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


class EducationLibraryMember(models.Model):
    _name = 'education.library.member'
    _description = 'Library Member'
    _rec_name = 'member_number'

    member_number = fields.Char(string='Member Number', required=True, copy=False)
    member_type = fields.Selection([
        ('student', 'Student'),
        ('faculty', 'Faculty'),
        ('staff', 'Staff')
    ], string='Member Type', required=True, default='student')
    
    student_id = fields.Many2one('education.student', string='Student')
    user_id = fields.Many2one('res.users', string='Related User')
    library_id = fields.Many2one('education.library', string='Library', required=True)
    
    membership_start = fields.Date(string='Membership Start Date', default=fields.Date.context_today)
    membership_end = fields.Date(string='Membership End Date')
    issue_limit = fields.Integer(string='Issue Limit', compute='_compute_issue_limit', store=True, readonly=False)
    active = fields.Boolean(default=True)

    issue_ids = fields.One2many('education.library.issue', 'member_id', string='Issues')

    _member_number_unique = models.Constraint('unique(member_number)', 'Member Number must be unique!')

    @api.constrains('student_id', 'member_type', 'active')
    def _check_student_member(self):
        for record in self:
            if record.member_type == 'student' and not record.student_id:
                raise ValidationError(_('Student member must reference a student record.'))
            if record.student_id and record.active:
                existing = self.search([('student_id', '=', record.student_id.id), ('id', '!=', record.id), ('active', '=', True)])
                if existing:
                    raise ValidationError(_('A student can only have one active membership.'))

    @api.depends('member_type')
    def _compute_issue_limit(self):
        # We fetch default limit from settings
        student_limit = int(self.env['ir.config_parameter'].sudo().get_param('education_library.student_issue_limit', 3))
        faculty_limit = int(self.env['ir.config_parameter'].sudo().get_param('education_library.faculty_issue_limit', 5))
        
        for record in self:
            if not record.issue_limit:
                if record.member_type == 'student':
                    record.issue_limit = student_limit
                else:
                    record.issue_limit = faculty_limit

    @api.onchange('student_id')
    def _onchange_student_id(self):
        if self.student_id and self.student_id.portal_user_id:
            self.user_id = self.student_id.portal_user_id.id