#include "cdp_http.h"

#include "crude_json.h"

#include <cstdio>
#include <cstring>
#include <sstream>

#ifdef _WIN32
#  define WIN32_LEAN_AND_MEAN
#  include <winsock2.h>
#  include <ws2tcpip.h>
#endif

namespace navegator {

namespace {

#ifdef _WIN32

bool set_socket_timeout(SOCKET s, int ms) {
    DWORD t = (DWORD)ms;
    if (setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, (const char*)&t, sizeof(t)) != 0) return false;
    if (setsockopt(s, SOL_SOCKET, SO_SNDTIMEO, (const char*)&t, sizeof(t)) != 0) return false;
    return true;
}

bool send_all(SOCKET s, const char* data, size_t len) {
    size_t sent = 0;
    while (sent < len) {
        int n = ::send(s, data + sent, (int)(len - sent), 0);
        if (n <= 0) return false;
        sent += (size_t)n;
    }
    return true;
}

bool recv_until_close(SOCKET s, std::string& out, size_t cap = 8 * 1024 * 1024) {
    char buf[8192];
    while (out.size() < cap) {
        int n = ::recv(s, buf, sizeof(buf), 0);
        if (n == 0) return true;        // peer closed
        if (n < 0)  return !out.empty(); // timeout/err: si tenemos algo, asumimos completo
        out.append(buf, (size_t)n);
    }
    return true;
}

bool parse_http_response(const std::string& raw, int& status, std::string& body, std::string& err) {
    auto eol = raw.find("\r\n");
    if (eol == std::string::npos) { err = "no status line"; return false; }
    std::string status_line = raw.substr(0, eol);
    int sp1 = (int)status_line.find(' ');
    int sp2 = (int)status_line.find(' ', sp1 + 1);
    if (sp1 < 0 || sp2 < 0) { err = "bad status line"; return false; }
    try { status = std::stoi(status_line.substr(sp1 + 1, sp2 - sp1 - 1)); }
    catch (...) { err = "bad status code"; return false; }

    auto headers_end = raw.find("\r\n\r\n");
    if (headers_end == std::string::npos) { err = "no header terminator"; return false; }
    body = raw.substr(headers_end + 4);

    // Si Transfer-Encoding: chunked, decodear. CDP rara vez lo usa pero por si acaso.
    std::string headers_lower;
    headers_lower.reserve(headers_end);
    for (size_t i = 0; i < headers_end; ++i) {
        char c = raw[i];
        headers_lower.push_back((c >= 'A' && c <= 'Z') ? (char)(c + 32) : c);
    }
    if (headers_lower.find("transfer-encoding: chunked") != std::string::npos) {
        std::string decoded;
        size_t p = 0;
        while (p < body.size()) {
            size_t crlf = body.find("\r\n", p);
            if (crlf == std::string::npos) break;
            std::string size_hex = body.substr(p, crlf - p);
            // strip extensions
            size_t semi = size_hex.find(';');
            if (semi != std::string::npos) size_hex.resize(semi);
            size_t chunk_size = 0;
            try { chunk_size = std::stoul(size_hex, nullptr, 16); }
            catch (...) { break; }
            if (chunk_size == 0) break;
            p = crlf + 2;
            if (p + chunk_size > body.size()) break;
            decoded.append(body, p, chunk_size);
            p += chunk_size + 2;
        }
        body = std::move(decoded);
    }
    return true;
}

CdpHttpResult do_request(const std::string& method,
                         int port,
                         const std::string& path,
                         const std::string& body,
                         int timeout_ms) {
    CdpHttpResult r;

    WSADATA wsa;
    static bool wsa_ok = (WSAStartup(MAKEWORD(2, 2), &wsa) == 0);
    if (!wsa_ok) { r.error = "WSAStartup failed"; return r; }

    SOCKET s = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (s == INVALID_SOCKET) { r.error = "socket() failed"; return r; }
    set_socket_timeout(s, timeout_ms);

    sockaddr_in addr{};
    addr.sin_family = AF_INET;
    addr.sin_port = htons((u_short)port);
    addr.sin_addr.s_addr = htonl(0x7F000001); // 127.0.0.1

    if (::connect(s, (sockaddr*)&addr, sizeof(addr)) != 0) {
        r.error = "connect failed (port " + std::to_string(port) + ")";
        closesocket(s);
        return r;
    }

    std::ostringstream req;
    req << method << " " << path << " HTTP/1.1\r\n"
        << "Host: 127.0.0.1:" << port << "\r\n"
        << "User-Agent: navegator_dashboard/1.0\r\n"
        << "Accept: */*\r\n"
        << "Connection: close\r\n";
    if (!body.empty()) {
        req << "Content-Type: application/json\r\n"
            << "Content-Length: " << body.size() << "\r\n";
    }
    req << "\r\n";
    if (!body.empty()) req << body;

    std::string raw_req = req.str();
    if (!send_all(s, raw_req.data(), raw_req.size())) {
        r.error = "send failed";
        closesocket(s);
        return r;
    }

    std::string raw_resp;
    if (!recv_until_close(s, raw_resp)) {
        r.error = "recv failed";
        closesocket(s);
        return r;
    }
    closesocket(s);

    int status = 0;
    std::string parsed_body;
    std::string err;
    if (!parse_http_response(raw_resp, status, parsed_body, err)) {
        r.error = err;
        return r;
    }
    r.ok = (status >= 200 && status < 300);
    r.status = status;
    r.body = std::move(parsed_body);
    return r;
}

#else

CdpHttpResult do_request(const std::string&, int, const std::string&, const std::string&, int) {
    CdpHttpResult r;
    r.error = "cdp_http: Windows-only";
    return r;
}

#endif

// ---------- JSON helpers ----------
std::string json_str_or_empty(const crude_json::value& v, const char* key) {
    if (!v.is_object()) return "";
    if (!v.contains(key)) return "";
    const auto& f = v[key];
    if (!f.is_string()) return "";
    return f.get<std::string>();
}

bool json_bool_or_false(const crude_json::value& v, const char* key) {
    if (!v.is_object() || !v.contains(key)) return false;
    const auto& f = v[key];
    if (!f.is_boolean()) return false;
    return f.get<bool>();
}

void parse_tab(const crude_json::value& v, CdpTab& out) {
    out.id          = json_str_or_empty(v, "id");
    out.type        = json_str_or_empty(v, "type");
    out.title       = json_str_or_empty(v, "title");
    out.url         = json_str_or_empty(v, "url");
    out.ws_url      = json_str_or_empty(v, "webSocketDebuggerUrl");
    out.favicon_url = json_str_or_empty(v, "faviconUrl");
    out.description = json_str_or_empty(v, "description");
    out.attached    = json_bool_or_false(v, "attached");
}

} // namespace

CdpHttpResult cdp_http_request(const std::string& method,
                               int port,
                               const std::string& path,
                               const std::string& body,
                               int timeout_ms) {
    return do_request(method, port, path, body, timeout_ms);
}

bool cdp_get_version(int port, CdpVersion& out, std::string* err) {
    auto r = do_request("GET", port, "/json/version", "", 3000);
    if (!r.ok) { if (err) *err = r.error.empty() ? ("HTTP " + std::to_string(r.status)) : r.error; return false; }
    crude_json::value v = crude_json::value::parse(r.body);
    if (!v.is_object()) { if (err) *err = "bad json"; return false; }
    out.browser           = json_str_or_empty(v, "Browser");
    out.protocol_version  = json_str_or_empty(v, "Protocol-Version");
    out.user_agent        = json_str_or_empty(v, "User-Agent");
    out.v8_version        = json_str_or_empty(v, "V8-Version");
    out.webkit_version    = json_str_or_empty(v, "WebKit-Version");
    out.browser_ws_url    = json_str_or_empty(v, "webSocketDebuggerUrl");
    return true;
}

bool cdp_list_tabs(int port, std::vector<CdpTab>& out, std::string* err) {
    out.clear();
    auto r = do_request("GET", port, "/json", "", 3000);
    if (!r.ok) { if (err) *err = r.error.empty() ? ("HTTP " + std::to_string(r.status)) : r.error; return false; }
    crude_json::value v = crude_json::value::parse(r.body);
    if (!v.is_array()) { if (err) *err = "bad json (not array)"; return false; }
    const auto& arr = v.get<crude_json::array>();
    for (const auto& item : arr) {
        CdpTab t;
        parse_tab(item, t);
        if (!t.id.empty()) out.push_back(std::move(t));
    }
    return true;
}

namespace {
std::string url_encode_query(const std::string& s) {
    static const char* hex = "0123456789ABCDEF";
    std::string out; out.reserve(s.size() * 3);
    for (unsigned char c : s) {
        bool unreserved =
            (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
            (c >= '0' && c <= '9') || c == '-' || c == '_' || c == '.' || c == '~' ||
            c == ':' || c == '/' || c == '?' || c == '#' || c == '=' || c == '&';
        if (unreserved) out.push_back((char)c);
        else { out.push_back('%'); out.push_back(hex[c >> 4]); out.push_back(hex[c & 0xF]); }
    }
    return out;
}
}

bool cdp_new_tab(int port, const std::string& url, CdpTab& out, std::string* err) {
    std::string path = "/json/new";
    if (!url.empty()) path += "?" + url_encode_query(url);
    // Chrome 137+ requiere PUT; versiones anteriores aceptan GET. Probamos PUT primero,
    // si responde 405, fallback a GET.
    auto r = do_request("PUT", port, path, "", 3000);
    if (r.status == 405 || r.status == 404 || (!r.ok && r.error.find("connect") != std::string::npos)) {
        if (r.status == 405 || r.status == 404) {
            r = do_request("GET", port, path, "", 3000);
        }
    }
    if (!r.ok) { if (err) *err = r.error.empty() ? ("HTTP " + std::to_string(r.status)) : r.error; return false; }
    crude_json::value v = crude_json::value::parse(r.body);
    if (!v.is_object()) { if (err) *err = "bad json"; return false; }
    parse_tab(v, out);
    return !out.id.empty();
}

bool cdp_activate_tab(int port, const std::string& tab_id, std::string* err) {
    if (tab_id.empty()) { if (err) *err = "empty tab id"; return false; }
    auto r = do_request("GET", port, "/json/activate/" + tab_id, "", 3000);
    if (!r.ok && err) *err = r.error.empty() ? ("HTTP " + std::to_string(r.status)) : r.error;
    return r.ok;
}

bool cdp_close_tab(int port, const std::string& tab_id, std::string* err) {
    if (tab_id.empty()) { if (err) *err = "empty tab id"; return false; }
    auto r = do_request("GET", port, "/json/close/" + tab_id, "", 3000);
    if (!r.ok && err) *err = r.error.empty() ? ("HTTP " + std::to_string(r.status)) : r.error;
    return r.ok;
}

} // namespace navegator