from odoo import models

class AccountMove(models.Model):
    _inherit = 'account.move'

    def _auto_create_asset(self):
        # We need to intercept standard behavior if we can link to an existing asset from Stock Move
        
        # This method iterates over self (invoices) and creates assets.
        # We can run the standard method, BUT standard method creates new assets.
        # We want to PREVENT creating new assets if one was already created by Stock Picking.
        
        # The standard method _auto_create_asset loops over invoice lines and creates assets.
        # It doesn't seem to have a hook to check for existing assets easily.
        # However, we can check if the invoice line is linked to a PO line, and that PO line linked to a Stock Move.
        
        # Strategy:
        # 1. Let standard create assets? No, duplicate.
        # 2. Override completely? risky for maintenance.
        # 3. Pre-process: if we find a link, set the asset_id on the move_line?
        #    If `move_line.asset_ids` is set, `_auto_create_asset` might skip?
        #    Checking standard code:
        #    `and not move_line.asset_ids` -> YES! definition at line 188 of account_move.py.
        
        # So strategy is:
        # Before calling super, try to find existing asset and link it to move_line.
        
        for move in self:
            if move.is_invoice():
                for line in move.invoice_line_ids:
                    # check purchase line
                    if line.purchase_line_id:
                        # Find related stock moves
                        # purchase_line_id.move_ids returns stock moves
                        related_stock_moves = line.purchase_line_id.move_ids.filtered(lambda m: m.state == 'done' and m.asset_id)
                        
                        if related_stock_moves:
                            # Link the first found asset
                            asset = related_stock_moves[0].asset_id
                            line.asset_ids = [(4, asset.id)]
                            
                            # Also update asset value if needed? 
                            # Usually creation from Stock might lack price if Price Unit was 0 or estimate.
                            # But let's assume standard behavior: Link is enough.
                            
                            # Log connection
                            asset.message_post(body=f"Linked to Vendor Bill: {move.name}")

        # Call super to generate new assets (if not linked above)
        created_assets = super(AccountMove, self)._auto_create_asset()
        
        # Post-process: Ensure Product ID is set and Asset Code is correct
        for asset in created_assets:
            # key: use sudo() to allow system to correct data even if user has no write access to asset
            # (e.g. Bill Clerk creating asset but not managing it)
            if not asset.product_id and asset.original_move_line_ids:
                # Find product from the first line
                # (Standard logic usually groups lines by account/product context, so one asset usually comes from one product type)
                product = asset.original_move_line_ids[0].product_id
                
                if product:
                    asset.sudo().product_id = product.id
                    
                    # Fix Asset Code if it defaults to AST but product has barcode
                    if asset.asset_code and asset.asset_code.startswith('AST') and product.barcode:
                        # Replace 'AST' prefix with Barcode
                        # Format is expected to be AST/YYYY/SEQ
                        new_code = asset.asset_code.replace('AST', product.barcode, 1)
                        asset.sudo().asset_code = new_code
                        
        return created_assets