Code generator for haskell-servant framework

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/HaskellServantCodegen.java

@@ -0,0 +1,345 @@
+package io.swagger.codegen.languages;
+
+import io.swagger.codegen.*;
+import io.swagger.models.properties.*;
+import io.swagger.models.Model;
+import io.swagger.models.Operation;
+import io.swagger.models.Swagger;
+
+import java.util.*;
+import java.io.File;
+
+public class HaskellServantCodegen extends DefaultCodegen implements CodegenConfig {
+
+  // source folder where to write the files
+  protected String sourceFolder = "src";
+  protected String apiVersion = "0.0.1";
+
+  /**
+   * Configures the type of generator.
+   * 
+   * @return  the CodegenType for this generator
+   * @see     io.swagger.codegen.CodegenType
+   */
+  public CodegenType getTag() {
+    return CodegenType.SERVER;
+  }
+
+  /**
+   * Configures a friendly name for the generator.  This will be used by the generator
+   * to select the library with the -l flag.
+   * 
+   * @return the friendly name for the generator
+   */
+  public String getName() {
+    return "haskell";
+  }
+
+  /**
+   * Returns human-friendly help for the generator.  Provide the consumer with help
+   * tips, parameters here
+   * 
+   * @return A string value for the help message
+   */
+  public String getHelp() {
+    return "Generates a HaskellServantCodegen library.";
+  }
+
+  public HaskellServantCodegen() {
+    super();
+
+    // set the output folder here
+    outputFolder = "generated-code/HaskellServantCodegen";
+
+    /**
+     * Models.  You can write model files using the modelTemplateFiles map.
+     * if you want to create one template for file, you can do so here.
+     * for multiple files for model, just put another entry in the `modelTemplateFiles` with
+     * a different extension
+     */
+    modelTemplateFiles.put(
+      "model.mustache", // the template to use
+      ".hs");       // the extension for each file to write
+
+    /**
+     * Api classes.  You can write classes for each Api file with the apiTemplateFiles map.
+     * as with models, add multiple entries with different extensions for multiple files per
+     * class
+     */
+    apiTemplateFiles.put(
+      "api.mustache",   // the template to use
+      ".hs");       // the extension for each file to write
+
+    /**
+     * Template Location.  This is the location which templates will be read from.  The generator
+     * will use the resource stream to attempt to read the templates.
+     */
+    embeddedTemplateDir = templateDir = "haskell";
+
+    /**
+     * Api Package.  Optional, if needed, this can be used in templates
+     */
+    apiPackage = "Api";
+
+    /**
+     * Model Package.  Optional, if needed, this can be used in templates
+     */
+    modelPackage = "Model";
+
+    /**
+     * Reserved words.  Override this with reserved words specific to your language
+     */
+    // from https://wiki.haskell.org/Keywords
+    reservedWords = new HashSet<String>(
+        Arrays.asList(
+            "as", "case", "of",
+            "class", "data", // "data family", "data instance",
+            "default", "deriving", // "deriving instance",
+            "do",
+            "forall", "foreign", "hiding",
+            "id",
+            "if", "then", "else",
+            "import", "infix", "infixl", "infixr",
+            "instance", "let", "in",
+            "mdo", "module", "newtype",
+            "proc", "qualified", "rec",
+            "type", // "type family", "type instance",
+            "where"
+        )
+    );
+
+    /**
+     * Additional Properties.  These values can be passed to the templates and
+     * are available in models, apis, and supporting files
+     */
+    additionalProperties.put("apiVersion", apiVersion);
+
+    /**
+     * Supporting Files.  You can write single files for the generator with the
+     * entire object tree available.  If the input file has a suffix of `.mustache
+     * it will be processed by the template engine.  Otherwise, it will be copied
+     */
+    supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
+    supportingFiles.add(new SupportingFile("stack.mustache", "", "stack.yaml"));
+    supportingFiles.add(new SupportingFile("haskell-servant-codegen.mustache", "", "haskell-servant-codegen.cabal"));
+    supportingFiles.add(new SupportingFile("Setup.mustache", "", "Setup.hs"));
+    supportingFiles.add(new SupportingFile("LICENSE", "", "LICENSE"));
+    supportingFiles.add(new SupportingFile("Apis.mustache", "lib", "Apis.hs"));
+    supportingFiles.add(new SupportingFile("Utils.mustache", "lib", "Utils.hs"));
+    supportingFiles.add(new SupportingFile("Client.mustache", "client", "Main.hs"));
+    supportingFiles.add(new SupportingFile("Server.mustache", "server", "Main.hs"));
+
+    /**
+     * Language Specific Primitives.  These types will not trigger imports by
+     * the client generator
+     */
+    languageSpecificPrimitives = new HashSet<String>(
+      Arrays.asList(
+        "Bool",
+        "String",
+        "Int",
+        "Integer",
+        "Float",
+        "Char",
+        "Double",
+        "List",
+        "FilePath"
+        )
+    );
+
+    typeMapping.clear();
+    // typeMapping.put("enum", "NSString");
+    typeMapping.put("array", "List");
+    typeMapping.put("set", "Set");
+    typeMapping.put("boolean", "Bool");
+    typeMapping.put("string", "String");
+    typeMapping.put("int", "Int");
+    typeMapping.put("long", "Integer");
+    typeMapping.put("float", "Float");
+    // typeMapping.put("byte", "Byte");
+    typeMapping.put("short", "Int");
+    typeMapping.put("char", "Char");
+    typeMapping.put("double", "Double");
+    typeMapping.put("DateTime", "Integer");
+    // typeMapping.put("object", "Map");
+    typeMapping.put("file", "FilePath");
+
+    importMapping.clear();
+    importMapping.put("Map", "qualified Data.Map as Map");
+
+    cliOptions.add(new CliOption(CodegenConstants.MODEL_PACKAGE, CodegenConstants.MODEL_PACKAGE_DESC));
+    cliOptions.add(new CliOption(CodegenConstants.API_PACKAGE, CodegenConstants.API_PACKAGE_DESC));
+  }
+
+  /**
+   * Escapes a reserved word as defined in the `reservedWords` array. Handle escaping
+   * those terms here.  This logic is only called if a variable matches the reseved words
+   * 
+   * @return the escaped term
+   */
+  @Override
+  public String escapeReservedWord(String name) {
+    return name + "_";
+  }
+
+  /**
+   * Location to write model files.  You can use the modelPackage() as defined when the class is
+   * instantiated
+   */
+  public String modelFileFolder() {
+    return outputFolder + File.separatorChar + "lib" + File.separatorChar + modelPackage().replace('.', File.separatorChar);
+  }
+
+  /**
+   * Location to write api files.  You can use the apiPackage() as defined when the class is
+   * instantiated
+   */
+  @Override
+  public String apiFileFolder() {
+    return outputFolder + File.separatorChar + "lib" + File.separatorChar + apiPackage().replace('.', File.separatorChar);
+  }
+
+  /**
+   * Optional - type declaration.  This is a String which is used by the templates to instantiate your
+   * types.  There is typically special handling for different property types
+   *
+   * @return a string value used as the `dataType` field for model templates, `returnType` for api templates
+   */
+  @Override
+  public String getTypeDeclaration(Property p) {
+    if(p instanceof ArrayProperty) {
+      ArrayProperty ap = (ArrayProperty) p;
+      Property inner = ap.getItems();
+      return "[" + getTypeDeclaration(inner) + "]";
+    }
+    else if (p instanceof MapProperty) {
+      MapProperty mp = (MapProperty) p;
+      Property inner = mp.getAdditionalProperties();
+      return "Map.Map String " + getTypeDeclaration(inner);
+    }
+    return super.getTypeDeclaration(p);
+  }
+
+  /**
+   * Optional - swagger type conversion.  This is used to map swagger types in a `Property` into 
+   * either language specific types via `typeMapping` or into complex models if there is not a mapping.
+   *
+   * @return a string value of the type or complex model for this property
+   * @see io.swagger.models.properties.Property
+   */
+  @Override
+  public String getSwaggerType(Property p) {
+    String swaggerType = super.getSwaggerType(p);
+    String type = null;
+    if(typeMapping.containsKey(swaggerType)) {
+      type = typeMapping.get(swaggerType);
+      if(languageSpecificPrimitives.contains(type))
+        return toModelName(type);
+    }
+    else
+      type = swaggerType;
+    return toModelName(type);
+  }
+
+  private String capturePath(String path, List<CodegenParameter> pathParams) {
+    for (CodegenParameter p : pathParams) {
+      String pName = "{"+p.baseName+"}";
+      if (path.indexOf(pName) >= 0) { 
+        path = path.replace(pName, "Capture " + "\""+p.baseName+"\" " + p.dataType);
+      }
+    }
+    return path;
+  }
+
+  private String queryPath(String path, List<CodegenParameter> queryParams) {
+    for (CodegenParameter p : queryParams) {
+      path += " :> QueryParam \"" + p.baseName + "\" " + p.dataType;
+    }
+    return path;
+  }
+
+  private String bodyPath(String path, List<CodegenParameter> bodyParams) {
+    for (CodegenParameter p : bodyParams) {
+      path += " :> ReqBody '[JSON] " + p.dataType;
+    }
+    return path;
+  }
+
+  private String formPath(String path, List<CodegenParameter> formParams) {
+    String names = "Form";
+    for (CodegenParameter p : formParams) {
+      if(p.dataType.equals("FilePath")){
+        // file data processing
+      } 
+      names += p.baseName;
+    }
+    if(formParams.size() > 0){
+      path += " :> ReqBody '[FormUrlEncoded] " + names;
+    }
+    return path;
+  }
+
+  private String headerPath(String path, List<CodegenParameter> headerParams) {
+    for (CodegenParameter p : headerParams) {
+      path += " :> Header \"" + p.baseName + "\" " + p.dataType;
+    }
+    return path;
+  }
+
+
+  private String filterReturnType(String rt) {
+    if (rt == null || rt.equals("null")) {
+      return "()";
+    } else if (rt.indexOf(" ") >= 0) {
+      return "(" + rt + ")";
+    }
+    return rt;
+  }
+
+  private String addReturnPath(String path, String httpMethod, String returnType) {
+    return path + " :> " + upperCaseFirst(httpMethod) + " '[JSON] " + filterReturnType(returnType);
+  }
+
+  private String joinStrings(String sep, List<String> ss) {
+    StringBuilder sb = new StringBuilder();
+    for (String s : ss) {
+      if (sb.length() > 0) {
+        sb.append(sep);
+      }
+      sb.append(s);
+    }
+    return sb.toString();
+  }
+
+  private String replacePathSplitter(String path) {
+    String[] ps = path.replaceFirst("/", "").split("/", 0);
+    List<String> rs = new ArrayList<String>();
+    for (String p : ps) {
+      if (p.indexOf("{") < 0) { 
+        rs.add("\"" + p + "\"");
+      } else {
+        rs.add(p);
+      }
+    }
+    return joinStrings(" :> ", rs);
+  }
+
+  private String upperCaseFirst(String str) {
+    char[] array = str.toLowerCase().toCharArray();
+    array[0] = Character.toUpperCase(array[0]);
+    return new String(array);
+  }
+
+  private String parseScheme(String basePath) {
+    return "Http";
+  }
+
+  @Override
+  public CodegenOperation fromOperation(String resourcePath, String httpMethod, Operation operation, Map<String, Model> definitions, Swagger swagger){
+    CodegenOperation op = super.fromOperation(resourcePath, httpMethod, operation, definitions, swagger);
+    String path = op.path;
+    op.nickname = addReturnPath(headerPath(formPath(bodyPath(queryPath(capturePath(replacePathSplitter(path), op.pathParams), op.queryParams), op.bodyParams), op.formParams), op.headerParams), op.httpMethod, op.returnType);
+    return op;
+  }
+
+}