#include "lv_setup.hpp"
#include "esp_heap_caps.h"
#include "esp_log.h"
#include "esp_timer.h"
#include "freertos/task.h"
#include "types.hpp"

internal const char *kTagLvgl = "LVGL";

SemaphoreHandle_t g_LvglMutex = nullptr;
lv_display_t *g_LvglDisplay = nullptr;
uint8_t *g_LvglDrawBuffer = nullptr;

internal void lvgl_tick_task(void *arg)
{
    while (true)
    {
        vTaskDelay(pdMS_TO_TICKS(10));

        if (xSemaphoreTake(g_LvglMutex, portMAX_DELAY) == pdTRUE)
        {
            lv_timer_handler();
            xSemaphoreGive(g_LvglMutex);
        }
    }
}

internal uint32_t my_tick_get_cb()
{
    return (uint32_t)(esp_timer_get_time() / 1000);
}

internal void lv_dummy_flush_cb(lv_display_t *disp, const lv_area_t *area, uint8_t *px_map)
{
    // Headless display, so we don't actually flush to SPI/I2C.
    // We just tell LVGL that the "flush" is completed so it unblocks wait_for_flushing.
    lv_display_flush_ready(disp);
}

internal void lv_draw_sample_ui()
{
    lv_obj_t *scr = lv_screen_active();
    // Default background to white for the grayscale PNG
    lv_obj_set_style_bg_color(scr, lv_color_white(), 0);

    lv_obj_t *label = lv_label_create(scr);
    lv_label_set_text(label, "Calendink Provider\nLVGL Headless Renderer");
    lv_obj_align(label, LV_ALIGN_CENTER, 0, 0);
}

void setup_lvgl()
{
    ESP_LOGI(kTagLvgl, "Initializing LVGL");

    g_LvglMutex = xSemaphoreCreateMutex();

    lv_init();
    lv_tick_set_cb(my_tick_get_cb);

    uint32_t width = CONFIG_CALENDINK_DISPLAY_WIDTH;
    uint32_t height = CONFIG_CALENDINK_DISPLAY_HEIGHT;

    // Create a virtual display
    g_LvglDisplay = lv_display_create(width, height);
    lv_display_set_flush_cb(g_LvglDisplay, lv_dummy_flush_cb);

    // Initialize LodePNG custom bump allocator
    lodepng_allocator_init();

    // Allocate draw buffers in PSRAM
    // Using LV_COLOR_FORMAT_L8 (1 byte per pixel)
    size_t buf_size = LV_DRAW_BUF_SIZE(width, height, LV_COLOR_FORMAT_L8);
    
    // Fallback to MALLOC_CAP_DEFAULT if we can't get SPIRAM (for debugging without it)
    void *buf1 = heap_caps_malloc(buf_size, MALLOC_CAP_SPIRAM);
    if (!buf1)
    {
        ESP_LOGW(kTagLvgl, "Failed to allocate LVGL draw buffer in PSRAM, falling back to internal RAM");
        buf1 = heap_caps_malloc(buf_size, MALLOC_CAP_DEFAULT);
    }
    
    if (!buf1)
    {
        ESP_LOGE(kTagLvgl, "Failed to allocate LVGL draw buffer entirely.");
        return;
    }

    g_LvglDrawBuffer = (uint8_t *)buf1;

    lv_display_set_buffers(g_LvglDisplay, buf1, nullptr, buf_size, LV_DISPLAY_RENDER_MODE_FULL);
    
    // Explicitly set the color format of the display if it's set in sdkconfig/driver
    lv_display_set_color_format(g_LvglDisplay, LV_COLOR_FORMAT_L8);

    // Create the background task for the LVGL timer
    xTaskCreate(lvgl_tick_task, "LVGL Tick", 4096, nullptr, 5, nullptr);

    // Draw the sample UI
    if (xSemaphoreTake(g_LvglMutex, portMAX_DELAY) == pdTRUE)
    {
        lv_draw_sample_ui();
        xSemaphoreGive(g_LvglMutex);
    }

    ESP_LOGI(kTagLvgl, "LVGL fully initialized. Display %lux%lu created.", width, height);
}