# -*- coding: utf-8 -*-
# pyrefly: ignore [missing-import]
from odoo import api, fields, models
# pyrefly: ignore [missing-import]
from odoo.exceptions import ValidationError
import base64

MAX_FILE_SIZE_BYTES = 5 * 1024 * 1024  # 5 MB


class EducationStudentDocument(models.Model):
    _name = 'education.student.document'
    _description = 'Student Document'
    _inherit = ['mail.thread', 'mail.activity.mixin']
    _order = 'upload_date desc, id desc'

    name = fields.Char(string='Document Title', required=True, tracking=True)
    student_id = fields.Many2one(
        'education.student',
        string='Student',
        required=True,
        ondelete='cascade',
        index=True,
        tracking=True
    )
    category = fields.Selection([
        ('identity', 'Identity Proof'),
        ('academic', 'Academic Certificate / Marksheet'),
        ('transfer', 'Transfer / Migration Certificate'),
        ('address', 'Address Proof'),
        ('other', 'Other Document'),
    ], string='Category', required=True, default='academic', tracking=True)

    document_file = fields.Binary(string='Document File', required=True, attachment=True)
    file_name = fields.Char(string='Filename')
    file_size = fields.Integer(string='File Size (Bytes)', compute='_compute_file_metadata', store=True)
    mime_type = fields.Char(string='MIME Type')

    verification_status = fields.Selection([
        ('submitted', 'Submitted'),
        ('verified', 'Verified'),
        ('rejected', 'Rejected'),
    ], string='Verification Status', default='submitted', required=True, tracking=True, index=True)

    verified_by = fields.Many2one('res.users', string='Verified By', readonly=True, tracking=True)
    verification_date = fields.Datetime(string='Verification Date', readonly=True, tracking=True)
    rejection_reason = fields.Text(string='Rejection Reason', tracking=True)
    upload_date = fields.Datetime(string='Upload Date', default=fields.Datetime.now, readonly=True)

    company_id = fields.Many2one(
        'res.company',
        string='Company',
        related='student_id.company_id',
        store=True,
        index=True
    )

    @api.depends('document_file')
    def _compute_file_metadata(self):
        for rec in self:
            if rec.document_file:
                try:
                    decoded = base64.b64decode(rec.document_file)
                    rec.file_size = len(decoded)
                except Exception:
                    rec.file_size = 0
            else:
                rec.file_size = 0

    @api.constrains('document_file', 'file_name')
    def _check_file_validity(self):
        for rec in self:
            if rec.document_file:
                decoded = base64.b64decode(rec.document_file)
                if len(decoded) > MAX_FILE_SIZE_BYTES:
                    raise ValidationError(f"File size exceeds the maximum allowed limit of 5 MB ({len(decoded)} bytes).")
                if rec.file_name:
                    ext = rec.file_name.split('.')[-1].lower() if '.' in rec.file_name else ''
                    if ext not in ['pdf', 'jpg', 'jpeg', 'png']:
                        raise ValidationError("Invalid file type. Allowed formats: PDF, JPG, JPEG, PNG.")

    def action_verify(self):
        for rec in self:
            if not (self.env.is_admin() or self.env.user.has_group('education_student.group_education_student_user')):
                raise ValidationError("Only authorized staff can verify student documents.")
            rec.write({
                'verification_status': 'verified',
                'verified_by': self.env.user.id,
                'verification_date': fields.Datetime.now(),
                'rejection_reason': False,
            })

    def action_reject(self, reason="Document details could not be verified."):
        for rec in self:
            if not (self.env.is_admin() or self.env.user.has_group('education_student.group_education_student_user')):
                raise ValidationError("Only authorized staff can reject student documents.")
            rec.write({
                'verification_status': 'rejected',
                'verified_by': self.env.user.id,
                'verification_date': fields.Datetime.now(),
                'rejection_reason': reason,
            })