datetime-parser: initial implementation. not used yet

1 files changed, 375 insertions, 0 deletions

diff --git a/src/datetime-parser.c b/src/datetime-parser.c
new file mode 100644
index 0000000..1d39490
--- /dev/null
+++ b/src/datetime-parser.c
@@ -0,0 +1,375 @@
+/*
+ * blogc: A blog compiler.
+ * Copyright (C) 2015 Rafael G. Martins <rafael@rafaelmartins.eng.br>
+ *
+ * This program can be distributed under the terms of the BSD License.
+ * See the file LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#ifdef HAVE_TIME_H
+#include <time.h>
+#endif /* HAVE_TIME_H */
+
+#include <string.h>
+#include <stdio.h>
+
+#include "error.h"
+#include "utils/utils.h"
+#include "datetime-parser.h"
+
+
+typedef enum {
+    DATETIME_FIRST_YEAR = 1,
+    DATETIME_SECOND_YEAR,
+    DATETIME_THIRD_YEAR,
+    DATETIME_FOURTH_YEAR,
+    DATETIME_FIRST_HYPHEN,
+    DATETIME_FIRST_MONTH,
+    DATETIME_SECOND_MONTH,
+    DATETIME_SECOND_HYPHEN,
+    DATETIME_FIRST_DAY,
+    DATETIME_SECOND_DAY,
+    DATETIME_SPACE,
+    DATETIME_FIRST_HOUR,
+    DATETIME_SECOND_HOUR,
+    DATETIME_FIRST_COLON,
+    DATETIME_FIRST_MINUTE,
+    DATETIME_SECOND_MINUTE,
+    DATETIME_SECOND_COLON,
+    DATETIME_FIRST_SECOND,
+    DATETIME_SECOND_SECOND,
+    DATETIME_DONE,
+} blogc_datetime_state_t;
+
+
+char*
+blogc_convert_datetime(const char *orig, const char *format,
+    blogc_error_t **err)
+{
+    if (err == NULL || *err != NULL)
+        return NULL;
+
+    struct tm t;
+    memset(&t, 0, sizeof(struct tm));
+    t.tm_isdst = -1;
+
+    blogc_datetime_state_t state = DATETIME_FIRST_YEAR;
+    int tmp = 0;
+    int diff = '0';
+
+    for (unsigned int i = 0; orig[i] != '\0'; i++) {
+        char c = orig[i];
+
+        switch (state) {
+
+            case DATETIME_FIRST_YEAR:
+                if (c >= '0' && c <= '9') {
+                    tmp += (c - diff) * 1000;
+                    state = DATETIME_SECOND_YEAR;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid first digit of year. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_SECOND_YEAR:
+                if (c >= '0' && c <= '9') {
+                    tmp += (c - diff) * 100;
+                    state = DATETIME_THIRD_YEAR;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid second digit of year. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_THIRD_YEAR:
+                if (c >= '0' && c <= '9') {
+                    tmp += (c - diff) * 10;
+                    state = DATETIME_FOURTH_YEAR;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid third digit of year. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_FOURTH_YEAR:
+                if (c >= '0' && c <= '9') {
+                    tmp += c - diff - 1900;
+                    if (tmp < 0) {
+                        *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                            "Invalid year. Found %d, must be >= 1900.",
+                            tmp + 1900);
+                        break;
+                    }
+                    t.tm_year = tmp;
+                    state = DATETIME_FIRST_HYPHEN;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid fourth digit of year. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_FIRST_HYPHEN:
+                if (c == '-') {
+                    tmp = 0;
+                    state = DATETIME_FIRST_MONTH;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid separator between year and month. "
+                    "Found '%c', must be '-'.", c);
+                break;
+
+            case DATETIME_FIRST_MONTH:
+                if (c >= '0' && c <= '1') {
+                    tmp += (c - diff) * 10;
+                    state = DATETIME_SECOND_MONTH;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid first digit of month. "
+                    "Found '%c', must be integer >= 0 and <= 1.", c);
+                break;
+
+            case DATETIME_SECOND_MONTH:
+                if (c >= '0' && c <= '9') {
+                    tmp += c - diff - 1;
+                    if (tmp < 0 || tmp > 11) {
+                        *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                            "Invalid month. Found %d, must be >= 1 and <= 12.",
+                            tmp + 1);
+                        break;
+                    }
+                    t.tm_mon = tmp;
+                    state = DATETIME_SECOND_HYPHEN;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid second digit of month. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_SECOND_HYPHEN:
+                if (c == '-') {
+                    tmp = 0;
+                    state = DATETIME_FIRST_DAY;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid separator between month and day. "
+                    "Found '%c', must be '-'.", c);
+                break;
+
+            case DATETIME_FIRST_DAY:
+                if (c >= '0' && c <= '3') {
+                    tmp += (c - diff) * 10;
+                    state = DATETIME_SECOND_DAY;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid first digit of day. "
+                    "Found '%c', must be integer >= 0 and <= 3.", c);
+                break;
+
+            case DATETIME_SECOND_DAY:
+                if (c >= '0' && c <= '9') {
+                    tmp += c - diff;
+                    if (tmp < 1 || tmp > 31) {
+                        *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                            "Invalid day. Found %d, must be >= 1 and <= 31.",
+                            tmp);
+                        break;
+                    }
+                    t.tm_mday = tmp;
+                    state = DATETIME_SPACE;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid second digit of day. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_SPACE:
+                if (c == ' ') {
+                    tmp = 0;
+                    state = DATETIME_FIRST_HOUR;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid separator between date and time. "
+                    "Found '%c', must be ' ' (empty space).", c);
+                break;
+
+            case DATETIME_FIRST_HOUR:
+                if (c >= '0' && c <= '2') {
+                    tmp += (c - diff) * 10;
+                    state = DATETIME_SECOND_HOUR;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid first digit of hours. "
+                    "Found '%c', must be integer >= 0 and <= 2.", c);
+                break;
+
+            case DATETIME_SECOND_HOUR:
+                if (c >= '0' && c <= '9') {
+                    tmp += c - diff;
+                    if (tmp < 0 || tmp > 23) {
+                        *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                            "Invalid hours. Found %d, must be >= 0 and <= 23.",
+                            tmp);
+                        break;
+                    }
+                    t.tm_hour = tmp;
+                    state = DATETIME_FIRST_COLON;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid second digit of hours. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_FIRST_COLON:
+                if (c == ':') {
+                    tmp = 0;
+                    state = DATETIME_FIRST_MINUTE;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid separator between hours and minutes. "
+                    "Found '%c', must be ':'.", c);
+                break;
+
+            case DATETIME_FIRST_MINUTE:
+                if (c >= '0' && c <= '5') {
+                    tmp += (c - diff) * 10;
+                    state = DATETIME_SECOND_MINUTE;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid first digit of minutes. "
+                    "Found '%c', must be integer >= 0 and <= 5.", c);
+                break;
+
+            case DATETIME_SECOND_MINUTE:
+                if (c >= '0' && c <= '9') {
+                    tmp += c - diff;
+                    if (tmp < 0 || tmp > 59) {
+                        // this won't happen because we are restricting the digits
+                        // to 00-59 already, but lets keep the code here for
+                        // reference.
+                        *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                            "Invalid minutes. Found %d, must be >= 0 and <= 59.",
+                            tmp);
+                        break;
+                    }
+                    t.tm_min = tmp;
+                    state = DATETIME_SECOND_COLON;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid second digit of minutes. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_SECOND_COLON:
+                if (c == ':') {
+                    tmp = 0;
+                    state = DATETIME_FIRST_SECOND;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid separator between minutes and seconds. "
+                    "Found '%c', must be ':'.", c);
+                break;
+
+            case DATETIME_FIRST_SECOND:
+                if (c >= '0' && c <= '6') {
+                    tmp += (c - diff) * 10;
+                    state = DATETIME_SECOND_SECOND;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid first digit of seconds. "
+                    "Found '%c', must be integer >= 0 and <= 6.", c);
+                break;
+
+            case DATETIME_SECOND_SECOND:
+                if (c >= '0' && c <= '9') {
+                    tmp += c - diff;
+                    if (tmp < 0 || tmp > 60) {
+                        *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                            "Invalid seconds. Found %d, must be >= 0 and <= 60.",
+                            tmp);
+                        break;
+                    }
+                    t.tm_sec = tmp;
+                    state = DATETIME_DONE;
+                    break;
+                }
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid second digit of seconds. "
+                    "Found '%c', must be integer >= 0 and <= 9.", c);
+                break;
+
+            case DATETIME_DONE:
+                // well, its done ;)
+                break;
+        }
+
+        if (*err != NULL)
+            return NULL;
+    }
+
+    if (*err == NULL) {
+        switch (state) {
+            case DATETIME_FIRST_YEAR:
+            case DATETIME_SECOND_YEAR:
+            case DATETIME_THIRD_YEAR:
+            case DATETIME_FOURTH_YEAR:
+            case DATETIME_FIRST_HYPHEN:
+            case DATETIME_FIRST_MONTH:
+            case DATETIME_SECOND_MONTH:
+            case DATETIME_SECOND_HYPHEN:
+            case DATETIME_FIRST_DAY:
+            case DATETIME_SECOND_DAY:
+            case DATETIME_FIRST_HOUR:
+            case DATETIME_SECOND_HOUR:
+            case DATETIME_FIRST_MINUTE:
+            case DATETIME_SECOND_MINUTE:
+            case DATETIME_FIRST_SECOND:
+            case DATETIME_SECOND_SECOND:
+                *err = blogc_error_new_printf(BLOGC_ERROR_DATETIME_PARSER,
+                    "Invalid datetime string. "
+                    "Found '%s', formats allowed are: 'yyyy-mm-dd hh:mm:ss', "
+                    "'yyyy-mm-dd hh:ss', 'yyyy-mm-dd hh' and 'yyyy-mm-dd'.",
+                    orig);
+                return NULL;
+
+            case DATETIME_SPACE:
+            case DATETIME_FIRST_COLON:
+            case DATETIME_SECOND_COLON:
+            case DATETIME_DONE:
+                break;  // these states are ok
+        }
+    }
+
+    mktime(&t);
+
+    char buf[1024];
+    if (0 == strftime(buf, sizeof(buf), format, &t)) {
+        fprintf(stderr, "blogc: warning: Failed to format DATE variable, "
+            "FORMAT is too long: %s\n", format);
+        return b_strdup(orig);
+    }
+
+    return b_strdup(buf);
+}