from odoo import api, fields, models

class CourseChapterResource(models.Model):
    _name = 'course.chapter.resource'
    _description = '章节资源'
    _rec_name = 'name'
    _order = 'chapter_id, sequence, id'

    name = fields.Char(string='资源名称', required=True)
    sequence = fields.Integer(string='序号', default=10)
    description = fields.Text(string='备注说明')
    chapter_id = fields.Many2one('course.chapter', string='所属章节', required=True)
    course_id = fields.Many2one(related="chapter_id.course_id", string='所属课程', required=True, ondelete='cascade')
    chapter_name = fields.Char(related="chapter_id.name", string="章节名称", readonly=True)
    chapter_sequence = fields.Integer(related="chapter_id.sequence", string="章节序号", readonly=True)
    chapter_is_published = fields.Boolean(related="chapter_id.is_published", string="章节发布状态", readonly=True)
    resource_type = fields.Selection([
        ('video', '视频'),
        ('pdf', 'PDF文档'),
        ('ppt', 'PPT演示文稿'),
        ('other', '其他'),
    ], string='资源类型', required=True)
    video_file = fields.Binary(string='视频文件', attachment=True)
    video_filename = fields.Char(string='视频文件名')
    video_url = fields.Char(string='视频链接')
    video_duration = fields.Integer(string='时长(秒)')
    doc_file = fields.Binary(string='文档文件', attachment=True)
    doc_filename = fields.Char(string='文档文件名')
    doc_page_count = fields.Integer(string='页数')
    # 添加教学班关联（可选，资源可共享给所有教学班）
    teaching_class_id = fields.Many2one('course.teaching_class', string='教学班',
                                        ondelete='cascade')
    preview_url = fields.Char(string='预览链接', compute='_compute_preview_url')
    is_hidden = fields.Boolean(string='是否隐藏', default=False)

    course_name = fields.Char(related="chapter_id.course_id.name", string="课程名称", readonly=True)
    course_code = fields.Char(related="chapter_id.course_id.code", string="课程代码", readonly=True)
    course_credit = fields.Float(related="chapter_id.course_id.credit", string="学分", readonly=True)

    # 新增：批量上传附件字段（核心）
    resource_attachment_ids = fields.Many2many(
        comodel_name='ir.attachment',
        relation='course_chapter_resource_attachment_rel',
        column1='resource_id',
        column2='attachment_id',
        string='批量上传资源附件',
    )
    # 新增：附件数量统计（可选，用于列表显示）
    attachment_count = fields.Integer(string="附件数", compute="_compute_attachment_count")

    @api.depends('resource_attachment_ids')
    def _compute_attachment_count(self):
        for rec in self:
            rec.attachment_count = len(rec.resource_attachment_ids)

    def _compute_preview_url(self):
        for record in self:
            # 优先使用批量附件中的第一个文件作为预览链接
            if record.resource_attachment_ids:
                first_attachment = record.resource_attachment_ids[0]
                record.preview_url = f'/web/content/{first_attachment.id}?download=false'
            elif record.resource_type == 'video' and record.video_file:
                record.preview_url = f'/web/content/course.chapter.resource/{record.id}/video_file'
            elif record.resource_type in ['pdf', 'ppt'] and record.doc_file:
                record.preview_url = f'/web/content/course.chapter.resource/{record.id}/doc_file'
            else:
                record.preview_url = False

    def action_toggle_hide(self):
        self.is_hidden = not self.is_hidden

    def action_preview(self):
        self.ensure_one()
        if self.preview_url:
            return {
                'type': 'ir.actions.act_url',
                'url': self.preview_url,
                'target': 'new'
            }
        return False