from odoo import models, fields, api
import logging
from markupsafe import Markup

_logger = logging.getLogger(__name__)

class KpiPeriodLine(models.Model):
    _name = 'kpi.period.line'
    _description = 'KPI Period Line (Worksheet)'
    _order = 'sequence, id'

    line_id = fields.Many2one('kpi.kpi.line', string='KPI Line', required=True, ondelete='cascade')
    name = fields.Char(string='Period', required=True)
    sequence = fields.Integer(string='Sequence', default=10)
    
    date_start = fields.Date(string='Start Date')
    date_end = fields.Date(string='End Date')
    
    realization = fields.Float(string='Realization', digits=(16, 2))
    target = fields.Float(string='Target (Period)', digits=(16, 2))
    
    state = fields.Selection([
        ('draft', 'Open'),
        ('closed', 'Closed'),
    ], string='Status', default='draft')

    def write(self, vals):
        # Track changes for visualization in chatter of the parent KPI
        tracked_fields = {'realization', 'target', 'state'}
        fields_to_check = tracked_fields.intersection(vals.keys())

        if fields_to_check:
            # Store old values to compare
            old_values = {rec.id: {f: rec[f] for f in fields_to_check} for rec in self}
            
            # Perform write
            result = super(KpiPeriodLine, self).write(vals)
            
            # Check and log
            for rec in self:
                for field in fields_to_check:
                    old_val = old_values[rec.id].get(field)
                    new_val = vals.get(field)
                    
                    # Handle comparisons safely
                    changed = False
                    if self._fields[field].type == 'float':
                        if float(old_val or 0.0) != float(new_val or 0.0):
                            changed = True
                    else:
                        if old_val != new_val:
                            changed = True
                            
                    if changed:
                        parent_kpi = rec.line_id.kpi_id
                        if parent_kpi:
                            field_label = self._fields[field].string
                            # Format values for display (mapped selection, etc) not fully implemented here but using raw strings for now is usually fine for floats/simple selects
                            # For State showing label would be better but raw value is understandable for "draft/closed"
                            
                            body = Markup("KPI Line <b>%s</b> - Period <b>%s</b> updated %s: %s &rarr; %s") % (
                                rec.line_id.name, 
                                rec.name, 
                                field_label,
                                old_val, 
                                new_val
                            )
                            parent_kpi.message_post(body=body)
            return result
        
        return super(KpiPeriodLine, self).write(vals)