"""Attaching artwork to an order: the rules shared by customers and operators.

A customer submits a correction and an operator submits the final set; both go
through the same checks, so the rule about what may be attached, when, and what
it does to retention lives in one place.
"""
from datetime import datetime, timedelta, timezone
from uuid import UUID, uuid4

from fastapi import HTTPException

from .runtime import upload_row
from .scanning import require_clean


def generated_owner(c, order, ref, kind):
    """The owner to look a generated print file up under, or None if it is not one.

    A generated file may be approved as the final for the item it was made
    from, and only while that item still has its original artwork: after a
    customer correction it reproduces a layout nobody wants printed.
    """
    generated = c.execute('''SELECT item_index FROM dtf_local.print_files
        WHERE order_id=%s AND upload_id=%s AND status='ready' ''', (order['id'], ref.upload_id)).fetchone()
    if not generated:
        return None
    if kind != 'final' or generated['item_index'] != ref.item_index:
        raise HTTPException(422, 'A generated print file can only be the final file of its own item')
    if c.execute("SELECT 1 FROM dtf_local.order_files WHERE order_id=%s AND kind='correction' LIMIT 1",
                 (order['id'],)).fetchone():
        raise HTTPException(409, 'A customer correction replaced the artwork this file was generated from')
    # A large sheet's print file is its original, owned by the customer.
    return c.execute('SELECT owner FROM dtf_local.uploads WHERE id=%s', (ref.upload_id,)).fetchone()['owner']

def submit_files(c, order, body, identity, kind, actor):
    if order['version'] != body.version:
        raise HTTPException(409, 'Order changed. Refresh before submitting files.')
    if kind == 'final' and order['state'] not in ('rec','tra','cor'):
        raise HTTPException(409, 'Final files can only change during artwork review')
    if kind == 'correction' and order['state'] != 'cor':
        raise HTTPException(409, 'This order is not awaiting artwork correction')
    if len({f.upload_id for f in body.files}) != len(body.files):
        raise HTTPException(422, 'Each uploaded file must appear once')
    count = len(order['snapshot']['items'])
    if any(f.item_index >= count for f in body.files):
        raise HTTPException(422, 'Invalid order item')
    if kind == 'final' and {f.item_index for f in body.files} != set(range(count)):
        raise HTTPException(422, 'Final-file set must cover every order item')
    original_ids = [UUID(uid) for item in order['snapshot']['items'] for uid in item['uploads']]
    first = c.execute('SELECT min(created_at) AS first FROM dtf_local.uploads WHERE id=ANY(%s)', (original_ids,)).fetchone()['first']
    expiry = first + timedelta(days=30)
    if expiry <= datetime.now(timezone.utc):
        raise HTTPException(410, 'Order artwork retention has expired')
    for ref in body.files:
        upload = upload_row(c, ref.upload_id, generated_owner(c, order, ref, kind) or identity, lock=True)
        if not upload['complete']:
            raise HTTPException(409, 'Complete all uploads first')
        require_clean(upload)
        if c.execute('SELECT id FROM dtf_local.order_files WHERE upload_id=%s', (ref.upload_id,)).fetchone():
            raise HTTPException(409, 'File is already attached. Upload a new revision.')
    # A new customer correction supersedes every final prepared from earlier
    # artwork, including finals uploaded while this order was in correction.
    if kind == 'correction':
        c.execute("UPDATE dtf_local.order_files SET active=false WHERE order_id=%s AND kind IN ('correction','final')", (order['id'],))
    else:
        c.execute('UPDATE dtf_local.order_files SET active=false WHERE order_id=%s AND kind=%s', (order['id'],kind))
    for ref in body.files:
        c.execute('INSERT INTO dtf_local.order_files(id,order_id,upload_id,item_index,kind,note,created_by) VALUES(%s,%s,%s,%s,%s,%s,%s)',
                  (uuid4(),order['id'],ref.upload_id,ref.item_index,kind,body.note,actor))
        # The order's window, whatever the upload's own hold was.
        c.execute('UPDATE dtf_local.uploads SET expires_at=%s WHERE id=%s', (expiry,ref.upload_id))
    c.execute('UPDATE dtf_local.orders SET version=version+1,updated_at=now() WHERE id=%s', (order['id'],))
    if kind == 'final':
        # Artwork approval, not commercial quote approval, starts original cleanup.
        # An original approved as its own print file is kept as the final.
        finals = [ref.upload_id for ref in body.files]
        c.execute("UPDATE dtf_local.uploads SET expires_at=LEAST(expires_at,now()+interval '7 days') WHERE id=ANY(%s) AND NOT id=ANY(%s)",
                  (original_ids, finals))
    return {'ok': True, 'version': order['version']+1, 'expires_at': expiry}