/*
 * probe.c -- I2C Bus Hardware Scanner module
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * I2C bus scanner.  Probes /dev/i2c-0 address space 0x03-0x77
 *       using SMBus receive-byte probe.  Displays responding devices
 *       in an LVGL list with green highlighting.
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include <linux/input.h>
#include "h2_ui.h"
#include "log_manager.h"

#define I2C_DEV   "/dev/i2c-0"
#define ADDR_START 0x03
#define ADDR_END   0x77
#define MAX_FOUND  16

static int i2c_fd = -1;

static int try_probe_addr(uint8_t addr) {
    if (ioctl(i2c_fd, I2C_SLAVE, addr) < 0) return 0;
    unsigned char dummy;
    return (read(i2c_fd, &dummy, 1) == 1);
}

int main(void) {
    init_h2_graphics_runtime("I2C CONTROLLER SCANNER");
    LOG_INF("probe module started");

    lv_obj_t *scr = lv_scr_act();

    lv_obj_t *title = lv_label_create(scr);
    lv_label_set_text(title, "I2C BUS HARDWARE SCAN");
    lv_obj_align(title, LV_ALIGN_TOP_MID, 0, 10);
    lv_obj_set_style_text_color(title, COLOR_PRIMARY, LV_PART_MAIN);

    lv_obj_t *list = lv_list_create(scr);
    lv_obj_set_size(list, 280, 160);
    lv_obj_align(list, LV_ALIGN_CENTER, 0, 15);

    uint8_t found_addrs[MAX_FOUND];
    int found_count = 0;

    i2c_fd = open(I2C_DEV, O_RDWR);
    if (i2c_fd < 0) {
        lv_list_add_text(list, "ERROR: Cannot open /dev/i2c-0");
        LOG_ERR("cannot open %s", I2C_DEV);
    } else {
        lv_list_add_text(list, "Probing 0x03 - 0x77 ...");
        LOG_INF("scanning I2C bus 0x03-0x77");

        for (int addr = ADDR_START; addr <= ADDR_END; addr++) {
            if (try_probe_addr((uint8_t)addr) && found_count < MAX_FOUND) {
                found_addrs[found_count++] = (uint8_t)addr;
            }
        }

        if (found_count == 0) {
            lv_list_add_text(list, "No devices responded.");
        }
        char buf[64];
        for (int i = 0; i < found_count; i++) {
            snprintf(buf, sizeof(buf), "  [0x%02X] ACK", found_addrs[i]);
            lv_obj_t *entry = lv_list_add_text(list, buf);
            lv_obj_set_style_text_color(entry, COLOR_ACCENT, LV_PART_MAIN);
        }
        snprintf(buf, sizeof(buf), "Scan complete: %d device(s)", found_count);
        lv_list_add_text(list, buf);
        LOG_INF("I2C scan found %d device(s)", found_count);
        close(i2c_fd);
        i2c_fd = -1;
    }

    int input_fd = open("/dev/input/event0", O_RDONLY | O_NONBLOCK);
    struct input_event ev;
    while (1) {
        lv_timer_handler();
        if (input_fd >= 0 && read(input_fd, &ev, sizeof(struct input_event)) > 0) {
            if (ev.type == EV_KEY && ev.code == H2_KEY_BACK && ev.value == 1) break;
        }
        usleep(20000);
    }
    if (input_fd >= 0) close(input_fd);
    LOG_INF("probe module exited");
    return 0;
}