#include <llmr/llmr.hpp>
#include <GLFW/glfw3.h>
#include <llmr/platform/platform.hpp>

#include <signal.h>
#include <getopt.h>

#include "settings.hpp"
#include "request.hpp"

std::forward_list<llmr::platform::Request *> requests;

static int fullscreen_flag = 0;

class MapView {
public:
    MapView() :
        dirty(true),
        tracking(false),
        rotating(false),
        last_click(-1),
        settings(),
        map(settings) {
    }

    void init() {
        if (!glfwInit()) {
            fprintf(stderr, "Failed to initialize glfw\n");
            exit(1);
        }

        GLFWmonitor *monitor = nullptr;

#ifdef GL_ES_VERSION_2_0
        if (fullscreen_flag) {
            monitor = glfwGetPrimaryMonitor();
        }

        glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
#endif

        glfwWindowHint(GLFW_RED_BITS, 8);
        glfwWindowHint(GLFW_GREEN_BITS, 8);
        glfwWindowHint(GLFW_BLUE_BITS, 8);
        glfwWindowHint(GLFW_ALPHA_BITS, 8);
        glfwWindowHint(GLFW_STENCIL_BITS, 8);
        glfwWindowHint(GLFW_DEPTH_BITS, 16);

        window = glfwCreateWindow(1024, 768, "llmr", monitor, NULL);
        if (!window) {
            glfwTerminate();
            fprintf(stderr, "Failed to initialize window\n");
            exit(1);
        }

        glfwSetWindowUserPointer(window, this);
        glfwMakeContextCurrent(window);

        int width, height;
        glfwGetWindowSize(window, &width, &height);
        int fb_width, fb_height;
        glfwGetFramebufferSize(window, &fb_width, &fb_height);

        settings.load();

        map.setup((double)fb_width / width);

        resize(window, 0, 0);

        map.loadSettings();

        glfwSetCursorPosCallback(window, mousemove);
        glfwSetMouseButtonCallback(window, mouseclick);
        glfwSetWindowSizeCallback(window, resize);
        glfwSetFramebufferSizeCallback(window, resize);
        glfwSetScrollCallback(window, scroll);
        glfwSetCharCallback(window, character);
        glfwSetKeyCallback(window, key);
    }

    static void character(GLFWwindow *window, unsigned int codepoint) {

    }


    static void key(GLFWwindow *window, int key, int scancode, int action, int mods) {
        MapView *mapView = (MapView *)glfwGetWindowUserPointer(window);

        if (action == GLFW_RELEASE) {
            switch (key) {
                case GLFW_KEY_ESCAPE:
                    glfwSetWindowShouldClose(window, true);
                    break;
                case GLFW_KEY_TAB:
                    mapView->map.toggleDebug();
                    break;
                case GLFW_KEY_R:
                    if (!mods) mapView->map.resetPosition();
                    break;
                case GLFW_KEY_N:
                    if (!mods) mapView->map.resetNorth();
                    break;
            }
        }
    }


    static void scroll(GLFWwindow *window, double xoffset, double yoffset) {
        MapView *mapView = (MapView *)glfwGetWindowUserPointer(window);
        double delta = yoffset * 40;

        bool is_wheel = delta != 0 && fmod(delta, 4.000244140625) == 0;

        double absdelta = delta < 0 ? -delta : delta;
        double scale = 2.0 / (1.0 + exp(-absdelta / 100.0));

        // Make the scroll wheel a bit slower.
        if (!is_wheel) {
            scale = (scale - 1.0) / 2.0 + 1.0;
        }

        // Zooming out.
        if (delta < 0 && scale != 0) {
            scale = 1.0 / scale;
        }

        mapView->map.startScaling();
        mapView->map.scaleBy(scale, mapView->last_x, mapView->last_y);
    }

    static void resize(GLFWwindow *window, int, int) {
        MapView *mapView = (MapView *)glfwGetWindowUserPointer(window);

        int width, height;
        glfwGetWindowSize(window, &width, &height);
        int fb_width, fb_height;
        glfwGetFramebufferSize(window, &fb_width, &fb_height);

        fprintf(stderr, "window size: %d/%d\n", width, height);

        mapView->map.resize(width, height, fb_width, fb_height);
    }

    static void mouseclick(GLFWwindow *window, int button, int action, int modifiers) {
        MapView *mapView = (MapView *)glfwGetWindowUserPointer(window);

        if (button == GLFW_MOUSE_BUTTON_RIGHT || (button == GLFW_MOUSE_BUTTON_LEFT && modifiers & GLFW_MOD_CONTROL)) {
            mapView->rotating = action == GLFW_PRESS;
            if (mapView->rotating) {
                mapView->start_x = mapView->last_x;
                mapView->start_y = mapView->last_y;
            } else {
                mapView->map.stopRotating();
            }
        } else if (button == GLFW_MOUSE_BUTTON_LEFT) {
            mapView->tracking = action == GLFW_PRESS;

            if (action == GLFW_RELEASE) {
                mapView->map.stopPanning();
                double now = glfwGetTime();
                if (now - mapView->last_click < 0.4) {
                    mapView->map.scaleBy(2.0, mapView->last_x, mapView->last_y);
                }
                mapView->last_click = now;
            }
        }
    }

    static void mousemove(GLFWwindow *window, double x, double y) {
        MapView *mapView = (MapView *)glfwGetWindowUserPointer(window);
        if (mapView->tracking) {
            double dx = x - mapView->last_x;
            double dy = y - mapView->last_y;
            if (dx || dy) {
                mapView->map.startPanning();
                mapView->map.moveBy(dx, dy);
            }
        } else if (mapView->rotating) {
            mapView->map.startRotating();
            mapView->map.rotateBy(mapView->start_x, mapView->start_y, mapView->last_x, mapView->last_y, x, y);
        }
        mapView->last_x = x;
        mapView->last_y = y;
    }

    int run() {
        while (!glfwWindowShouldClose(window)) {
            bool& dirty = this->dirty;
            requests.remove_if([&dirty](llmr::platform::Request * req) {
                if (req->done) {
                    req->foreground_callback();
                    delete req;
                    dirty = true;
                    return true;
                } else {
                    return false;
                }
            });

            if (dirty) {
                try {
                    dirty = render();
                } catch (std::exception& ex) {
                    fprintf(stderr, "exception: %s\n", ex.what());
                }
                glfwSwapBuffers(window);
                fps();
            }

            if (!requests.empty() || dirty) {
                glfwPollEvents();
            } else {
                glfwWaitEvents();
            }
        }

        return 0;
    }

    bool render() {
        return map.render();
    }

    void fps() {
        static int frames = 0;
        static double time_elapsed = 0;

        frames++;
        double current_time = glfwGetTime();

        if (current_time - time_elapsed >= 1) {
            fprintf(stderr, "FPS: %4.2f\n", frames / (current_time - time_elapsed));
            time_elapsed = current_time;
            frames = 0;
        }
    }

    ~MapView() {
        glfwTerminate();
    }

public:
    bool dirty;
    double last_x, last_y;
    bool tracking;

    double start_x, start_y;
    bool rotating;

    double last_click;

    GLFWwindow *window;
    llmr::Settings_MacOSX settings;
    llmr::Map map;
};

MapView *mapView = nullptr;

namespace llmr {
namespace platform {

void restart() {
    if (mapView) {
        mapView->dirty = true;
    }
}

Request *request_http(std::string url, std::function<void(Response&)> background_function, std::function<void()> foreground_callback) {
    Request *req = new Request(url, background_function, foreground_callback);
    requests.push_front(req);
    return req;
}

void cancel_request_http(Request *request) {
    for (Request *req : requests) {
        if (req == request) {
            req->cancel();
        }
    }
}

double time() {
    return glfwGetTime();
}

}
}

void quit_handler(int s) {
    if (mapView) {
        fprintf(stderr, "waiting for quit...\n");
        glfwSetWindowShouldClose(mapView->window, true);
        llmr::platform::restart();
    } else {
        exit(0);
    }
}



static struct option long_options[] = {
    {"fullscreen", no_argument, &fullscreen_flag, 1},
    {0, 0, 0, 0}
};

int main(int argc, char *argv[]) {
    while (true) {
        int option_index = 0;
        int c = getopt_long(argc, argv, "f", long_options, &option_index);
        if (c == -1) break;
    }

    // // sigint handling
    // struct sigaction sigIntHandler;
    // sigIntHandler.sa_handler = quit_handler;
    // sigemptyset(&sigIntHandler.sa_mask);
    // sigIntHandler.sa_flags = 0;
    // sigaction(SIGINT, &sigIntHandler, NULL);


    // curl init
    curl_global_init(CURL_GLOBAL_ALL);

    llmr::platform::Request::initialize();


    // main loop
    mapView = new MapView();
    mapView->init();
    int ret = mapView->run();
    mapView->settings.sync();
    delete mapView;


    llmr::platform::Request::finish();

    curl_global_cleanup();
    return ret;
}