added ios module

ios/OralTrainer/Services/ImitationAssessor.swift

@@ -0,0 +1,124 @@
+import CryptoKit
+import Foundation
+
+enum ImitationAssessorError: LocalizedError {
+    case invalidHash
+    case cannotReadRecording
+
+    var errorDescription: String? {
+        switch self {
+        case .invalidHash:
+            return "视频 id 必须是 64 位 SHA-256 十六进制字符串"
+        case .cannotReadRecording:
+            return "无法读取录音文件"
+        }
+    }
+}
+
+enum ImitationAssessor {
+    /// 分块计算文件的 SHA-256（与安卓端一致，适合大视频文件）。
+    static func sha256Hex(of fileURL: URL) throws -> String {
+        let handle: FileHandle
+        do {
+            handle = try FileHandle(forReadingFrom: fileURL)
+        } catch {
+            throw ImitationAssessorError.cannotReadRecording
+        }
+        defer { try? handle.close() }
+        var hasher = SHA256()
+        while true {
+            guard let data = try? handle.read(upToCount: 1 << 20), !data.isEmpty else {
+                break
+            }
+            hasher.update(data: data)
+        }
+        return hasher.finalize().map { String(format: "%02x", $0) }.joined()
+    }
+
+    /// 复制到缓存目录的同时计算 SHA-256（单次读取完成两件事）。
+    static func copyAndHash(from source: URL, to destination: URL) throws -> String {
+        let input: FileHandle
+        do {
+            input = try FileHandle(forReadingFrom: source)
+        } catch {
+            throw ImitationAssessorError.cannotReadRecording
+        }
+        defer { try? input.close() }
+        try? FileManager.default.removeItem(at: destination)
+        FileManager.default.createFile(atPath: destination.path, contents: nil)
+        let output = try FileHandle(forWritingTo: destination)
+        defer { try? output.close() }
+        var hasher = SHA256()
+        while true {
+            guard let data = try input.read(upToCount: 1 << 20), !data.isEmpty else {
+                break
+            }
+            hasher.update(data: data)
+            try output.write(contentsOf: data)
+        }
+        try output.synchronize()
+        return hasher.finalize().map { String(format: "%02x", $0) }.joined()
+    }
+
+    /// 上传一句录音到服务端 MOSS 评测接口（multipart/form-data，与安卓端字段一致）。
+    static func assess(request: ImitationAssessmentRequest) async throws -> ImitationAssessmentResult {
+        let hash = request.mediaId.lowercased()
+        guard hash.range(of: AppConfig.sha256Pattern, options: .regularExpression) != nil else {
+            throw ImitationAssessorError.invalidHash
+        }
+        let path = "api/v1/videos/\(hash)/sentences/\(request.sentence.index)/assessments"
+        let boundary = "----OralTrainer-\(UUID().uuidString)"
+        var body = Data()
+        appendField(&body, boundary: boundary, name: "language", value: request.locale ?? request.sentence.language ?? "")
+        let recordingData: Data
+        do {
+            recordingData = try Data(contentsOf: request.recordingURL)
+        } catch {
+            throw ImitationAssessorError.cannotReadRecording
+        }
+        let filename = request.recordingURL.lastPathComponent
+        let mimeType = request.recordingURL.pathExtension.lowercased() == "wav" ? "audio/wav" : "audio/m4a"
+        appendFile(&body, boundary: boundary, name: "audio", filename: filename, mimeType: mimeType, data: recordingData)
+        body.append(Data("--\(boundary)--\r\n".utf8))
+
+        let result = try await HTTPClient.execute(
+            baseURL: AppConfig.serverBaseURL,
+            path: path,
+            method: "POST",
+            timeout: AppConfig.assessmentTimeout,
+            headers: [
+                "Accept": "application/json",
+                "Content-Type": "multipart/form-data; boundary=\(boundary)",
+                "X-Client-Key": AppConfig.assessmentAPIKey,
+            ],
+            body: body
+        )
+        guard (200...299).contains(result.statusCode) else {
+            let responseBody = String(data: result.body, encoding: .utf8) ?? ""
+            throw HTTPClientError.badStatus(result.statusCode, responseBody)
+        }
+        return try JSONDecoder().decode(ImitationAssessmentResult.self, from: result.body)
+    }
+
+    private static func appendField(_ body: inout Data, boundary: String, name: String, value: String) {
+        body.append(Data("--\(boundary)\r\n".utf8))
+        body.append(Data("Content-Disposition: form-data; name=\"\(name)\"\r\n\r\n".utf8))
+        body.append(Data(value.utf8))
+        body.append(Data("\r\n".utf8))
+    }
+
+    private static func appendFile(
+        _ body: inout Data,
+        boundary: String,
+        name: String,
+        filename: String,
+        mimeType: String,
+        data: Data
+    ) {
+        body.append(Data("--\(boundary)\r\n".utf8))
+        body.append(Data("Content-Disposition: form-data; name=\"\(name)\"; filename=\"\(filename)\"\r\n".utf8))
+        body.append(Data("Content-Type: \(mimeType)\r\n\r\n".utf8))
+        body.append(data)
+        body.append(Data("\r\n".utf8))
+    }
+}