syntax = "proto3";
package authzed.api.v1;

option go_package = "github.com/authzed/authzed-go/proto/authzed/api/v1";
option java_package = "com.authzed.api.v1";

import "google/protobuf/struct.proto";
import "google/api/annotations.proto";
import "validate/validate.proto";

import "authzed/api/v1/core.proto";

// PermissionsService implements a set of RPCs that perform operations on
// relationships and permissions.
service PermissionsService {
  // ReadRelationships reads a set of the relationships matching one or more
  // filters.
  rpc ReadRelationships(ReadRelationshipsRequest)
    returns (stream ReadRelationshipsResponse) {
      option (google.api.http) = {
        post: "/v1/relationships/read"
        body: "*"
      };
  }

  // WriteRelationships atomically writes and/or deletes a set of specified
  // relationships. An optional set of preconditions can be provided that must
  // be satisfied for the operation to commit.
  rpc WriteRelationships(WriteRelationshipsRequest)
    returns (WriteRelationshipsResponse) {
      option (google.api.http) = {
        post: "/v1/relationships/write"
        body: "*"
      };
    }

  // DeleteRelationships atomically bulk deletes all relationships matching the
  // provided filter. If no relationships match, none will be deleted and the
  // operation will succeed. An optional set of preconditions can be provided that must
  // be satisfied for the operation to commit.
  rpc DeleteRelationships(DeleteRelationshipsRequest)
    returns (DeleteRelationshipsResponse) {
      option (google.api.http) = {
        post: "/v1/relationships/delete"
        body: "*"
      };
    }

  // CheckPermission determines for a given resource whether a subject computes
  // to having a permission or is a direct member of a particular relation.
  rpc CheckPermission(CheckPermissionRequest)
    returns (CheckPermissionResponse) {
      option (google.api.http) = {
        post: "/v1/permissions/check"
        body: "*"
      };
    }

  // ExpandPermissionTree reveals the graph structure for a resource's
  // permission or relation. This RPC does not recurse infinitely deep and may
  // require multiple calls to fully unnest a deeply nested graph.
  rpc ExpandPermissionTree(ExpandPermissionTreeRequest)
    returns (ExpandPermissionTreeResponse) {
      option (google.api.http) = {
        post: "/v1/permissions/expand"
        body: "*"
      };
    }

  // LookupResources returns all the resources of a given type that a subject
  // can access whether via a computed permission or relation membership.
  rpc LookupResources(LookupResourcesRequest)
    returns (stream LookupResourcesResponse) {
      option (google.api.http) = {
        post: "/v1/permissions/resources"
        body: "*"
      };
    }

  // LookupSubjects returns all the subjects of a given type that
  // have access whether via a computed permission or relation membership.
  rpc LookupSubjects(LookupSubjectsRequest)
    returns (stream LookupSubjectsResponse) {
      option (google.api.http) = {
        post: "/v1/permissions/subjects"
        body: "*"
      };
    }
}

// Consistency will define how a request is handled by the backend.
// By defining a consistency requirement, and a token at which those
// requirements should be applied, where applicable.
message Consistency {
  oneof requirement {
    option (validate.required) = true;

    // minimize_latency indicates that the latency for the call should be
    // minimized by having the system select the fastest snapshot available.
    bool minimize_latency = 1 [ (validate.rules).bool.const = true ];

    // at_least_as_fresh indicates that all data used in the API call must be
    // *at least as fresh* as that found in the ZedToken; more recent data might
    // be used if available or faster.
    ZedToken at_least_as_fresh = 2;

    // at_exact_snapshot indicates that all data used in the API call must be
    // *at the given* snapshot in time; if the snapshot is no longer available,
    // an error will be returned to the caller.
    ZedToken at_exact_snapshot = 3;

    // fully_consistent indicates that all data used in the API call *must* be
    // at the most recent snapshot found.
    //
    // NOTE: using this method can be *quite slow*, so unless there is a need to
    // do so, it is recommended to use `at_least_as_fresh` with a stored
    // ZedToken.
    bool fully_consistent = 4 [ (validate.rules).bool.const = true ];
  }
}

// RelationshipFilter is a collection of filters which when applied to a
// relationship will return relationships that have exactly matching fields.
//
// resource_type is required. All other fields are optional and if left
// unspecified will not filter relationships.
message RelationshipFilter {
  string resource_type = 1 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,61}[a-z0-9]/)?[a-z][a-z0-9_]{1,62}[a-z0-9]$",
    max_bytes : 128,
  } ];

  string optional_resource_id = 2 [ (validate.rules).string = {
    pattern : "^([a-zA-Z0-9_][a-zA-Z0-9/_|-]{0,127})?$",
    max_bytes : 128,
  } ];

  string optional_relation = 3 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,62}[a-z0-9])?$",
    max_bytes : 64,
  } ];

  SubjectFilter optional_subject_filter = 4;
}

// SubjectFilter specifies a filter on the subject of a relationship.
//
// subject_type is required and all other fields are optional, and will not
// impose any additional requirements if left unspecified.
message SubjectFilter {
  message RelationFilter {
    string relation = 1 [ (validate.rules).string = {
      pattern : "^([a-z][a-z0-9_]{1,62}[a-z0-9])?$",
      max_bytes : 64,
    } ];
  }

  string subject_type = 1 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,61}[a-z0-9]/)?[a-z][a-z0-9_]{1,62}[a-z0-9]$",
    max_bytes : 128,
  } ];

  string optional_subject_id = 2 [ (validate.rules).string = {
    pattern : "^(([a-zA-Z0-9_][a-zA-Z0-9/_|-]{0,127})|\\*)?$",
    max_bytes : 128,
  } ];

  RelationFilter optional_relation = 3;
}

// ReadRelationshipsRequest specifies one or more filters used to read matching
// relationships within the system.
message ReadRelationshipsRequest {
  Consistency consistency = 1;
  RelationshipFilter relationship_filter = 2
      [ (validate.rules).message.required = true ];
}

// ReadRelationshipsResponse contains a Relationship found that matches the
// specified relationship filter(s). A instance of this response message will
// be streamed to the client for each relationship found.
message ReadRelationshipsResponse {
  ZedToken read_at = 1 [ (validate.rules).message.required = true ];
  Relationship relationship = 2 [ (validate.rules).message.required = true ];
}

// Precondition specifies how and the existence or absence of certain
// relationships as expressed through the accompanying filter should affect
// whether or not the operation proceeds.
//
// MUST_NOT_MATCH will fail the parent request if any relationships match the
// relationships filter.
// MUST_MATCH will fail the parent request if there are no
// relationships that match the filter.
message Precondition {
  enum Operation {
    OPERATION_UNSPECIFIED = 0;
    OPERATION_MUST_NOT_MATCH = 1;
    OPERATION_MUST_MATCH = 2;
  }

  Operation operation = 1 [ (validate.rules).enum = {defined_only: true, not_in: [0]} ];
  RelationshipFilter filter = 2 [ (validate.rules).message.required = true ];
}

// WriteRelationshipsRequest contains a list of Relationship mutations that
// should be applied to the service. If the optional_preconditions parameter
// is included, all of the specified preconditions must also be satisfied before
// the write will be committed.
message WriteRelationshipsRequest {
  repeated RelationshipUpdate updates = 1
      [ (validate.rules).repeated .items.message.required = true ];

  repeated Precondition optional_preconditions = 2
      [ (validate.rules).repeated .items.message.required =
            true ]; // To be bounded by configuration
}

message WriteRelationshipsResponse { ZedToken written_at = 1; }

// DeleteRelationshipsRequest specifies which Relationships should be deleted,
// requesting the delete of *ALL* relationships that match the specified
// filters. If the optional_preconditions parameter is included, all of the
// specified preconditions must also be satisfied before the delete will be
// executed.
message DeleteRelationshipsRequest {
  RelationshipFilter relationship_filter = 1
      [ (validate.rules).message.required = true ];

  repeated Precondition optional_preconditions = 2
      [ (validate.rules).repeated .items.message.required =
            true ]; // To be bounded by configuration
}

message DeleteRelationshipsResponse { ZedToken deleted_at = 1; }

// CheckPermissionRequest issues a check on whether a subject has a permission
// or is a member of a relation, on a specific resource.
message CheckPermissionRequest {
  Consistency consistency = 1;

  // resource is the resource on which to check the permission or relation.
  ObjectReference resource = 2 [ (validate.rules).message.required = true ];

  // permission is the name of the permission (or relation) on which to execute
  // the check.
  string permission = 3 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,62}[a-z0-9])?$",
    max_bytes : 64,
  } ];

  // subject is the subject that will be checked for the permission or relation.
  SubjectReference subject = 4 [ (validate.rules).message.required = true ];

  /** context consists of named values that are injected into the caveat evaluation context **/
  google.protobuf.Struct context = 5 [ (validate.rules).message.required = false ];
}

message CheckPermissionResponse {
  enum Permissionship {
    PERMISSIONSHIP_UNSPECIFIED = 0;
    PERMISSIONSHIP_NO_PERMISSION = 1;
    PERMISSIONSHIP_HAS_PERMISSION = 2;
    PERMISSIONSHIP_CONDITIONAL_PERMISSION = 3;
  }

  ZedToken checked_at = 1 [ (validate.rules).message.required = false ];

  // Permissionship communicates whether or not the subject has the requested
  // permission or has a relationship with the given resource, over the given
  // relation.
  //
  // This value will be authzed.api.v1.PERMISSIONSHIP_HAS_PERMISSION if the
  // requested subject is a member of the computed permission set or there
  // exists a relationship with the requested relation from the given resource
  // to the given subject.
  Permissionship permissionship = 2 [ (validate.rules).enum = {defined_only: true, not_in: [0]} ];

  // partial_caveat_info holds information of a partially-evaluated caveated response
  PartialCaveatInfo partial_caveat_info = 3 [ (validate.rules).message.required = false ];
}

// ExpandPermissionTreeRequest returns a tree representing the expansion of all
// relationships found accessible from a permission or relation on a particular
// resource.
//
// ExpandPermissionTreeRequest is typically used to determine the full set of
// subjects with a permission, along with the relationships that grant said
// access.
message ExpandPermissionTreeRequest {
  Consistency consistency = 1;

  // resource is the resource over which to run the expansion.
  ObjectReference resource = 2 [ (validate.rules).message.required = true ];

  // permission is the name of the permission or relation over which to run the
  // expansion for the resource.
  string permission = 3 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,62}[a-z0-9])?$",
    max_bytes : 64,
  } ];
}

message ExpandPermissionTreeResponse {
  ZedToken expanded_at = 1;

  // tree_root is a tree structure whose leaf nodes are subjects, and
  // intermediate nodes represent the various operations (union, intersection,
  // exclusion) to reach those subjects.
  PermissionRelationshipTree tree_root = 2;
}

// LookupResourcesRequest performs a lookup of all resources of a particular
// kind on which the subject has the specified permission or the relation in
// which the subject exists, streaming back the IDs of those resources.
message LookupResourcesRequest {
  Consistency consistency = 1;

  // resource_object_type is the type of resource object for which the IDs will
  // be returned.
  string resource_object_type = 2 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,61}[a-z0-9]/)?[a-z][a-z0-9_]{1,62}[a-z0-9]$",
    max_bytes : 128,
  } ];

  // permission is the name of the permission or relation for which the subject
  // must Check.
  string permission = 3 [ (validate.rules).string = {
    pattern : "^[a-z][a-z0-9_]{1,62}[a-z0-9]$",
    max_bytes : 64,
  } ];

  // subject is the subject with access to the resources.
  SubjectReference subject = 4 [ (validate.rules).message.required = true ];

  /** context consists of named values that are injected into the caveat evaluation context **/
  google.protobuf.Struct context = 5 [ (validate.rules).message.required = false ];
}

// LookupPermissionship represents whether a Lookup response was partially evaluated or not
enum LookupPermissionship {
  LOOKUP_PERMISSIONSHIP_UNSPECIFIED = 0;
  LOOKUP_PERMISSIONSHIP_HAS_PERMISSION = 1;
  LOOKUP_PERMISSIONSHIP_CONDITIONAL_PERMISSION = 2;
}

// LookupResourcesResponse contains a single matching resource object ID for the
// requested object type, permission, and subject.
message LookupResourcesResponse {
  ZedToken looked_up_at = 1;
  string resource_object_id = 2;

  // permissionship indicates whether the response was partially evaluated or not
  LookupPermissionship permissionship = 3 [ (validate.rules).enum = {defined_only: true, not_in: [0]} ];

  // partial_caveat_info holds information of a partially-evaluated caveated response
  PartialCaveatInfo partial_caveat_info = 4  [ (validate.rules).message.required = false ];
}

// LookupSubjectsRequest performs a lookup of all subjects of a particular
// kind for which the subject has the specified permission or the relation in
// which the subject exists, streaming back the IDs of those subjects.
message LookupSubjectsRequest {
  Consistency consistency = 1;

  // resource is the resource for which all matching subjects for the permission
  // or relation will be returned.
  ObjectReference resource = 2 [ (validate.rules).message.required = true ];

  // permission is the name of the permission (or relation) for which to find
  // the subjects.
  string permission = 3 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,62}[a-z0-9])?$",
    max_bytes : 64,
  } ];

  // subject_object_type is the type of subject object for which the IDs will
  // be returned.
  string subject_object_type = 4 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,61}[a-z0-9]/)?[a-z][a-z0-9_]{1,62}[a-z0-9]$",
    max_bytes : 128,
  } ];

  // optional_subject_relation is the optional relation for the subject.
  string optional_subject_relation = 5 [ (validate.rules).string = {
    pattern : "^([a-z][a-z0-9_]{1,62}[a-z0-9])?$",
    max_bytes : 64,
  } ];

  /** context consists of named values that are injected into the caveat evaluation context **/
  google.protobuf.Struct context = 6 [ (validate.rules).message.required = false ];
}

// LookupSubjectsResponse contains a single matching subject object ID for the
// requested subject object type on the permission or relation.
message LookupSubjectsResponse {
  ZedToken looked_up_at = 1;

  // subject_object_id is the Object ID of the subject found. May be a `*` if
  // a wildcard was found.
  // deprecated: use `subject`
  string subject_object_id = 2 [deprecated = true];

  // excluded_subject_ids are the Object IDs of the subjects excluded. This list
  // will only contain object IDs if `subject_object_id` is a wildcard (`*`) and
  // will only be populated if exclusions exist from the wildcard.
  // deprecated: use `excluded_subjects`
  repeated string excluded_subject_ids = 3 [deprecated = true];

  // permissionship indicates whether the response was partially evaluated or not
  // deprecated: use `subject.permissionship`
  LookupPermissionship permissionship = 4 [ deprecated = true, (validate.rules).enum = {defined_only: true, not_in: [0]} ];

  // partial_caveat_info holds information of a partially-evaluated caveated response
  // deprecated: use `subject.partial_caveat_info`
  PartialCaveatInfo partial_caveat_info = 5 [ deprecated = true, (validate.rules).message.required = false ];

  // subject is the subject found, along with its permissionship.
  ResolvedSubject subject = 6;

  // excluded_subjects are the subjects excluded. This list
  // will only contain subjects if `subject.subject_object_id` is a wildcard (`*`) and
  // will only be populated if exclusions exist from the wildcard.
  repeated ResolvedSubject excluded_subjects = 7;
}

// ResolvedSubject is a single subject resolved within LookupSubjects.
message ResolvedSubject {
  // subject_object_id is the Object ID of the subject found. May be a `*` if
  // a wildcard was found.
  string subject_object_id = 1;

  // permissionship indicates whether the response was partially evaluated or not
  LookupPermissionship permissionship = 2 [ (validate.rules).enum = {defined_only: true, not_in: [0]} ];

  // partial_caveat_info holds information of a partially-evaluated caveated response
  PartialCaveatInfo partial_caveat_info = 3 [ (validate.rules).message.required = false ];
}