
        ('draft', 'Draft'),
        ('active', 'Active'),
        ('done', 'Completed'),
        ('cancelled', 'Cancelled')
    ], string='Status', default='draft')

    note = fields.Text(string='Notes')

    @api.depends('start_date', 'term')
    def _compute_end_date(self):
        for rec in self:
            if rec.start_date and rec.term:
                rec.end_date = rec.start_date + relativedelta(months=rec.term)
            else:
                rec.end_date = False

    @api.onchange('loan_request_id')
    def _onchange_loan_request_id(self):
        for rec in self:
            if rec.loan_request_id:
                rec.borrower_id = rec.loan_request_id.borrower_id
                rec.loan_type_id = rec.loan_request_id.loan_type_id
                rec.amount = rec.loan_request_id.amount
                rec.interest_rate = rec.loan_request_id.interest_rate
                rec.term = rec.loan_request_id.term
                rec.repayment_type = rec.loan_request_id.repayment_type

    @api.depends('loan_request_id')
    def _compute_processing_fee_amount_count(self):
        for rec in self:
            if rec.loan_request_id:
                rec.tinterest_rate = rec.loan_request_id.interest_rate or 0.0
                rec.amount = rec.loan_request_id.amount or 0.0
                rec.processing_fee = rec.amount - (rec.amount * rec.rate / 100)
                rec.amount_count = rec.amount + rec.processing_fee
            else:
                rec.processing_fee = 0.0
                rec.amount_count = 0.0
    @api.model
    def create(self, vals):
        if vals.get('loan_request_id'):
            request = self.env['loan.request'].browse(vals['loan_request_id'])
            vals['repayment_type'] = request.repayment_type
            vals['payment_method'] = request.payment_method

            return super().create(vals)
    @api.model
    def write(self, vals):
        res = super().write(vals)
        for contract in self:
            if vals.get('state') == 'active':
                contract._generate_repayment_schedule()
        return res
    def _generate_repayment_schedule(self):
        self.repayment_line_ids.unlink()  # Xóa cũ nếu có
        start_date = self.start_date
        monthly_rate = self.interest_rate / 100 / 12
        principal = self.amount
        term = self.term

        for i in range(1, term + 1):
            due_date = start_date + relativedelta(months=i)
            if self.repayment_type == 'fixed_principal':
                principal_amount = principal / term
                remaining = principal - principal_amount * (i - 1)
                interest = remaining * monthly_rate
            elif self.repayment_type == 'annuity':
                annuity = principal * monthly_rate / (1 - (1 + monthly_rate) ** (-term))
                interest = (principal - (i - 1) * (annuity - principal * monthly_rate)) * monthly_rate
                principal_amount = annuity - interest
            elif self.repayment_type == 'interest_only':
                principal_amount = 0.0 if i < term else principal
                interest = principal * monthly_rate
            elif self.repayment_type == 'lump_sum':
                principal_amount = principal if i == term else 0.0
                interest = principal * monthly_rate if i == term else 0.0
            else:
                principal_amount = interest = 0.0

            self.env['repayment.line'].create({
            'contract_id': self.id,
            'installment': i,
            'due_date': due_date,
            'principal': principal_amount,
            'interest': interest,
            'total': principal_amount + interest,
        })