# -*- coding: utf-8 -*-
"""
itsulu.blog.topic — Topic queue for AI blog post generation.

Topics come from ITSulu's (or the deploying company's) service portfolio.
Users curate this list in the backend; the scheduler pops the highest-priority
pending topic for each generation run.
"""
from odoo import api, fields, models
from odoo.exceptions import ValidationError


class BlogTopic(models.Model):
    _name = 'itsulu.blog.topic'
    _description = 'Blog Publisher — Topic Queue'
    _order = 'priority_order asc, sequence asc, id asc'

    # ------------------------------------------------------------------ #
    # Fields                                                               #
    # ------------------------------------------------------------------ #

    name = fields.Char(
        string='Topic / Title Hint',
        required=True,
        help='What the blog post should be about. Can be a title, a question, '
             'or a brief description. The LLM will elaborate from this.',
    )

    sequence = fields.Integer(
        string='Sequence',
        default=10,
        help='Lower number = picked first within the same priority level.',
    )

    priority = fields.Selection(
        selection=[
            ('low',    'Low'),
            ('normal', 'Normal'),
            ('high',   'High'),
            ('urgent', 'Urgent'),
        ],
        string='Priority',
        default='normal',
        required=True,
        index=True,
    )

    # Numeric equivalent for clean ordering in _order
    priority_order = fields.Integer(
        string='Priority Order',
        compute='_compute_priority_order',
        store=True,
        help='Computed from priority for clean DB ordering.',
    )

    state = fields.Selection(
        selection=[
            ('pending', 'Pending'),
            ('used',    'Used'),
            ('skipped', 'Skipped'),
        ],
        string='State',
        default='pending',
        required=True,
        index=True,
    )

    blog_id = fields.Many2one(
        comodel_name='blog.blog',
        string='Target Blog',
        ondelete='set null',
        help='Optional — force this topic to publish to a specific blog. '
             'If blank, the schedule slot\'s configured blog is used.',
    )

    notes = fields.Text(
        string='Notes / Context',
        help='Additional context for the LLM — e.g. specific services to highlight, '
             'recent news to reference, or a preferred angle.',
    )

    tone = fields.Char(
        string='Tone Override',
        help='E.g. "technical", "beginner-friendly", "thought leadership". '
             'Overrides the schedule slot\'s default tone.',
    )

    used_date = fields.Datetime(
        string='Used On',
        readonly=True,
        help='Timestamp when this topic was sent to the LLM.',
    )

    generation_log_id = fields.Many2one(
        comodel_name='itsulu.blog.generation.log',
        string='Generation Log',
        readonly=True,
        ondelete='set null',
    )

    # ------------------------------------------------------------------ #
    # Computed fields                                                      #
    # ------------------------------------------------------------------ #

    @api.depends('priority')
    def _compute_priority_order(self):
        _map = {'urgent': 1, 'high': 2, 'normal': 3, 'low': 4}
        for rec in self:
            rec.priority_order = _map.get(rec.priority, 3)

    # ------------------------------------------------------------------ #
    # Constraints                                                          #
    # ------------------------------------------------------------------ #

    @api.constrains('name')
    def _check_name_not_empty(self):
        for rec in self:
            if not (rec.name or '').strip():
                raise ValidationError("Topic name cannot be empty.")

    # ------------------------------------------------------------------ #
    # Business logic                                                       #
    # ------------------------------------------------------------------ #

    @api.model
    def get_next_topic(self):
        """
        Return the single highest-priority pending topic, or an empty recordset.
        Priority order: urgent > high > normal > low.
        Within the same priority, sequence ASC then id ASC.
        """
        return self.search([('state', '=', 'pending')], limit=1)

    def mark_used(self, generation_log=None):
        """Set state to 'used' and record the timestamp."""
        self.ensure_one()
        vals = {
            'state': 'used',
            'used_date': fields.Datetime.now(),
        }
        if generation_log:
            vals['generation_log_id'] = generation_log.id
        self.write(vals)

    def action_mark_pending(self):
        """Reset a used/skipped topic back to pending for re-use."""
        self.write({'state': 'pending', 'used_date': False, 'generation_log_id': False})

    def action_mark_skipped(self):
        self.write({'state': 'skipped'})