from odoo import api, fields, models


class EducationLibraryBook(models.Model):
    _name = 'education.library.book'
    _description = 'Library Book Master'
    
    name = fields.Char(string='Title', related='title', store=True)
    title = fields.Char(string='Title', required=True)
    subtitle = fields.Char(string='Subtitle')
    isbn = fields.Char(string='ISBN')
    author = fields.Char(string='Author', required=True)
    publisher = fields.Char(string='Publisher')
    edition = fields.Char(string='Edition')
    publication_year = fields.Char(string='Publication Year')
    language = fields.Char(string='Language', default='English')
    category_id = fields.Many2one('education.library.category', string='Category')
    subject_id = fields.Many2one('education.subject', string='Subject')
    description = fields.Text(string='Description')
    cover_image = fields.Image(string='Cover Image', max_width=1920, max_height=1920)
    active = fields.Boolean(default=True)

    copy_ids = fields.One2many('education.library.book.copy', 'book_id', string='Physical Copies')
    
    total_copies = fields.Integer(string='Total Copies', compute='_compute_copy_stats', store=True)
    available_copies = fields.Integer(string='Available Copies', compute='_compute_copy_stats', store=True)
    issued_copies = fields.Integer(string='Issued Copies', compute='_compute_copy_stats', store=True)

    @api.depends('copy_ids', 'copy_ids.status', 'copy_ids.active')
    def _compute_copy_stats(self):
        for book in self:
            active_copies = book.copy_ids.filtered(lambda c: c.active)
            book.total_copies = len(active_copies)
            book.available_copies = len(active_copies.filtered(lambda c: c.status == 'available'))
            book.issued_copies = len(active_copies.filtered(lambda c: c.status == 'issued'))