#include <filesystem>
#include <fstream>
#include <iostream>
#include <sstream>

#if __has_include("pocketpy_c.h")
    #include "pocketpy_c.h"
#else
    // for amalgamated build
    #include "pocketpy.h"
#endif

#ifdef _WIN32

    #include <windows.h>

std::string pkpy_platform_getline(bool* eof) {
    HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE);
    std::wstringstream wss;
    WCHAR buf;
    DWORD read;
    while (ReadConsoleW(hStdin, &buf, 1, &read, NULL) && buf != L'\n') {
        if (eof && buf == L'\x1A') *eof = true;  // Ctrl+Z
        wss << buf;
    }
    std::wstring wideInput = wss.str();
    int length =
        WideCharToMultiByte(CP_UTF8, 0, wideInput.c_str(),
                            (int)wideInput.length(), NULL, 0, NULL, NULL);
    std::string output;
    output.resize(length);
    WideCharToMultiByte(CP_UTF8, 0, wideInput.c_str(), (int)wideInput.length(),
                        &output[0], length, NULL, NULL);
    if (!output.empty() && output.back() == '\r') output.pop_back();
    return output;
}

#else

std::string pkpy_platform_getline(bool* eof) {
    std::string output;
    if (!std::getline(std::cin, output)) {
        if (eof) *eof = true;
    }
    return output;
}

#endif

static int f_input(pkpy_vm* vm) {
    if (!pkpy_is_none(vm, -1)) {
        pkpy_CString prompt;
        bool ok = pkpy_to_string(vm, -1, &prompt);
        if (!ok) return 0;
        std::cout << prompt << std::flush;
    }
    bool eof;
    std::string output = pkpy_platform_getline(&eof);
    pkpy_push_string(vm, pkpy_string(output.c_str()));
    return 1;
}

int main(int argc, char** argv) {
#if _WIN32
    SetConsoleCP(CP_UTF8);
    SetConsoleOutputCP(CP_UTF8);
#endif
    pkpy_vm* vm = pkpy_new_vm(true);

    pkpy_push_function(vm, "input(prompt=None) -> str", f_input);
    pkpy_py_import(vm, "builtins");
    pkpy_setattr(vm, pkpy_name("input"));

    if (argc == 1) {
        void* repl = pkpy_new_repl(vm);
        bool need_more_lines = false;
        while (true) {
            std::cout << (need_more_lines ? "... " : ">>> ");
            bool eof = false;
            std::string line = pkpy_platform_getline(&eof);
            if (eof) break;
            need_more_lines = pkpy_repl_input(repl, line.c_str());
        }
        pkpy_delete_vm(vm);
        return 0;
    }

    if (argc == 2) {
        std::string argv_1 = argv[1];
        if (argv_1 == "-h" || argv_1 == "--help") goto __HELP;

        std::filesystem::path filepath(argv[1]);
        filepath = std::filesystem::absolute(filepath);
        if (!std::filesystem::exists(filepath)) {
            std::cerr << "File not found: " << argv_1 << std::endl;
            return 2;
        }
        std::ifstream file(filepath);
        if (!file.is_open()) {
            std::cerr << "Failed to open file: " << argv_1 << std::endl;
            return 3;
        }
        std::string src((std::istreambuf_iterator<char>(file)),
                        std::istreambuf_iterator<char>());
        file.close();

        pkpy_set_main_argv(vm, argc, argv);

        bool ok = pkpy_exec_2(vm, src.c_str(),
                              filepath.filename().string().c_str(), 0, NULL);
        if (!ok) pkpy_clear_error(vm, NULL);
        pkpy_delete_vm(vm);
        return ok ? 0 : 1;
    }

__HELP:
    std::cout << "Usage: pocketpy [filename]" << std::endl;
    return 0;
}