/**
 * V2X-Display Driver - ST7735 SPI (T-Dongle-C5)
 * 
 * Verwendet den ESP-IDF nativen ST7735 Treiber (aus LilyGO T-Dongle-C5 Demo)
 * 
 * Display: ST7735, 80x160 Pixel
 * GPIO: CS=10, DC=3, RST=1, BL=0, MOSI=2, SCK=6
 * 
 * Rotation: 3 (invertiert 90°)
 * Offset: x=26, y=1 (nicht-Zentriert)
 */

#include "esp_log.h"
#include "v2x_display.h"
#include "st7735.h"
#include "driver/gpio.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_timer.h"
#include <stdio.h>

static const char *TAG = "v2x-display";

static void *s_dev = NULL;
static bool s_initialized = false;

/* Globale Variablen */
bool g_disp_initialized = false;
void *g_disp_panel = NULL;

esp_err_t v2x_display_init(void)
{
    esp_err_t ret;

    ESP_LOGI(TAG, "Initialisiere ST7735 Display via eigenem ESP-IDF Treiber...");
    ESP_LOGI(TAG, "GPIO: CS=%d, DC=%d, RST=%d, BL=%d, MOSI=%d, SCK=%d",
             DISP_GPIO_CS, DISP_GPIO_DC, DISP_GPIO_RST, DISP_GPIO_BL,
             DISP_GPIO_SDA, DISP_GPIO_SCK);

    /* GPIO-Konfiguration mit eigenem Treiber */
    st7735_gpio_config_t gpio_cfg = {
        .cs_gpio = DISP_GPIO_CS,
        .dc_gpio = DISP_GPIO_DC,
        .rst_gpio = DISP_GPIO_RST,
        .bl_gpio = DISP_GPIO_BL,
        .mosi_gpio = DISP_GPIO_SDA,
        .sck_gpio = DISP_GPIO_SCK,
    };

    /* ST7735 initialisieren - Rotation 3 (invertiert, 90° gedreht) */
    ret = st7735_init(&gpio_cfg, 3, (void **)&s_dev);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "ST7735 Init fehlgeschlagen: %s", esp_err_to_name(ret));
        return ret;
    }

    /* Display ausschalten (Backlight an, Panel aus) */
    st7735_display_off((void *)s_dev);

    /* Backlight an (aktiv LOW bei LilyGO) */
    gpio_set_level(DISP_GPIO_BL, 0);

    vTaskDelay(pdMS_TO_TICKS(50));

    /* Display einschalten */
    st7735_display_on((void *)s_dev);

    /* Vollbild weiß */
    st7735_fill_screen((void *)s_dev, DISP_COLOR_WHITE);

    s_initialized = true;
    g_disp_initialized = true;
    g_disp_panel = (void *)s_dev;
    ESP_LOGI(TAG, "ST7735 Display bereit (80x160, SPI, Rot=3)");
    return ESP_OK;
}

esp_err_t v2x_display_clear(uint16_t color)
{
    if (!s_initialized || !s_dev) return ESP_ERR_INVALID_STATE;
    st7735_fill_screen((void *)s_dev, color);
    return ESP_OK;
}

esp_err_t v2x_display_rect(int16_t x, int16_t y, int16_t w, int16_t h, uint16_t color, bool filled)
{
    if (!s_initialized || !s_dev) return ESP_ERR_INVALID_STATE;

    if (filled) {
        /* Gefülltes Rechteck zeichnen */
        for (int16_t py = 0; py < h; py++) {
            for (int16_t px = 0; px < w; px++) {
                st7735_draw_pixel((void *)s_dev, x + px, y + py, color);
            }
        }
    } else {
        /* Nur Rahmen zeichnen */
        for (int16_t px = 0; px < w; px++) {
            st7735_draw_pixel((void *)s_dev, x + px, y, color);
            st7735_draw_pixel((void *)s_dev, x + px, y + h - 1, color);
        }
        for (int16_t py = 0; py < h; py++) {
            st7735_draw_pixel((void *)s_dev, x, y + py, color);
            st7735_draw_pixel((void *)s_dev, x + w - 1, y + py, color);
        }
    }
    return ESP_OK;
}

esp_err_t v2x_display_line(int16_t x0, int16_t y0, int16_t x1, int16_t y1, uint16_t color)
{
    if (!s_initialized || !s_dev) return ESP_ERR_INVALID_STATE;
    return st7735_draw_line((void *)s_dev, x0, y0, x1, y1, color);
}

esp_err_t v2x_display_off(void)
{
    if (!s_initialized || !s_dev) return ESP_ERR_INVALID_STATE;
    st7735_display_off((void *)s_dev);
    gpio_set_level(DISP_GPIO_BL, 1); /* Backlight aus */
    return ESP_OK;
}

esp_err_t v2x_display_progress_bar(int16_t x, int16_t y, int16_t w, int16_t h, float progress,
                                    uint16_t fg_color, uint16_t bg_color)
{
    progress = (progress < 0.0f) ? 0.0f : (progress > 1.0f) ? 1.0f : progress;

    for (int16_t py = 0; py < h; py++) {
        for (int16_t px = 0; px < w; px++) {
            st7735_draw_pixel((void *)s_dev, x + px, y + py, bg_color);
        }
    }

    int16_t fw = (int16_t)(w * progress);
    if (fw > 0) {
        for (int16_t py = 0; py < h; py++) {
            for (int16_t px = 0; px < fw; px++) {
                st7735_draw_pixel((void *)s_dev, x + px, y + py, fg_color);
            }
        }
    }

    for (int i = 0; i < w; i++) {
        st7735_draw_pixel((void *)s_dev, x + i, y, DISP_COLOR_BLACK);
        st7735_draw_pixel((void *)s_dev, x + i, y + h - 1, DISP_COLOR_BLACK);
    }
    for (int i = 0; i < h; i++) {
        st7735_draw_pixel((void *)s_dev, x, y + i, DISP_COLOR_BLACK);
        st7735_draw_pixel((void *)s_dev, x + w - 1, y + i, DISP_COLOR_BLACK);
    }
    return ESP_OK;
}

esp_err_t v2x_display_rssi_gauge(int8_t rssi)
{
    if (rssi < -100) rssi = -100;
    if (rssi > -20) rssi = -20;
    float pct = (float)(rssi + 100) / 80.0f;
    uint16_t color = DISP_COLOR_RED;
    if (pct > 0.6f) color = DISP_COLOR_GREEN;
    else if (pct > 0.3f) color = DISP_COLOR_YELLOW;
    return v2x_display_progress_bar(0, 0, DISP_W, 3, pct, color, DISP_COLOR_BLACK);
}

esp_err_t v2x_display_render_frame_line(int16_t x, int16_t y, const disp_frame_info_t *info,
                                        uint16_t bg_color)
{
    for (int16_t py = 0; py < 12; py++) {
        for (int16_t px = 0; px < DISP_W; px++) {
            st7735_draw_pixel((void *)s_dev, x + px, y + py, bg_color);
        }
    }
    if (info->rssi != 0) {
        int8_t r = info->rssi;
        if (r < -100) r = -100;
        if (r > -20) r = -20;
        float pct = (float)(r + 100) / 80.0f;
        uint16_t bar_color = DISP_COLOR_RED;
        if (pct > 0.6f) bar_color = DISP_COLOR_GREEN;
        else if (pct > 0.3f) bar_color = DISP_COLOR_YELLOW;
        for (int16_t py = 1; py < 11; py++) {
            for (int16_t px = 0; px < 5; px++) {
                st7735_draw_pixel((void *)s_dev, x + px, y + py, bar_color);
            }
        }
    }
    (void)x; (void)y;
    return ESP_OK;
}