# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.

from odoo import api, fields, models, SUPERUSER_ID, _
from odoo.exceptions import UserError, ValidationError


class PosSession(models.Model):
    _name = 'pos.session'
    _order = 'id desc'
    _description = 'Point of Sale Session'

    POS_SESSION_STATE = [
        ('opening_control', 'Opening Control'),  # method action_pos_session_open
        ('opened', 'In Progress'),               # method action_pos_session_closing_control
        ('closing_control', 'Closing Control'),  # method action_pos_session_close
        ('closed', 'Closed & Posted'),
    ]

    def _confirm_orders(self):
        for session in self:
            company_id = session.config_id.journal_id.company_id.id
            orders = session.order_ids.filtered(lambda order: order.state == 'paid')
            journal_id = self.env['ir.config_parameter'].sudo().get_param(
                'pos.closing.journal_id_%s' % company_id, default=session.config_id.journal_id.id)
            if not journal_id:
                raise UserError(_("You have to set a Sale Journal for the POS:%s") % (session.config_id.name,))

            move = self.env['pos.order'].with_context(force_company=company_id)._create_account_move(session.start_at, session.name, int(journal_id), company_id)
            orders.with_context(force_company=company_id)._create_account_move_line(session, move)
            for order in session.order_ids.filtered(lambda o: o.state not in ['done', 'invoiced']):
                if order.state not in ('paid'):
                    raise UserError(
                        _("You cannot confirm all orders of this session, because they have not the 'paid' status.\n"
                          "{reference} is in state {state}, total amount: {total}, paid: {paid}").format(
                            reference=order.pos_reference or order.name,
                            state=order.state,
                            total=order.amount_total,
                            paid=order.amount_paid,
                        ))
                order.action_pos_order_done()
            orders_to_reconcile = session.order_ids._filtered_for_reconciliation()
            orders_to_reconcile.sudo()._reconcile_payments()

    config_id = fields.Many2one(
        'pos.config', string='Point of Sale',
        help="The physical point of sale you will use.",
        required=True,
        index=True)
    name = fields.Char(string='Session ID', required=True, readonly=True, default='/')
    user_id = fields.Many2one(
        'res.users', string='Responsible',
        required=True,
        index=True,
        readonly=True,
        states={'opening_control': [('readonly', False)]},
        default=lambda self: self.env.uid)
    currency_id = fields.Many2one('res.currency', related='config_id.currency_id', string="Currency", readonly=False)
    start_at = fields.Datetime(string='Opening Date', readonly=True)
    stop_at = fields.Datetime(string='Closing Date', readonly=True, copy=False)

    state = fields.Selection(
        POS_SESSION_STATE, string='Status',
        required=True, readonly=True,
        index=True, copy=False, default='opening_control')

    sequence_number = fields.Integer(string='Order Sequence Number', help='A sequence number that is incremented with each order', default=1)
    login_number = fields.Integer(string='Login Sequence Number', help='A sequence number that is incremented each time a user resumes the pos session', default=0)

    cash_control = fields.Boolean(compute='_compute_cash_all', string='Has Cash Control')
    cash_journal_id = fields.Many2one('account.journal', compute='_compute_cash_all', string='Cash Journal', store=True)
    cash_register_id = fields.Many2one('account.bank.statement', compute='_compute_cash_all', string='Cash Register', store=True)

    cash_register_balance_end_real = fields.Monetary(
        related='cash_register_id.balance_end_real',
        string="Ending Balance",
        help="Total of closing cash control lines.",
        readonly=True)
    cash_register_balance_start = fields.Monetary(
        related='cash_register_id.balance_start',
        string="Starting Balance",
        help="Total of opening cash control lines.",
        readonly=True)
    cash_register_total_entry_encoding = fields.Monetary(
        related='cash_register_id.total_entry_encoding',
        string='Total Cash Transaction',
        readonly=True,
        help="Total of all paid sales orders")
    cash_register_balance_end = fields.Monetary(
        related='cash_register_id.balance_end',
        digits=0,
        string="Theoretical Closing Balance",
        help="Sum of opening balance and transactions.",
        readonly=True)
    cash_register_difference = fields.Monetary(
        related='cash_register_id.difference',
        string='Difference',
        help="Difference between the theoretical closing balance and the real closing balance.",
        readonly=True)

    journal_ids = fields.Many2many(
        'account.journal',
        related='config_id.journal_ids',
        readonly=True,
        string='Available Payment Methods')
    order_ids = fields.One2many('pos.order', 'session_id',  string='Orders')
    statement_ids = fields.One2many('account.bank.statement', 'pos_session_id', string='Bank Statement', readonly=True)
    picking_count = fields.Integer(compute='_compute_picking_count')
    rescue = fields.Boolean(string='Recovery Session',
        help="Auto-generated session for orphan orders, ignored in constraints",
        readonly=True,
        copy=False)

    _sql_constraints = [('uniq_name', 'unique(name)', "The name of this POS Session must be unique !")]

    @api.multi
    def _compute_picking_count(self):
        for pos in self:
            pickings = pos.order_ids.mapped('picking_id').filtered(lambda x: x.state != 'done')
            pos.picking_count = len(pickings.ids)

    @api.multi
    def action_stock_picking(self):
        pickings = self.order_ids.mapped('picking_id').filtered(lambda x: x.state != 'done')
        action_picking = self.env.ref('stock.action_picking_tree_ready')
        action = action_picking.read()[0]
        action['context'] = {}
        action['domain'] = [('id', 'in', pickings.ids)]
        return action

    @api.depends('config_id', 'statement_ids')
    def _compute_cash_all(self):
        for session in self:
            session.cash_journal_id = session.cash_register_id = session.cash_control = False
            if session.config_id.cash_control:
                for statement in session.statement_ids:
                    if statement.journal_id.type == 'cash':
                        session.cash_control = True
                        session.cash_journal_id = statement.journal_id.id
                        session.cash_register_id = statement.id
                if not session.cash_control and session.state != 'closed':
                    raise UserError(_("Cash control can only be applied to cash journals."))

    @api.constrains('user_id', 'state')
    def _check_unicity(self):
        # open if there is no session in 'opening_control', 'opened', 'closing_control' for one user
        if self.search_count([
                ('state', 'not in', ('closed', 'closing_control')),
                ('user_id', '=', self.user_id.id),
                ('rescue', '=', False)
            ]) > 1:
            raise ValidationError(_("You cannot create two active sessions with the same responsible."))

    @api.constrains('config_id')
    def _check_pos_config(self):
        if self.search_count([
                ('state', '!=', 'closed'),
                ('config_id', '=', self.config_id.id),
                ('rescue', '=', False)
            ]) > 1:
            raise ValidationError(_("Another session is already opened for this point of sale."))

    @api.model
    def create(self, values):
        config_id = values.get('config_id') or self.env.context.get('default_config_id')
        if not config_id:
            raise UserError(_("You should assign a Point of Sale to your session."))

        # journal_id is not required on the pos_config because it does not
        # exists at the installation. If nothing is configured at the
        # installation we do the minimal configuration. Impossible to do in
        # the .xml files as the CoA is not yet installed.
        pos_config = self.env['pos.config'].browse(config_id)
        ctx = dict(self.env.context, company_id=pos_config.company_id.id)
        if not pos_config.journal_id:
            default_journals = pos_config.with_context(ctx).default_get(['journal_id', 'invoice_journal_id'])
            if (not default_journals.get('journal_id') or
                    not default_journals.get('invoice_journal_id')):
                raise UserError(_("Unable to open the session. You have to assign a sales journal to your point of sale."))
            pos_config.with_context(ctx).sudo().write({
                'journal_id': default_journals['journal_id'],
                'invoice_journal_id': default_journals['invoice_journal_id']})
        # define some cash journal if no payment method exists
        if not pos_config.journal_ids:
            Journal = self.env['account.journal']
            journals = Journal.with_context(ctx).search([('journal_user', '=', True), ('type', '=', 'cash')])
            if not journals:
                journals = Journal.with_context(ctx).search([('type', '=', 'cash')])
                if not journals:
                    journals = Journal.with_context(ctx).search([('journal_user', '=', True)])
            if not journals:
                raise ValidationError(_("No payment method configured! \nEither no Chart of Account is installed or no payment method is configured for this POS."))
            journals.sudo().write({'journal_user': True})
            pos_config.sudo().write({'journal_ids': [(6, 0, journals.ids)]})

        pos_name = self.env['ir.sequence'].with_context(ctx).next_by_code('pos.session')
        if values.get('name'):
            pos_name += ' ' + values['name']

        statements = []
        ABS = self.env['account.bank.statement']
        uid = SUPERUSER_ID if self.env.user.has_group('point_of_sale.group_pos_user') else self.env.user.id
        for journal in pos_config.journal_ids:
            # set the journal_id which should be used by
            # account.bank.statement to set the opening balance of the
            # newly created bank statement
            ctx['journal_id'] = journal.id if pos_config.cash_control and journal.type == 'cash' else False
            st_values = {
                'journal_id': journal.id,
                'user_id': self.env.user.id,
                'name': pos_name,
                'balance_start': self.env["account.bank.statement"]._get_opening_balance(journal.id) if journal.type == 'cash' else 0
            }

            statements.append(ABS.with_context(ctx).sudo(uid).create(st_values).id)

        values.update({
            'name': pos_name,
            'statement_ids': [(6, 0, statements)],
            'config_id': config_id
        })

        res = super(PosSession, self.with_context(ctx).sudo(uid)).create(values)
        if not pos_config.cash_control:
            res.action_pos_session_open()

        return res

    @api.multi
    def unlink(self):
        for session in self.filtered(lambda s: s.statement_ids):
            session.statement_ids.unlink()
        return super(PosSession, self).unlink()

    @api.multi
    def login(self):
        self.ensure_one()
        self.write({
            'login_number': self.login_number + 1,
        })

    @api.multi
    def action_pos_session_open(self):
        # second browse because we need to refetch the data from the DB for cash_register_id
        # we only open sessions that haven't already been opened
        for session in self.filtered(lambda session: session.state == 'opening_control'):
            values = {}
            if not session.start_at:
                values['start_at'] = fields.Datetime.now()
            values['state'] = 'opened'
            session.write(values)
            session.statement_ids.button_open()
        return True

    @api.multi
    def action_pos_session_closing_control(self):
        self._check_pos_session_balance()
        for session in self:
            session.write({'state': 'closing_control', 'stop_at': fields.Datetime.now()})
            if not session.config_id.cash_control:
                session.action_pos_session_close()

    @api.multi
    def _check_pos_session_balance(self):
        for session in self:
            for statement in session.statement_ids:
                if (statement != session.cash_register_id) and (statement.balance_end != statement.balance_end_real):
                    statement.write({'balance_end_real': statement.balance_end})

    @api.multi
    def action_pos_session_validate(self):
        self._check_pos_session_balance()
        self.action_pos_session_close()

    @api.multi
    def action_pos_session_close(self):
        # Close CashBox
        for session in self:
            company_id = session.config_id.company_id.id
            ctx = dict(self.env.context, force_company=company_id, company_id=company_id)
            ctx_notrack = dict(ctx, mail_notrack=True)
            for st in session.statement_ids:
                if abs(st.difference) > st.journal_id.amount_authorized_diff:
                    # The pos manager can close statements with maximums.
                    if not self.user_has_groups("point_of_sale.group_pos_manager"):
                        raise UserError(_("Your ending balance is too different from the theoretical cash closing (%.2f), the maximum allowed is: %.2f. You can contact your manager to force it.") % (st.difference, st.journal_id.amount_authorized_diff))
                if (st.journal_id.type not in ['bank', 'cash']):
                    raise UserError(_("The journal type for your payment method should be bank or cash."))
                st.with_context(ctx_notrack).sudo().button_confirm_bank()
        self.with_context(ctx)._confirm_orders()
        self.write({'state': 'closed'})
        return {
            'type': 'ir.actions.client',
            'name': 'Point of Sale Menu',
            'tag': 'reload',
            'params': {'menu_id': self.env.ref('point_of_sale.menu_point_root').id},
        }

    @api.multi
    def open_frontend_cb(self):
        if not self.ids:
            return {}
        for session in self.filtered(lambda s: s.user_id.id != self.env.uid):
            raise UserError(_("You cannot use the session of another user. This session is owned by %s. "
                              "Please first close this one to use this point of sale.") % session.user_id.name)
        return {
            'type': 'ir.actions.act_url',
            'target': 'self',
            'url':   '/pos/web/',
        }

    @api.multi
    def open_cashbox(self):
        self.ensure_one()
        context = dict(self._context)
        balance_type = context.get('balance') or 'start'
        context['bank_statement_id'] = self.cash_register_id.id
        context['balance'] = balance_type
        context['default_pos_id'] = self.config_id.id

        action = {
            'name': _('Cash Control'),
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': 'account.bank.statement.cashbox',
            'view_id': self.env.ref('account.view_account_bnk_stmt_cashbox').id,
            'type': 'ir.actions.act_window',
            'context': context,
            'target': 'new'
        }

        cashbox_id = None
        if balance_type == 'start':
            cashbox_id = self.cash_register_id.cashbox_start_id.id
        else:
            cashbox_id = self.cash_register_id.cashbox_end_id.id
        if cashbox_id:
            action['res_id'] = cashbox_id

        return action
