// Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
// This source code is licensed under the Apache 2.0 license found
// in the LICENSE file in the root directory of this source tree.

// Code generated (@generated) by entc, DO NOT EDIT.

package ent

import (
	"context"
	"fmt"

	"github.com/facebookincubator/ent/dialect/sql"
	"github.com/facebookincubator/ent/entc/integration/template/ent/group"
	"github.com/facebookincubator/ent/entc/integration/template/ent/predicate"
)

// GroupUpdate is the builder for updating Group entities.
type GroupUpdate struct {
	config
	max_users    *int
	addmax_users *int
	predicates   []predicate.Group
}

// Where adds a new predicate for the builder.
func (gu *GroupUpdate) Where(ps ...predicate.Group) *GroupUpdate {
	gu.predicates = append(gu.predicates, ps...)
	return gu
}

// SetMaxUsers sets the max_users field.
func (gu *GroupUpdate) SetMaxUsers(i int) *GroupUpdate {
	gu.max_users = &i
	gu.addmax_users = nil
	return gu
}

// AddMaxUsers adds i to max_users.
func (gu *GroupUpdate) AddMaxUsers(i int) *GroupUpdate {
	if gu.addmax_users == nil {
		gu.addmax_users = &i
	} else {
		*gu.addmax_users += i
	}
	return gu
}

// Save executes the query and returns the number of rows/vertices matched by this operation.
func (gu *GroupUpdate) Save(ctx context.Context) (int, error) {
	return gu.sqlSave(ctx)
}

// SaveX is like Save, but panics if an error occurs.
func (gu *GroupUpdate) SaveX(ctx context.Context) int {
	affected, err := gu.Save(ctx)
	if err != nil {
		panic(err)
	}
	return affected
}

// Exec executes the query.
func (gu *GroupUpdate) Exec(ctx context.Context) error {
	_, err := gu.Save(ctx)
	return err
}

// ExecX is like Exec, but panics if an error occurs.
func (gu *GroupUpdate) ExecX(ctx context.Context) {
	if err := gu.Exec(ctx); err != nil {
		panic(err)
	}
}

func (gu *GroupUpdate) sqlSave(ctx context.Context) (n int, err error) {
	var (
		builder  = sql.Dialect(gu.driver.Dialect())
		selector = builder.Select(group.FieldID).From(builder.Table(group.Table))
	)
	for _, p := range gu.predicates {
		p(selector)
	}
	rows := &sql.Rows{}
	query, args := selector.Query()
	if err = gu.driver.Query(ctx, query, args, rows); err != nil {
		return 0, err
	}
	defer rows.Close()

	var ids []int
	for rows.Next() {
		var id int
		if err := rows.Scan(&id); err != nil {
			return 0, fmt.Errorf("ent: failed reading id: %v", err)
		}
		ids = append(ids, id)
	}
	if len(ids) == 0 {
		return 0, nil
	}

	tx, err := gu.driver.Tx(ctx)
	if err != nil {
		return 0, err
	}
	var (
		res     sql.Result
		updater = builder.Update(group.Table)
	)
	updater = updater.Where(sql.InInts(group.FieldID, ids...))
	if value := gu.max_users; value != nil {
		updater.Set(group.FieldMaxUsers, *value)
	}
	if value := gu.addmax_users; value != nil {
		updater.Add(group.FieldMaxUsers, *value)
	}
	if !updater.Empty() {
		query, args := updater.Query()
		if err := tx.Exec(ctx, query, args, &res); err != nil {
			return 0, rollback(tx, err)
		}
	}
	if err = tx.Commit(); err != nil {
		return 0, err
	}
	return len(ids), nil
}

// GroupUpdateOne is the builder for updating a single Group entity.
type GroupUpdateOne struct {
	config
	id           int
	max_users    *int
	addmax_users *int
}

// SetMaxUsers sets the max_users field.
func (guo *GroupUpdateOne) SetMaxUsers(i int) *GroupUpdateOne {
	guo.max_users = &i
	guo.addmax_users = nil
	return guo
}

// AddMaxUsers adds i to max_users.
func (guo *GroupUpdateOne) AddMaxUsers(i int) *GroupUpdateOne {
	if guo.addmax_users == nil {
		guo.addmax_users = &i
	} else {
		*guo.addmax_users += i
	}
	return guo
}

// Save executes the query and returns the updated entity.
func (guo *GroupUpdateOne) Save(ctx context.Context) (*Group, error) {
	return guo.sqlSave(ctx)
}

// SaveX is like Save, but panics if an error occurs.
func (guo *GroupUpdateOne) SaveX(ctx context.Context) *Group {
	gr, err := guo.Save(ctx)
	if err != nil {
		panic(err)
	}
	return gr
}

// Exec executes the query on the entity.
func (guo *GroupUpdateOne) Exec(ctx context.Context) error {
	_, err := guo.Save(ctx)
	return err
}

// ExecX is like Exec, but panics if an error occurs.
func (guo *GroupUpdateOne) ExecX(ctx context.Context) {
	if err := guo.Exec(ctx); err != nil {
		panic(err)
	}
}

func (guo *GroupUpdateOne) sqlSave(ctx context.Context) (gr *Group, err error) {
	var (
		builder  = sql.Dialect(guo.driver.Dialect())
		selector = builder.Select(group.Columns...).From(builder.Table(group.Table))
	)
	group.ID(guo.id)(selector)
	rows := &sql.Rows{}
	query, args := selector.Query()
	if err = guo.driver.Query(ctx, query, args, rows); err != nil {
		return nil, err
	}
	defer rows.Close()

	var ids []int
	for rows.Next() {
		var id int
		gr = &Group{config: guo.config}
		if err := gr.FromRows(rows); err != nil {
			return nil, fmt.Errorf("ent: failed scanning row into Group: %v", err)
		}
		id = gr.ID
		ids = append(ids, id)
	}
	switch n := len(ids); {
	case n == 0:
		return nil, &ErrNotFound{fmt.Sprintf("Group with id: %v", guo.id)}
	case n > 1:
		return nil, fmt.Errorf("ent: more than one Group with the same id: %v", guo.id)
	}

	tx, err := guo.driver.Tx(ctx)
	if err != nil {
		return nil, err
	}
	var (
		res     sql.Result
		updater = builder.Update(group.Table)
	)
	updater = updater.Where(sql.InInts(group.FieldID, ids...))
	if value := guo.max_users; value != nil {
		updater.Set(group.FieldMaxUsers, *value)
		gr.MaxUsers = *value
	}
	if value := guo.addmax_users; value != nil {
		updater.Add(group.FieldMaxUsers, *value)
		gr.MaxUsers += *value
	}
	if !updater.Empty() {
		query, args := updater.Query()
		if err := tx.Exec(ctx, query, args, &res); err != nil {
			return nil, rollback(tx, err)
		}
	}
	if err = tx.Commit(); err != nil {
		return nil, err
	}
	return gr, nil
}
