syntax = "proto3";

package flyteidl.core;

option go_package = "github.com/flyteorg/flyte/flyteidl/gen/pb-go/flyteidl/core";

import "flyteidl/core/literals.proto";

// Defines a 2-level tree where the root is a comparison operator and Operands are primitives or known variables.
// Each expression results in a boolean result.
message ComparisonExpression {
    // Binary Operator for each expression
    enum Operator {
        EQ = 0;
        NEQ = 1;
        // Greater Than
        GT = 2;
        GTE = 3;
        // Less Than
        LT = 4;
        LTE = 5;
    }

    Operator operator = 1;
    Operand left_value = 2;
    Operand right_value = 3;
}

// Defines an operand to a comparison expression.
message Operand {
    oneof val {
        // Can be a constant
        core.Primitive primitive = 1 [deprecated = true];
        // Or one of this node's input variables
        string var = 2;
        // Replace the primitive field
        core.Scalar scalar = 3;
    }
}

// Defines a boolean expression tree. It can be a simple or a conjunction expression.
// Multiple expressions can be combined using a conjunction or a disjunction to result in a final boolean result.
message BooleanExpression {
    oneof expr {
        ConjunctionExpression conjunction = 1;
        ComparisonExpression comparison = 2;
    }
}

// Defines a conjunction expression of two boolean expressions.
message ConjunctionExpression {
    // Nested conditions. They can be conjoined using AND / OR
    // Order of evaluation is not important as the operators are Commutative
    enum LogicalOperator {
        // Conjunction
        AND = 0;
        OR = 1;
    }

    LogicalOperator operator = 1;
    BooleanExpression left_expression = 2;
    BooleanExpression right_expression = 3;
}