#include <cstring>
#include "Ninja.hpp"
#include "../../include/FileUtil.hpp"
#include "../../include/Exec.hpp"
#include "../../include/PkgConfig.hpp"
#include "../../include/GlobalLib.hpp"

using namespace std;
using namespace sibs;

#if OS_FAMILY == OS_FAMILY_POSIX
#define nprintf printf
#else
#define nprintf wprintf
#endif

namespace backend
{
    string join(const vector<string> &list, const char *joinStr)
    {
        if(list.empty()) return "";
        string result;
        long stringSize = 0;
        long joinStrLen = strlen(joinStr);
        int i = 0;
        for(const string &str : list)
        {
            stringSize += str.size();
            if(!str.empty() && i > 0)
                stringSize += joinStrLen;
            ++i;
        }

        result.reserve(stringSize);

        i = 0;
        for(const string &str : list)
        {
            if(i > 0)
                result += joinStr;
            result += str;
            ++i;
        }

        return move(result);
    }

    string getIncludeOptionFlag(Compiler compiler, const string &filepath)
    {
        string result;
        switch (compiler)
        {
            case Compiler::GCC:
            {
                result = "'-I";
                result += filepath;
                result += "'";
                break;
            }
            case Compiler::MSVC:
            {
                result = "/I \"";
                result += filepath;
                result += "\"";
                break;
            }
        }
        return result;
    }

    string getCompileWithoutLinkingFlag(Compiler compiler)
    {
        string result;
        switch (compiler)
        {
            case Compiler::GCC:
            {
                result = "-c";
                break;
            }
            case Compiler::MSVC:
            {
                result = "/c";
                break;
            }
        }
        return result;
    }

    string getObjectFileNameFlag(Compiler compiler, const string &objectFileName)
    {
        string result;
        switch (compiler)
        {
            case Compiler::GCC:
            {
                result = "-o ";
                result += objectFileName;
                break;
            }
            case Compiler::MSVC:
            {
                result = "/Fo";
                result += objectFileName;
                break;
            }
        }
        return result;
    }

    const char* getObjectFileExtension(Compiler compiler)
    {
        switch (compiler)
        {
            case Compiler::GCC:     return ".o";
            case Compiler::MSVC:    return ".obj";
        }
    }

    Ninja::Ninja(LibraryType _libraryType) :
        libraryType(_libraryType)
    {

    }

    void Ninja::addSourceFile(const char *filepath)
    {
        string filePathStr = filepath ? filepath : "";
        if(filepath && !containsSourceFile(filePathStr))
        {
            sourceFiles.emplace_back(filePathStr);
            printf("Adding source file: %s\n", filepath);
        }
    }

    void Ninja::addTestSourceDir(const char *dir)
    {
        string dirStr = dir ? dir : "";
        if(dir && !containsTestSourceDir(dirStr))
        {
            testSourceDirs.emplace_back(dirStr);
            printf("Adding test source directory: %s\n", dir);
        }
    }

    void Ninja::addDependency(const std::string &binaryFile)
    {
        if(!containsDependency(binaryFile))
            binaryDependencies.emplace_back(binaryFile);
    }

    const std::vector<std::string>& Ninja::getSourceFiles() const
    {
        return sourceFiles;
    }

    bool Ninja::containsSourceFile(const string &filepath) const
    {
        for(const string &sourceFile : sourceFiles)
        {
            if(sourceFile == filepath)
                return true;
        }
        return false;
    }

    bool Ninja::containsTestSourceDir(const string &dir) const
    {
        for(const string &testSourceDir : testSourceDirs)
        {
            if(testSourceDir == dir)
                return true;
        }
        return false;
    }

    bool Ninja::containsDependency(const string &dependency) const
    {
        for(const string &binaryDependency : binaryDependencies)
        {
            if(binaryDependency == dependency)
                return true;
        }
        return false;
    }
	
#if OS_FAMILY == OS_FAMILY_POSIX
    Result<bool> validatePkgConfigPackageVersionExists(const Dependency &dependency)
    {
        Result<bool> dependencyValidationResult = PkgConfig::validatePackageExists(dependency.name);
        if(dependencyValidationResult.isErr())
            return Result<bool>::Err(dependencyValidationResult.getErrMsg());

        Result<bool> dependencyVersionValidationResult = PkgConfig::validatePackageVersionAtLeast(dependency.name, dependency.version);
        if(dependencyVersionValidationResult.isErr())
            return Result<bool>::Err(dependencyVersionValidationResult.getErrMsg());

        return Result<bool>::Ok(true);
    }
#endif
    // TODO: First check if pkg-config is installed. If it's not, only check dependencies that exists in the dependencies sub directory.
    // If pkg-config is installed and dependency is not installed, check in dependencies sub directory.
    Result<bool> Ninja::getLinkerFlags(const SibsConfig &config, LinkerFlagCallbackFunc staticLinkerFlagCallbackFunc, LinkerFlagCallbackFunc dynamicLinkerFlagCallback) const
    {
        const vector<Dependency> &dependencies = config.getDependencies();
        if(dependencies.empty()) return Result<bool>::Ok(true);

        Result<FileString> globalLibDirResult = getHomeDir();
        if (!globalLibDirResult)
            return Result<bool>::Err(globalLibDirResult);
        FileString globalLibDir = globalLibDirResult.unwrap();
        globalLibDir += TINYDIR_STRING("/.sibs/lib");
        Result<bool> createGlobalLibDirResult = createDirectoryRecursive(globalLibDir.c_str());
        if(createGlobalLibDirResult.isErr())
            return createGlobalLibDirResult;

        vector<Dependency> globalLibDependencies;
#if OS_FAMILY == OS_FAMILY_POSIX
        vector<Dependency> pkgConfigDependencies;
        for(const Dependency &dependency : dependencies)
        {
            Result<bool> pkgConfigDependencyValidation = validatePkgConfigPackageVersionExists(dependency);
            if(pkgConfigDependencyValidation.isOk())
            {
                pkgConfigDependencies.push_back(dependency);
            }
            else
            {
                globalLibDependencies.push_back(dependency);
            }
        }

        Result<string> pkgConfigLinkerFlagsResult = PkgConfig::getDynamicLibsLinkerFlags(pkgConfigDependencies);
        if (pkgConfigLinkerFlagsResult.isErr())
        {
            printf("%s, using global lib...\n", pkgConfigLinkerFlagsResult.getErrMsg().c_str());
            globalLibDependencies.reserve(globalLibDependencies.size() + pkgConfigDependencies.size());
            for (const Dependency &pkgConfigDependency : pkgConfigDependencies)
            {
                globalLibDependencies.push_back(pkgConfigDependency);
            }
            pkgConfigDependencies.clear();
        }
        else
        {
            if (!pkgConfigLinkerFlagsResult.unwrap().empty())
                dynamicLinkerFlagCallback(pkgConfigLinkerFlagsResult.unwrap());
        }
#else
        for (const Dependency &dependency : dependencies)
        {
            globalLibDependencies.push_back(dependency);
        }
#endif

        for(const Dependency &globalLibDependency : globalLibDependencies)
        {
            printf("Dependency %s is missing from pkg-config, trying global lib\n", globalLibDependency.name.c_str());
            Result<string> globalLibLinkerFlagsResult = GlobalLib::getLibsLinkerFlags(config, globalLibDir, globalLibDependency.name, globalLibDependency.version, staticLinkerFlagCallbackFunc, dynamicLinkerFlagCallback);
            if(globalLibLinkerFlagsResult.isErr())
            {
                if(globalLibLinkerFlagsResult.getErrorCode() == GlobalLib::DependencyError::DEPENDENCY_NOT_FOUND || globalLibLinkerFlagsResult.getErrorCode() == GlobalLib::DependencyError::DEPENDENCY_VERSION_NO_MATCH)
                {
                    printf("Dependency not found in global lib, trying to download from github\n");
                    // TODO: Download several dependencies at the same time by adding them to a list
                    // and then iterate them and download them all using several threads.
                    // All dependecies should be downloaded at the same time, this includes dependencies of dependencies.
                    // If a dependency is missing, fail build BEFORE downloading dependencies and before compiling anything.
                    // You do not want to possibly wait several minutes only for build to fail when there is no compilation error.

                    // TODO: If return error is invalid url, then the message should be converted to
                    // invalid package name/version. A check should be done if it is the name or version
                    // that is invalid.
                    Result<bool> downloadDependencyResult = GlobalLib::downloadDependency(globalLibDependency);
                    if(downloadDependencyResult.isErr())
                        return downloadDependencyResult;

                    globalLibLinkerFlagsResult = GlobalLib::getLibsLinkerFlags(config, globalLibDir, globalLibDependency.name, globalLibDependency.version, staticLinkerFlagCallbackFunc, dynamicLinkerFlagCallback);
                    if(globalLibLinkerFlagsResult.isErr())
                        return Result<bool>::Err(globalLibLinkerFlagsResult);
                }
                else
                {
                    return Result<bool>::Err(globalLibLinkerFlagsResult);
                }
            }
        }

        return Result<bool>::Ok(true);
    }

    Result<bool> Ninja::build(const SibsConfig &config, const _tinydir_char_t *savePath, LinkerFlagCallbackFunc staticLinkerFlagCallbackFunc, LinkerFlagCallbackFunc dynamicLinkerFlagCallback)
    {
        // TODO: Do not quit here if no source files are provided. The source-less project could have dependencies
        if(sourceFiles.empty())
            return Result<bool>::Err("No source files provided");

        Result<bool> createBuildDirResult = createDirectoryRecursive(savePath);
        if(createBuildDirResult.isErr())
            return createBuildDirResult;

        string savePathUtf8 = toUtf8(savePath);

        FileString ninjaBuildFilePath = savePath;
        ninjaBuildFilePath += TINYDIR_STRING("/build.ninja");

        string result;
        result.reserve(16384);

        Result<FileString> globalIncDirResult = getHomeDir();
        if (!globalIncDirResult)
            return Result<bool>::Err(globalIncDirResult);

        FileString globalIncDir = globalIncDirResult.unwrap();
        globalIncDir += TINYDIR_STRING("/.sibs/lib");

        result += "globalIncDir = ";
        result += getIncludeOptionFlag(config.getCompiler(), toUtf8(globalIncDir));
        for(const auto &includeDir : config.getIncludeDirs())
        {
            string includeDirRelative = "../../";
            includeDirRelative += includeDir;
            result += " ";
            result += getIncludeOptionFlag(config.getCompiler(), includeDirRelative);
        }
        result += "\n\n";

        string compilerName;
        switch (config.getCompiler())
        {
            case Compiler::GCC:
                compilerName = "ccache c++";
                break;
            case Compiler::MSVC:
                compilerName = "cl.exe";
                break;
        }

        string buildJob;
        switch(libraryType)
        {
            case LibraryType::EXECUTABLE:
            {
                switch (config.getCompiler())
                {
                    case Compiler::GCC:
                    {
                        result += "rule cpp_COMPILER\n";
                        result += "  command = ccache c++ $ARGS -c $in -o $out\n\n";

                        result += "rule cpp_BUILD_EXEC\n";
                        result += "  command = ccache c++ $ARGS -o $out $in $LINK_ARGS $aliasing\n\n";
                        break;
                    }
                    case Compiler::MSVC:
                    {
                        result += "rule cpp_COMPILER\n";
                        result += "  command = cl.exe $ARGS /c $in /Fo$out\n\n";

                        result += "rule cpp_BUILD_EXEC\n";
                        result += "  command = cl.exe $ARGS $in /Fe$out $LINK_ARGS\n\n";
                        break;
                    }
                }

                buildJob = "cpp_BUILD_EXEC";
                break;
            }
            case LibraryType::STATIC:
            {
                // TODO: Write equivalent code for msvc
                result += "rule cpp_COMPILER\n";
                result += "  command = ccache c++ $ARGS -c -fPIC $in -o $out\n\n";

                result += "rule cpp_BUILD_STATIC\n";
                result += "  command = ar rcs lib";
                result += config.getPackageName();
                result += ".a";
                result += " $in\n\n";
                buildJob = "cpp_BUILD_STATIC";
                break;
            }
            case LibraryType::DYNAMIC:
            {
                switch (config.getCompiler())
                {
                    case Compiler::GCC:
                    {
                        result += "rule cpp_COMPILER\n";
                        result += "  command = ccache c++ $ARGS -c -fPIC $in -o $out\n\n";

                        // --whole-archive
                        result += "rule cpp_BUILD_DYNAMIC\n";
                        result += "  command = ccache c++ $in -shared -o $out $LINK_ARGS $aliasing\n\n";
                        break;
                    }
                    case Compiler::MSVC:
                    {
                        result += "rule cpp_COMPILER\n";
                        result += "  command = cl.exe $ARGS /c $in /Fo$out\n\n";

                        //result += "rule cpp_BUILD_DYNAMIC\n";
                        //result += "  command = cl.exe /LD $in /Fe$out $LINK_ARGS\n\n";

                        result += "rule cpp_BUILD_DYNAMIC\n";
                        result += "  command = lib.exe /OUT:$out $in\n\n";
                        break;
                    }
                }

                buildJob = "cpp_BUILD_DYNAMIC";
                break;
            }
            default:
                assert(false);
                return Result<bool>::Err("Unexpected error");
        }

        string optimizationFlags;
        switch(config.getOptimizationLevel())
        {
            case OPT_LEV_DEBUG:
                optimizationFlags = "'-O0'";
                break;
            case OPT_LEV_RELEASE:
                optimizationFlags = "'-O3' '-DNDEBUG'";
                break;
        }

        vector<string> objectNames;
        objectNames.reserve(sourceFiles.size());
        for(const string &sourceFile : sourceFiles)
        {
            //string sourceFileEncoded = sourceFile;
            //replace(sourceFileEncoded, '/', '@');
            string objectName = config.getPackageName() + "@exe/" + sourceFile;
            objectName += getObjectFileExtension(config.getCompiler());
            result += "build ";
            result += objectName;
            result += ": cpp_COMPILER ../../";
            result += sourceFile;
            result += "\n";
            result += "  ARGS = $globalIncDir";
            if(config.getCompiler() != Compiler::MSVC)
                result += " '-I" + config.getPackageName() + "@exe' '-I..' '-fdiagnostics-color=always' '-pipe' '-D_FILE_OFFSET_BITS=64' '-Wall' '-Winvalid-pch' '-Wnon-virtual-dtor' " + optimizationFlags + " '-g'";
            result += "\n\n";
            objectNames.emplace_back(objectName);
        }

#if OS_TYPE == OS_TYPE_LINUX
        // TODO: Allow configuring default linking flags. Maybe have `package.useThreads = false` to disable this flag
        string allLinkerFlags = "-pthread";
#else
        string allLinkerFlags = "";
#endif

        // TODO: Somehow check loading order, because it has to be correct to work.. Or does it for dynamic libraries?
        // Anyways it's required for static libraries (especially on Windows)
        for(const string &binaryDependency : binaryDependencies)
        {
            allLinkerFlags += " ";
            allLinkerFlags += binaryDependency;
        }

        if(!staticLinkerFlagCallbackFunc || libraryType == LibraryType::DYNAMIC)
        {
            staticLinkerFlagCallbackFunc = [&allLinkerFlags](const string &linkerFlag)
            {
                allLinkerFlags += " ";
                allLinkerFlags += linkerFlag;
            };
        }

        // TODO: If project contains no source files, then we shouldn't override this function
        dynamicLinkerFlagCallback = [&allLinkerFlags](const string &linkerFlag)
        {
            allLinkerFlags += " ";
            allLinkerFlags += linkerFlag;
        };

        Result<bool> linkerFlags = getLinkerFlags(config, staticLinkerFlagCallbackFunc, dynamicLinkerFlagCallback);
        if(linkerFlags.isErr())
            return Result<bool>::Err(linkerFlags.getErrMsg());

        string projectGeneratedBinary = allLinkerFlags;
        projectGeneratedBinary += " '";
        projectGeneratedBinary += savePathUtf8;
        projectGeneratedBinary += "/";
        switch(libraryType)
        {
            case LibraryType::EXECUTABLE:
            {
                result += "build ";
                result += config.getPackageName();
                result += ": " + buildJob + " ";
                result += join(objectNames, " ");
                result += "\n";
                switch (config.getCompiler())
                {
                    case Compiler::GCC:
                    {
                        result += "  LINK_ARGS = '-Wl,--no-undefined,--as-needed' ";
                        break;
                    }
                    case Compiler::MSVC:
                    {
                        result += "  LINK_ARGS = ";
                        break;
                    }
                }
                
                if(!allLinkerFlags.empty())
                {
                    result += allLinkerFlags;
                }
                result += "\n\n";
                projectGeneratedBinary += config.getPackageName();
                break;
            }
            case LibraryType::STATIC:
            {
                result += "build ";
                result += config.getPackageName();
                result += ": " + buildJob + " ";
                result += join(objectNames, " ");
                result += "\n\n";

                switch (config.getCompiler())
                {
                    case Compiler::GCC:
                    {
                        projectGeneratedBinary += config.getPackageName() + ".a";
                        break;
                    }
                    case Compiler::MSVC:
                    {
                        projectGeneratedBinary += config.getPackageName() + ".lib";
                        break;
                    }
                }
                break;
            }
            case LibraryType::DYNAMIC:
            {
                switch (config.getCompiler())
                {
                    case Compiler::GCC:
                    {
                        result += "build lib";
                        result += config.getPackageName();
                        result += ".so: " + buildJob + " ";
                        result += join(objectNames, " ");
                        result += "\n";
                        result += "  LINK_ARGS = '-Wl,--no-undefined,--as-needed' ";
                        projectGeneratedBinary += "lib" + config.getPackageName() + ".so";
                        break;
                    }
                    case Compiler::MSVC:
                    {
                        result += "build ";
                        result += config.getPackageName();
                        result += ".lib: " + buildJob + " ";
                        result += join(objectNames, " ");
                        result += "\n";
                        result += "  LINK_ARGS = ";
                        projectGeneratedBinary += config.getPackageName() + ".lib";
                        break;
                    }
                }

                if(!allLinkerFlags.empty())
                {
                    result += allLinkerFlags;
                    //result += " '-Wl,--no-whole-archive'";
                }
                result += "\n\n";
                break;
            }
            default:
                assert(false);
                return Result<bool>::Err("Unexpected error");
        }
        projectGeneratedBinary += "'";

        Result<bool> fileOverwriteResult = sibs::fileOverwrite(ninjaBuildFilePath.c_str(), sibs::StringView(result.data(), result.size()));
        if(fileOverwriteResult.isErr())
            return fileOverwriteResult;

        nprintf(TINYDIR_STRING("Created ninja build file: %s\n"), ninjaBuildFilePath.c_str());

        Result<bool> buildResult = build(savePath);
        if(!buildResult)
            return buildResult;

        Result<bool> buildTestResult = buildTests(config, projectGeneratedBinary);
        if(!buildTestResult)
            return buildTestResult;

        return Result<bool>::Ok(true);
    }

    const _tinydir_char_t *sourceFileExtensions[] = { TINYDIR_STRING("c"), TINYDIR_STRING("cc"), TINYDIR_STRING("cpp"), TINYDIR_STRING("cxx") };
    bool isSourceFile(tinydir_file *file)
    {
        if(!file->is_reg)
            return false;

        for(const _tinydir_char_t *sourceFileExtension : sourceFileExtensions)
        {
            if(_tinydir_strcmp(sourceFileExtension, file->extension) == 0)
                return true;
        }

        return false;
    }

    Result<bool> Ninja::buildTests(const SibsConfig &parentConfig, const std::string &projectGeneratedBinary)
    {
        if(testSourceDirs.empty())
            return Result<bool>::Ok(true);

        // TODO: Include executable as dependency??? or compile project as dynamic library even if it's not a library
        if(libraryType == LibraryType::EXECUTABLE)
            return Result<bool>::Err("Unit tests are currently only supported in projects that compile to static/dynamic library");

        for(const string &testSourceDir : testSourceDirs)
        {
#if OS_FAMILY == OS_FAMILY_POSIX
            FileString testSourceDirNative = testSourceDir;
            FileString projectConfFilePath = testSourceDir;
#else
            FileString testSourceDirNative = utf8To16(testSourceDir);
            FileString projectConfFilePath = testSourceDirNative;
#endif
            projectConfFilePath += TINYDIR_STRING("/project.conf");

            FileType projectConfFileType = getFileType(projectConfFilePath.c_str());
            SibsTestConfig sibsTestConfig(parentConfig.getCompiler(), testSourceDirNative);
            if(projectConfFileType == FileType::REGULAR)
            {
                Result<bool> result = Config::readFromFile(projectConfFilePath.c_str(), sibsTestConfig);
                if(!result)
                    return result;
            }

            backend::Ninja ninja;
            ninja.addDependency(projectGeneratedBinary);
            walkDirFilesRecursive(testSourceDirNative.c_str(), [&ninja, &sibsTestConfig](tinydir_file *file)
            {
                if (isSourceFile(file))
                {
                    string filePathUtf8 = toUtf8(file->path + sibsTestConfig.getProjectPath().size() + 1);
                    ninja.addSourceFile(filePathUtf8.c_str());
                }
                else
                {
                    //printf("Ignoring non-source file: %s\n", file->path + projectPath.size());
                }
            });

            if(!ninja.getSourceFiles().empty())
            {
                FileString debugBuildPath = testSourceDirNative + TINYDIR_STRING("/sibs-build/debug");
                Result<bool> buildFileResult = ninja.build(sibsTestConfig, debugBuildPath.c_str());
                if (!buildFileResult)
                    return buildFileResult;

                Result<bool> buildResult = ninja.build(debugBuildPath.c_str());
                if (!buildResult)
                    return buildResult;
            }
        }

        return Result<bool>::Ok(true);
    }

    Result<bool> Ninja::build(const _tinydir_char_t *buildFilePath)
    {
        FileString command = TINYDIR_STRING("ninja -C \"");
        command += buildFilePath;
        command += TINYDIR_STRING("\"");
        Result<ExecResult> execResult = exec(command.c_str(), true);
        if(execResult.isOk())
        {
            if(execResult.unwrap().exitCode == 0)
                return Result<bool>::Ok(true);
            else
                return Result<bool>::Err(execResult.unwrap().execStdout);
        }
        else
            return Result<bool>::Err(execResult.getErrMsg());
    }
}