package models

import (
	"context"
	"time"

	"code.crute.us/mcrute/golib/db/mongodb"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
)

const userCol = "users"

type UserStore interface {
	List(context.Context) ([]*User, error)
	Get(context.Context, string) (*User, error) // Error on not found
	Put(context.Context, *User) error
	Delete(context.Context, *User) error
}

type AuthToken struct {
	Kind  string `json:"kind"`
	Token string `json:"token"`

	// Do not expose refresh tokens in JSON as they are long-lived tokens that
	// are harder to invalidate and thus rather security sensitive.
	RefreshToken string `json:"-"`
}

type User struct {
	Username   string                 `bson:"_id" json:"key_id"`
	IsAdmin    bool                   `json:"is_admin"`
	IsService  bool                   `json:"is_service"`
	Keys       map[string]*SessionKey `json:"keys,omitempty"`        // kid  -> key
	AuthTokens map[string]*AuthToken  `json:"auth_tokens,omitempty"` // kind -> token
	Deleted    *time.Time             `json:"deleted,omitempty"`
}

// GCKeys garbage collects keys that are no longer valid
func (u *User) GCKeys() {
	for k, v := range u.Keys {
		if v.IsGarbage() {
			delete(u.Keys, k)
		}
	}
}

// GetKey returns a key for a key ID. It will only return valid keys.
func (u *User) GetKey(kid string) *SessionKey {
	if u.Keys != nil {
		if k := u.Keys[kid]; k != nil && k.IsValid() {
			return k
		}
	}
	return nil
}

func (u *User) AddKey(k *SessionKey) {
	if u.Keys == nil {
		u.Keys = map[string]*SessionKey{}
	}
	u.Keys[k.KeyId] = k
}

func (u *User) AddToken(t *AuthToken) {
	if u.AuthTokens == nil {
		u.AuthTokens = map[string]*AuthToken{}
	}
	u.AuthTokens[t.Kind] = t
}

type MongoDbUserStore struct {
	Db *mongodb.Mongo

	// ReturnDeleted will allow all methods to return deleted items. By default
	// items where the Deleted field is set will not be returned. This should
	// be the common cast for most code using this store but in some Admin
	// use-cases it would be useful to show deleted accounts.
	ReturnDeleted bool
}

func (s *MongoDbUserStore) List(ctx context.Context) ([]*User, error) {
	var out []*User

	filter := bson.M{}
	if !s.ReturnDeleted {
		filter["deleted"] = primitive.Null{}
	}

	if err := s.Db.FindAllByFilter(ctx, userCol, filter, &out); err != nil {
		return nil, err
	}

	return out, nil
}

func (s *MongoDbUserStore) Get(ctx context.Context, username string) (*User, error) {
	var u User

	filter := bson.M{"_id": username}
	if !s.ReturnDeleted {
		filter["deleted"] = primitive.Null{}
	}

	if err := s.Db.FindOneByFilter(ctx, userCol, filter, &u); err != nil {
		return nil, err
	}

	return &u, nil
}

func (s *MongoDbUserStore) Put(ctx context.Context, u *User) error {
	if err := s.Db.ReplaceOneById(ctx, userCol, u.Username, u); err != nil {
		return err
	}
	return nil
}

func (s *MongoDbUserStore) Delete(ctx context.Context, u *User) error {
	u, err := s.Get(ctx, u.Username)
	if err != nil {
		return err
	}

	now := time.Now()
	u.Deleted = &now

	return s.Put(ctx, u)
}

var _ UserStore = (*MongoDbUserStore)(nil)