const fs = require("node:fs");
const path = require("node:path");

function createModelHandlers({ callServer, fetchImpl = fetch }) {
  return {
    list(request) {
      return callServer({
        type: "listModels",
        folder: `${request.deviceId}/model_config`
      }, request.credentials);
    },

    async upload(request) {
      if (!request.sourcePath || !request.fileName) throw new Error("请先选择模型文件");
      const sourcePath = path.resolve(request.sourcePath);
      const fileName = path.basename(request.fileName);
      const modelName = path.basename(request.modelName || fileName);
      await fs.promises.access(sourcePath, fs.constants.R_OK);
      const issued = await callServer({
        type: "issueModelUpload",
        deviceId: request.deviceId,
        fileName,
        modelName,
        overwrite: request.overwrite === true
      }, request.credentials);
      const form = new FormData();
      form.append("file", new Blob([await fs.promises.readFile(sourcePath)]), fileName);
      const response = await fetchImpl(issued.uploadMetadata.url, { method: "POST", body: form });
      if (![200, 204].includes(response.status)) throw new Error(`模型上传失败: HTTP ${response.status}`);
      return {
        success: true,
        fileID: issued.fileID,
        fileName: issued.fileName,
        originalFileName: issued.originalFileName
      };
    },

    delete(request) {
      return callServer({ type: "deleteModel", fileID: request.fileID }, request.credentials);
    }
  };
}

module.exports = { createModelHandlers };