#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "fsctl/fugue/logger.h"

//---
// Public
//---

/* fugue_logger_init() : initialize internal logger buffer at fixed size */
int fugue_logger_init(fugue_logger_t *logger, size_t buffer_size)
{
    if (logger == NULL)
        return -1;
    logger->buffer.data = calloc(buffer_size, sizeof(char));
    if (logger->buffer.data == NULL)
        return -1;
    logger->buffer.size = buffer_size;
    logger->buffer.pos  = 0;
    return 0;
}

/* fugue_logger_quit() : uninit logger internal information */
int fugue_logger_quit(fugue_logger_t *logger)
{
    if (logger == NULL)
        return -1;
    if (logger->buffer.data == NULL)
        return -1;
    free(logger->buffer.data);
    logger->buffer.data = NULL;
    logger->buffer.size = 0;
    logger->buffer.pos  = 0;
    return 0;
}

/* fugue_logger_clear() : clear buffer content */
int fugue_logger_clear(fugue_logger_t *logger)
{
    if (logger == NULL)
        return -1;
    memset(logger->buffer.data, 0x00, logger->buffer.size);
    logger->buffer.pos = 0;
    return 0;
}

/* fugue_logger_getline() : getline-like function */
ssize_t fugue_logger_getline(fugue_logger_t *logger, char **str, size_t *ssz)
{
    char *str_end;

    if (logger == NULL)
        return -1;
    if (*str == NULL) {
        *str = &logger->buffer.data[0];
    } else {
        str_end = &((*str)[*ssz]);
        if (str_end[0] == '\0') {
            *str = NULL;
            *ssz = 0;
            return -1;
        }
        if (str_end[0] == '\n') {
            *str = &str_end[1];
        }
    }
    str_end = strchrnul(*str, '\n');
    *ssz = (ptrdiff_t)(str_end - *str);
    return 0;
}

/* fugue_logger_vwrite() : write primitive (va-arg) */
ssize_t fugue_logger_vwrite(fugue_logger_t *logger, char *format, va_list ap)
{
    int sz;

    if (logger == NULL)
        return -1;
    if (logger->buffer.pos >= (signed)logger->buffer.size)
        return -1;
    sz = vsnprintf(
        &logger->buffer.data[logger->buffer.pos],
        logger->buffer.size - logger->buffer.pos,
        format,
        ap
    );
    logger->buffer.pos += sz;
    return sz;
}

/* fugue_logger_write() : write primitive (va-arg) */
ssize_t fugue_logger_write(fugue_logger_t *logger, char *format, ...)
{
    va_list ap;
    ssize_t sz;

    if (logger == NULL)
        return -1;
    va_start(ap, format);
    sz = fugue_logger_vwrite(logger, format, ap);
    va_end(ap);
    return sz;
}