import 'package:analyzer/dart/element/element.dart';
import 'package:build/build.dart';
import 'package:router_gen/annotation/router_table.dart';
import 'package:router_gen/model/router.dart';
import 'package:source_gen/source_gen.dart';
import 'package:path/path.dart' as Path;

/// generate router table
class RouterTableGenerator extends GeneratorForAnnotation<RouterTable> {
  @override
  generateForAnnotatedElement(
      Element element, ConstantReader annotation, BuildStep buildStep) {

    String path = buildStep.inputId.path; // lib/xxx.dart
    String relatedFileName = Path.basename(path); // xxx.dart
    String relatedClassName = element.name;

    String imports = "";
    for (String import in router.imports) {
      imports = imports + "import '" + import + "';\n";
    }
    // all router's name
    List<String> routeNames = router.routerMap.keys.toList();
    String pathFiled = _generateFields(routeNames, router.routerMap);
    String register = _generateRouterRegister(routeNames, router.routerMap);

    return """
import '${relatedFileName}';
import 'package:fluro/fluro.dart' as fluro;
import 'package:school_parent/base_plugin/routes.dart';
${imports}

class \$${relatedClassName} implements ${relatedClassName} {
  ${pathFiled}
  @override
  void registerRoutes(fluro.Router router) {
    ${register}
  }
}
""";
  }

  _generateFields(List<String> routeNames, Map<String, Page> page) {
    String field = "";
    routeNames.forEach((e) {
      field += "static final ${e} = \"${page[e].path}\";\n";
    });
    return field;
  }

  _generateRouterRegister(List<String> routeNames, Map<String, Page> page) {
    String register = "";
    routeNames.forEach((e) {
      String params = "";
      page[e].arguments.forEach((element) {
        params +=
        "${element.name}: IRoutesProvider.getParams<${element.type}>(p, \"${element.name}\"),\n";
      });

      register += """
     router.define(${e},
        handler: fluro.Handler(
          handlerFunc: (c, p) => ${page[e].name}(
            ${params}
          ),
        ),
     ); 
""";
    });

    return register;
  }
}