#include "picker_state.h"

#include "cdp_ws.h"
#include "py_subprocess.h"   // for py_resolve_registry_root

// crude_json del vendor imgui-node-editor (ya linkado por CMakeLists.txt).
#include "crude_json.h"

#include <atomic>
#include <cstdio>
#include <fstream>
#include <mutex>
#include <sstream>
#include <thread>

namespace navegator {

namespace {

std::mutex                         g_mu;
std::unique_ptr<CdpWs>             g_ws;
std::atomic<bool>                  g_active{false};
std::atomic<bool>                  g_stop_pump{false};
std::thread                        g_pump_thread;
PickedElement                      g_last;

std::string slurp(const std::string& path) {
    std::ifstream f(path, std::ios::binary);
    if (!f) return "";
    std::ostringstream ss; ss << f.rdbuf();
    return ss.str();
}

// JS-string-literal escape (NO JSON encoding — el JSON wrapper se hace al construir params).
std::string js_str_escape(const std::string& s) {
    std::string out; out.reserve(s.size() + 8);
    for (char c : s) {
        switch (c) {
            case '\\': out += "\\\\"; break;
            case '"':  out += "\\\""; break;
            case '\n': out += "\\n";  break;
            case '\r': out += "\\r";  break;
            case '\t': out += "\\t";  break;
            default:
                if ((unsigned char)c < 0x20) {
                    char buf[8]; std::snprintf(buf, sizeof(buf), "\\u%04x", (unsigned)c);
                    out += buf;
                } else out += c;
        }
    }
    return out;
}

void pump_loop() {
    while (!g_stop_pump.load()) {
        std::vector<std::string> msgs;
        {
            std::lock_guard<std::mutex> lk(g_mu);
            if (!g_ws || !g_ws->is_connected()) break;
            msgs = g_ws->drain(64);
        }
        for (const auto& m : msgs) {
            crude_json::value v = crude_json::value::parse(m);
            if (!v.is_object()) continue;
            // Filtrar method=Runtime.consoleAPICalled, args[0].value=="__fn_picked__"
            if (!v.contains("method")) continue;
            const auto& method = v["method"];
            if (!method.is_string()) continue;
            if (method.get<std::string>() != "Runtime.consoleAPICalled") continue;
            if (!v.contains("params")) continue;
            const auto& params = v["params"];
            if (!params.is_object() || !params.contains("args")) continue;
            const auto& args = params["args"];
            if (!args.is_array()) continue;
            const auto& args_arr = args.get<crude_json::array>();
            if (args_arr.size() < 2) continue;
            const auto& a0 = args_arr[0];
            if (!a0.is_object() || !a0.contains("value")) continue;
            const auto& v0 = a0["value"];
            if (!v0.is_string() || v0.get<std::string>() != "__fn_picked__") continue;
            const auto& a1 = args_arr[1];
            if (!a1.is_object() || !a1.contains("value")) continue;
            const auto& v1 = a1["value"];
            // v1.value puede ser string (JSON serializado) o un objeto. El JS
            // hace console.log("__fn_picked__", JSON.stringify(payload)).
            std::string payload;
            if (v1.is_string()) payload = v1.get<std::string>();
            else                payload = v1.dump();
            crude_json::value p = crude_json::value::parse(payload);
            if (!p.is_object()) continue;
            PickedElement el;
            auto get = [&](const char* k) -> std::string {
                if (!p.contains(k)) return "";
                const auto& x = p[k];
                if (x.is_string()) return x.get<std::string>();
                if (x.is_null())   return "";
                return x.dump();
            };
            el.selector = get("selector");
            el.xpath    = get("xpath");
            el.tag      = get("tag");
            el.text     = get("text");
            if (p.contains("rect")) {
                el.rect_str = p["rect"].dump();
            }
            el.valid = true;
            {
                std::lock_guard<std::mutex> lk(g_mu);
                g_last = std::move(el);
            }
        }
        std::this_thread::sleep_for(std::chrono::milliseconds(80));
    }
    g_active.store(false);
}

} // anon

std::string picker_load_js() {
    std::string root = py_resolve_registry_root();
    if (root.empty()) return "";
#ifdef _WIN32
    std::string path = root + "\\functions\\browser\\cdp_pick_element_js.js";
#else
    std::string path = root + "/functions/browser/cdp_pick_element_js.js";
#endif
    return slurp(path);
}

std::string picker_start(int /*port*/, const std::string& /*tab_id*/, const std::string& ws_url) {
    if (ws_url.empty()) return "no ws_url";
    picker_stop();
    std::string js = picker_load_js();
    if (js.empty()) return "could not load cdp_pick_element_js.js (set FN_REGISTRY_ROOT)";

    std::string host, path;
    int p = 0;
    if (!CdpWs::parse_ws_url(ws_url, host, p, path)) return "invalid ws_url";

    auto ws = std::make_unique<CdpWs>();
    CdpWsConfig cfg;
    cfg.host = host;
    cfg.port = p;
    cfg.path = path;
    cfg.timeout_ms = 5000;
    std::string err;
    if (!ws->connect(cfg, &err)) return "ws connect failed: " + err;

    // Enable Runtime (necesario para consoleAPICalled).
    ws->send_command("Runtime.enable", "");

    // Inyectar el JS via Runtime.evaluate. expression es el codigo.
    // El payload del JS termina con un IIFE; envolvemos en wrapper sin returnByValue.
    std::ostringstream params;
    params << "{\"expression\":\"" << js_str_escape(js)
           << "\",\"includeCommandLineAPI\":true"
           << ",\"awaitPromise\":false"
           << ",\"returnByValue\":false}";
    ws->send_command("Runtime.evaluate", params.str());

    {
        std::lock_guard<std::mutex> lk(g_mu);
        g_ws = std::move(ws);
    }
    g_stop_pump.store(false);
    g_active.store(true);
    g_pump_thread = std::thread(pump_loop);
    return "";
}

void picker_stop() {
    g_stop_pump.store(true);
    {
        std::lock_guard<std::mutex> lk(g_mu);
        if (g_ws) g_ws->close();
    }
    if (g_pump_thread.joinable()) g_pump_thread.join();
    {
        std::lock_guard<std::mutex> lk(g_mu);
        g_ws.reset();
    }
    g_active.store(false);
}

bool picker_is_active() { return g_active.load(); }

PickedElement picker_last() {
    std::lock_guard<std::mutex> lk(g_mu);
    return g_last;
}

void picker_clear_last() {
    std::lock_guard<std::mutex> lk(g_mu);
    g_last = PickedElement{};
}

} // namespace navegator