package models

import (
	"database/sql"
	"errors"
	"fmt"
	"time"

	"github.com/jmoiron/sqlx"
	"github.com/jmoiron/sqlx/types"
	"github.com/odwrtw/polochon/lib/papi"
)

const (
	addUserQuery = `INSERT INTO
		users (name, hash, admin, polochon_id, token)
	VALUES ($1, $2, $3, $4, $5)
	RETURNING id;`
	getUserQuery     = `SELECT * FROM users WHERE name=$1;`
	getUserByIDQuery = `SELECT * FROM users WHERE id=$1;`
	updateUserQuery  = `UPDATE users SET
		name=:name, hash=:hash, admin=:admin, activated=:activated,
		rawconfig=:rawconfig, polochon_id=:polochon_id, token=:token,
		polochon_activated=:polochon_activated
	WHERE id=:id
	RETURNING *;`
	deleteUserQuery = `DELETE FROM users WHERE id=:id;`

	getAllUsersQuery = `
	SELECT u.*, tok.last_seen
	FROM users u
	LEFT OUTER JOIN (
		SELECT username, MAX(last_used) AS last_seen
		FROM tokens GROUP BY username
	) AS tok
	ON u.name = tok.username
	ORDER by u.created_at;
	`
	getPolochonUsersQuery = `SELECT * FROM users WHERE polochon_id = $1;`
)

const (
	// UserRole represents the user's role
	UserRole = "user"
	// AdminRole represents the admin's role
	AdminRole = "admin"
)

// ErrUnknownUser returned when a user does'nt exist
var ErrUnknownUser = fmt.Errorf("users: user does'nt exist")

// User represents an user
type User struct {
	BaseModel
	Name              string         `json:"name"`
	Hash              string         `json:"-"`
	Admin             bool           `json:"admin"`
	RawConfig         types.JSONText `json:"raw_config"`
	Token             string         `json:"token"`
	Activated         bool           `json:"activated"`
	PolochonID        sql.NullString `json:"polochon_id" db:"polochon_id"`
	PolochonActivated bool           `json:"polochon_activated" db:"polochon_activated"`
	Polochon          *Polochon      `json:"polochon"`
	LastSeen          *time.Time     `json:"last_seen" db:"last_seen"`
}

// NewPapiClient creates a new papi client for the given user
func (u *User) NewPapiClient(db *sqlx.DB) (*papi.Client, error) {
	polochon, err := u.GetPolochon(db)
	if err != nil {
		return nil, err
	}

	client, err := papi.New(polochon.URL)
	if err != nil {
		return nil, errors.New("error getting papi client")
	}

	if u.Token != "" {
		client.SetToken(u.Token)
	}
	return client, nil
}

// GetUser returns user with specified name
func GetUser(q sqlx.Queryer, name string) (*User, error) {
	u := &User{}
	err := q.QueryRowx(getUserQuery, name).StructScan(u)
	if err != nil {
		if err == sql.ErrNoRows {
			return nil, ErrUnknownUser
		}
		return nil, err
	}
	return u, nil
}

// GetUserByID returns user using its id
func GetUserByID(q sqlx.Queryer, id string) (*User, error) {
	u := &User{}
	err := q.QueryRowx(getUserByIDQuery, id).StructScan(u)
	if err != nil {
		if err == sql.ErrNoRows {
			return nil, ErrUnknownUser
		}
		return nil, err
	}
	return u, nil
}

// GetAllUsers returns all the users
func GetAllUsers(db *sqlx.DB) ([]*User, error) {
	users := []*User{}
	err := db.Select(&users, getAllUsersQuery)
	if err != nil {
		return nil, err
	}
	return users, nil
}

// GetPolochonUsers returns all the users of a polochon
func GetPolochonUsers(db *sqlx.DB, id string) ([]*User, error) {
	users := []*User{}
	err := db.Select(&users, getPolochonUsersQuery, id)
	if err != nil {
		return nil, err
	}
	return users, nil
}

// Add user to database or raises an error
func (u *User) Add(q sqlx.Queryer) error {
	var id string
	err := q.QueryRowx(addUserQuery, u.Name, u.Hash, u.Admin, u.PolochonID, u.Token).Scan(&id)
	if err != nil {
		return err
	}
	u.ID = id
	return nil
}

// Update user on database or raise an error
func (u *User) Update(ex *sqlx.DB) error {
	rows, err := ex.NamedQuery(updateUserQuery, u)
	if err != nil {
		return err
	}
	for rows.Next() {
		if err := rows.StructScan(u); err != nil {
			return err
		}
	}
	return nil
}

// Delete user from database or raise an error
func (u *User) Delete(ex *sqlx.DB) error {
	_, err := ex.NamedExec(deleteUserQuery, u)
	return err
}

// HasRole checks if a user as a role
func (u *User) HasRole(role string) bool {
	if role == AdminRole && !u.Admin {
		return false
	}
	return true
}

// IsAdmin checks if a user is admin
func (u *User) IsAdmin() bool {
	return u.HasRole(AdminRole)
}

// IsActivated checks if a user is activated
func (u *User) IsActivated() bool {
	return u.Activated
}

// GetPolochon returns the user's polochon
func (u *User) GetPolochon(db *sqlx.DB) (*Polochon, error) {
	return GetPolochonByID(db, u.PolochonID.String)
}