/*
Copyright 2017-2022 CAcert Inc.
SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package models

import (
	"context"
	"errors"
	"fmt"
	"strings"

	"github.com/jmoiron/sqlx"
)

const (
	RoleAdmin     string = "ADMIN"
	RoleSecretary string = "SECRETARY"
	RoleVoter     string = "VOTER"
)

type User struct {
	ID       int64 `db:"id"`
	Name     string
	Reminder string  // reminder email address
	roles    []*Role `db:"-"`
}

func (v *User) Roles() ([]*Role, error) {
	if v.roles != nil {
		return v.roles, nil
	}

	return nil, errors.New("call to GetRoles required")
}

func (v *User) HasRole(roles []string) (bool, error) {
	userRoles, err := v.Roles()
	if err != nil {
		return false, err
	}

	roleMatched := false

outer:
	for _, role := range userRoles {
		for _, checkRole := range roles {
			if role.Name == checkRole {
				roleMatched = true

				break outer
			}
		}
	}

	return roleMatched, nil
}

type UserModel struct {
	DB *sqlx.DB
}

func (m *UserModel) GetReminderVoters(_ context.Context) ([]*User, error) {
	panic("not implemented")
}

func (m *UserModel) GetUser(ctx context.Context, emails []string) (*User, error) {
	query, args, err := sqlx.In(
		`SELECT DISTINCT v.id, v.name, v.reminder
FROM voters v
         JOIN emails e ON e.voter = v.id
WHERE e.address IN (?)`, emails)
	if err != nil {
		return nil, fmt.Errorf("could not build query: %w", err)
	}

	rows, err := m.DB.QueryxContext(ctx, query, args...)
	if err != nil {
		return nil, fmt.Errorf("could not run query: %w", err)
	}

	defer func(rows *sqlx.Rows) {
		_ = rows.Close()
	}(rows)

	var (
		user  User
		count int
	)

	for rows.Next() {
		count++

		if count > 1 {
			return nil, fmt.Errorf(
				"multiple voters found for addresses in certificate %s",
				strings.Join(emails, ", "),
			)
		}

		if err := rows.Err(); err != nil {
			return nil, fmt.Errorf("could not fetch row: %w", err)
		}

		if err := rows.StructScan(&user); err != nil {
			return nil, fmt.Errorf("could not get user from row: %w", err)
		}
	}

	if user.roles, err = m.GetRoles(ctx, &user); err != nil {
		return nil, fmt.Errorf("could not retrieve roles for user %s: %w", user.Name, err)
	}

	return &user, nil
}

type Role struct {
	Name string `db:"role"`
}

func (m *UserModel) GetRoles(ctx context.Context, user *User) ([]*Role, error) {
	rows, err := m.DB.QueryxContext(ctx, `SELECT role FROM user_roles WHERE voter_id=?`, user.ID)
	if err != nil {
		return nil, fmt.Errorf("could not query roles for %s: %w", user.Name, err)
	}

	defer func(rows *sqlx.Rows) {
		_ = rows.Close()
	}(rows)

	result := make([]*Role, 0)

	for rows.Next() {
		if err := rows.Err(); err != nil {
			return nil, fmt.Errorf("could not retrieve row: %w", err)
		}

		var role Role

		if err := rows.StructScan(&role); err != nil {
			return nil, fmt.Errorf("could not get role from row: %w", err)
		}

		result = append(result, &role)
	}

	return result, nil
}

func (m *UserModel) CreateUser(ctx context.Context, name string, reminder string, emails []string) (int64, error) {
	tx, err := m.DB.BeginTxx(ctx, nil)
	if err != nil {
		return 0, fmt.Errorf("could not start transaction: %w", err)
	}

	defer func(tx *sqlx.Tx) {
		_ = tx.Rollback()
	}(tx)

	res, err := tx.Exec(`INSERT INTO voters (name, reminder, enabled) VALUES (?, ?, 0)`, name, reminder)
	if err != nil {
		return 0, fmt.Errorf("could not insert user: %w", err)
	}

	userID, err := res.LastInsertId()
	if err != nil {
		return 0, fmt.Errorf("could not get user id: %w", err)
	}

	for i := range emails {
		_, err := tx.Exec(`INSERT INTO emails (voter, address) VALUES (?, ?)`, userID, emails[i])
		if err != nil {
			return 0, fmt.Errorf("could not insert email %s for voter %s: %w", emails[i], name, err)
		}
	}

	if err := tx.Commit(); err != nil {
		return 0, fmt.Errorf("could not commit user transaction: %w", err)
	}

	return userID, nil
}