#include "Lexer.h"
#include "Parser.h"

#include <llvm/Support/CommandLine.h>
#include <llvm/Support/ErrorOr.h>
#include <llvm/Support/MemoryBuffer.h>

static llvm::cl::opt<std::string> inputFilename(llvm::cl::Positional,
                                                llvm::cl::desc("<input hello file>"),
                                                llvm::cl::init("-"),
                                                llvm::cl::value_desc("filename"));

namespace
{
    enum Action { None, DumpSyntaxNode };
}

static llvm::cl::opt<Action> emitAction("emit", llvm::cl::desc("Select the kind of output desired"),
                                        llvm::cl::values(clEnumValN(DumpSyntaxNode, "ast", "Dump syntax node")));

std::unique_ptr<hello::Module> parseInputFile(llvm::StringRef filename)
{
    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> fileOrErr =
        llvm::MemoryBuffer::getFileOrSTDIN(filename);
    if (std::error_code ec = fileOrErr.getError())
    {
        llvm::errs() << "Could not open input file: " << ec.message() << "\n";
        return nullptr;
    }
    auto buffer = fileOrErr.get()->getBuffer();
    hello::LexerBuffer lexer(buffer.begin(), buffer.end(), std::string(filename));
    hello::Parser parser(lexer);
    return parser.parseModule();
}

int main(int argc, char** argv)
{
    llvm::cl::ParseCommandLineOptions(argc, argv, "Hello MLIR Compiler\n");

    auto module = parseInputFile(inputFilename);

    if (!module)
    {
        return 1;
    }

    switch (emitAction)
    {
    case DumpSyntaxNode:
        module->dump();
        return 0;
    default:
        llvm::errs() << "Unrecognized action\n";
        return 1;
    }
}