1 files changed, 194 insertions, 0 deletions
diff --git a/src/version_spec.c b/src/version_spec.c
new file mode 100644
index 0000000..7669608
--- /dev/null
+++ b/src/version_spec.c
@@ -0,0 +1,194 @@
+#include "spm.h"
+
+char *version_suffix_get_alpha(char *str) {
+    size_t i;
+    size_t len = strlen(str);
+    for (i = 0; i < len; i++) {
+        // return pointer to the first alphabetic character we find
+        if (isalpha(str[i])) {
+            return &str[i];
+        }
+    }
+    return NULL;
+}
+
+char *version_suffix_get_modifier(char *str) {
+    size_t i;
+    char *modifiers[] = {
+            "rc",
+            "pre",
+            "dev",
+            "post",
+            NULL,
+    };
+    for (i = 0; i < strlen(str); i++) {
+        for (int m = 0; modifiers[m] != NULL; m++) {
+            if (strncasecmp(&str[i], modifiers[m], strlen(modifiers[m])) == 0) {
+                return &str[i];
+            }
+        }
+    }
+    return NULL;
+}
+
+int64_t version_suffix_modifier_calc(char *str) {
+    int64_t result = 0;
+    char *tmp_s = str;
+
+    if (strncasecmp(str, "rc", 2) == 0) {
+        // do rc
+        tmp_s += strlen("rc");
+        if (isdigit(*tmp_s)) {
+            result -= atoi(tmp_s);
+        }
+        else {
+            result -= 1;
+        }
+    }
+    else if (strncasecmp(str, "pre", 3) == 0) {
+        // do pre
+        tmp_s += strlen("pre");
+        if (isdigit(*tmp_s)) {
+            result -= atoi(tmp_s);
+        }
+        else {
+            result -= 1;
+        }
+    }
+    else if (strncasecmp(str, "dev", 3) == 0) {
+        // do dev
+        tmp_s += strlen("dev");
+        if (isdigit(*tmp_s)) {
+            result -= atoi(tmp_s);
+        }
+        else {
+            result -= 1;
+        }
+    }
+    else if (strncasecmp(str, "post", 4) == 0) {
+        // do post
+        tmp_s += strlen("post");
+        if (isdigit(*tmp_s)) {
+            result += atoi(tmp_s);
+        }
+        else {
+            result += 1;
+        }
+    }
+
+    return result;
+}
+
+int version_suffix_alpha_calc(char *str) {
+    if (version_suffix_get_modifier(str) != NULL) {
+        return 0;
+    }
+    int x = 0;
+    char chs[255];
+    char *ch = chs;
+    memset(chs, '\0', sizeof(chs));
+    strncpy(chs, str, strlen(str));
+
+    // Convert character to hex-ish
+    x =  (*ch - 'a') + 0xa;
+
+    // Ensure the string ends with a digit
+    if (strlen(str) == 1) {
+        strcat(ch, "0");
+    }
+
+    // Convert trailing numerical value to an integer
+    while (*ch != '\0') {
+        if (!isdigit(*ch)) {
+            ch++;
+            continue;
+        }
+        x += atoi(ch);
+        break;
+    }
+
+    return x;
+}
+
+int64_t version_from(const char *version_str) {
+    const char *delim = ".";
+    int64_t result = 0;
+
+    int seen_alpha = 0;     // Does the tail contain a single character, but not a modifier?
+    int seen_modifier = 0;  // Does the tail contain "rc", "dev", "pre", and so forth?
+    char head[255];         // digits of the string
+    char tail[255];         // alphabetic characters of the string
+    char *suffix_alpha = NULL;      // pointer to location of the first character after the version
+    char *suffix_modifier = NULL;   // pointer to location of the modifier after the version
+    char *x = NULL;         // pointer to each string delimited by "."
+    char *vstr = calloc(strlen(version_str) + 1, sizeof(char));
+    if (!vstr) {
+        perror("Version string copy");
+        return -1;
+    }
+
+    memset(head, '\0', sizeof(head));
+    memset(tail, '\0', sizeof(tail));
+    strncpy(vstr, version_str, strlen(version_str));
+
+    // Split the version into parts
+    while ((x = strsep(&vstr, delim)) != NULL) {
+        int64_t tmp = 0;
+
+        // populate the head (numeric characters)
+        strncpy(head, x, strlen(x));
+        for (int i = 0; i < strlen(head); i++) {
+            if (isalpha(head[i])) {
+                // populate the tail (alphabetic characters)
+                strncpy(tail, &head[i], strlen(&head[i]));
+                head[i] = '\0';
+                break;
+            }
+        }
+
+        // Detect alphabetic suffix
+        if (!seen_alpha) {
+            if ((suffix_alpha = version_suffix_get_alpha(x)) != NULL) {
+                seen_alpha = 1;
+            }
+        }
+
+        // Detect modifier suffix
+        if (!seen_modifier) {
+            if ((suffix_modifier = version_suffix_get_modifier(x)) != NULL) {
+                seen_modifier = 1;
+            }
+        }
+
+        // Stop processing if the head starts with something other than numbers
+        if (!isdigit(head[0])) {
+            break;
+        }
+
+        // Convert the head to an integer
+        tmp = atoi(head);
+        // Update result. Each portion of the numeric version is its own byte
+        // Version PARTS are limited to 255
+        result = result << 8 | tmp;
+    }
+
+    if (suffix_alpha != NULL) {
+        // Convert the alphabetic suffix to an integer
+        int64_t sac = version_suffix_alpha_calc(suffix_alpha);
+        result += sac;
+    }
+
+    if (suffix_modifier != NULL) {
+        // Convert the modifier string to an integer
+        int64_t smc = version_suffix_modifier_calc(suffix_modifier);
+        if (smc < 0) {
+            result -= ~smc + 1;
+        }
+        else {
+            result += smc;
+        }
+    }
+
+    free(vstr);
+    return result;
+}