#include "chrome_launcher.h"

#include <cstdio>
#include <string>

#ifdef _WIN32
#  define WIN32_LEAN_AND_MEAN
#  include <windows.h>
#endif

namespace navegator {

namespace {

#ifdef _WIN32
const char* kChromePaths[] = {
    "C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe",
    "C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe",
};

bool file_exists_w(const char* path) {
    DWORD attrs = GetFileAttributesA(path);
    return (attrs != INVALID_FILE_ATTRIBUTES) && !(attrs & FILE_ATTRIBUTE_DIRECTORY);
}

std::string find_chrome() {
    for (const char* p : kChromePaths) {
        if (file_exists_w(p)) return p;
    }
    return "";
}

// Quote para argv en CreateProcess (rules de MSVCR / Chromium):
// envolver en " y escapar las " internas con \" y los \ que preceden a " con \\.
std::string quote_arg(const std::string& a) {
    if (a.empty()) return "\"\"";
    bool needs = a.find_first_of(" \t\"") != std::string::npos;
    if (!needs) return a;
    std::string out = "\"";
    int backslashes = 0;
    for (char c : a) {
        if (c == '\\') {
            ++backslashes;
            out += c;
        } else if (c == '"') {
            // Duplicar las \\ acumuladas + escapar la "
            for (int i = 0; i < backslashes; ++i) out += '\\';
            backslashes = 0;
            out += "\\\"";
        } else {
            backslashes = 0;
            out += c;
        }
    }
    // Cerrar: duplicar \\ pendientes.
    for (int i = 0; i < backslashes; ++i) out += '\\';
    out += '"';
    return out;
}
#endif

} // namespace

LaunchResult launch_chrome(const LaunchOpts& opts) {
    LaunchResult r;
#ifndef _WIN32
    (void)opts;
    r.error = "launch_chrome: solo Windows en v0";
    return r;
#else
    std::string chrome = opts.chrome_path.empty() ? find_chrome() : opts.chrome_path;
    if (chrome.empty()) {
        r.error = "chrome.exe no encontrado en Program Files";
        return r;
    }
    if (opts.user_data_dir.empty()) {
        r.error = "user_data_dir obligatorio para aislar perfil";
        return r;
    }

    // Crear el directorio si no existe (ignoramos errores, Chrome se queja si no puede).
    CreateDirectoryA(opts.user_data_dir.c_str(), nullptr);

    char port_buf[32];
    std::snprintf(port_buf, sizeof(port_buf), "--remote-debugging-port=%d", opts.port);

    std::string cmd;
    cmd  = quote_arg(chrome);
    cmd += " ";
    cmd += quote_arg(port_buf);
    cmd += " --remote-allow-origins=*";
    cmd += " ";
    cmd += quote_arg(std::string("--user-data-dir=") + opts.user_data_dir);
    cmd += " --no-first-run --no-default-browser-check";
    if (opts.headless) {
        cmd += " --headless=new --disable-gpu";
    }
    if (!opts.start_url.empty()) {
        cmd += " ";
        cmd += quote_arg(opts.start_url);
    } else {
        cmd += " about:blank";
    }

    STARTUPINFOA si{};
    si.cb = sizeof(si);
    PROCESS_INFORMATION pi{};

    // CreateProcess modifica el commandline buffer — copia mutable.
    std::string mutable_cmd = cmd;
    BOOL ok = CreateProcessA(
        nullptr,
        mutable_cmd.data(),
        nullptr, nullptr, FALSE,
        CREATE_NEW_PROCESS_GROUP | DETACHED_PROCESS,
        nullptr, nullptr, &si, &pi);
    if (!ok) {
        DWORD err = GetLastError();
        char buf[64];
        std::snprintf(buf, sizeof(buf), "CreateProcess failed (err=%lu)", (unsigned long)err);
        r.error = buf;
        return r;
    }
    r.ok = true;
    r.pid = (uint32_t)pi.dwProcessId;
    CloseHandle(pi.hProcess);
    CloseHandle(pi.hThread);
    return r;
#endif
}

} // namespace navegator