// !!! THIS CODE IS AUTOMATICALLY GENERATED, DO NOT EDIT BY HAND !!!
//
// Copyright 2018-19 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
//
//     https://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.

import CTensorFlow

/// **WARNING:** After constructing a `TFE_Op`, any one of its `execute` methods must be called
/// *exactly once*. If not called, then a memory leak is introduced due to the underlying TensorFlow
/// eager op object not being freed. If called more than once, then a SEGFAULT may occur due to
/// trying to execute a TensorFlow eager op that has already been freed.
@usableFromInline
internal struct TFE_Op : TFTensorOperation {
  @usableFromInline internal let status: CTFStatus
  @usableFromInline internal let op: CTFEOp
  @usableFromInline internal let outputCount: Int

  @usableFromInline
  internal init(_ name: String, _ outputCount: Int) {
    self.status = TF_NewStatus()
    self.op = TFE_NewOp(_ExecutionContext.global.eagerContext, name, status)
    self.outputCount = outputCount
  }

  @inlinable @inline(__always)
  internal func addInput(_ input: _AnyTensorHandle) {
    TFE_OpAddInput(op, input._cTensorHandle, status)
    checkOk(status)
  }

  @inlinable @inline(__always)
  internal func addInput<Scalar: TensorFlowScalar>(_ input: Tensor<Scalar>) {
    TFE_OpAddInput(op, input.handle._cTensorHandle, status)
    checkOk(status)
  }

  @inlinable @inline(__always)
  internal func addInput(_ input: StringTensor) {
    TFE_OpAddInput(op, input.handle._cTensorHandle, status)
    checkOk(status)
  }

  @inlinable @inline(__always)
  internal func addInput(_ input: ResourceHandle) {
    TFE_OpAddInput(op, input._cTensorHandle, status)
    checkOk(status)
  }

  @inlinable @inline(__always)
  internal func addInput(_ input: VariantHandle) {
    TFE_OpAddInput(op, input._cTensorHandle, status)
    checkOk(status)
  }

  @inlinable @inline(__always)
  internal func addInputList<T: TensorArrayProtocol>(_ input: T) {
    let count = input._tensorHandleCount
    var buffer = UnsafeMutableBufferPointer<CTensorHandle>.allocate(capacity: Int(count))
    defer { buffer.deallocate() }
    let pointer = UnsafeMutablePointer<OpaquePointer?>(buffer.baseAddress)
    input._unpackTensorHandles(into: buffer.baseAddress)
    TFE_OpAddInputList(op, pointer, count, status)
    // TODO: checkOk(status)
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: Bool) {
    TFE_OpSetAttrBool(op, name, value ? 1 : 0)
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: Int) {
    TFE_OpSetAttrInt(op, name, Int64(value))
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: Int32) {
    TFE_OpSetAttrInt(op, name, Int64(value))
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: Int64) {
    TFE_OpSetAttrInt(op, name, value)
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: Float) {
    TFE_OpSetAttrFloat(op, name, value)
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: Double) {
    TFE_OpSetAttrFloat(op, name, Float(value))
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: String) {
    value.utf8CString.withUnsafeBufferPointer { buffer in
      // utf8CString is null-terminated; TFE_OpSetAttrString wants
      // non-null-terminated.
      TFE_OpSetAttrString(op, name, buffer.baseAddress, buffer.count - 1)
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: TensorDataType) {
    TFE_OpSetAttrType(op, name, value._cDataType)
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: TensorShape) {
    let dimensions: [Int64] = value.dimensions.map(Int64.init)
    dimensions.withUnsafeBufferPointer { buffer in
      TFE_OpSetAttrShape(op, name, buffer.baseAddress, Int32(buffer.count), status)
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: TensorShape?) {
    guard let shape = value else {
      TFE_OpSetAttrShape(op, name, nil, -1, status)
      return
    }
    updateAttribute(name, shape)
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [Bool]) {
    value.map({ $0 ? UInt8(1) : UInt8(0) }).withUnsafeBufferPointer { buffer in
      TFE_OpSetAttrBoolList(op, name, buffer.baseAddress, Int32(buffer.count))
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [Int]) {
    updateAttribute(name, value.map(Int64.init))
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [Int32]) {
    updateAttribute(name, value.map(Int64.init))
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [Int64]) {
    value.withUnsafeBufferPointer { buffer in
      TFE_OpSetAttrIntList(op, name, buffer.baseAddress, Int32(buffer.count))
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [Float]) {
    value.withUnsafeBufferPointer { buffer in
      TFE_OpSetAttrFloatList(op, name, buffer.baseAddress, Int32(buffer.count))
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [Double]) {
    updateAttribute(name, value.map(Float.init))
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [String]) {
    // Collect all the strings' utf8 bytes into a single array so that we can
    // address all the strings with a single
    // `flattenedStringBytes.withUnsafeBufferPointer`.
    var flattenedStringBytes: [CChar] = []
    var lengths: [Int] = []
    for string in value {
      // Don't include the null-terminator because TFE_OpSetAttrStringList uses
      // lengths instead of null-terminators.
      let stringBytes = string.utf8CString.dropLast()
      flattenedStringBytes.append(contentsOf: stringBytes)
      lengths.append(stringBytes.count)
    }

    // Calculate the addresses of all the strings within our single buffer, and
    // then call TFE_OpSetAttrStringList.
    flattenedStringBytes.withUnsafeBufferPointer { flattenedStringBytesBuffer in
      var stringAddrs: [UnsafeRawPointer?] = []
      var currentStringAddr =
        flattenedStringBytesBuffer.baseAddress.map(UnsafeRawPointer.init)
      for length in lengths {
        stringAddrs.append(currentStringAddr)
        currentStringAddr = currentStringAddr?.advanced(by: length)
      }

      stringAddrs.withUnsafeBufferPointer { stringAddrsBuffer in
        lengths.withUnsafeBufferPointer { lengthsBuffer in
          TFE_OpSetAttrStringList(op, name, stringAddrsBuffer.baseAddress,
            lengthsBuffer.baseAddress, Int32(value.count))
        }
      }
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [TensorDataType]) {
    value.withUnsafeBufferPointer { buffer in
      buffer.withMemoryRebound(to: TF_DataType.self) { reboundBuffer in
        TFE_OpSetAttrTypeList(op, name, reboundBuffer.baseAddress, Int32(reboundBuffer.count))
      }
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [TensorShape]) {
    let flattenedDims = value.flatMap { $0.dimensions.map(Int64.init) }
    let ranks = value.map { Int32($0.rank) }
    flattenedDims.withUnsafeBufferPointer { flattenedDimsBuffer in
      var dimsPtr: UnsafePointer<Int64>? = flattenedDimsBuffer.baseAddress
      var dims: [UnsafePointer<Int64>?] = []
      for rank in ranks {
        dims.append(dimsPtr)
        if rank >= 0 {
          dimsPtr = dimsPtr.map { $0.advanced(by: Int(rank)) }
        }
      }
      dims.withUnsafeMutableBufferPointer { dimsBuffer in
        ranks.withUnsafeBufferPointer { ranksBuffer in
          TFE_OpSetAttrShapeList(
            op, name, dimsBuffer.baseAddress, ranksBuffer.baseAddress,
            Int32(ranksBuffer.count), status)
        }
      }
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute(_ name: String, _ value: [TensorShape?]) {
    let flattenedDims = value.flatMap { (tensorShapeOpt) -> [Int64] in
      if let tensorShape = tensorShapeOpt {
        return tensorShape.dimensions.map(Int64.init)
      }
      return []
    }
    let ranks = value.map { shape in (shape?.rank).map(Int32.init) ?? -1 }
    flattenedDims.withUnsafeBufferPointer { flattenedDimsBuffer in
      var dimsPtr: UnsafePointer<Int64>? = flattenedDimsBuffer.baseAddress
      var dims: [UnsafePointer<Int64>?] = []
      for rank in ranks {
        dims.append(dimsPtr)
        if rank >= 0 {
          dimsPtr = dimsPtr.map { $0.advanced(by: Int(rank)) }
        }
      }
      dims.withUnsafeMutableBufferPointer { dimsBuffer in
        ranks.withUnsafeBufferPointer { ranksBuffer in
          TFE_OpSetAttrShapeList(
            op, name, dimsBuffer.baseAddress, ranksBuffer.baseAddress,
            Int32(ranksBuffer.count), status)
        }
      }
    }
  }

  @inlinable @inline(__always)
  internal func updateAttribute<In: TensorGroup, Out: TensorGroup>(_ name: String, _ value: (In) -> Out) {
    _tffunc(value).utf8CString.withUnsafeBufferPointer { buffer in
      // utf8CString is null-terminated; TFE_OpSetAttrFunctionName wants
      // non-null-terminated.
      TFE_OpSetAttrFunctionName(op, name, buffer.baseAddress, buffer.count - 1)
    }
  }

  /// **WARNING:** After constructing a `TFE_Op`, any one of its `execute` methods must be called
  /// *exactly once*. If not called, then a memory leak is introduced due to the underlying
  /// TensorFlow eager op object not being freed. If called more than once, then a SEGFAULT may
  /// occur due to trying to execute a TensorFlow eager op that has already been freed.

  @inlinable @inline(__always)
  internal func evaluateUnsafe() -> UnsafeMutablePointer<CTensorHandle> {
    var count: Int32 = Int32(self.outputCount)
    let buffer: UnsafeMutablePointer<CTensorHandle> =
    UnsafeMutablePointer.allocate(capacity: Int(count))
    _TFCOpSetDeviceFromScope(op, status)
    checkOk(status)
    _TFCEagerExecute(op, UnsafeMutablePointer<CTensorHandle?>(buffer), &count, status)
    checkOk(status)
    TFE_DeleteOp(op)
    TF_DeleteStatus(status)
    return buffer
  }

  @inlinable @inline(__always)
  internal func execute() {
    let _ = evaluateUnsafe()
  }

%for n in range(1, 10 + 1):
  @inlinable @inline(__always)
  internal func execute<${", ".join(["T" + str(i) + " : TensorArrayProtocol" for i in range(n)])}>(
    ${",\n    ".join(["_ count" + str(i) + ": Int" for i in range(n)])}
  ) -> (${", ".join(["T" + str(i) for i in range(n)])}) {
    let buffer = evaluateUnsafe()
%for i in range(n):
    let offset${i} = ${"Int32(0)" if i == 0 else "offset" + str(i - 1) + " + Int32(count" + str(i - 1) + ")"}
%end
    let result = (
      ${",\n      ".join(["T" + str(i) + ".init(_owning: buffer.advanced(by: Int(offset" + str(i) + ")), count: count" + str(i) + ")" for i in range(n)])})
    buffer.deallocate()
    return result
  }

%end
}