aisl-sdk/components/todo.c

/******************************************************************************
 *
 *                Copyright (c) 2017-2019 by Löwenware Ltd
 *             Please, refer LICENSE file for legal information
 *
 ******************************************************************************/

/**
 * @file todo.c
 * @author Ilja Kartašov <ik@lowenware.com>
 * @brief 
 *
 * @see https://lowenware.com/
 */

#include <stdlib.h>
#include <string.h>
#include <uuid.h>
#include <errno.h>
#include <cStuff/string.h>
#include <components/log.h>
#include "todo.h"


AislStatus
ax_todo_init(AxTodo self, const char *file)
{
	FILE *f;
	uuid_generate(self->id);

	if (!(f = fopen(file, "a+"))) {
		return AISL_SYSCALL_ERROR;
	}

	if (cstuff_list_init(&self->list, 16) != CSTUFF_SUCCESS) {
		fclose(f);
		return AISL_MALLOC_ERROR;
	}

	self->fd = f;

	return AISL_SUCCESS;
}


void
ax_todo_release(AxTodo self)
{
	if (self->fd)
		fclose(self->fd);

	cstuff_list_release(&self->list, (CStuffListFree)ax_todo_task_free);
}


AislStatus
ax_todo_read(AxTodo self)
{
	FILE *f = self->fd;
	size_t sz = 256;
	char *buf;
	ssize_t rs;
	AislStatus result = AISL_SUCCESS;
	
	if ((fseek(f, 0L, SEEK_SET) != 0))
		return AISL_SYSCALL_ERROR;

	if (!(buf = malloc(sz)))
		return AISL_MALLOC_ERROR;

	while ((rs = getdelim(&buf, &sz, '\n', f)) != -1) {
		AxTodoTask task;

		if (!(task = ax_todo_task_new()))
			goto e_malloc;

		if (ax_todo_task_set(task, buf, rs) != 0) {
			ax_todo_task_free(task);
			goto e_input;
		}

		if (cstuff_list_append(&self->list, task) == -1) {
			ax_todo_task_free(task);
			goto e_malloc;
		}
	}

	switch(errno) {
	case 0:
		goto finally;

	case ENOMEM:
		goto e_malloc;

	default:
		goto e_syscall;
	}

e_input:
	result = AISL_INPUT_ERROR;
	goto finally;

e_malloc:
	result = AISL_MALLOC_ERROR;
	goto finally;

e_syscall:
	result = AISL_SYSCALL_ERROR;

finally:
	free(buf);
	return result;
}


static void
ax_todo__write_dt(FILE *f, time_t dt)
{
	char str_dt[16];
	struct tm *p_stm = gmtime(&dt);
	(void) strftime(str_dt, sizeof (str_dt), "%Y-%m-%d", p_stm);
	fprintf(f, "%s ", str_dt);
}


AislStatus
ax_todo_write(AxTodo self)
{
	FILE *f = self->fd;
	int i;

	if ((fseek(f, 0L, SEEK_SET) != 0))
		return AISL_SYSCALL_ERROR;

	f = self->fd;

	for (i = 0; i < self->list.length; i++) {
		AxTodoTask task = (AxTodoTask) self->list.items[i];

		if (task->is_done) {
			fwrite("x ", 1, 2, f);
		}

		if (task->priority) {
			fprintf(f, "(%c) ", task->priority);
		}

		if (task->is_done) {
			if (task->completion) {
				ax_todo__write_dt(f, task->completion);
				if (task->creation) {
					ax_todo__write_dt(f, task->creation);
				}
			}
		} else if (task->creation) {
			ax_todo__write_dt(f, task->creation);
		}

		fprintf(f, "%s\n", task->description);
	}

	return (fflush(f) == 0) ? AISL_SUCCESS : AISL_SYSCALL_ERROR;
}


AxTodoTask
ax_todo_task_new(void)
{
	AxTodoTask result;

	if ((result = calloc(1, sizeof (struct ax_todo_task))) != NULL) {
		uuid_generate(result->task_id);
	}

	return result;
}


void
ax_todo_task_release(AxTodoTask task)
{
	if (task->description)
		free(task->description);
}


void
ax_todo_task_free(AxTodoTask task)
{
	ax_todo_task_release(task);
	free(task);
}


static int
ax_todo__get_priority(char *buf, char *p_priority)
{
	int result;
	char priority = 0;
	const char fmt[] = {'(', 'A', ')', ' '};

	for (result = 0; result < 4; result++) {
		switch (result) {
		case 0:
		case 2:
		case 3:
			if (buf[result] == fmt[result])
				continue;
			break;
		case 1:
			priority = buf[result];
			if (!(priority < 0x41 || priority > 0x5A))
				continue;
			break;
		}
		return 0;
	}
	*p_priority = priority;
	return result;
}


static int
ax_todo__get_dt(char *buf, time_t *p_dt)
{
	struct tm stm = {0};
	int result, *p_num = NULL, b_hour = 0, b_min = 0, usec = 0, z_bias = 0;
	const char fmt[] = "Y-M-DTH:m:s.uZB:b ", *f = fmt;
	char *ptr = NULL;

	for (result = 0; *f != 0; result++, f++) {
		switch(*f) {
			case 'Y':
				p_num = &stm.tm_year;
				break;
			case 'M':
				p_num = &stm.tm_mon;
				break;
			case 'D':
				p_num = &stm.tm_mday;
				break;
			case 'H':
				p_num = &stm.tm_hour;
				break;
			case 'm':
				p_num = &stm.tm_min;
				break;
			case 's':
				p_num = &stm.tm_sec;
				break;
			case 'u':
				p_num = &usec;
				break;
			case 'B':
				p_num = &b_hour;
				break;
			case 'b':
				p_num = &b_min;
				break;

			case '.':
				if (buf[result] != *f) {
					f++;
				}
				continue;

			case 'T':
				if (buf[result] == *f)
					continue;
					
				if (buf[result] == ' ') {
					f = &fmt[17];
					continue;
				}
				goto e_input;

			case 'Z':
				if (buf[result] == *f) {
					f += 3;
					z_bias = 'Z';
				} else if (buf[result] == '-') {
					z_bias = -1;
				} else if (buf[result] == '+') {
					z_bias = 1;
				} else {
					goto e_input;
				}
				continue;

			case '-':
			case ':':
			case ' ':
				if (buf[result] == *f)
					continue;
				/* go through */
			default:
				goto e_input;
		} /* switch */

		*p_num = strtol(&buf[result], &ptr, 10);

		if (!ptr || ptr == &buf[result]) {
			if (f > &fmt[6] && buf[result] == ' ') {
				f = &fmt[17];
				/* skip optional part of timestamp */
				continue;
			}
			goto e_input;
		}

		result += (ptr - &buf[result] - 1);
	} /* for */

	/* validate results */
	/* ToDo: improve (stm.tm_mday < 31) check */
	if (!(stm.tm_year < 1900) && (stm.tm_mon) && (stm.tm_mday) &&
			(stm.tm_mon < 13) && (stm.tm_mday < 31) && (stm.tm_hour < 24) &&
			(stm.tm_min < 60) && (stm.tm_sec < 60)) {
		stm.tm_year -= 1900;
		stm.tm_mon--;

		if (z_bias == 0) { /* local time zone */
			*p_dt = mktime(&stm);
			return result;
		}
		
		if (z_bias != 'Z') {
			stm.tm_hour += (b_hour * z_bias);
			stm.tm_min += (b_min * z_bias);
		}

		setenv("TZ", "UTC", 1);
		*p_dt = mktime(&stm);
		unsetenv("TZ");

		return result;
	}

e_input:
	AX_LOG_DEBUG("Parse error: %c(%d) at %d", *f, (int) (f - fmt), result);
	return 0;
	(void) usec;
}


AislStatus
ax_todo_task_set(AxTodoTask task, char *buf, ssize_t length)
{
	bool is_done;
	int l;

	if (strncmp(buf, "x ", 2) == 0) {
		is_done = true;
		buf += 2;
	} else {
		is_done = false;
	}

	task->is_done = is_done;

	if ((l = ax_todo__get_priority(buf, &task->priority)) != 0) {
		buf += l;
	}

	l = ax_todo__get_dt(buf, (is_done) ? &task->completion : &task->creation);

	if (l != 0) {
		buf += l;
		if (is_done && (l = ax_todo__get_dt(buf, &task->creation)) != 0) {
			buf += l;
		}
	}

	if ((l = cstuff_strcpy(&task->description, buf)) == -1) {
		return AISL_MALLOC_ERROR;
	}

	if (l > 1 && task->description[l-1] == '\n')
		task->description[l-1] = 0;

	return AISL_SUCCESS;
}