#include "VK_Log.h"
#include <ulog.h>
#include <string.h>

typedef struct
{
    rt_uint16_t year;
    rt_uint8_t month;
    rt_uint8_t day;
    rt_uint8_t hour;
    rt_uint8_t minute;
    rt_uint8_t second;
    rt_tick_t base_tick;
    rt_bool_t valid;
} log_clock_t;

static log_clock_t log_clock;

static rt_bool_t is_leap_year(rt_uint16_t year)
{
    return (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
}

static rt_uint8_t days_in_month(rt_uint16_t year, rt_uint8_t month)
{
    static const rt_uint8_t days[] = {31, 28, 31, 30, 31, 30,
                                      31, 31, 30, 31, 30, 31};
    return (month == 2 && is_leap_year(year)) ? 29 : days[month - 1];
}

static void log_clock_add_seconds(rt_uint32_t seconds,
                                  rt_uint16_t *year, rt_uint8_t *month,
                                  rt_uint8_t *day, rt_uint8_t *hour,
                                  rt_uint8_t *minute, rt_uint8_t *second)
{
    rt_uint32_t days;

    *second += seconds % 60;
    if (*second >= 60) { *second -= 60; seconds = seconds / 60 + 1; }
    else { seconds /= 60; }
    *minute += seconds % 60;
    if (*minute >= 60) { *minute -= 60; seconds = seconds / 60 + 1; }
    else { seconds /= 60; }
    *hour += seconds % 24;
    days = seconds / 24;
    if (*hour >= 24) { *hour -= 24; days++; }

    while (days > 0) {
        rt_uint8_t month_days = days_in_month(*year, *month);
        if (*day < month_days) { (*day)++; days--; }
        else {
            *day = 1;
            if (*month < 12) (*month)++;
            else { *month = 1; (*year)++; }
            days--;
        }
    }
}

int dev_log_time_set_from_at(const char *response)
{
    const char *p;
    rt_uint16_t year = 0;
    rt_uint8_t fields[5];
    int year_digits = 0;
    int i;

    if (response == RT_NULL) return -1;
    p = rt_strstr(response, "+QLTS:");
    if (p != RT_NULL) year_digits = 4;
    else {
        p = rt_strstr(response, "+CCLK:");
        if (p == RT_NULL) return -1;
        year_digits = 2;
    }
    p = strchr(p, '"');
    if (p == RT_NULL || p[1] == '"') return -1;
    p++;
    for (i = 0; i < year_digits; i++) {
        if (p[i] < '0' || p[i] > '9') return -1;
        year = (rt_uint16_t)(year * 10 + p[i] - '0');
    }
    p += year_digits;
    if (*p++ != '/') return -1;
    for (i = 0; i < 5; i++) {
        if (p[0] < '0' || p[0] > '9' || p[1] < '0' || p[1] > '9') return -1;
        fields[i] = (rt_uint8_t)((p[0] - '0') * 10 + p[1] - '0');
        p += 2;
        if (i == 0 && *p++ != '/') return -1;
        if (i == 1 && *p++ != ',') return -1;
        if (i >= 2 && i < 4 && *p++ != ':') return -1;
    }
    if ((year_digits == 4 && (year < 2000 || year > 2099)) ||
        (year_digits == 2 && year == 70 && fields[0] == 1 && fields[1] == 1) ||
        fields[0] < 1 || fields[0] > 12 || fields[1] < 1 ||
        fields[1] > days_in_month(year_digits == 2 ? (rt_uint16_t)(2000 + year) : year,
                                  fields[0]) || fields[2] > 23 ||
        fields[3] > 59 || fields[4] > 59) return -1;

    log_clock.year = year_digits == 2 ? (rt_uint16_t)(2000 + year) : year;
    log_clock.month = fields[0]; log_clock.day = fields[1];
    log_clock.hour = fields[2]; log_clock.minute = fields[3];
    log_clock.second = fields[4];
    log_clock.base_tick = rt_tick_get();
    log_clock.valid = RT_TRUE;
    return 0;
}

static struct ulog_backend vcom_backend;
static rt_device_t log_dev = RT_NULL;

static void vcom_log_output(struct ulog_backend *backend,
                            rt_uint32_t level,
                            const char *tag,
                            rt_bool_t is_raw,
                            const char *log,
                            size_t len)
{
    (void)backend;
    (void)level;
    (void)tag;
    (void)is_raw;

    if (log_dev != RT_NULL && len > 0) {
        char prefix[32];
        rt_uint16_t year = log_clock.year;
        rt_uint8_t month = log_clock.month, day = log_clock.day;
        rt_uint8_t hour = log_clock.hour, minute = log_clock.minute;
        rt_uint8_t second = log_clock.second;
        if (log_clock.valid) {
            log_clock_add_seconds((rt_uint32_t)((rt_tick_get() - log_clock.base_tick) /
                                                RT_TICK_PER_SECOND),
                                  &year, &month, &day, &hour, &minute, &second);
            rt_snprintf(prefix, sizeof(prefix), "[%04u-%02u-%02u %02u:%02u:%02u] ",
                        year, month, day, hour, minute, second);
            (void)rt_device_write(log_dev, 0, prefix, rt_strlen(prefix));
        }
        (void)rt_device_write(log_dev, 0, log, len);
    }
}

int dev_log_backend_init(rt_device_t dev)
{
    if (dev == RT_NULL)
    {
        return -RT_EINVAL;
    }

    log_dev = dev;
    rt_memset(&vcom_backend, 0, sizeof(vcom_backend));
    vcom_backend.output = vcom_log_output;

    return ulog_backend_register(&vcom_backend, "vcom", RT_FALSE);
}