#include "slang_rs_pragma_handler.h"

#include "clang/Basic/TokenKinds.h"

#include "clang/Lex/LiteralSupport.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/Token.h"

#include "slang_rs_context.h"

using namespace slang;

namespace {  // Anonymous namespace

class RSExportVarPragmaHandler : public RSPragmaHandler {
 private:
  void handleItem(const std::string &Item) {
    mContext->addExportVar(Item);
  }

 public:
  RSExportVarPragmaHandler(llvm::StringRef Name, RSContext *Context)
      : RSPragmaHandler(Name, Context) {
    return;
  }

  void HandlePragma(clang::Preprocessor &PP, clang::Token &FirstToken) {
    this->handleItemListPragma(PP, FirstToken);
  }
};

class RSExportVarAllPragmaHandler : public RSPragmaHandler {
 public:
  RSExportVarAllPragmaHandler(llvm::StringRef Name, RSContext *Context)
      : RSPragmaHandler(Name, Context) { return; }

  void HandlePragma(clang::Preprocessor &PP, clang::Token &FirstToken) {
    this->handleNonParamPragma(PP, FirstToken);
    mContext->setExportAllNonStaticVars(true);
  }
};

class RSExportFuncPragmaHandler : public RSPragmaHandler {
 private:
  void handleItem(const std::string &Item) {
    mContext->addExportFunc(Item);
  }

 public:
  RSExportFuncPragmaHandler(llvm::StringRef Name,
                            RSContext *Context)
      : RSPragmaHandler(Name, Context) { return; }

  void HandlePragma(clang::Preprocessor &PP, clang::Token &FirstToken) {
    this->handleItemListPragma(PP, FirstToken);
  }
};

class RSExportFuncAllPragmaHandler : public RSPragmaHandler {
 public:
  RSExportFuncAllPragmaHandler(llvm::StringRef Name, RSContext *Context)
      : RSPragmaHandler(Name, Context) { return; }

  void HandlePragma(clang::Preprocessor &PP, clang::Token &FirstToken) {
    this->handleNonParamPragma(PP, FirstToken);
    mContext->setExportAllNonStaticFuncs(true);
  }
};

class RSExportTypePragmaHandler : public RSPragmaHandler {
 private:
  void handleItem(const std::string &Item) {
    mContext->addExportType(Item);
  }

 public:
  RSExportTypePragmaHandler(llvm::StringRef Name, RSContext *Context)
      : RSPragmaHandler(Name, Context) { return; }

  void HandlePragma(clang::Preprocessor &PP, clang::Token &FirstToken) {
    this->handleItemListPragma(PP, FirstToken);
  }
};

class RSJavaPackageNamePragmaHandler : public RSPragmaHandler {
 public:
  RSJavaPackageNamePragmaHandler(llvm::StringRef Name, RSContext *Context)
      : RSPragmaHandler(Name, Context) { return; }

  void HandlePragma(clang::Preprocessor &PP, clang::Token &FirstToken) {
    // FIXME: Need to validate the extracted package name from paragma.
    // Currently "all chars" specified in pragma will be treated as package
    // name.
    //
    // 18.1 The Grammar of the Java Programming Language
    // (http://java.sun.com/docs/books/jls/third_edition/html/syntax.html#18.1)
    //
    // CompilationUnit:
    //     [[Annotations] package QualifiedIdentifier   ;  ] {ImportDeclaration}
    //     {TypeDeclaration}
    //
    // QualifiedIdentifier:
    //     Identifier { . Identifier }
    //
    // Identifier:
    //     IDENTIFIER
    //
    // 3.8 Identifiers
    // (http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#3.8)
    //
    //

    clang::Token &PragmaToken = FirstToken;
    std::string PackageName;

    // Skip first token, "java_package_name"
    PP.LexUnexpandedToken(PragmaToken);

    // Now, the current token must be clang::tok::lpara
    if (PragmaToken.isNot(clang::tok::l_paren))
      return;

    while (PragmaToken.isNot(clang::tok::eom)) {
      // Lex package name
      PP.LexUnexpandedToken(PragmaToken);

      bool Invalid;
      std::string Spelling = PP.getSpelling(PragmaToken, &Invalid);
      if (!Invalid)
        PackageName.append(Spelling);

      // Pre-mature end (syntax error will be triggered by preprocessor later)
      if (PragmaToken.is(clang::tok::eom) || PragmaToken.is(clang::tok::eof)) {
        break;
      } else {
        // Next token is ')' (end of paragma)
        const clang::Token &NextTok = PP.LookAhead(0);
        if (NextTok.is(clang::tok::r_paren)) {
          mContext->setReflectJavaPackageName(PackageName);
          // Lex until meets clang::tok::eom
          do {
            PP.LexUnexpandedToken(PragmaToken);
          } while (PragmaToken.isNot(clang::tok::eom));
          break;
        }
      }
    }
    return;
  }
};

class RSReflectLicensePragmaHandler : public RSPragmaHandler {
 private:
  void handleItem(const std::string &Item) {
    mContext->setLicenseNote(Item);
  }

 public:
  RSReflectLicensePragmaHandler(llvm::StringRef Name, RSContext *Context)
      : RSPragmaHandler(Name, Context) { return; }

  void HandlePragma(clang::Preprocessor &PP, clang::Token &FirstToken) {
    this->handleOptionalStringLiateralParamPragma(PP, FirstToken);
  }
};

}   // Anonymous namespace

RSPragmaHandler *
RSPragmaHandler::CreatePragmaExportVarHandler(RSContext *Context) {
  return new RSExportVarPragmaHandler("export_var", Context);
}

RSPragmaHandler *
RSPragmaHandler::CreatePragmaExportVarAllHandler(RSContext *Context) {
  return new RSExportVarPragmaHandler("export_var_all", Context);
}

RSPragmaHandler *
RSPragmaHandler::CreatePragmaExportFuncHandler(RSContext *Context) {
  return new RSExportFuncPragmaHandler("export_func", Context);
}

RSPragmaHandler *
RSPragmaHandler::CreatePragmaExportFuncAllHandler(RSContext *Context) {
  return new RSExportFuncPragmaHandler("export_func_all", Context);
}

RSPragmaHandler *
RSPragmaHandler::CreatePragmaExportTypeHandler(RSContext *Context) {
  return new RSExportTypePragmaHandler("export_type", Context);
}

RSPragmaHandler *
RSPragmaHandler::CreatePragmaJavaPackageNameHandler(RSContext *Context) {
  return new RSJavaPackageNamePragmaHandler("java_package_name", Context);
}

RSPragmaHandler *
RSPragmaHandler::CreatePragmaReflectLicenseHandler(RSContext *Context) {
  return new RSJavaPackageNamePragmaHandler("set_reflect_license", Context);
}

void RSPragmaHandler::handleItemListPragma(clang::Preprocessor &PP,
                                           clang::Token &FirstToken) {
  clang::Token &PragmaToken = FirstToken;

  // Skip first token, like "export_var"
  PP.LexUnexpandedToken(PragmaToken);

  // Now, the current token must be clang::tok::lpara
  if (PragmaToken.isNot(clang::tok::l_paren))
    return;

  while (PragmaToken.isNot(clang::tok::eom)) {
    // Lex variable name
    PP.LexUnexpandedToken(PragmaToken);
    if (PragmaToken.is(clang::tok::identifier))
      this->handleItem(PP.getSpelling(PragmaToken));
    else
      break;

    assert(PragmaToken.isNot(clang::tok::eom));

    PP.LexUnexpandedToken(PragmaToken);

    if (PragmaToken.isNot(clang::tok::comma))
      break;
  }
  return;
}

void RSPragmaHandler::handleNonParamPragma(clang::Preprocessor &PP,
                                           clang::Token &FirstToken) {
  clang::Token &PragmaToken = FirstToken;

  // Skip first token, like "export_var_all"
  PP.LexUnexpandedToken(PragmaToken);

  // Should be end immediately
  if (PragmaToken.isNot(clang::tok::eom))
    fprintf(stderr, "RSPragmaHandler::handleNonParamPragma: "
                    "expected a clang::tok::eom\n");
  return;
}

void RSPragmaHandler::handleOptionalStringLiateralParamPragma(
    clang::Preprocessor &PP, clang::Token &FirstToken) {
  clang::Token &PragmaToken = FirstToken;

  // Skip first token, like "set_reflect_license"
  PP.LexUnexpandedToken(PragmaToken);

  // Now, the current token must be clang::tok::lpara
  if (PragmaToken.isNot(clang::tok::l_paren))
    return;

  // If not ')', eat the following string literal as the license
  PP.LexUnexpandedToken(PragmaToken);
  if (PragmaToken.isNot(clang::tok::r_paren)) {
    // Eat the whole string literal
    clang::StringLiteralParser StringLiteral(&PragmaToken, 1, PP);
    if (StringLiteral.hadError)
      fprintf(stderr, "RSPragmaHandler::handleOptionalStringLiateralParamPragma"
                      ": illegal string literal\n");
    else
      this->handleItem(std::string(StringLiteral.GetString()));

    // The current token should be clang::tok::r_para
    PP.LexUnexpandedToken(PragmaToken);
    if (PragmaToken.isNot(clang::tok::r_paren))
      fprintf(stderr, "RSPragmaHandler::handleOptionalStringLiateralParamPragma"
                      ": expected a ')'\n");
  } else {
    // If no argument, remove the license
    this->handleItem("");
  }
}