firebase-ios-sdk/Firestore/Swift/Source/SwiftAPI/Pipeline/Aggregates/AggregateFunction.swift

// Copyright 2025 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

extension AggregateFunction {
  func toBridge() -> AggregateFunctionBridge {
    return (self as AggregateBridgeWrapper).bridge
  }
}

public class AggregateFunction: AggregateBridgeWrapper, @unchecked Sendable {
  let bridge: AggregateFunctionBridge

  let functionName: String
  let args: [Expression]

  public init(_ functionName: String, _ args: [Expression]) {
    self.functionName = functionName
    self.args = args
    bridge = AggregateFunctionBridge(
      name: functionName,
      args: self.args.map { $0.toBridge()
      }
    )
  }

  public func `as`(_ name: String) -> AliasedAggregate {
    return AliasedAggregate(aggregate: self, alias: name)
  }
}