syntax = "proto3";

package org.kubeflow.pipelines.components.v1alpha1;
import "google/protobuf/struct.proto";

// Describes the component input specification
message InputSpec {
    string name = 1;
    TypeSpecType type = 2;
    string description = 3;
    string default = 4;
    bool optional = 5;
}

// Describes the component output specification
message OutputSpec {
    string name = 1;
    TypeSpecType type = 2;
    string description = 3;
}

message StringOrPlaceholder {
    oneof oneof {
        // Constant string
        string constantValue = 1;

        // Represents the command-line argument placeholder that will be replaced at run-time by the input argument value.
        string inputValue = 2; // == input value for <Input name>

        // Represents the command-line argument placeholder that will be replaced at run-time by a local file path pointing to a file containing the input argument value.
        string inputPath = 3; // == input path for <Input name>

        // Represents the command-line argument placeholder that will be replaced at run-time by a local file path pointing to a file where the program should write its output data.
        string outputPath = 4; // == output path for <Output name>

        // Represents the command-line argument placeholder that will be replaced at run-time by the concatenated values of its items.
        ConcatPlaceholder concat = 5;

        // Represents the command-line argument placeholder that will be replaced at run-time by a boolean value specifying whether the caller has passed an argument for the specified optional input.
        IfPlaceholder if = 6;
    }
}

message ContainerSpec {
    // Docker image name.
    string image = 1;

    // Entrypoint array. Not executed within a shell. The docker image's ENTRYPOINT is used if this is not provided.
    repeated StringOrPlaceholder command = 2;

    // Arguments to the entrypoint. The docker image's CMD is used if this is not provided.
    repeated StringOrPlaceholder args = 3;

    // List of environment variables to set in the container.
    map<string, string> env = 4;

    // Legacy. Deprecated. Can be used to specify output paths for programs that do not allow setting the path of some output using command-line.
    map<string, string> fileOutputs = 5;
}

// Represents the container component implementation.
message ContainerImplementation {
    ContainerSpec container = 1;
}

// Component specification. Describes the metadata (name, description, source), the interface (inputs and outputs) and the implementation of the component.
message ComponentSpec {
    string name = 1;
    string description = 2;
    repeated InputSpec inputs = 3;
    repeated OutputSpec outputs = 4;
    ImplementationType implementation = 5;
    string version = 6;
    MetadataSpec metadata = 7;
}

// Component reference. Contains information that can be used to locate and load a component by name, digest or URL
message ComponentReference {
    string name = 1;
    string digest = 2;
    string tag = 3;
    string url = 4;
    ComponentSpec spec = 5;
}

// References the input of the graph.
message GraphInputReference {
    string inputName = 1;
    TypeSpecType type = 2;
}

// References the output of a sibling task.
message TaskOutputReference {
    string outputName = 1;
    string taskId = 2;
    TypeSpecType type = 3;
}


message TaskArgumentType {
    oneof oneof {
        // Constant task argument.
        string string_value = 1;
        
        // Represents the task argument value that comes from the graph component input.
        GraphInputReference graphInput = 2;

        // Represents the task argument value that comes from the output of a sibling task.
        TaskOutputReference taskOutput = 3;
    }
}

// Task specification. Task is a configured component - a component supplied with arguments and other applied configuration changes.
message TaskSpec {
    ComponentReference componentRef = 1; // Reference to the component from which the task is instantiated

    map<string, TaskArgumentType> arguments = 2; // Arguments to pass to the component

    PredicateType isEnabled = 3; // Specifies predicate to execute the task conditionally

    ExecutionOptionsSpec executionOptions = 4;
}

// Describes the graph component implementation. It represents a graph of component tasks connected to the upstream sources of data using the argument specifications. It also describes the sources of graph output values.
message GraphSpec {
    map<string, TaskSpec> tasks = 1; // List of tasks (components and their arguments) belonging to the graph.
    map<string, TaskArgumentType> outputValues = 2; // Sources of the graph component output values.
}

// The implementation of the component
message ImplementationType {
    oneof oneof {
        ContainerSpec container = 1; // Represents the component implementated as a containerized program
        GraphSpec graph = 2; // Represents the component implementated as graph of connected tasks
    }
}

// The object that can be sent to the backend to start a new Run.
message PipelineRunSpec {
    TaskSpec rootTask = 1;
    TaskSpec onExitTask = 2;
}

message TypeSpecType {
    message Properties {
        map<string, TypeSpecType> type = 1;
    }
    
    oneof oneof {
        string type_name = 1;
        Properties properties = 2;
    }
}

// Represents the command-line argument placeholder that will be replaced at run-time by the concatenated values of its items.
message ConcatPlaceholder {
    // Items to concatenate
    repeated StringOrPlaceholder items = 1;
}

message IfConditionArgumentType {
    oneof oneof {
        bool boolean_value = 1; // e.g. True
        string string_value = 2; // e.g. "true"
        string isPresent = 3; // Checks whether an argument for some input was passed to the component // Represents the command-line argument placeholder that will be replaced at run-time by a boolean value specifying whether the caller has passed an argument for the specified optional input.
    }
}

message IfPlaceholder {
    IfConditionArgumentType cond = 1;
    repeated StringOrPlaceholder then = 2;
    repeated StringOrPlaceholder else = 3;
}

message MetadataSpec {
    map<string, string> annotations = 1;
}

// Represents a logical expression. Used to specify condition for conditional task executed.
message PredicateType {
    oneof oneof {
        PredicateType not = 1;

        TwoLogicalOperands and = 2;
        TwoLogicalOperands or = 3;

        TwoArgumentOperands eq = 4;
        TwoArgumentOperands ne = 5;
        TwoArgumentOperands gt = 6;
        TwoArgumentOperands ge = 7;
        TwoArgumentOperands lt = 8;
        TwoArgumentOperands le = 9;
    }
}

// Pair of operands for a binary operation.
message TwoArgumentOperands {
    TaskArgumentType op1 = 1;
    TaskArgumentType op2 = 2;
}

// Pair of operands for a binary logical operation.
message TwoLogicalOperands {
    PredicateType op1 = 1;
    PredicateType op2 = 2;
}

// Optional configuration that specifies how the task should be retried if it fails.
message RetryStrategySpec {
    int32 maxRetries = 1;
}

// Optional configuration that specifies how the task should be executed. Can be used to set some platform-specific options.
message ExecutionOptionsSpec {
    RetryStrategySpec retryStrategy = 1;
}