#include "os_app.h"
#include "os_gfx.h"
#include "os_status.h"
#include "os_event.h"
#include <string.h>
#include "esp_log.h"

static const char *TAG = "SYS_APP";

#define MAX_APPS 16
static const sys_app_t *s_registry[MAX_APPS];
static size_t s_app_count = 0;

static const sys_app_t *s_current_app = NULL;
static bool s_in_launcher = true;
static size_t s_launcher_selected = 0;

static void launcher_update(uint32_t delta_ms)
{
    sys_status_t status;
    sys_status_get(&status);
    sys_gfx_draw_status_bar(&status);

    sys_gfx_draw_str_3x5(2, 9, "--- APPS ---", COLOR_WHITE);

    const char *names[MAX_APPS];
    for (size_t i = 0; i < s_app_count; i++) {
        names[i] = s_registry[i]->name;
    }
    sys_gfx_draw_menu(15, names, s_app_count, s_launcher_selected);
}

static void launcher_handle_input(input_action_t action)
{
    if (s_app_count == 0) return;

    if (action == INPUT_ACTION_CLICK) {
        s_launcher_selected = (s_launcher_selected + 1) % s_app_count;
    } else if (action == INPUT_ACTION_DOUBLE_CLICK) {
        if (s_launcher_selected == 0) {
            s_launcher_selected = s_app_count - 1;
        } else {
            s_launcher_selected--;
        }
    } else if (action == INPUT_ACTION_LONG_PRESS) {
        sys_app_launch_by_index(s_launcher_selected);
    }
}

esp_err_t sys_app_init(void)
{
    s_app_count = 0;
    s_current_app = NULL;
    s_in_launcher = true;
    s_launcher_selected = 0;
    sys_status_set_active_app_name("Launcher");
    ESP_LOGI(TAG, "App Manager initialized");
    return ESP_OK;
}

esp_err_t sys_app_register(const sys_app_t *app)
{
    if (!app || !app->id || !app->name) return ESP_ERR_INVALID_ARG;
    if (s_app_count >= MAX_APPS) return ESP_ERR_NO_MEM;

    s_registry[s_app_count++] = app;
    if (app->init) {
        app->init();
    }
    ESP_LOGI(TAG, "Registered app: [%s] '%s'", app->id, app->name);
    return ESP_OK;
}

esp_err_t sys_app_launch_by_id(const char *id)
{
    if (!id) return ESP_ERR_INVALID_ARG;
    for (size_t i = 0; i < s_app_count; i++) {
        if (strcmp(s_registry[i]->id, id) == 0) {
            return sys_app_launch_by_index(i);
        }
    }
    ESP_LOGW(TAG, "App not found: %s", id);
    return ESP_ERR_NOT_FOUND;
}

esp_err_t sys_app_launch_by_index(size_t index)
{
    if (index >= s_app_count) return ESP_ERR_INVALID_ARG;

    if (s_current_app && s_current_app->exit) {
        s_current_app->exit();
    }

    s_current_app = s_registry[index];
    s_in_launcher = false;
    sys_status_set_active_app_name(s_current_app->name);

    if (s_current_app->enter) {
        s_current_app->enter();
    }

    sys_event_post(SYS_EVENT_APP_SWITCH, (int32_t)index, (void *)s_current_app->id);
    sys_gfx_show_toast(s_current_app->name, 800);
    ESP_LOGI(TAG, "Switched to app: %s", s_current_app->name);
    return ESP_OK;
}

void sys_app_launch_launcher(void)
{
    if (s_current_app && s_current_app->exit) {
        s_current_app->exit();
    }
    s_current_app = NULL;
    s_in_launcher = true;
    sys_status_set_active_app_name("Launcher");
    sys_gfx_show_toast("Launcher", 600);
    ESP_LOGI(TAG, "Returned to App Launcher");
}

const sys_app_t *sys_app_get_current(void)
{
    return s_current_app;
}

void sys_app_update(uint32_t delta_ms)
{
    if (s_in_launcher) {
        launcher_update(delta_ms);
    } else if (s_current_app && s_current_app->update) {
        s_current_app->update(delta_ms);
    }
}

void sys_app_dispatch_input(input_action_t action)
{
    if (action == INPUT_ACTION_HOLD_HOME) {
        sys_app_launch_launcher();
        return;
    }

    if (s_in_launcher) {
        launcher_handle_input(action);
    } else if (s_current_app && s_current_app->handle_input) {
        s_current_app->handle_input(action);
    }
}

size_t sys_app_get_count(void)
{
    return s_app_count;
}

const sys_app_t *sys_app_get_by_index(size_t index)
{
    if (index >= s_app_count) return NULL;
    return s_registry[index];
}