Raise DistroUnsupported for unsupported distros

pkgsync

@@ -25,6 +25,10 @@ class HistoryFileNotFoundError(Exception):
     pass
 
 
+class DistroUnsupported(Exception):
+    pass
+
+
 def detect_distro():
     """Get the Linux distribution"""
     distro = None
@@ -47,8 +51,8 @@ def detect_distro():
     return distro
 
 
-def compare_version(a, b):
+def compare_debian_version(a, b):
-    """Compare package versions"""
+    """Compare Debian package versions"""
     re_digits_non_digits = re.compile(r'\d+|\D+')
     re_digits = re.compile(r'\d+')
     re_digit = re.compile(r'\d')
@@ -142,6 +146,155 @@ def compare_version(a, b):
     return 0
 
 
+def compare_redhat_version(a, b):
+    """Compare RedHat package versions"""
+    def compare_parts(part1, part2):
+        if part1 == part2:
+            return 0
+        p1 = list(part1)
+        p2 = list(part2)
+
+        while p1 or p2:
+            for c in list(p1):
+                if not c.isalnum() and not c == '~':
+                    p1.pop(0)
+                else:
+                    break
+            for c in list(p2):
+                if not c.isalnum() and not c == '~':
+                    p2.pop(0)
+                else:
+                    break
+            try:
+                c1 = p1[0]
+            except IndexError:
+                c1 = ''
+
+            try:
+                c2 = p2[0]
+            except IndexError:
+                c2 = ''
+
+            if c1 == '~' and c2 == '~':
+                p1.pop(0)
+                p2.pop(0)
+            elif c1 == '~':
+                return 1
+            elif c2 == '~':
+                return -1
+
+            if not c1 and not c2:
+                break
+
+            lhs_is_digit = c1.isdigit()
+
+            if c1.isdigit():
+                r1 = []
+                for cx in list(p1):
+                    if cx.isdigit():
+                        r1.append(p1.pop(0))
+                    else:
+                        break
+                r2 = []
+                for c in list(p2):
+                    if c.isdigit():
+                        r2.append(p2.pop(0))
+                    else:
+                        break
+                if r1:
+                    while r1 and r1[0] == '0':
+                        r1.pop(0)
+                if r2:
+                    while r2 and r2[0] == '0':
+                        r2.pop(0)
+
+                if r1 == r2:
+                    continue
+
+                if not r2:
+                    if lhs_is_digit:
+                        return -1
+                    else:
+                        return 1
+                if len(r1) != len(r2):
+                    if len(r1) > len(r2):
+                        return -1
+                    else:
+                        return 1
+                elif r1 == r2:
+                    return 0
+                elif r1 > r2:
+                    return -1
+                else:
+                    return 1
+
+            else:
+                r1 = []
+                for cx in list(p1):
+                    if cx.isalpha():
+                        r1.append(p1.pop(0))
+                    else:
+                        break
+                r2 = []
+                for cy in list(p2):
+                    if cy.isalpha():
+                        r2.append(p2.pop(0))
+                    else:
+                        break
+
+                if not r2:
+                    if lhs_is_digit:
+                        return -1
+                    else:
+                        return 1
+
+                if len(r1) != len(r2):
+                    if len(r1) > len(r2):
+                        return -1
+                    else:
+                        return 1
+                elif r1 == r2:
+                    continue
+                elif r1 > r2:
+                    return -1
+                else:
+                    return 1
+        return 0
+
+    e1 = int(a.epoch)
+    e2 = int(b.epoch)
+
+    if e1 < e2:
+        return 1
+    if e1 > e2:
+        return -1
+
+    v1 = a.version
+    v2 = b.version
+
+    rc = compare_parts(v1, v2)
+
+    if rc != 0:
+        return rc
+
+    r1 = a.release
+    r2 = b.release
+
+    rc = compare_parts(r1, r2)
+
+    if rc != 0:
+        return rc
+
+    return 0
+
+def compare_version(v1, v2, distro):
+    if distro in RH_FAMILY:
+        return compare_redhat_version(v1, v2)
+    elif distro in DEB_FAMILY:
+        return compare_debian_version(v1, v2)
+    raise DistroUnsupported(distro)
+
+
 def dict_factory(cursor, row):
     d = dict()
     for idx, col in enumerate(cursor.description):
@@ -382,6 +535,8 @@ def list_packages(distro):
                 raise HistoryFileNotFoundError()
     elif distro in DEB_FAMILY:
         packages = list_packages_dpkg()
+    else:
+        raise DistroUnsupported(distro)
 
     return packages
 
@@ -406,7 +561,8 @@ def package_full(d, distro):
         if release:
             package.extend(['-', release])
         return ''.join(package)
-    return '{name}'.format(**d)  # need a better default
+    raise DistroUnsupported(distro)
+
 
 
 def package_name(d, distro):
@@ -415,7 +571,7 @@ def package_name(d, distro):
         return '{name}.{arch}'.format(**d)
     elif distro in DEB_FAMILY:
         return '{name}:{arch}'.format(**d)
-    return '{name}'.format(**d)
+    raise DistroUnsupported(distro)
 
 
 def is_valid_input(d):
@@ -480,7 +636,7 @@ def main(options):
                 current = current_packages.get(pkg)
                 imported = imported_packages.get(pkg)
 
-                rc = compare_version(current, imported)
+                rc = compare_version(current, imported, distro)
 
                 if rc == 1 and options.upgraded:
                     logger.debug('Upgrade: {0} (current) - {1} (imported)'.format(current, imported))