# Copyright 2025 Codeium
# License LGPL-3.0 or later (https://www.gnu.org/licenses/lgpl-3.0.html)

"""Synchronization Queue Management.

This module implements the queue system for managing synchronization operations
between Odoo instances. It handles the scheduling, retry logic, and status
tracking of synchronization tasks.
"""

import json
import logging

from odoo import api, fields, models

_logger = logging.getLogger(__name__)

class OdooSyncQueue(models.Model):
    _name = 'odoo.sync.queue'
    _description = 'Synchronization Queue'
    _order = 'priority desc, retry_count, create_date'

    name = fields.Char(
        string='Name', 
        compute='_compute_name', 
        store=True
    )

    model_id = fields.Many2one(
        comodel_name='odoo.sync.model',
        string='Model',
        required=True
    )

    record_id = fields.Integer(
        string='Record ID', 
        required=True
    )

    operation = fields.Selection(
        selection=[
            ('create', 'Create'),
            ('write', 'Update'),
            ('unlink', 'Delete')
        ],
        required=True
    )

    state = fields.Selection(
        selection=[
            ('draft', 'Draft'),
            ('pending', 'Pending'),
            ('processing', 'Processing'),
            ('done', 'Done'),
            ('error', 'Error'),
            ('cancelled', 'Cancelled')
        ],
        default='draft', 
        required=True
    )

    priority = fields.Integer(
        string='Priority', 
        default=1
    )

    retry_count = fields.Integer(
        string='Retry Count', 
        default=0
    )

    max_retries = fields.Integer(
        string='Max Retries', 
        default=3
    )

    next_retry = fields.Datetime(
        string='Next Retry'
    )

    data = fields.Text(
        string='Data', 
        help='JSON data to synchronize'
    )

    error_message = fields.Text(
        string='Error Message'
    )

    log_ids = fields.One2many(
        comodel_name='odoo.sync.log', 
        inverse_name='queue_id', 
        string='Logs'
    )

    @api.depends('model_id', 'record_id', 'operation')
    def _compute_name(self):
        """Compute the display name of the queue entry.
        
        The name is generated using the format: 'operation - model_name#record_id'
        e.g., 'create - res.partner#42'
        
        Triggered by changes to: model_id, record_id, or operation fields.
        """
        for record in self:
            record.name = f'{record.operation} - {record.model_id.name}#{record.record_id}'

    def action_reset(self):
        """Reset a failed queue entry to pending state.
        
        This method:
        - Changes state back to 'pending'
        - Resets retry count to 0
        - Clears error message and next retry time
        
        Returns:
            dict: Result of the write operation
        """
        return self.write({
            'state': 'pending',
            'retry_count': 0,
            'error_message': False,
            'next_retry': False
        })

    def action_cancel(self):
        """Cancel the queue entry.
        
        Changes the state of the queue entry to 'cancelled',
        preventing further processing attempts.
        
        Returns:
            dict: Result of the write operation
        """
        return self.write({'state': 'cancelled'})

    @api.model
    def _process_sync_queue(self):
        """Process pending synchronization queue entries.
        
        This method is called by the cron job to process pending queue entries.
        It will:
        1. Find pending entries that are ready for processing
        2. Process each entry according to its operation type
        3. Update the entry status and create log entries
        
        Returns:
            bool: True if processing completed successfully
        """
        # Find pending entries ready for processing
        domain = [
            ('state', '=', 'pending'),
            '|',
            ('next_retry', '=', False),
            ('next_retry', '<=', fields.Datetime.now())
        ]
        entries = self.search(domain, order='priority desc, retry_count, create_date')
        
        for entry in entries:
            try:
                # Mark as processing
                entry.write({'state': 'processing'})
                
                # TODO: Implement actual synchronization logic here
                # This will be implemented in a future update
                
                # For now, just mark as done
                entry.write({'state': 'done'})
                
                # Create success log
                self.env['odoo.sync.log'].create({
                    'queue_id': entry.id,
                    'state': 'success',
                    'message': 'Synchronization completed successfully'
                })
                
            except Exception as e:
                _logger.error('Error processing queue entry %s: %s', entry.name, str(e))
                
                # Update retry count and status
                vals = {
                    'state': 'error',
                    'retry_count': entry.retry_count + 1,
                    'error_message': str(e)
                }
                
                # Schedule next retry if not exceeded max retries
                if entry.retry_count < entry.max_retries:
                    vals.update({
                        'state': 'pending',
                        'next_retry': fields.Datetime.now() + timedelta(minutes=5 * (entry.retry_count + 1))
                    })
                
                entry.write(vals)
                
                # Create error log
                self.env['odoo.sync.log'].create({
                    'queue_id': entry.id,
                    'state': 'error',
                    'message': str(e),
                    'details': str(e)
                })
        
        return True