feat: Generate schemas with native-Swift code generator

Package.swift

@@ -270,9 +270,15 @@ let package = Package(
         .executableTarget(
             name: "SmithyCodegenCLI",
             dependencies: [
+                "SmithyCodegenCore",
                 .product(name: "ArgumentParser", package: "swift-argument-parser"),
             ]
         ),
+        .target(
+            name: "SmithyCodegenCore",
+            dependencies: ["Smithy"],
+            resources: [ .process("Resources") ]
+        ),
         .testTarget(
             name: "ClientRuntimeTests",
             dependencies: [
@@ -353,5 +359,9 @@ let package = Package(
             name: "SmithyStreamsTests",
             dependencies: ["SmithyStreams", "Smithy"]
         ),
+        .testTarget(
+            name: "SmithyCodegenCoreTests",
+            dependencies: ["SmithyCodegenCore"]
+        ),
     ].compactMap { $0 }
 )

Sources/Smithy/Schema/SchemaTraits.swift

@@ -0,0 +1,21 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+/// The trait IDs that should be copied into schemas.  Other traits are omitted for brevity.
+///
+/// This list can be expanded as features are added to Smithy/SDK that use them.
+public let permittedTraitIDs: Set<String> = [
+    "smithy.api#sparse",
+    "smithy.api#input",
+    "smithy.api#output",
+    "smithy.api#error",
+    "smithy.api#enumValue",
+    "smithy.api#jsonName",
+    "smithy.api#required",
+    "smithy.api#default",
+    "smithy.api#timestampFormat",
+]

Sources/SmithyCodegenCLI/SmithyCodegenCLI.swift

@@ -7,6 +7,7 @@
 
 import ArgumentParser
 import Foundation
+import struct SmithyCodegenCore.CodeGenerator
 
 @main
 struct SmithyCodegenCLI: AsyncParsableCommand {
@@ -31,12 +32,8 @@ struct SmithyCodegenCLI: AsyncParsableCommand {
         // If --schemas-path was supplied, create the schema file URL
         let schemasFileURL = resolve(paramName: "--schemas-path", path: schemasPath)
 
-        // All file URLs needed for code generation have now been resolved.
-        // Implement code generation here.
-        if let schemasFileURL {
-            print("Schemas file path: \(schemasFileURL)")
-            FileManager.default.createFile(atPath: schemasFileURL.path, contents: Data())
-        }
+        // Use resolved file URLs to run code generator
+        try CodeGenerator(modelFileURL: modelFileURL, schemasFileURL: schemasFileURL).run()
     }
 
     private func currentWorkingDirectoryFileURL() -> URL {

Sources/SmithyCodegenCore/AST/ASTError.swift

@@ -0,0 +1,14 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+public struct ASTError: Error {
+    public let localizedDescription: String
+
+    init(_ localizedDescription: String) {
+        self.localizedDescription = localizedDescription
+    }
+}

Sources/SmithyCodegenCore/AST/ASTMember.swift

@@ -0,0 +1,11 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+struct ASTMember: Decodable {
+    let target: String
+    let traits: [String: ASTNode]?
+}

Sources/SmithyCodegenCore/AST/ASTModel.swift

@@ -0,0 +1,12 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+struct ASTModel: Decodable {
+    let smithy: String
+    let metadata: ASTNode?
+    let shapes: [String: ASTShape]
+}

Sources/SmithyCodegenCore/AST/ASTNode.swift

@@ -0,0 +1,45 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+/// Contains the value of a Smithy Node, as used in a JSON AST.
+///
+/// Smithy node data is basically the same as the data that can be stored in JSON.
+/// The root of a Smithy node may be of any type, i.e. unlike JSON, the root element is not limited to object or list.
+///
+/// See the definition of node value in the Smithy spec: https://smithy.io/2.0/spec/model.html#node-values
+enum ASTNode: Sendable {
+    case object([String: ASTNode])
+    case list([ASTNode])
+    case string(String)
+    case number(Double)
+    case boolean(Bool)
+    case null
+}
+
+extension ASTNode: Decodable {
+
+    init(from decoder: any Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        if container.decodeNil() {
+            self = .null
+        } else if let bool = try? container.decode(Bool.self) {
+            self = .boolean(bool)
+        } else if let int = try? container.decode(Int.self) {
+            self = .number(Double(int))
+        } else if let double = try? container.decode(Double.self) {
+            self = .number(double)
+        } else if let string = try? container.decode(String.self) {
+            self = .string(string)
+        } else if let array = try? container.decode([ASTNode].self) {
+            self = .list(array)
+        } else if let dictionary = try? container.decode([String: ASTNode].self) {
+            self = .object(dictionary)
+        } else {
+            throw ASTError("Undecodable value in AST node")
+        }
+    }
+}

Sources/SmithyCodegenCore/AST/ASTReference.swift

@@ -0,0 +1,10 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+struct ASTReference: Decodable {
+    let target: String
+}

Sources/SmithyCodegenCore/AST/ASTShape.swift

@@ -0,0 +1,31 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+struct ASTShape: Decodable {
+    let type: ASTType
+    let traits: [String: ASTNode]?
+    let member: ASTMember?
+    let key: ASTMember?
+    let value: ASTMember?
+    let members: [String: ASTMember]?
+    let version: String?
+    let operations: [ASTReference]?
+    let resources: [ASTReference]?
+    let errors: [ASTReference]?
+    let rename: [String: String]?
+    let identifiers: [String: ASTReference]?
+    let properties: [String: ASTReference]?
+    let create: ASTReference?
+    let put: ASTReference?
+    let read: ASTReference?
+    let update: ASTReference?
+    let delete: ASTReference?
+    let list: ASTReference?
+    let collectionOperations: [ASTReference]?
+    let input: ASTReference?
+    let output: ASTReference?
+}

Sources/SmithyCodegenCore/AST/ASTType.swift

@@ -0,0 +1,37 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+enum ASTType: String, Decodable {
+    // These cases are all the Smithy shape types
+    case blob
+    case boolean
+    case string
+    case timestamp
+    case byte
+    case short
+    case integer
+    case long
+    case float
+    case document
+    case double
+    case bigDecimal
+    case bigInteger
+    case `enum`
+    case intEnum
+    case list
+    case set
+    case map
+    case structure
+    case union
+    case member
+    case service
+    case resource
+    case operation
+
+    // Special for AST, added 'apply' case
+    case apply
+}

Sources/SmithyCodegenCore/CodeGenerator.swift

@@ -0,0 +1,30 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import struct Foundation.Data
+import struct Foundation.URL
+
+public struct CodeGenerator {
+    let modelFileURL: URL
+    let schemasFileURL: URL?
+
+    public init(modelFileURL: URL, schemasFileURL: URL?) {
+        self.modelFileURL = modelFileURL
+        self.schemasFileURL = schemasFileURL
+    }
+
+    public func run() throws {
+        // Load the model from the model file
+        let model = try Model(modelFileURL: modelFileURL)
+
+        // If a schema file URL was provided, generate it
+        if let schemasFileURL {
+            let schemaContents = try SmithySchemaCodegen().generate(model: model)
+            try Data(schemaContents.utf8).write(to: schemasFileURL)
+        }
+    }
+}

Sources/SmithyCodegenCore/CodegenError.swift

@@ -0,0 +1,14 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+struct CodegenError: Error {
+    let localizedDescription: String
+
+    init(_ localizedDescription: String) {
+        self.localizedDescription = localizedDescription
+    }
+}

Sources/SmithyCodegenCore/Model/Model.swift

@@ -0,0 +1,87 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import struct Foundation.Data
+import class Foundation.JSONDecoder
+import struct Foundation.URL
+
+public class Model {
+    public let version: String
+    public let metadata: Node?
+    public let shapes: [ShapeID: Shape]
+
+    public convenience init(modelFileURL: URL) throws {
+        let modelData = try Data(contentsOf: modelFileURL)
+        let astModel = try JSONDecoder().decode(ASTModel.self, from: modelData)
+        try self.init(astModel: astModel)
+    }
+
+    init(astModel: ASTModel) throws {
+        self.version = astModel.smithy
+        self.metadata = astModel.metadata?.modelNode
+        let idToShapePairs = try astModel.shapes.map { try Self.shapePair(id: $0.key, astShape: $0.value) }
+        let idToMemberShapePairs = try astModel.shapes.flatMap { astShape in
+            try Self.memberShapePairs(id: astShape.key, astShape: astShape.value)
+        }
+        self.shapes = Dictionary(uniqueKeysWithValues: idToShapePairs + idToMemberShapePairs)
+
+        // self is now initialized, perform post-initialization wireup
+
+        // set the Shapes with references back to this model
+        self.shapes.values.forEach { $0.model = self }
+
+        // set the memberIDs for each Shape
+        self.shapes.values.filter { $0.type != .member }.forEach { shape in
+            let namespace = shape.id.namespace
+            let name = shape.id.name
+            let memberIDs: [ShapeID] = Array(self.shapes.keys)
+            let filteredMemberIDs = memberIDs.filter {
+                $0.namespace == namespace && $0.name == name && $0.member != nil
+            }
+            shape.memberIDs = filteredMemberIDs.sorted()
+        }
+    }
+
+    private static func shapePair(id: String, astShape: ASTShape) throws -> (ShapeID, Shape) {
+        let shapeID = try ShapeID(id)
+        let idToTraitPairs = try astShape.traits?.map { (try ShapeID($0.key), $0.value.modelNode) } ?? []
+        let shape = Shape(
+            id: shapeID,
+            type: astShape.type.modelType,
+            traits: Dictionary(uniqueKeysWithValues: idToTraitPairs),
+            targetID: nil
+        )
+        return (shapeID, shape)
+    }
+
+    private static func memberShapePairs(id: String, astShape: ASTShape) throws -> [(ShapeID, Shape)] {
+        var baseMembers = (astShape.members ?? [:])
+        if let member = astShape.member {
+            baseMembers["member"] = member
+        }
+        if let key = astShape.key {
+            baseMembers["key"] = key
+        }
+        if let value = astShape.value {
+            baseMembers["value"] = value
+        }
+        return try baseMembers.map { astMember in
+            let memberID = ShapeID(id: try ShapeID(id), member: astMember.key)
+            let traitPairs = try astMember.value.traits?.map { (try ShapeID($0.key), $0.value.modelNode) }
+            let traits = Dictionary(uniqueKeysWithValues: traitPairs ?? [])
+            let targetID = try ShapeID(astMember.value.target)
+            return (memberID, Shape(id: memberID, type: .member, traits: traits, targetID: targetID))
+        }
+    }
+
+    func expectShape(id: ShapeID) throws -> Shape {
+        guard let shape = shapes[id] else {
+            throw ModelError("ShapeID \(id) was expected in model but not found")
+        }
+        return shape
+    }
+}

Sources/SmithyCodegenCore/Model/ModelError.swift

@@ -0,0 +1,14 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+public struct ModelError: Error {
+    public let localizedDescription: String
+
+    init(_ localizedDescription: String) {
+        self.localizedDescription = localizedDescription
+    }
+}