import base64
import logging

from odoo import fields, http
from odoo.http import request

_logger = logging.getLogger(__name__)


def _require_login(path):
    """Redirect to login if visitor is not authenticated."""
    if request.env.user._is_public():
        return request.redirect(f'/web/login?redirect={path}')
    return None


class SchoolAssignmentController(http.Controller):

    def _get_student_for_user(self):
        """Return the community.school.student record linked to the current portal user."""
        partner = request.env.user.partner_id
        return request.env['community.school.student'].sudo().search(
            [('partner_id', '=', partner.id)], limit=1
        )

    def _get_teacher_classes(self):
        partner = request.env.user.partner_id
        return request.env['community.school.class'].sudo().search(
            [('teacher_id', '=', partner.id)]
        )

    # ─────────────────────────────────────────────────────────────
    #  TEACHER: Create / manage assignments
    # ─────────────────────────────────────────────────────────────

    @http.route('/school/assignments/teacher', type='http', auth='public', website=True)
    def teacher_assignment_list(self, **kwargs):
        redirect = _require_login('/school/assignments/teacher')
        if redirect:
            return redirect
        classes = self._get_teacher_classes()
        if not classes:
            return request.render('community_school.portal_no_classes', {})
        assignments = request.env['community.school.assignment'].sudo().search(
            [('class_id', 'in', classes.ids)], order='due_date asc'
        )
        return request.render('community_school.portal_teacher_assignment_list', {
            'assignments': assignments,
            'classes': classes,
        })

    @http.route('/school/assignments/teacher/new', type='http', auth='public', website=True)
    def teacher_assignment_new(self, **kwargs):
        redirect = _require_login('/school/assignments/teacher/new')
        if redirect:
            return redirect
        classes = self._get_teacher_classes()
        if not classes:
            return request.render('community_school.portal_no_classes', {})

        if request.httprequest.method == 'POST':
            class_id = int(kwargs.get('class_id', 0))
            klass = classes.filtered(lambda c: c.id == class_id)
            if not klass:
                return request.redirect('/school/assignments/teacher')
            vals = {
                'name': kwargs.get('title', '').strip(),
                'class_id': class_id,
                'description': kwargs.get('description', '').strip() or False,
                'due_date': kwargs.get('due_date') or False,
                'max_score': int(kwargs.get('max_score') or 100),
                'state': 'published',
            }
            request.env['community.school.assignment'].sudo().create(vals)
            return request.redirect('/school/assignments/teacher')

        return request.render('community_school.portal_teacher_assignment_form', {
            'classes': classes,
            'assignment': None,
        })

    @http.route('/school/assignments/teacher/<int:assignment_id>/edit',
                type='http', auth='public', website=True)
    def teacher_assignment_edit(self, assignment_id, **kwargs):
        redirect = _require_login(f'/school/assignments/teacher/{assignment_id}/edit')
        if redirect:
            return redirect
        classes = self._get_teacher_classes()
        assignment = request.env['community.school.assignment'].sudo().browse(assignment_id)
        if not assignment.exists() or assignment.class_id not in classes:
            return request.redirect('/school/assignments/teacher')

        if request.httprequest.method == 'POST':
            vals = {
                'name': kwargs.get('title', '').strip(),
                'class_id': int(kwargs.get('class_id', assignment.class_id.id)),
                'description': kwargs.get('description', '').strip() or False,
                'due_date': kwargs.get('due_date') or False,
                'max_score': int(kwargs.get('max_score') or 100),
            }
            action = kwargs.get('action_state')
            if action == 'publish':
                vals['state'] = 'published'
            elif action == 'close':
                vals['state'] = 'closed'
            elif action == 'draft':
                vals['state'] = 'draft'
            assignment.write(vals)
            return request.redirect('/school/assignments/teacher')

        return request.render('community_school.portal_teacher_assignment_form', {
            'classes': classes,
            'assignment': assignment,
        })

    @http.route('/school/assignments/teacher/<int:assignment_id>/submissions',
                type='http', auth='public', website=True)
    def teacher_view_submissions(self, assignment_id, **kwargs):
        redirect = _require_login(f'/school/assignments/teacher/{assignment_id}/submissions')
        if redirect:
            return redirect
        classes = self._get_teacher_classes()
        assignment = request.env['community.school.assignment'].sudo().browse(assignment_id)
        if not assignment.exists() or assignment.class_id not in classes:
            return request.redirect('/school/assignments/teacher')

        submissions = request.env['community.school.submission'].sudo().search(
            [('assignment_id', '=', assignment_id)]
        )
        return request.render('community_school.portal_teacher_submissions', {
            'assignment': assignment,
            'submissions': submissions,
        })

    @http.route('/school/assignments/teacher/submission/<int:submission_id>/grade',
                type='http', auth='public', website=True, methods=['POST'])
    def teacher_grade_submission(self, submission_id, **kwargs):
        redirect = _require_login(f'/school/assignments/teacher/submission/{submission_id}/grade')
        if redirect:
            return redirect
        classes = self._get_teacher_classes()
        submission = request.env['community.school.submission'].sudo().browse(submission_id)
        if not submission.exists() or submission.assignment_id.class_id not in classes:
            return request.redirect('/school/assignments/teacher')

        score = kwargs.get('score', '').strip()
        feedback = kwargs.get('feedback', '').strip()
        vals = {'feedback': feedback or False, 'state': 'graded'}
        if score.isdigit():
            vals['score'] = int(score)
        submission.write(vals)
        return request.redirect(
            f'/school/assignments/teacher/{submission.assignment_id.id}/submissions'
        )

    # ─────────────────────────────────────────────────────────────
    #  STUDENT: View assignments & upload submissions
    # ─────────────────────────────────────────────────────────────

    @http.route('/school/assignments/student', type='http', auth='public', website=True)
    def student_assignment_list(self, **kwargs):
        redirect = _require_login('/school/assignments/student')
        if redirect:
            return redirect
        student = self._get_student_for_user()
        if not student:
            return request.render('community_school.portal_no_student', {})

        enrolled_class_ids = student.enrollment_ids.filtered(
            lambda e: e.state == 'enrolled'
        ).mapped('class_id').ids

        assignments = request.env['community.school.assignment'].sudo().search(
            [('class_id', 'in', enrolled_class_ids), ('state', '=', 'published')],
            order='due_date asc',
        )
        # Build map of existing submissions for this student
        my_submissions = request.env['community.school.submission'].sudo().search(
            [('student_id', '=', student.id), ('assignment_id', 'in', assignments.ids)]
        )
        submission_by_assignment = {s.assignment_id.id: s for s in my_submissions}

        return request.render('community_school.portal_student_assignment_list', {
            'assignments': assignments,
            'submission_by_assignment': submission_by_assignment,
            'student': student,
        })

    @http.route('/school/assignments/student/<int:assignment_id>',
                type='http', auth='public', website=True)
    def student_assignment_detail(self, assignment_id, **kwargs):
        redirect = _require_login(f'/school/assignments/student/{assignment_id}')
        if redirect:
            return redirect
        student = self._get_student_for_user()
        if not student:
            return request.render('community_school.portal_no_student', {})

        assignment = request.env['community.school.assignment'].sudo().browse(assignment_id)
        if not assignment.exists() or assignment.state != 'published':
            return request.redirect('/school/assignments/student')

        # Verify student is enrolled in this class
        enrollment = student.enrollment_ids.filtered(
            lambda e: e.class_id.id == assignment.class_id.id and e.state == 'enrolled'
        )
        if not enrollment:
            return request.redirect('/school/assignments/student')

        existing_submission = request.env['community.school.submission'].sudo().search(
            [('assignment_id', '=', assignment_id), ('student_id', '=', student.id)], limit=1
        )

        if request.httprequest.method == 'POST':
            if existing_submission:
                return request.redirect(f'/school/assignments/student/{assignment_id}')

            notes = kwargs.get('notes', '').strip()
            file_upload = request.httprequest.files.get('submission_file')
            attachment_data = False
            attachment_name = False
            if file_upload and file_upload.filename:
                try:
                    attachment_data = base64.b64encode(file_upload.read())
                    attachment_name = file_upload.filename
                except Exception:
                    _logger.warning('Failed to read uploaded submission file')

            request.env['community.school.submission'].sudo().create({
                'assignment_id': assignment_id,
                'enrollment_id': enrollment[0].id,
                'notes': notes or False,
                'attachment_data': attachment_data,
                'attachment_name': attachment_name,
                'submitted_on': fields.Datetime.now(),
                'state': 'submitted',
            })
            return request.redirect(f'/school/assignments/student/{assignment_id}')

        return request.render('community_school.portal_student_assignment_detail', {
            'assignment': assignment,
            'submission': existing_submission,
            'student': student,
        })