"""Cached AI-generated commentary for a report run.

One row per (report, period_from, period_to, comparison_mode, company).
Refreshed on demand or via cron when the underlying data has changed."""

from odoo import _, api, fields, models


class FusionReportCommentary(models.Model):
    _name = "fusion.report.commentary"
    _description = "AI-Generated Report Commentary Cache"
    _order = "generated_at desc"

    report_id = fields.Many2one('fusion.report', required=True, ondelete='cascade')
    company_id = fields.Many2one('res.company', required=True,
                                 default=lambda self: self.env.company)
    period_from = fields.Date(required=True)
    period_to = fields.Date(required=True)
    comparison_mode = fields.Selection([
        ('none', 'None'),
        ('previous_period', 'Previous Period'),
        ('previous_year', 'Previous Year'),
    ], default='none', required=True)

    summary = fields.Text()
    highlights = fields.Json()  # list of strings
    concerns = fields.Json()    # list of strings
    next_actions = fields.Json()  # list of strings

    generated_at = fields.Datetime(default=fields.Datetime.now, required=True)
    generated_by = fields.Selection([
        ('on_demand', 'On Demand'),
        ('cron', 'Cron'),
        ('templated', 'Templated Fallback'),
    ], default='on_demand', required=True)

    provider = fields.Char(help="LLM provider used (e.g. 'openai', 'claude', 'local'). "
                                "Empty for templated fallback.")

    _unique_period = models.Constraint(
        'UNIQUE(report_id, company_id, period_from, period_to, comparison_mode)',
        'Only one commentary cache row per report+period+mode.',
    )