package accesscontrol

import (
	"encoding/json"
	"errors"
	"fmt"
	"strings"
	"time"

	"github.com/grafana/grafana/pkg/infra/slugify"
	"github.com/grafana/grafana/pkg/services/annotations"
	"github.com/grafana/grafana/pkg/services/org"
	"github.com/grafana/grafana/pkg/util/errutil"
)

var ErrInternal = errutil.Internal("accesscontrol.internal")

// RoleRegistration stores a role and its assignments to built-in roles
// (Viewer, Editor, Admin, Grafana Admin)
type RoleRegistration struct {
	Role   RoleDTO
	Grants []string
}

// Role is the model for Role in RBAC.
type Role struct {
	ID          int64  `json:"-" xorm:"pk autoincr 'id'"`
	OrgID       int64  `json:"-" xorm:"org_id"`
	Version     int64  `json:"version"`
	UID         string `xorm:"uid" json:"uid"`
	Name        string `json:"name"`
	DisplayName string `json:"displayName,omitempty"`
	Group       string `xorm:"group_name" json:"group"`
	Description string `json:"description"`
	Hidden      bool   `json:"hidden"`

	Updated time.Time `json:"updated"`
	Created time.Time `json:"created"`
}

func (r *Role) Global() bool {
	return r.OrgID == GlobalOrgID
}

func (r *Role) IsFixed() bool {
	return strings.HasPrefix(r.Name, FixedRolePrefix)
}

func (r *Role) IsBasic() bool {
	return strings.HasPrefix(r.Name, BasicRolePrefix) || strings.HasPrefix(r.UID, BasicRoleUIDPrefix)
}

func (r Role) MarshalJSON() ([]byte, error) {
	type Alias Role

	return json.Marshal(&struct {
		Alias
		Global bool `json:"global" xorm:"-"`
	}{
		Alias:  (Alias)(r),
		Global: r.Global(),
	})
}

type RoleDTO struct {
	Version     int64        `json:"version"`
	UID         string       `xorm:"uid" json:"uid"`
	Name        string       `json:"name"`
	DisplayName string       `json:"displayName,omitempty"`
	Description string       `json:"description"`
	Group       string       `xorm:"group_name" json:"group"`
	Permissions []Permission `json:"permissions,omitempty"`
	Delegatable *bool        `json:"delegatable,omitempty"`
	Hidden      bool         `json:"hidden,omitempty"`

	ID    int64 `json:"-" xorm:"pk autoincr 'id'"`
	OrgID int64 `json:"-" xorm:"org_id"`

	Updated time.Time `json:"updated"`
	Created time.Time `json:"created"`
}

func (r *RoleDTO) LogID() string {
	var org string

	if r.Global() {
		org = "Global"
	} else {
		org = fmt.Sprintf("OrgId:%v", r.OrgID)
	}

	if r.UID != "" {
		return fmt.Sprintf("[%s RoleUID:%v]", org, r.UID)
	}
	return fmt.Sprintf("[%s Role:%v]", org, r.Name)
}

func (r *RoleDTO) Role() Role {
	return Role{
		ID:          r.ID,
		OrgID:       r.OrgID,
		UID:         r.UID,
		Version:     r.Version,
		Name:        r.Name,
		DisplayName: r.DisplayName,
		Group:       r.Group,
		Description: r.Description,
		Hidden:      r.Hidden,
		Updated:     r.Updated,
		Created:     r.Created,
	}
}

func (r *RoleDTO) Global() bool {
	return r.OrgID == GlobalOrgID
}

func (r *RoleDTO) IsManaged() bool {
	return strings.HasPrefix(r.Name, ManagedRolePrefix)
}

func (r *RoleDTO) IsFixed() bool {
	return strings.HasPrefix(r.Name, FixedRolePrefix)
}

func (r *RoleDTO) IsPlugin() bool {
	return strings.HasPrefix(r.Name, PluginRolePrefix)
}

func (r *RoleDTO) IsBasic() bool {
	return strings.HasPrefix(r.Name, BasicRolePrefix) || strings.HasPrefix(r.UID, BasicRoleUIDPrefix)
}

func (r *RoleDTO) IsExternalService() bool {
	return strings.HasPrefix(r.Name, ExternalServiceRolePrefix) || strings.HasPrefix(r.UID, ExternalServiceRoleUIDPrefix)
}

func (r RoleDTO) MarshalJSON() ([]byte, error) {
	type Alias RoleDTO

	return json.Marshal(&struct {
		Alias
		Global bool `json:"global" xorm:"-"`
	}{
		Alias:  (Alias)(r),
		Global: r.Global(),
	})
}

type TeamRole struct {
	ID     int64 `json:"id" xorm:"pk autoincr 'id'"`
	OrgID  int64 `json:"orgId" xorm:"org_id"`
	RoleID int64 `json:"roleId" xorm:"role_id"`
	TeamID int64 `json:"teamId" xorm:"team_id"`

	Created time.Time
}

type UserRole struct {
	ID     int64 `json:"id" xorm:"pk autoincr 'id'"`
	OrgID  int64 `json:"orgId" xorm:"org_id"`
	RoleID int64 `json:"roleId" xorm:"role_id"`
	UserID int64 `json:"userId" xorm:"user_id"`

	Created time.Time
}

type BuiltinRole struct {
	ID     int64 `json:"id" xorm:"pk autoincr 'id'"`
	RoleID int64 `json:"roleId" xorm:"role_id"`
	OrgID  int64 `json:"orgId" xorm:"org_id"`
	Role   string

	Updated time.Time
	Created time.Time
}

// Permission is the model for access control permissions.
type Permission struct {
	ID     int64  `json:"-" xorm:"pk autoincr 'id'"`
	RoleID int64  `json:"-" xorm:"role_id"`
	Action string `json:"action"`
	Scope  string `json:"scope"`

	Kind       string `json:"-"`
	Attribute  string `json:"-"`
	Identifier string `json:"-"`

	Updated time.Time `json:"updated"`
	Created time.Time `json:"created"`
}

func (p Permission) OSSPermission() Permission {
	return Permission{
		Action: p.Action,
		Scope:  p.Scope,
	}
}

// SplitScope returns kind, attribute and Identifier
func (p Permission) SplitScope() (string, string, string) {
	if p.Scope == "" {
		return "", "", ""
	}

	fragments := strings.Split(p.Scope, ":")
	switch l := len(fragments); l {
	case 1: // Splitting a wildcard scope "*" -> kind: "*"; attribute: "*"; identifier: "*"
		return fragments[0], fragments[0], fragments[0]
	case 2: // Splitting a wildcard scope with specified kind "dashboards:*" -> kind: "dashboards"; attribute: "*"; identifier: "*"
		return fragments[0], fragments[1], fragments[1]
	default: // Splitting a scope with all fields specified "dashboards:uid:my_dash" -> kind: "dashboards"; attribute: "uid"; identifier: "my_dash"
		return fragments[0], fragments[1], strings.Join(fragments[2:], ":")
	}
}

type GetUserPermissionsQuery struct {
	OrgID        int64
	UserID       int64
	Roles        []string
	TeamIDs      []int64
	RolePrefixes []string
}

// ResourcePermission is structure that holds all actions that either a team / user / builtin-role
// can perform against specific resource.
type ResourcePermission struct {
	ID               int64
	RoleName         string
	Actions          []string
	Scope            string
	UserId           int64
	UserLogin        string
	UserEmail        string
	TeamId           int64
	TeamEmail        string
	Team             string
	BuiltInRole      string
	IsManaged        bool
	IsInherited      bool
	IsServiceAccount bool
	Created          time.Time
	Updated          time.Time
}

func (p *ResourcePermission) Contains(targetActions []string) bool {
	if len(p.Actions) < len(targetActions) {
		return false
	}

	var contain = func(arr []string, s string) bool {
		for _, item := range arr {
			if item == s {
				return true
			}
		}
		return false
	}

	for _, a := range targetActions {
		if !contain(p.Actions, a) {
			return false
		}
	}

	return true
}

type SetResourcePermissionCommand struct {
	UserID      int64  `json:"userId,omitempty"`
	TeamID      int64  `json:"teamId,omitempty"`
	BuiltinRole string `json:"builtInRole,omitempty"`
	Permission  string `json:"permission"`
}

type SaveExternalServiceRoleCommand struct {
	OrgID             int64
	Global            bool
	ExternalServiceID string
	ServiceAccountID  int64
	Permissions       []Permission
}

func (cmd *SaveExternalServiceRoleCommand) Validate() error {
	if cmd.ExternalServiceID == "" {
		return errors.New("external service id not specified")
	}

	// slugify the external service id ID for the role to have correct name and uid
	cmd.ExternalServiceID = slugify.Slugify(cmd.ExternalServiceID)

	if (cmd.OrgID == GlobalOrgID) != cmd.Global {
		return fmt.Errorf("invalid org id %d for global role %t", cmd.OrgID, cmd.Global)
	}

	// Check and deduplicate permissions
	if cmd.Permissions == nil || len(cmd.Permissions) == 0 {
		return errors.New("no permissions provided")
	}
	dedupMap := map[Permission]bool{}
	dedup := make([]Permission, 0, len(cmd.Permissions))
	for i := range cmd.Permissions {
		if len(cmd.Permissions[i].Action) == 0 {
			return fmt.Errorf("external service %v requests a permission with no Action", cmd.ExternalServiceID)
		}
		if dedupMap[cmd.Permissions[i]] {
			continue
		}
		dedupMap[cmd.Permissions[i]] = true
		dedup = append(dedup, cmd.Permissions[i])
	}
	cmd.Permissions = dedup

	if cmd.ServiceAccountID <= 0 {
		return fmt.Errorf("invalid service account id %d", cmd.ServiceAccountID)
	}

	return nil
}

const (
	GlobalOrgID      = 0
	GeneralFolderUID = "general"
	RoleGrafanaAdmin = "Grafana Admin"

	// Permission actions

	ActionAPIKeyRead   = "apikeys:read"
	ActionAPIKeyCreate = "apikeys:create"
	ActionAPIKeyDelete = "apikeys:delete"

	// Users actions
	ActionUsersRead        = "users:read"
	ActionUsersWrite       = "users:write"
	ActionUsersImpersonate = "users:impersonate"

	// We can ignore gosec G101 since this does not contain any credentials.
	// nolint:gosec
	ActionUsersAuthTokenList = "users.authtoken:read"
	// We can ignore gosec G101 since this does not contain any credentials.
	// nolint:gosec
	ActionUsersAuthTokenUpdate = "users.authtoken:write"
	// We can ignore gosec G101 since this does not contain any credentials.
	// nolint:gosec
	ActionUsersPasswordUpdate    = "users.password:write"
	ActionUsersDelete            = "users:delete"
	ActionUsersCreate            = "users:create"
	ActionUsersEnable            = "users:enable"
	ActionUsersDisable           = "users:disable"
	ActionUsersPermissionsUpdate = "users.permissions:write"
	ActionUsersLogout            = "users:logout"
	ActionUsersQuotasList        = "users.quotas:read"
	ActionUsersQuotasUpdate      = "users.quotas:write"
	ActionUsersPermissionsRead   = "users.permissions:read"

	// Org actions
	ActionOrgsRead             = "orgs:read"
	ActionOrgsPreferencesRead  = "orgs.preferences:read"
	ActionOrgsQuotasRead       = "orgs.quotas:read"
	ActionOrgsWrite            = "orgs:write"
	ActionOrgsPreferencesWrite = "orgs.preferences:write"
	ActionOrgsQuotasWrite      = "orgs.quotas:write"
	ActionOrgsDelete           = "orgs:delete"
	ActionOrgsCreate           = "orgs:create"

	ActionOrgUsersRead   = "org.users:read"
	ActionOrgUsersAdd    = "org.users:add"
	ActionOrgUsersRemove = "org.users:remove"
	ActionOrgUsersWrite  = "org.users:write"

	// LDAP actions
	ActionLDAPUsersRead    = "ldap.user:read"
	ActionLDAPUsersSync    = "ldap.user:sync"
	ActionLDAPStatusRead   = "ldap.status:read"
	ActionLDAPConfigReload = "ldap.config:reload"

	// Server actions
	ActionServerStatsRead = "server.stats:read"

	// Settings actions
	ActionSettingsRead  = "settings:read"
	ActionSettingsWrite = "settings:write"

	// Datasources actions
	ActionDatasourcesExplore = "datasources:explore"

	// Global Scopes
	ScopeGlobalUsersAll = "global.users:*"

	// APIKeys scope
	ScopeAPIKeysAll = "apikeys:*"

	// Users scope
	ScopeUsersAll    = "users:*"
	ScopeUsersPrefix = "users:id:"

	// Settings scope
	ScopeSettingsAll  = "settings:*"
	ScopeSettingsAuth = "settings:auth:*"
	ScopeSettingsSAML = "settings:auth.saml:*"

	// Team related actions
	ActionTeamsCreate           = "teams:create"
	ActionTeamsDelete           = "teams:delete"
	ActionTeamsRead             = "teams:read"
	ActionTeamsWrite            = "teams:write"
	ActionTeamsPermissionsRead  = "teams.permissions:read"
	ActionTeamsPermissionsWrite = "teams.permissions:write"

	// Team related scopes
	ScopeTeamsAll = "teams:*"

	// Annotations related actions
	ActionAnnotationsCreate = "annotations:create"
	ActionAnnotationsDelete = "annotations:delete"
	ActionAnnotationsRead   = "annotations:read"
	ActionAnnotationsWrite  = "annotations:write"

	// Alert scopes are divided into two groups. The internal (to Grafana) and the external ones.
	// For the Grafana ones, given we have ACID control we're able to provide better granularity by defining CRUD options.
	// For the external ones, we only have read and write permissions due to the lack of atomicity control of the external system.

	// Alerting rules actions
	ActionAlertingRuleCreate = "alert.rules:create"
	ActionAlertingRuleRead   = "alert.rules:read"
	ActionAlertingRuleUpdate = "alert.rules:write"
	ActionAlertingRuleDelete = "alert.rules:delete"

	// Alerting instances (+silences) actions
	ActionAlertingInstanceCreate = "alert.instances:create"
	ActionAlertingInstanceUpdate = "alert.instances:write"
	ActionAlertingInstanceRead   = "alert.instances:read"

	// Alerting Notification policies actions
	ActionAlertingNotificationsRead  = "alert.notifications:read"
	ActionAlertingNotificationsWrite = "alert.notifications:write"

	// External alerting rule actions. We can only narrow it down to writes or reads, as we don't control the atomicity in the external system.
	ActionAlertingRuleExternalWrite = "alert.rules.external:write"
	ActionAlertingRuleExternalRead  = "alert.rules.external:read"

	// External alerting instances actions. We can only narrow it down to writes or reads, as we don't control the atomicity in the external system.
	ActionAlertingInstancesExternalWrite = "alert.instances.external:write"
	ActionAlertingInstancesExternalRead  = "alert.instances.external:read"

	// External alerting notifications actions. We can only narrow it down to writes or reads, as we don't control the atomicity in the external system.
	ActionAlertingNotificationsExternalWrite = "alert.notifications.external:write"
	ActionAlertingNotificationsExternalRead  = "alert.notifications.external:read"

	// Alerting provisioning actions
	ActionAlertingProvisioningRead        = "alert.provisioning:read"
	ActionAlertingProvisioningReadSecrets = "alert.provisioning.secrets:read"
	ActionAlertingProvisioningWrite       = "alert.provisioning:write"

	// Feature Management actions
	ActionFeatureManagementRead  = "featuremgmt.read"
	ActionFeatureManagementWrite = "featuremgmt.write"

	// Library Panel actions
	ActionLibraryPanelsCreate = "library.panels:create"
	ActionLibraryPanelsRead   = "library.panels:read"
	ActionLibraryPanelsWrite  = "library.panels:write"
	ActionLibraryPanelsDelete = "library.panels:delete"
)

var (
	// Team scope
	ScopeTeamsID = Scope("teams", "id", Parameter(":teamId"))

	// Annotation scopes
	ScopeAnnotationsRoot             = "annotations"
	ScopeAnnotationsProvider         = NewScopeProvider(ScopeAnnotationsRoot)
	ScopeAnnotationsAll              = ScopeAnnotationsProvider.GetResourceAllScope()
	ScopeAnnotationsID               = Scope(ScopeAnnotationsRoot, "id", Parameter(":annotationId"))
	ScopeAnnotationsTypeDashboard    = ScopeAnnotationsProvider.GetResourceScopeType(annotations.Dashboard.String())
	ScopeAnnotationsTypeOrganization = ScopeAnnotationsProvider.GetResourceScopeType(annotations.Organization.String())
)

func BuiltInRolesWithParents(builtInRoles []string) map[string]struct{} {
	res := map[string]struct{}{}

	for _, br := range builtInRoles {
		res[br] = struct{}{}
		if br != RoleGrafanaAdmin {
			for _, parent := range org.RoleType(br).Parents() {
				res[string(parent)] = struct{}{}
			}
		}
	}

	return res
}

// Evaluators

// TeamsAccessEvaluator is used to protect the "Configuration > Teams" page access
// grants access to a user when they can either create teams or can read and update a team
var TeamsAccessEvaluator = EvalAny(
	EvalPermission(ActionTeamsCreate),
	EvalAll(
		EvalPermission(ActionTeamsRead),
		EvalAny(
			EvalPermission(ActionTeamsWrite),
			EvalPermission(ActionTeamsPermissionsWrite),
		),
	),
)

// TeamsEditAccessEvaluator is used to protect the "Configuration > Teams > edit" page access
var TeamsEditAccessEvaluator = EvalAll(
	EvalPermission(ActionTeamsRead),
	EvalAny(
		EvalPermission(ActionTeamsCreate),
		EvalPermission(ActionTeamsWrite),
		EvalPermission(ActionTeamsPermissionsWrite),
	),
)

// OrgPreferencesAccessEvaluator is used to protect the "Configure > Preferences" page access
var OrgPreferencesAccessEvaluator = EvalAny(
	EvalAll(
		EvalPermission(ActionOrgsRead),
		EvalPermission(ActionOrgsWrite),
	),
	EvalAll(
		EvalPermission(ActionOrgsPreferencesRead),
		EvalPermission(ActionOrgsPreferencesWrite),
	),
)

// OrgsAccessEvaluator is used to protect the "Server Admin > Orgs" page access
// (you need to have read access to update or delete orgs; read is the minimum)
var OrgsAccessEvaluator = EvalPermission(ActionOrgsRead)

// OrgsCreateAccessEvaluator is used to protect the "Server Admin > Orgs > New Org" page access
var OrgsCreateAccessEvaluator = EvalAll(
	EvalPermission(ActionOrgsRead),
	EvalPermission(ActionOrgsCreate),
)

// ApiKeyAccessEvaluator is used to protect the "Configuration > API keys" page access
var ApiKeyAccessEvaluator = EvalPermission(ActionAPIKeyRead)