#include "BackendUtils.hpp"
#include "../include/FileUtil.hpp"
#include "../include/Exec.hpp"
#include "ninja/Ninja.hpp"

using namespace std;
using namespace sibs;

static const char *cCompilerPath = nullptr;
static const char *cppCompilerPath = nullptr;
static const char *linkerPath = nullptr;

namespace backend
{
    static bool isPathSubPathOf(const FileString &path, const FileString &subPathOf)
    {
        return _tinydir_strncmp(path.c_str(), subPathOf.c_str(), subPathOf.size()) == 0;
    }

    const _tinydir_char_t *cFileExtensions[] = 
    { 
        TINYDIR_STRING("c"),
        TINYDIR_STRING("C"),
        TINYDIR_STRING("cc")
    };
    
    const _tinydir_char_t *cppFileExtensions[] = 
    { 
        TINYDIR_STRING("cp"),
        TINYDIR_STRING("cpp"),
        TINYDIR_STRING("cxx"),
        TINYDIR_STRING("c++")
    };

    sibs::FileString BackendUtils::getFileExtension(const sibs::FileString &filepath)
    {
        size_t indexOfDot = filepath.find_last_of('.');
        if(indexOfDot == sibs::FileString::npos)
            return TINYDIR_STRING("");
        
        indexOfDot += 1;
        return filepath.substr(indexOfDot);
    }

    sibs::Language BackendUtils::getFileLanguage(const _tinydir_char_t *extension)
    {
        for(const _tinydir_char_t *sourceFileExtension : cFileExtensions)
        {
            if(_tinydir_strcmp(sourceFileExtension, extension) == 0)
                return sibs::Language::C;
        }

        for(const _tinydir_char_t *sourceFileExtension : cppFileExtensions)
        {
            if(_tinydir_strcmp(sourceFileExtension, extension) == 0)
                return sibs::Language::CPP;
        }

        if(_tinydir_strcmp(TINYDIR_STRING("zig"), extension) == 0)
            return sibs::Language::ZIG;

        return sibs::Language::NONE;
    }

    sibs::Language BackendUtils::getFileLanguage(tinydir_file *file)
    {
        if(!file->is_reg)
            return sibs::Language::NONE;

        return getFileLanguage(file->extension);
    }
    
    void BackendUtils::collectSourceFiles(const _tinydir_char_t *projectPath, Ninja *ninjaProject, const SibsConfig &sibsConfig, bool recursive)
    {
        walkDir(projectPath, [ninjaProject, &sibsConfig, recursive](tinydir_file *file)
        {
            FileString pathNative = file->path;
            #if OS_FAMILY == OS_FAMILY_WINDOWS
            replaceChar(pathNative, L'/', L'\\');
            #endif
            if(file->is_reg)
            {
                sibs::Language fileLanguage = getFileLanguage(file);
                if (fileLanguage != sibs::Language::NONE)
                {
                    string filePathUtf8 = toUtf8(pathNative.c_str() + sibsConfig.getProjectPath().size());
                    ninjaProject->addSourceFile(fileLanguage, filePathUtf8.c_str());
                }
                else
                {
                    //printf("Ignoring non-source file: %s\n", file->path + projectPath.size());
                }
            }
            else
            {
                if (!sibsConfig.getTestPath().empty() && isPathSubPathOf(pathNative.c_str(), sibsConfig.getTestPath()))
                {
                    string filePathUtf8 = toUtf8(pathNative.c_str());
                    ninjaProject->setTestSourceDir(filePathUtf8.c_str());
                }
                else if(recursive && !directoryToIgnore(pathNative, sibsConfig.getIgnoreDirs()) && _tinydir_strcmp(file->name, TINYDIR_STRING("sibs-build")) != 0)
                {
                    FileString projectConfPath = file->path;
                    #if OS_FAMILY == OS_FAMILY_WINDOWS
                    projectConfPath += L'\\';
                    #else
                    projectConfPath += '/';
                    #endif
                    projectConfPath += TINYDIR_STRING("project.conf");
                    
                    auto projectConfFileType = getFileType(projectConfPath.c_str());
                    if(!sibsConfig.isTest() && getFileType(projectConfPath.c_str()) == FileType::REGULAR)
                    {
                        backend::Ninja *subProject = new backend::Ninja();
                        
                        SibsConfig *subProjectConfig = new SibsConfig(sibsConfig.getCompiler(), file->path, sibsConfig.getOptimizationLevel(), false);
                        subProjectConfig->packaging = sibsConfig.packaging;
                        subProjectConfig->platform = sibsConfig.platform;
                        subProjectConfig->bundling = sibsConfig.bundling;
                        FileString subProjectBuildPath;
                        readSibsConfig(file->path, projectConfPath, *subProjectConfig, subProjectBuildPath);

                        collectSourceFiles(file->path, subProject, *subProjectConfig, true);
                        ninjaProject->addSubProject(subProject, subProjectConfig, move(subProjectBuildPath));
                    }
                    else
                        collectSourceFiles(file->path, ninjaProject, sibsConfig, true);
                }
            }
            return true;
        });
    }

    string BackendUtils::getCompilerCExecutable(Compiler compiler)
    {
        if(cCompilerPath)
            return cCompilerPath;

        char *cc = std::getenv("CC");
        if(cc)
        {
            cCompilerPath = cc;
            return cCompilerPath;
        }

        switch(compiler)
        {
            case Compiler::GCC:
                cCompilerPath = "ccache cc";
                break;
            case Compiler::MINGW_W64:
                cCompilerPath = "x86_64-w64-mingw32-cc";
                break;
            case Compiler::MSVC:
                cCompilerPath = "cl.exe";
                break;
        }
        return cCompilerPath;
    }

    string BackendUtils::getCompilerCppExecutable(Compiler compiler)
    {
        if(cppCompilerPath)
            return cppCompilerPath;

        char *cxx = std::getenv("CXX");
        if(cxx)
        {
            cppCompilerPath = cxx;
            return cppCompilerPath;
        }

        switch(compiler)
        {
            case Compiler::GCC:
                cppCompilerPath = "ccache c++";
                break;
            case Compiler::MINGW_W64:
                cppCompilerPath = "x86_64-w64-mingw32-c++";
                break;
            case Compiler::MSVC:
                cppCompilerPath = "cl.exe";
                break;
        }
        return cppCompilerPath;
    }

    string BackendUtils::getCompilerLinker(Compiler compiler)
    {
        if(linkerPath)
            return linkerPath;

        char *ar = std::getenv("AR");
        if(ar)
        {
            linkerPath = ar;
            return linkerPath;
        }

        switch(compiler)
        {
            case Compiler::GCC:
                linkerPath = "ar";
                break;
            case Compiler::MINGW_W64:
                linkerPath = "x86_64-w64-mingw32-ar";
                break;
            case Compiler::MSVC:
                linkerPath = "lib.exe";
                break;
        }
        return linkerPath;
    }

    RuntimeCompilerType BackendUtils::getCCompilerType(Compiler compiler)
    {
        RuntimeCompilerType cCompilerType = RuntimeCompilerType::NONE;
        Result<ExecResult> cCompilerVersion = exec(toFileString(getCompilerCExecutable(compiler)) + TINYDIR_STRING(" --version"));
        if(cCompilerVersion && cCompilerVersion.unwrap().exitCode == 0)
        {
            if(cCompilerVersion.unwrap().execStdout.find("Emscripten") != string::npos)
                cCompilerType = RuntimeCompilerType::EMSCRIPTEN;
            else if(cCompilerVersion.unwrap().execStdout.find("clang") != string::npos)
                cCompilerType = RuntimeCompilerType::CLANG;
            else
                cCompilerType = RuntimeCompilerType::OTHER;
        }
        return cCompilerType;
    }

    RuntimeCompilerType BackendUtils::getCppCompilerType(Compiler compiler)
    {
        RuntimeCompilerType cppCompilerType = RuntimeCompilerType::NONE;
        Result<ExecResult> cppCompilerVersion = exec(toFileString(getCompilerCppExecutable(compiler)) + TINYDIR_STRING(" --version"));
        if(cppCompilerVersion && cppCompilerVersion.unwrap().exitCode == 0)
        {
            if(cppCompilerVersion.unwrap().execStdout.find("Emscripten") != string::npos)
                cppCompilerType = RuntimeCompilerType::EMSCRIPTEN;
            else if(cppCompilerVersion.unwrap().execStdout.find("clang") != string::npos)
                cppCompilerType = RuntimeCompilerType::CLANG;
            else
                cppCompilerType = RuntimeCompilerType::OTHER;
        }
        return cppCompilerType;
    }
}